JP6636206B2 - Apparatus and method for correcting torque pulsation of electric motor, control device for elevator - Google Patents

Description

  The present invention is applied to, for example, a control device of an elevator hoist, a control device of an on-vehicle motor, or a control device of a motor of a machine tool, and corrects a periodic torque pulsation uniquely determined according to a rotational position of the motor. And the like.

It has been known that torque pulsation generated in an electric motor mainly occurs depending on a rotor position, and a method of repeatedly generating a compensation signal by regarding this as a periodic disturbance has been considered.
In Patent Document 1 below, a compensation current for suppressing a torque pulsation is obtained by learning a torque pulsation frequency component of an electric motor from a detected shaft torque value, and the compensation current is superimposed on a current control command of an inverter to obtain a compensation current for each frequency component. To suppress torque pulsation.
The learning of the compensation current for suppressing the torque pulsation is automatically and repeatedly executed at a plurality of different operating points, and the learning data is generated as a compensation current table.

JP 2011-50119 A

However, the related art has the following problems.
In a conventional torque pulsation correction device, frequency analysis of a shaft torque detection value is repeatedly performed at a plurality of operating points, and a torque pulsation compensation current table is generated based on this data. Here, a large number of data (learning) is required to create the table data based on the learning result.In particular, when the torque pulsation is adjusted after the electric motor and its control device are installed in the mechanical system, the operation is required. Since it is difficult to acquire data under a number of operating conditions before the start, it is an issue to correct torque pulsation with a simpler configuration.

  The present invention has been made in order to solve the above-described problems, and provides a motor torque pulsation correction device and a motor torque pulsation correction method capable of estimating and correcting torque pulsation with a simple configuration. The purpose is to get.

  The present invention is a motor torque pulsation correction device that corrects a periodic torque pulsation included in the torque of the electric motor with respect to a current command value for controlling the electric motor in the electric motor control device.When the electric motor is rotated, A frequency analysis unit that calculates the rotation speed of the motor from the rotation position of the motor from a position detector, performs frequency analysis of the rotation speed, calculates the amplitude and phase of a specific frequency, and outputs the result as a frequency analysis result; A torque pulsation estimating unit that inputs a motor operation command to the device and rotates the motor, estimates the amplitude and phase of torque pulsation generated in the motor from the frequency analysis result, and outputs the estimated value as a torque pulsation estimation value, A torque pulsation correction current value is calculated based on the torque pulsation estimated value, the motor current detected by the current detector, and the position detection signal. A torque pulsation correction unit that corrects the current command value of the motor control device, and the torque pulsation estimation unit causes the frequency analysis unit to calculate the frequency analysis result for a plurality of conditions where the current of the motor is different, A torque pulsation correction device for an electric motor or the like obtains an amplitude or a phase of a torque pulsation as a function of a current from a plurality of the obtained frequency analysis results.

  The present invention can provide a torque pulsation correction device and a torque pulsation correction method for an electric motor that can estimate and correct torque pulsation with a simple configuration.

FIG. 1 is a block diagram showing an overall view of a motor control system including a motor torque pulsation correction device according to Embodiments 1 and 2 of the present invention. FIG. 2 is a block diagram illustrating an example of a configuration of a motor control device of the motor control system illustrated in FIG. 1. FIG. 4 is a block diagram clearly showing an output of a torque pulsation correction unit in the motor torque pulsation correction device according to Embodiment 1 of the present invention. FIG. 3 is a block diagram showing a transfer characteristic from an output of a torque pulsation correction unit to a motor speed in a motor torque pulsation correction device according to Embodiment 1 of the present invention by a transfer function. FIG. 4 is a diagram illustrating an example of a transfer function of a transfer characteristic from an output of a torque pulsation correction unit to a motor speed in the motor torque pulsation correction device according to Embodiment 1 of the present invention. 3 is a flowchart showing a process of the electric motor torque pulsation correction device according to Embodiment 1 of the present invention. FIG. 3 is a schematic diagram illustrating a relationship between an amplitude of torque pulsation of the electric motor and a current value according to Embodiment 1 of the present invention. 4 is a flowchart showing a process of a torque pulsation estimating unit of the electric motor torque pulsation correction device according to Embodiment 1 of the present invention. FIG. 11 is a schematic diagram illustrating a relationship between a phase of a torque pulsation of an electric motor and a current value according to Embodiment 2 of the present invention. 9 is a flowchart illustrating a process of a torque pulsation estimating unit of the electric motor torque pulsation correction device according to the second embodiment of the present invention. FIG. 13 is a block diagram showing an overall view of a motor control system including a motor torque pulsation correction device according to Embodiment 3 of the present invention. FIG. 14 is a schematic configuration diagram illustrating an elevator system including an elevator control device according to Embodiment 4 of the present invention. FIG. 1 is a diagram illustrating an example of a hardware configuration of a control portion of a control system for a motor including a torque pulsation correction device for a motor according to an embodiment of the present invention.

  Hereinafter, a torque pulsation correction device and a correction method for an electric motor according to the present invention, and an elevator control device will be described with reference to the drawings according to each embodiment. In each embodiment, the same or corresponding portions are denoted by the same reference numerals, and overlapping description will be omitted.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing an overall configuration of a motor control system including a motor torque pulsation correction device according to Embodiment 1 of the present invention. 1, the motor control system includes a motor control device 4, a position detector 2, a current detector 3, and a torque pulsation correction device 5. Hereinafter, the control system of the electric motor including the electric motor 1 may be described.

  The motor control device 4 is a device that controls the rotation speed and the rotation position of the motor 1. Here, a case where the motor control device 4 controls the rotation speed of the motor 1 will be described with reference to FIG. FIG. 2 is a block diagram showing a configuration of the motor control device 4 of the motor control system shown in FIG.

  2, the motor control device 4 includes a speed calculation unit 41, a speed control unit 42, a current control unit 43, and a power converter 44. The speed calculation unit 41 calculates the rotation speed MRS of the electric motor 1 based on the rotation position MRP or the angle information of the electric motor 1 detected by the position detector 2. In the simplest configuration, the speed calculator 41 calculates the rotation speed by time differentiation of the position information or the angle information.

  The speed control unit 42 calculates a current command value ic that is a torque command value tc of the electric motor 1 so that the rotation speed MRS of the electric motor 1 becomes a predetermined set speed. Note that the current command value ic is a speed control signal. Further, to the output of the speed control unit 42, the torque pulsation correction current signal Itpc or the test signal TS, which is the output from the torque pulsation correction unit 53, is added by the addition unit AD1. Thus, the current command value IC is a torque command value TC for correcting the torque pulsation of the electric motor 1. The details of the torque pulsation correction current signal Itpc and the test signal TS will be described later. The current control unit 43 controls the voltage command value VC of the motor 1 so that the current command value IC output from the speed control unit 42 matches the motor current Im that is the current of the motor 1 detected by the current detector 3. Is calculated. The power converter 44 applies the motor application voltage Vma to the motor 1 based on the voltage command value VC output from the current control unit 43 in order to control the motor current Im.

  Here, P control, PI control, and PID control are generally often used for control by the speed control unit 42 and the current control unit 43, but various control methods can be used. In addition, vector control is generally used for the current control of the motor 1, and the motor current and the motor applied voltage are converted into d-q axes, and the converted current and voltage are subjected to the above-described PID control or the like. A control method is used.

  In general, an inverter is used as the power converter 44 that applies a voltage to the electric motor 1. The inverter converts a voltage of a power supply (not shown) into a voltage having a desired variable voltage and variable frequency. In the present invention, the power converter 44 is a power converter that converts an AC voltage into a DC voltage by a converter and then converts the DC voltage into an AC voltage by an inverter, or a matrix, like a commonly sold inverter device. A variable voltage variable frequency power converter including a power converter that directly converts an AC voltage into an AC variable voltage variable frequency voltage, such as a converter.

  Further, the inverter according to Embodiment 1 of the present invention, that is, power converter 44, may include a function of coordinate conversion in addition to the inverter described above. That is, when the voltage command value VC is a dq axis voltage command value, the dq axis voltage command value is converted into a phase voltage or a line voltage, and the voltage command value is in accordance with the commanded voltage command value. It also includes a coordinate conversion function for converting to voltage. The present invention can be applied even if a device or means for correcting the dead time of the inverter is provided.

  When controlling the rotational position of the electric motor 1, a position control unit 42 a is added above the speed control unit 42. The position control unit 42a calculates the speed command value SC of the electric motor 1 input to the speed control unit 42 so that the rotational position of the electric motor 1 is at a desired position. The speed control unit 42 executes the above-described control with the speed command value SC as a desired speed. In general, P control, PI control, and PID control are often used for control by the position control unit 42a, but various control methods can be used.

  Further, the motor control device 4 may be configured by the position control unit 42a and the current control unit 43 without using the speed control unit 42. In this case, the position control unit 42a calculates the current command value IC of the electric motor 1 so that the rotational position of the electric motor 1 becomes a desired position.

  Returning to FIG. 1, the current detector 3 measures the current of the electric motor 1. For example, when the motor 1 is a three-phase motor, a two-phase current is often measured, but a three-phase current may be measured. In FIG. 1, the current detector 3 measures the output of the motor control device 4, that is, the output current of the power converter 44, but the current detector 3 uses the one-shunt resistor to measure the current as shown in FIG. The bus current of the power converter 44 may be measured to estimate each phase current. Even in this case, the present invention is not affected at all.

  Here, the torque output from the electric motor 1 includes torque pulsation. Since the electric motor 1 has structural magnetic flux distortion and cogging torque, it generates torque pulsation that contributes to vibration and noise in accordance with rotation. Further, the torque pulsation generated in the electric motor 1 is complicatedly related to various factors such as magnetic imperfection of a motor structure, a response error or a current error of an inverter driving the motor structure, and mechanical characteristics. . However, when focusing on the pulsation cycle of the electric motor, it is known that the pulsation occurs mainly depending on the rotor position.

  Hereinafter, a torque pulsation uniquely determined according to the rotational position of the electric motor 1 is expressed as Tr. The present invention can be applied to the case where the electric motor 1 includes a periodic torque pulsation uniquely determined according to the rotational position, and the main component order of the torque pulsation Tr is known.

  The periodic torque pulsation Tr of the electric motor 1 can be approximately expressed using a sine wave as in the following equation (1). Since there is no essential difference between the notation using a sine wave and the notation using a cosine wave, the notation using a sine wave is used in the first embodiment of the present invention.

_Tr = A _r1 sin (N ₁ θ _m + φ _r1 ) + A _r2 sin (N ₂ θ _m + φ _r2 ) +... + A _rn sin (N _n θ _m + φ _rn ) (1)

However, in equation (1),
θ _m : mechanical angle of electric motor 1 A _r1 : amplitude of torque pulsation in order of N ₁ order A _r2 : amplitude of torque pulsation in order of N ₂ A _rn : amplitude of torque pulsation in order of N _n order φ _r1 : N _1st order phase shift with respect to mechanical angle of motor 1 (initial phase)
φ _r2 : phase shift with respect to the mechanical angle of the electric motor 1 in the order of N ₂ φ _rn : phase shift with respect to the mechanical angle of the electric motor 1 in the order of N _n .

The order of N ₁ , N _2, ... N _{n in} the equation (1) does not need to be continuous integers such as 1, 2,... N _n , and is periodically determined uniquely according to the rotational position of the electric motor 1. This is the order of the principal components of the torque pulsation. The term “principal component” as used herein refers to a component whose amplitude in the order is larger than the amplitude of another frequency. Further, although the equation (1) is described as a combination of three or more frequency components, the frequency component of the periodic torque pulsation Tr is composed of one or two or more components. It may be.

  Here, the current value corresponding to the expression (1) can be expressed as the following expression (2) using the current value of the q axis on the dq axis.

i _qr = I _qr1 sin (N ₁ θ _m + φ _r1 ) + I _qr2 sin (N ₂ θ _m + φ _r2 ) +.
+ I _qrn sin (N _n θ _m + φ _rn ) (2)

  The relationship between the torque pulsation Tr and the corresponding q-axis current value iqr can be expressed by the following equation using the torque constant Kt.

T _r = K _t · i _qr (3)

Therefore, the amplitude of the torque pulsation and the amplitude of the current conversion value are, for example,
I _qr1 = A _r1 / K _t
It becomes the relationship. Accordingly, the torque pulsation is corrected by superimposing the torque pulsation correction current signal reproduced by the equation (2) similar to the torque pulsation represented by the equation (1) on the current command value ic output from the speed control unit 42. be able to.

  The position detector 2 detects a rotation position of the electric motor 1 necessary for controlling the electric motor 1 such as an optical encoder, a magnetic encoder, and a resolver, and outputs a position detection signal indicated by the electric motor rotation position MRP. Although it is output, the information on the rotational position output by the position detector 2 includes a periodic error uniquely determined according to the rotational position of the electric motor 1.

Here, the periodic error uniquely determined according to the rotational position of the electric motor 1 refers to a rotational error, such as a detection error of a resolver, a pulse omission due to a slit defect in an optical encoder, and an imbalance in inter-pulse distance. Indicates a reproducible error accordingly. When a periodic error uniquely determined according to the rotational position of the electric motor 1 is expressed as an angle error θ _{err obtained} by converting position information into an angle, it is approximately expressed using a sine wave as in the following equation (4). be able to. Since there is no essential difference between the notation using a sine wave and the notation using a cosine wave, the notation using a sine wave is used in the first embodiment of the present invention.

θ _err = A _err1 sin (X ₁ θ _m + ψ ₁ ) + A _err2 sin (X ₂ θ _m + ψ ₂ ) +.
_{+ A errn sin (X n θ} m + ψ n) (4)

However, in equation (4),
θ _m : mechanical angle A _err1 of motor 1: error amplitude A _err2 in the _first order of X ₁ error amplitude A _{errn in the second} order of the order A _errn : error amplitude in the order of the X _n order ψ ₁ : error amplitude in the _first order of X ₁ Phase shift of motor 1 relative to machine angle (initial phase)
ψ ₂ : The phase shift of the motor 1 in the X ₂ order with respect to the mechanical angle ψ _n : The phase shift of the X ₁ order with respect to the mechanical angle of the motor 1.

Note that the order of X ₁ , X ₂ ... X _{n in} the equation (4) does not need to be continuous integers such as 1, 2,... X _n , and is periodically determined uniquely according to the rotational position of the electric motor 1. This is the order of the principal component of the error. The term “principal component” as used herein refers to a component whose amplitude in the order is larger than the amplitude of another frequency. Equation (4) is described as a combination of three or more frequency components. However, the frequency component of the periodic angle error θ _err is calculated from one or two or more components. It may be configured.

  Here, when a periodic torque pulsation uniquely determined according to the rotational position of the electric motor 1 is included in the output torque of the electric motor 1, it is understood that a velocity pulsation including a frequency component of the same dimension as the torque pulsation occurs. ing. Similarly, it is known that when a specific periodic signal is generated by the torque pulsation correction unit 53 and added to the output of the speed control unit 42, a speed pulsation including the same frequency component as the added signal is generated.

Therefore, when the torque pulsation of the electric motor 1 shown in the equation (1) matches the order of the periodic error of the position detector 2 shown in the equation (4), that is, in the equations (1) and (4), , N ₁ = X ₁ , N ₂ = X ₂ , N _n = X _n , the rotational speed of the motor 1 includes a speed pulsation component due to torque pulsation of the motor 1 and a speed due to an angular error of the position detector 2. The sum of the pulsation components will be included. This is expressed as the following equation (5).

ω _err = Y _err1 sin (N ₁ θ _m + γ ₁ ) + Y _err2 sin (N ₂ θ _m + γ ₂ ) +.
+ Y _errn sin (N _n θm + γ _n )
_{= Y err1 sin (X 1 θ} m + γ 1) + Y err2 sin (X 2 θ m + γ 2) + ...
+ Y _errn sin (X _n θ _m + γ _n ) (5)

Here, in equation (5),
θ _m : mechanical angle of motor 1 Y _err1 : speed pulsation amplitude in N ₁ or X ₁ order Y _err2 : error amplitude in N ₂ or X ₂ order Y _errn : N _n or X _n order Error amplitude γ _{1 in order} : phase shift (initial phase) with respect to mechanical angle of motor _{1 in} order of N ₁ or X ₁
γ ₂ : phase shift with respect to the mechanical angle of the electric motor 1 in the order of the N ₂ or X ₂ order γ _n : phase shift with respect to the mechanical angle of the electric motor 1 in the order of the N _n or X _n order.

  When the torque pulsation of the electric motor 1 shown in the equation (1) does not match the order of the periodic error of the position detector 2 shown in the equation (4), the speed pulsation is equal to the component due to the torque pulsation of the electric motor 1. The velocity pulsation component due to the error of the position detector 2 can be handled separately.

  Hereinafter, it is assumed that the torque pulsation of the electric motor 1 shown in the equation (1) and the order of the periodic error of the position detector 2 shown in the equation (4) match. That is, the speed pulsation included in the rotation speed of the electric motor 1 is the sum of the torque pulsation component of the electric motor 1 and the angle error component of the position detector 2.

  Next, in the first embodiment of the present invention, the torque pulsation correction device 5 includes a frequency analysis unit 51, a torque pulsation estimation unit 52, and a torque pulsation correction unit 53. The torque pulsation estimating unit 52 estimates the torque pulsation of the electric motor 1 as a function having the same form as the equation (1) based on the frequency analysis result FAR of the rotation speed of the electric motor 1 analyzed by the frequency analyzing unit 51. In this embodiment, since the order of the torque pulsation of the electric motor 1 and the order of the periodic error of the position detector 2 match, the velocity pulsation due to the error of the position detector 2 is corrected with respect to the equation (1). It is estimated in a form in which the torque pulsation correction value is added.

  The torque pulsation correction unit 53 includes an input signal from the torque pulsation estimation unit 52, a torque pulsation estimation value (TPE), a rotation position signal (MRP) from the position detector 2, and a motor current signal from the current detector 3. (Im) to generate an addition signal. Specifically, the torque pulsation correction unit 53 generates a torque pulsation correction value of the same type as in the equation (1) based on the estimation result of the torque pulsation, and generates a torque command value (tc) as shown in FIG. The torque pulsation is corrected by adding it to a certain current command value (ic).

  Hereinafter, the operation of the torque pulsation correction device 5 will be described. The frequency analysis unit 51 calculates the rotation speed MRS of the electric motor 1 based on the rotation position MRP or the angle information of the electric motor 1 detected by the position detector 2, and outputs the rotation speed MRS and the output from the position detector 2. At least one of the amplitude (A1) and the phase (φ1) at a specific frequency of the motor speed is calculated based on the one piece of rotational position information MRP or the angle information. Note that the speed calculation in the frequency analysis unit 51 is the same as the speed calculation unit 41 included in the motor control device 4. Further, the speed calculation function included in the frequency analysis unit 51 may not be the same as the speed calculation unit 41. Various methods for calculating the rotation speed of the electric motor 1 can be applied. The motor speed refers to the rotation speed of the motor, and the same applies hereinafter.

  Here, the frequency analysis unit 51 is preferably configured to obtain the amplitude and phase at a desired frequency of the input signal, such as Fourier transform, Fourier series analysis, or fast Fourier transform. Like a filter, a configuration may be employed in which a desired frequency signal is extracted and a desired amplitude and phase of an input signal are calculated by an amplitude detection unit and a phase detection unit. Further, the filter used here may be an electric filter combining a resistor, a capacitor, a coil, and the like, or may be a process performed in a computer.

  Here, the signal of the desired frequency, that is, the signal of the specific frequency is the signal of the same frequency as the main component of the torque pulsation Tr caused by the torque pulsation Tr of the electric motor 1 or the speed pulsation caused by the angular error of the position detector 2. Or a signal having the same frequency as the main component of the test signal TS generated by the torque pulsation correction unit 53. The details of the test signal will be described later.

  The torque pulsation estimating unit 52 calculates the velocity amplitude value (A1) of the desired frequency component, which is the frequency analysis result (FAR) of the output of the frequency analysis unit 51, or the velocity amplitude value (A1) and the phase value (φ1), Using the rotational position (MRP) or the angle information of the motor 1 output from the detector 2 and the angle information, and the motor current (Im) output from the current detector 3, the motor 1 is uniquely determined according to the rotational position of the motor 1. The determined periodic torque pulsation Tr is estimated by an estimation method described later, and an estimated torque pulsation value (TPE) is output to the torque pulsation correction unit 53.

  The torque pulsation correction unit 53 supplies the electric motor control device 4 with the addition (AD1) to the output (ic) of the speed control unit 42 and the torque based on the torque pulsation estimation value (TPE) output from the torque pulsation estimation unit 52. The pulsation correction current signal (Itpc) or the test signal (TS) is added to output a current command value (IC) which is a torque command value (TC) for correcting torque pulsation. Therefore, the adder AD1 in FIG. 2 indicates the function of the torque pulsation corrector 53.

  In addition, as shown in the above equation (1), when there are a plurality of frequency components of the torque pulsation, the angle errors may be sequentially estimated and added for each component, or the plurality of frequency components may be estimated simultaneously. . At this time, the estimation time can be reduced in the case of simultaneous estimation, as compared with the case of estimating torque pulsation with each component sequentially. Here, in order to simplify the description, a case will be described in which the torque pulsation includes only a single frequency component.

  When the frequency signal is frequency-analyzed by the frequency analysis unit 51, a speed pulsation component caused by torque pulsation of the electric motor 1 and an angle error of the position detector 2 can be extracted. When performing frequency analysis, estimation is performed under the condition that the acceleration is constant. In particular, it is desirable to perform the estimation under the condition that the acceleration is zero, that is, the motor 1 is rotating at a constant speed.

  The torque pulsation and the signal from the torque pulsation correction unit 53 generate a speed pulsation in accordance with a transmission characteristic determined by a dynamic characteristic of a load composed of the electric motor control device 4, the electric motor 1, and an elevator sheave described below connected to the electric motor 1. Let it. Further, although the angle error of the position detector 2 is determined by the characteristics of only the position detector 2, it can be considered that the angle error of the position detector 2 is caused by torque pulsation of the electric motor 1.

  Therefore, if this transfer characteristic can be obtained, a torque pulsation signal that causes a speed pulsation can be estimated. That is, the torque pulsation that causes the speed pulsation can be calculated back from the obtained transmission characteristics and the speed pulsation.

  Hereinafter, a method of estimating a transfer characteristic, a periodic torque pulsation, and the like from a frequency analysis result of the speed of the electric motor 1 will be described. The estimation of the transfer characteristics and the periodic torque pulsation is performed by the torque pulsation estimation unit 52.

  FIG. 3 is a block diagram clearly showing the output of torque pulsation correction section 53 in the torque pulsation correction device according to Embodiment 1 of the present invention. In FIG. 3, the torque pulsation correction unit 53 generates a torque pulsation correction current value (Itpc). The current command value IC obtained by adding the torque pulsation correction current value (Itpc) generated by the torque pulsation correction unit 53 to the output of the speed control unit 42, that is, the current command value ic, is input to the current control unit 43. The current controller 43 calculates a voltage command value VC based on the current command value IC and the motor current Im detected by the current detector 3. The calculated voltage command value VC is input to the power converter 44, and the power converter 44 applies a voltage to the electric motor 1, and as a result, the electric motor 1 rotates. Then, the position detector 2 detects the rotation of the electric motor 1.

At this time, if the transfer characteristic TCH from the torque pulsation correction current Itpc to the electric motor speed MRS of the electric motor 1 is represented by G _{Tr_ω} (s) in a transfer function expression, a block diagram is shown in FIG. FIG. 4 is a block diagram showing the transfer characteristics from the output of torque pulsation correction unit 53 to the motor speed in the transfer function expression in the torque pulsation correction device according to Embodiment 1 of the present invention. Here, "s" is a Laplace operator. When a load is connected to the motor 1, it is represented by G _{Tr_ω} (s) including the dynamic characteristics of the load.

According to the present invention, a gain and a phase indicating the amplitude of G _{Tr — ω} (s) at the frequency of the speed pulsation or at a specific frequency are obtained, and the torque pulsation is estimated from the obtained gain and phase. FIG. 5 shows an example of G _{Tr —ω} (s). FIG. 5 is a diagram illustrating an example of a transfer characteristic from the output of the torque pulsation correction unit to the motor speed in the torque pulsation correction device according to Embodiment 1 of the present invention.

  In FIG. 5, the upper part 5A shows gain characteristics, and the lower part 5B shows phase characteristics. When the frequency of the torque pulsation changes, the amplitude and phase of the motor speed pulsation corresponding to the torque pulsation change according to the characteristics as shown in FIG. Further, the frequency of the torque pulsation changes depending on the rotation speed MRS of the electric motor 1. That is, the phase and the amplitude of the speed pulsation caused by the torque pulsation change according to the rotation speed.

  Further, the relationship between the speed pulsation and the torque pulsation correction current Itpc shown in Expression (5) is determined by the transfer characteristics in FIG. Therefore, if the transfer characteristic TCH of FIG. 5 can be obtained, a current correction value for correcting the speed pulsation can be obtained, and conversely, the speed pulsation can be obtained from the current correction value. Therefore, the speed pulsation due to the error of the position detector 2 can be corrected by the current correction value if the transfer characteristics shown in FIG. 5 can be obtained. The same applies to the speed pulsation caused by the torque pulsation of the electric motor 1. When the torque pulsation of the electric motor 1 and the order of the periodic error of the position detector 2 match, the speed pulsation due to the torque pulsation of the electric motor 1 and the speed pulsation due to the error of the position detector 2 are determined by the transfer characteristics shown in FIG. What is necessary is just to obtain a current correction value for simultaneously correcting the pulsation.

  Next, the processing of the torque pulsation correction device 5 according to Embodiment 1 of the present invention will be described with reference to the flowchart of FIG.

  First, when torque pulsation estimation is started, the torque pulsation estimation unit 52 outputs an operation command MDC of the electric motor 1 to the electric motor control device 4. As a result, the operation command MDC is input to, for example, the speed control unit 42 of the motor control device 4 shown in FIG. At this time, the torque pulsation estimation unit 52 outputs a command to set the torque pulsation correction signal to zero, that is, a command to set the test signal TS to zero, to the torque pulsation correction unit 53 (step S1). As a result, the torque pulsation correction unit 53 sets the torque pulsation correction current Itpc to zero, and rotates the electric motor 1 in a state where the correction of the torque pulsation is not performed. This means that the motor 1 is operated without adding the test signal TS.

  Next, the torque pulsation estimation unit 52 outputs the frequency analysis command FAC to the frequency analysis unit 51, and the frequency analysis unit 51 analyzes the frequency of the rotation speed MRS of the electric motor 1 according to the electric motor rotation position MRP (step S2). The frequency analysis result FAR is input to the torque pulsation estimation unit 52. At this time, the frequency analysis unit 51 performs frequency analysis of the rotation speed of the electric motor 1 at a frequency corresponding to the frequency of the torque pulsation.

This is performed, for example, by obtaining a Fourier coefficient of a speed pulsation corresponding to a specific frequency. In the following, a description will be given of a case where a Fourier coefficient of a speed pulsation is obtained with respect to a speed signal according to the motor rotation position MRP, with respect to the frequency analysis in the frequency analysis unit 51. The Fourier coefficient at the frequency M ₁ [Hz] of the speed pulsation corresponding to the frequency of the torque pulsation can be obtained by the following equations (6) and (7).

A _n1 = 2 / T∫ ^{T / 2} _{-T / 2} ω (t) cos (2πM ₁ t) dt (6)
B _n1 = 2 / T∫ ^{T / 2} _{-T / 2} ω (t) sin (2πM ₁ t) dt (7)

In equations (6) and (7),
ω (t): Motor speed (= MRS)
T indicates a speed pulsation cycle of a frequency M ₁ [Hz].
Note that T = 1 / M ₁ . A _n1 and B _n1 represent the coefficients of a cosine wave and a sine wave, respectively.

  Expressions (6) and (7) show the case of obtaining in the form of time integration, but they may be obtained in the form of integration based on the rotation angle of the electric motor 1. Equations (6) and (7) are arithmetic expressions in the continuous time domain. However, when the torque pulsation correction device 5 is configured by a computer such as a computer, the equations are converted into discrete time domain equations and executed. I do. Equations (6) and (7) can be calculated by using a cosine-wave or sine-wave signal generator, a multiplier, or an integrator, and can be easily configured by a computer.

  In the equations (6) and (7), the Fourier coefficients are calculated by integrating one cycle of the signal. However, the Fourier coefficients may be integrated over several cycles, and the integral value may be calculated as a value obtained by dividing the integrated value by the number of cycles. . In this case, since the average value is obtained for several periods, it is possible to reduce the influence of variations in current pulsation and disturbance. It is desirable that the start time of the integration be started from a reference point of the rotation angle of the electric motor 1, for example, zero degree. Thereby, the Fourier coefficient based on the rotation angle of the electric motor 1 can be obtained.

Here, Equation (6), the Fourier coefficients of (7), the following equation amplitude A _.omega.1 and phase phi _.omega.1 velocity ripple component (8) can be obtained by (9).

A _ω1 = √ (A _n1 ² + B _n1 ² ) (8)
φ _ω1 = tan ^-1 (A _n1 / + B _n1 ) (9)

The torque pulsation estimating unit 52 stores the amplitude A _ω1 and the phase φ _ω1 obtained by the equations (8) and (9). It should be noted that the Fourier coefficients A _n1 and B _n1 may be stored, and the amplitude and the phase may be calculated by the equations (8) and (9).
The amplitude and phase obtained in step S2 are referred to as amplitude (A1a) and phase (φ1a).

  Subsequently, the torque pulsation estimation unit 52 operates the motor 1 by adding the test signal TS (step S3), and causes the frequency analysis unit 51 to analyze the frequency of the motor speed while the motor 1 is rotating (step S4). ). The rotation speed of the electric motor 1 at this time is set to be the same as that in step S1. The operation command MDC of the electric motor 1 is input from the torque pulsation estimating unit 52 to, for example, the speed control unit 42 of the electric motor control device 4, and the set value of the test signal TS is output from the torque pulsation estimating unit 52 to the torque pulsation correcting unit 53. Is done. The frequency analysis result FAR is input from the frequency analysis unit 51 to the torque pulsation estimation unit 52.

Here, the test signal TS is a sine or cosine wave test signal having a preset amplitude, frequency, and initial phase, and the torque pulsation correction unit 53 generates the test signal TS. Add to output ic. Since the sine wave and the cosine wave can be mutually converted by changing the initial phase, they will be described below as sine waves. Also, a preset amplitude of the test signal TS and A _t, the initial phase and phi _t. The frequency of the test signal TS is the same as the frequency of the torque pulsation.

When frequency analysis of the motor speed MRS is performed in step S4, frequency analysis is performed at a frequency corresponding to the test signal TS added in step S3. Frequency analysis is obtained by calculation from the equation (6) the same as (9), M ₁ and T is a value obtained by replacing the frequency and period corresponding to the test signal TS, which is a frequency of the torque pulsation is there.

At this time, the frequency analysis result FAR of the speed pulsation is a frequency analysis result of the speed pulsation generated by the torque pulsation of the electric motor 1 and the error signal of the position detector 2 and the test signal TS and the synthesized signal. .
The amplitude and phase obtained in step S4 are referred to as amplitude (A1b) and phase (φ1b).

  Subsequently, in step S5, the torque pulsation estimating unit 52 estimates torque pulsation based on the frequency analysis result FAR obtained in step S2 and the frequency analysis result FAR obtained in step S4. At this time, as described above, the frequency analysis result FAR obtained in step S4 is based on the frequency pulsation caused by the torque pulsation of the electric motor 1, the error of the position detector 2, and the speed pulsation generated from the synthesized signal obtained by synthesizing the test signal. Since it is an analysis result and the amplitude and the initial phase of the torque pulsation and the error of the position detector are unknown, the transmission characteristics at the frequency of the torque pulsation cannot be obtained from this result.

  Therefore, first, from the frequency analysis result FAR obtained in step S4, an operation for separating a speed pulsation component caused by the torque pulsation and the error of the position detector from a speed pulsation component caused by the test signal TS is performed. This can be performed using each frequency analysis result in step S2 and step S4.

  For example, as an example of the calculation, the separation can be performed by subtracting the frequency analysis result at the time of operation without adding the test signal TS in step S2 from the frequency analysis result in step S4. That is, the difference between the Fourier coefficients obtained in steps S4 and S2 becomes the Fourier coefficient of the velocity pulsation component caused by the test signal TS.

  Using the Fourier coefficient which is the frequency analysis result of the speed pulsation component resulting from the test signal TS extracted in this way, the transfer characteristic at the frequency of the torque pulsation signal equal to the frequency of the test signal TS is obtained to estimate the torque pulsation. .

That is, the amplitude and the phase corresponding to the test signal TS are set to _Aωt and _φωt , respectively, using the Fourier coefficient of the velocity pulsation component caused by the extracted test signal TS.

Next, the torque pulsation estimation unit 52 calculates an estimated torque pulsation value of the electric motor 1 (step S5). In step S4, the relative amplitude A _t test signals, since the corresponding speed pulsation amplitude was A _.omega.t, speed pulsations, it can be seen the amplitude of the test signal is obtained by multiplying A _.omega.t / A _t.

Here, when the frequency of the torque pulsation and the frequency of the test signal are the same, regarding the speed pulsation caused by the torque pulsation, the magnification of the amplitude of the speed pulsation with respect to the amplitude of the torque pulsation is considered to be the same as the above-described magnification, and is obtained in step S2. The amplitude of the error signal that generates the current pulsation amplitude _Aω1 for the error signal can be determined. That is, the amplitude of the error signal when the A _1, can be obtained by the following equation (10).

_{A 1 = (A ω1 / A} ωt) A t (10)

Further, in step S4, with respect to the initial phase and is phi _t test signals, since the corresponding speed pulsation phase was phi _.omega.t, velocity pulsation phase, phi _.omega.t -.phi the phase of the test signal It can be seen that they are shifted by _t .

Here, when the torque pulsation frequency and the frequency of the test signal are the same, regarding the speed pulsation caused by the torque pulsation, the phase shift of the motor speed pulsation amplitude with respect to the torque pulsation amplitude is regarded as the same as the phase shift of the test signal. The phase of the error signal that generates the current pulsation phase φ _ω1 with respect to the obtained error signal can be obtained. That is, when the phase of the error signal and phi _1, can be obtained by the following equation (11).
The amplitude and phase obtained in step S5 are referred to as amplitude (A2) and phase (φ2).

φ ₁ = φ _ω1 − (φ _ωt −φ _t ) (11)

  As described above, the sine wave having the amplitude and the phase obtained by the equations (10) and (11) is estimated as the torque pulsation estimated value TPE. When the estimation of the torque pulsation is completed, the torque pulsation correction unit 53 generates a torque pulsation correction current signal Itpc that cancels the torque pulsation based on the torque pulsation generated from the estimated torque pulsation value TPE. Output in addition to output ic.

  In the first embodiment of the present invention, the torque analysis is performed based on the frequency analysis result FAR of the speed pulsation when the torque pulsation is not corrected and the frequency analysis result FAR of the speed pulsation when the operation is performed by adding the predetermined test signal TS. Estimates the pulsation. This means that the transmission characteristic TCH from the torque pulsation correction current to the rotation speed of the electric motor is obtained in the frequency band of the speed pulsation caused by the torque pulsation, and the torque pulsation is converted using the transmission characteristic.

For example, in FIG. 5, if the frequency corresponding to the torque pulsation is point A, in the first embodiment of the present invention, the test signal TS is set at point A, and the operation at the point A Find transfer characteristics (gain and phase). Then, the torque pulsation is estimated from the amplitude and the phase of the speed pulsation obtained in the operation without adding the test signal. In this manner, by analyzing the frequency of the speed signal MRS, a current command value for correcting torque pulsation, that is, a torque pulsation correction current signal Itpc can be obtained.
The current command value ic output from the speed control unit 42 of the motor control device 4 is corrected by the torque pulsation correction current signal Itpc obtained by the torque pulsation correction device 5, and the motor 1 is driven by the corrected current command value IC. Is done.

  Note that the torque pulsation correction unit 53 may perform the operation to which the test signal TS is added a plurality of times to estimate the torque pulsation a plurality of times. Referring to FIG. 6, steps S3 to S5 are repeatedly performed. Further, a plurality of estimation results obtained may be averaged to obtain a final estimated value. Thereby, the reliability of the estimation result can be improved.

  Further, the operation with the test signal added while changing the amplitude and phase of the test signal TS may be performed a plurality of times to estimate the torque pulsation a plurality of times. Referring to FIG. 6, the amplitude and phase of the test signal added in step S3 are changed, and steps S3 to S5 are repeatedly performed. Further, a plurality of estimation results obtained may be averaged to obtain a final estimated value. Thereby, the reliability of the estimation result can be improved.

  It is possible to estimate the torque pulsation by frequency-analyzing the speed signal by the above-described method. However, a synthesized signal of the speed pulsation due to the torque pulsation of the electric motor 1 and the speed pulsation due to the error included in the position detector 2 is obtained. Is frequency-analyzed to obtain a correction value. In this case, the torque pulsation of the electric motor 1 and the speed pulsation due to the error of the position detector 2 are regarded as being caused by the torque pulsation and are simultaneously corrected.

  The error of the position detector 2 is uniquely determined according to the rotation angle of the electric motor 1, but the torque pulsation of the electric motor 1 changes according to the current value. Therefore, the correction value obtained by the above procedure is effective only under the current condition when the estimation is completed, and an error may occur in the correction value under the other current conditions. It cannot be corrected. If the torque pulsation of the electric motor 1 does not change according to the current amount, the estimated value can sufficiently correct the torque pulsation. However, since the torque pulsation of the electric motor 1 generally changes according to the current value, It is necessary to make the correction of the torque pulsation variable in accordance with the current value.

  Here, when the torque pulsation of the electric motor 1 is proportional to the current value, the amplitude of the torque pulsation is as shown in FIG. The amplitude of the torque pulsation of the electric motor 1 is represented by a straight line L1 in FIG. 7 and is a function a × i proportional to the current value i. Here, a is the inclination of the straight line L1 or the straight line L2. Although FIG. 7 shows that the amplitude of the torque pulsation changes linearly with respect to the current value, it may be a quadratic function or a higher-order function. Further, the amplitude of the torque pulsation independent of the current value, that is, the amplitude when the error of the position detector 2 is considered to be due to the torque pulsation in the first embodiment does not change in accordance with the current value. b.

Therefore, when the frequency of the torque pulsation of the electric motor 1 and the frequency of the error of the position detector 2 coincide with each other, when the torque pulsation is estimated by frequency analysis of the rotational speed of the electric motor 1, a point on the straight line L2 is obtained. Will be. For example, current requirements when performing torque pulsation estimation when i ₁ would amplitude A _r1 is obtained. Here, when the estimation result due to the error of the position detector 2 is excluded and only the torque pulsation of the electric motor 1 is extracted, the fact that the slopes of the straight line L1 and the straight line L2 are the same is used. This is because a torque pulsation is estimated a plurality of times under the condition that the current value i of the electric motor 1 is different, and a difference between the estimated values is taken, thereby eliminating a speed pulsation component due to an error of the position detector 2 that does not change according to the current value. I do.

First, to estimate the torque pulsation when the current i _1, to obtain an amplitude of torque pulsation. The obtained amplitude of the torque pulsation is the sum of the amplitude of the torque pulsation of the electric motor 1 and the amplitude when the speed pulsation due to the error of the position detector 2 is regarded as the torque pulsation.

A _r1 = A _Tr1 + A _S (12)

here,
A _Tr1 : Amplitude of torque pulsation of electric motor ₁ at current i ₁ A _S : Amplitude when speed pulsation due to error of position detector 2 is caused by torque pulsation.
Next, it is similarly obtained under the current condition 2.

A _r2 = A _Tr2 + A _S (13)

here,
A _Tr2 : Amplitude of torque pulsation of electric motor 1 at current i ₂ A _S : Amplitude when speed pulsation due to error of position detector 2 is caused by torque pulsation.
When the difference between the amplitudes obtained under the current conditions 1 and 2 is calculated, the following equation (14) is obtained. The error component of the position detector 2 is canceled, and the difference becomes the amplitude of the torque pulsation of the electric motor 1.

A _r2 -A _r1 = A _Tr2 -A _Tr1 (14)

Further, since the current values when the amplitude of the torque pulsation of the electric motor 1 is obtained are i ₁ and i ₂ , the slope a with respect to the current value of the torque pulsation of the electric motor 1 can be calculated by the following equation (15).

a = (A _r2 −A _r1 ) / (i ₂ −i ₁ ) (15)

  When the slope a is obtained, the intercept b, that is, the amplitude when the error of the position detector 2 is considered to be caused by torque pulsation can be obtained by the following equation (16).

b = A _r2 −ai ₂
b = A _r1 −ai ₁ (16)

  Equation (16) has the same value in both cases. Therefore, the amplitude of the torque pulsation of the electric motor 1 that can be varied according to the current amount and the amplitude when the speed pulsation due to the error of the position detector 2 that does not depend on the current amount is corrected by the torque can be calculated by the following equation (17). .

    A = ai + b (17)

  Assuming that the phase of the torque pulsation of the electric motor 1 does not change according to the current value, the phase obtained under the current condition 1 and the phase obtained under the current condition 2 are the same, and either one may be used. Alternatively, the average value of the phases obtained under the current conditions 1 and 2 may be used.

Next, a method of obtaining the amplitude of the torque pulsation that is variable by the current will be described with reference to the flowchart of FIG. First, when starting the estimation of the torque pulsation, the torque pulsation estimation unit 52 outputs the operation command MDC of the motor 1 to the motor control unit 4 is operated so that the current condition is i ₁ (step S81). Then, when the current condition is i _1, to estimate the torque pulsation. Incidentally, the estimation of the torque pulsation performed by the current condition i ₁ are as in the flowchart of FIG. At the end the estimation of the torque pulsation in current condition i _1, and stores the combined current value i ₁ and the estimated amplitude value A _r1 (step S82).

Next, the operation such that the current condition is i ₂ (step S83). Then, when the current condition is i _2, to estimate the torque pulsation. Incidentally, the estimation of the torque pulsation performed by the current condition i ₂ are as in the flowchart of FIG. At the end the estimation of the torque pulsation in current condition i _2, and stores the combined current i ₂ and the amplitude estimate A _r2 (step S84). In this flow chart, the phase is provided to store the value obtained when the current condition i _1, when the phase does not change in accordance with the current value may be stored a value determined by the current condition i ₂ . Alternatively, both the phases obtained under the current conditions i ₁ and i ₂ may be stored, and the average value thereof may be obtained.

  When the estimation is completed under different current conditions, the amplitude of the torque pulsation is calculated as a function of the current value according to Expressions (15) and (16) (Step S85). Thus, even if there is another pulsation having the same frequency as the frequency of the torque pulsation of the electric motor 1, that is, even if there is a pulsation due to an error of the position detector 2, each can be accurately estimated. When the frequency of the torque pulsation of the electric motor 1 and the frequency of the error of the position detector 2 are different, the expression (16) becomes zero.

  In the first embodiment, the estimation method based on the two current conditions has been described, but the current conditions may be any two or more conditions. Further, although an example of linear approximation under two conditions has been described, learning and correction can be performed by the same method even if the number of conditions is increased and the dimension of a function such as a quadratic function or a cubic function is increased. Therefore, the present invention can be applied to a case where the torque pulsation of the electric motor 1 is nonlinear.

  The estimation of the torque pulsation of the electric motor 1 can be performed when the control system of the electric motor including the electric motor 1 is installed. In addition, the operation can be performed in any state whether the load is attached to the electric motor 1 or not. For this reason, it is not necessary to make adjustments before shipping and the torque pulsation can be easily corrected at the time of installation. Further, the estimation of the torque pulsation can be performed at the time of maintenance of the device or at the time of replacement of the electric motor 1, and may be performed periodically at the time of operation of the device. According to the present invention, since the transfer characteristics of the control system of the electric motor are obtained by the operation based on the test signal TS, the torque pulsation can be estimated regardless of the presence or absence of the load.

  Further, in the present invention, in estimating the torque pulsation, it is only necessary to perform a minimum of four types of frequency analysis including two types of presence / absence of a test signal and two types of current conditions. In addition, since the frequency analysis performed by the frequency analysis unit 51 can be performed while the electric motor 1 is rotated by about one rotation, the torque pulsation can be estimated in a short time. Furthermore, since the flowcharts of FIGS. 6 and 8 can be performed continuously without stopping the electric motor 1, the torque pulsation can be estimated in a short time.

  In addition, as shown by the above formula (1), when there are a plurality of frequency components of the torque pulsation, the torque pulsation may be sequentially estimated and added for each component, or the plurality of frequency components may be estimated simultaneously. . When a plurality of frequency components are to be estimated at the same time, the test signal TS is simultaneously input in accordance with the frequency of the torque pulsation to be estimated when the operation is performed using the test signal TS. In the frequency analysis performed in steps S2 and S4, the frequency analysis is performed for all the speed pulsation components caused by the test signal.

  In the first embodiment, the torque pulsation estimation unit 52 outputs the operation command MDC of the electric motor 1 in steps S1 and S3, and outputs the frequency analysis command FAC in steps S2 and S4. An operation sequence control unit that performs operation sequence control of torque pulsation estimation may be provided separately in the torque pulsation correction device 5 or the motor control device 4, or may be provided as a dedicated control device.

  As described above, according to the first embodiment, the torque pulsation correction device can perform frequency analysis of a specific frequency component of the motor speed, and can estimate periodic torque pulsation of motor 1 based on the frequency analysis result. At this time, a step of frequency-analyzing the rotational speed of the electric motor under a plurality of current conditions, a step of estimating a torque pulsation from the frequency analysis result, and a step of obtaining the torque pulsation as a function of the current from the calculated plurality of torque pulsation estimation results , The torque pulsation is estimated. Therefore, it is possible to obtain a torque pulsation correction device and a torque pulsation correction method that can accurately estimate and correct torque pulsation.

Embodiment 2 FIG.
In the second embodiment of the present invention, the torque pulsation correcting device 5 shown in FIG. 1 learns the phase of the torque pulsation as a function of the current value. FIG. 9 is a schematic diagram when the phase of the torque pulsation of the electric motor 1 changes according to the current value, similarly to FIG.

  The phase of the torque pulsation of the electric motor 1 is represented by a straight line L3 in FIG. 9 and is a function c × i proportional to the current value i. Here, c is the inclination of the straight line L3 or the straight line L4. Although the phase of the torque pulsation changes linearly with respect to the current value in FIG. 9, it may be a quadratic function or a higher-order function. Further, the phase of the torque pulsation independent of the current value, that is, the phase when the error of the position detector 2 is considered to be due to the torque pulsation in the second embodiment does not change in accordance with the current value, and thus the offset value represented as d.

Therefore, when the frequency of the torque pulsation of the electric motor 1 and the frequency of the error of the position detector 2 coincide with each other, a point on the straight line L4 is obtained by frequency analysis of the rotational speed of the electric motor 1. For example, current requirements when performing torque pulsation estimation when i ₁ would phase phi _r1 is obtained. Here, when the estimation result due to the error of the position detector 2 is excluded and only the torque pulsation of the electric motor 1 is extracted, the fact that the slopes of the straight line L3 and the straight line L4 are the same is used. This is because a torque pulsation is estimated a plurality of times under the condition that the current value i of the electric motor 1 is different, and a difference between the estimated values is taken, thereby eliminating a speed pulsation component due to an error of the position detector 2 that does not change according to the current value. I do.

First, to estimate the torque pulsation when the current i _1, obtains the phase of the torque pulsation. The obtained phase of the torque pulsation is the sum of the phase of the torque pulsation of the electric motor 1 and the phase when the speed pulsation due to the error of the position detector 2 is regarded as the torque pulsation.

φ _r1 = φ _Tr1 + φ _S (18)

here,
φ _Tr1 : phase of torque pulsation of motor ₁ at current i ₁ φ _s : phase when speed pulsation due to error of position detector 2 is attributed to torque pulsation.
Next, it is similarly obtained under the current condition 2.

φ _r2 = φ _Tr2 + φ _S (19)

here,
φ _Tr2 : phase of torque pulsation of electric motor 1 at current i ₂ φ _s : phase when speed pulsation due to error of position detector 2 is caused by torque pulsation.
When the difference between the phases obtained under the current conditions 1 and 2 is calculated, the following equation (20) is obtained. The error component of the position detector 2 is canceled out, and the phase difference of the torque pulsation of the electric motor 1 is obtained.

φ _r2 −φ _r1 = φ _Tr2 −φ _Tr1 (20)

Further, since the current values when the phase of the torque pulsation of the motor 1 is obtained are i ₁ and i ₂ , the slope c with respect to the current value of the torque pulsation of the motor 1 can be calculated by the following equation (21).

c = (φ _r2 −φ _r1 ) / (i ₂ −i ₁ ) (21)

  When the slope c is obtained, the intercept d, that is, the phase when the error of the position detector 2 is considered to be caused by torque pulsation can be obtained by the following equation (22).

d = φ _r2 −ci ₂
d = φ _r1 −ci ₁ (22)

  Equation (22) has the same value in both cases. Therefore, the following equation (23) can be used to calculate the phase of the torque pulsation of the electric motor 1 that is variable according to the amount of current and the phase when the speed pulsation due to the error of the position detector 2 that does not depend on the amount of current is corrected by the torque. .

        φ = ci + d (23)

Next, a method of obtaining the phase of the torque pulsation that is variable by the current will be described with reference to the flowchart of FIG. First, when starting the estimation of the torque pulsation, the torque pulsation estimation unit 52 outputs the operation command MDC of the motor 1 to the motor control unit 4 is operated so that the current condition is i ₁ (step S101). Then, when the current condition is i _1, to estimate the torque pulsation. Incidentally, the estimation of the torque pulsation performed by the current condition i ₁ are as in the flowchart of FIG. At the end the estimation of the torque pulsation in current condition i _1, and stores the combined current value i ₁ and the phase estimate phi _r1 (step S102).

Next, the operation such that the current condition is i ₂ (step S103). Then, when the current condition is i _2, to estimate the torque pulsation. Incidentally, the estimation of the torque pulsation performed by the current condition i ₂ are as in the flowchart of FIG. At the end the estimation of the torque pulsation in current condition i _2, and stores the combined current i ₂ and phase estimate phi _r2 (step S104).

  When the estimation is completed under different current conditions, the phase of the torque pulsation is calculated as a function of the current value according to equations (21) and (22) (step S105). Thus, even if there is another pulsation having the same frequency as the frequency of the torque pulsation of the electric motor 1, that is, even if there is a pulsation due to an error of the position detector 2, each can be accurately estimated. If the frequency of the torque pulsation of the electric motor 1 and the frequency of the error of the position detector 2 are different, the expression (22) becomes zero.

  In the second embodiment, the estimation method based on two current conditions has been described. However, the current conditions may be any two or more conditions. Further, although an example of linear approximation under two conditions has been described, learning and correction can be performed by the same method even if the number of conditions is increased and the dimension of a function such as a quadratic function or a cubic function is increased. Therefore, the present invention can be applied to a case where the torque pulsation of the electric motor 1 is nonlinear.

  Since the phase estimation is performed in the same manner as the amplitude estimation, the flowchart of FIG. 10 can be executed simultaneously with the flowchart of FIG. 8, and in this case, both the amplitude and the phase are functions of the current value. Can be obtained as Therefore, it is not necessary to newly perform a process of obtaining the phase as a function of the current value, so that the estimation time of the torque pulsation can be reduced. According to the second embodiment, it is possible to accurately correct the torque pulsation even when the phase of the torque pulsation of the electric motor 1 changes according to the current value.

Embodiment 3 FIG.
FIG. 11 is a block diagram showing an overall configuration of a motor control system including a torque pulsation correcting device according to Embodiment 3 of the present invention. 11, elements denoted by the same reference numerals as those in FIG. 1 perform the same operations as those described in the first embodiment.

  In the third embodiment of the present invention, a torque pulsation correction device 5A is provided instead of the torque pulsation correction device 5 shown in FIG. The torque pulsation correction device 5A includes a frequency analysis unit 51, a torque pulsation estimation unit 52A, a torque pulsation correction unit 53, and a resonance determination unit 54A. That is, it has a torque pulsation estimation unit 52A that operates differently from the torque pulsation estimation unit 52 shown in FIG. 1, and further has a resonance determination unit 54A.

  The resonance determination unit 54A determines whether the frequency of the torque pulsation of the electric motor 1 or the frequency of the test signal TS is based on the frequency analysis result FAR of the frequency analysis unit 51 or the estimated torque pulsation TPE of the torque pulsation estimation unit 52A. It is determined whether or not the resonance frequency matches the resonance frequency of the control system, and the determination result DR is output to the torque pulsation estimation unit 52A.

  When the motor 1 is connected to a load such as an elevator sheave described below, the control system of the motor may have a resonance point depending on the dynamic characteristics of the load. When the frequency of the torque pulsation and the frequency of the test signal TS are close to or coincide with the resonance frequency which is the frequency of the resonance point during the operation of the electric motor 1, the estimation accuracy of the torque pulsation estimation may be deteriorated.

Therefore, in a third embodiment of the present invention, a torque pulsation correction device 5A that can avoid such a case and can perform torque pulsation estimation stably with high accuracy will be described. Hereinafter, the operation of the resonance determination unit 54A will be described. Before performing the torque pulsation estimation described in the first and second embodiments, resonance determination section 54A operates motor 1 to determine whether the frequency of the torque pulsation and the frequency of test signal TS match the frequency of the resonance point. Determine whether or not.
When the resonance determining unit 54a determines that the specific frequency corresponding to the torque pulsation matches the resonance frequency of the control system of the electric motor, the torque pulsation estimating unit 52A changes the rotational speed or the rotational position of the electric motor 1 to reduce the torque. Estimate the pulsation.

  Here, when the resonance point does not change depending on the rotational position of the motor 1, for example, when the load is a rotating machine or the like, the motor 1 is operated while changing the operating speed, and the frequency analysis of the motor current Im is performed.

  Further, based on the frequency analysis of the motor current, based on the values of the above equations (6) and (7), or the above equations (8) and (9), it is determined whether or not the frequency of the torque pulsation is near the resonance frequency. Is determined. In the vicinity of the resonance frequency, the amplitude of the speed pulsation sharply increases or decreases, or the phase rapidly changes by nearly 180 degrees.

  Therefore, it is checked whether or not the amount of change in the speed pulsation amplitude (A) or the phase (φ) obtained by the frequency analysis exceeds a predetermined set value. It is determined that the operating speed of the electric motor 1 is close to the resonance frequency. For example, when at least one of the amplitude change amount and the phase change amount of the speed pulsation of the electric motor exceeds a set value, it is determined that resonance occurs. The same applies hereinafter.

  Further, the torque pulsation estimating unit 52A outputs an operation command MDC to the motor control device 4 based on the determination result of the resonance determining unit 54A such that the motor 1 is operated under a condition that does not approach the resonance frequency.

  The torque pulsation estimation unit 52A estimates the torque pulsation by the method described in the first and second embodiments. In this case, the operating speed of the electric motor 1 is changed to avoid the resonance frequency. When the operating speed of the motor 1 is changed, the frequency of the torque pulsation and the frequency of the test signal change, so that the resonance frequency can be avoided.

  As described above, in the third embodiment of the present invention, the resonance determination unit 54A determines whether or not the frequency of the torque pulsation and the frequency of the test signal match the resonance frequency of the control system of the electric motor. Since the torque pulsation is estimated under the condition that they do not match, the torque pulsation can be stably and accurately estimated. In particular, since the resonance frequency can be avoided even in the state where the load is attached, the adjustment at the time of installation of the control system of the electric motor can be performed with high accuracy.

  In the third embodiment, the example in which the torque pulsation estimating unit 52A outputs the operation command MDC of the electric motor 1 so as to avoid the resonance frequency, but the torque pulsation such as the operation command of the electric motor 1 as described above is described. The estimation operation sequence may be performed by the operation sequence control unit described in the above embodiment, or may be provided as a dedicated control device.

Embodiment 4 FIG.
FIG. 12 is a schematic configuration diagram showing an elevator system including an elevator control device according to Embodiment 4 of the present invention. FIG. 12 shows a configuration diagram in a case where the motor control system including the torque pulsation correction devices according to the first to third embodiments is applied to, for example, an elevator as an application. In FIG. 12, portions denoted by the same reference numerals as those in FIG. 1 or FIG. 11 perform the same operations as those described in the first to third embodiments.

  In FIG. 12, a car 7 and a counterweight 9 of an elevator are respectively connected to both ends of a hoisting rope 8 and hung in a sheave manner on a sheave 6. The sheave 6 is connected to the electric motor 1 which is a motor for driving the car 7, and the car 7 is moved up and down by the power of the electric motor 1.

  Here, for example, torque pulsation is estimated when the hoist is installed. Specifically, after the hoist, which is the electric motor 1 in the elevator system, is installed, the torque pulsation is estimated in a state where the rope 8 is not hung on the sheave 6 or in a state where the rope 8 is hung on the sheave 6. Is performed, and the hoisting machine (1) is rotated to estimate the torque pulsation.

  At this time, if the estimation of the torque pulsation is performed only in the section where the car 7 is traveling at a constant speed, stable estimation can be performed. In addition, in order to extend a section where the vehicle is traveling at a constant speed, the vehicle may be operated at a traveling speed lower than the rated speed of the elevator. Further, in order to increase the estimation accuracy, the traveling speed of the elevator may be changed so that the traveling speed becomes such that the amplitude of the speed pulsation becomes large. The position of the car 7 is not limited, and can be estimated at any position in the hoistway on which the car 7 travels.

  Further, in order to increase the amplitude of the speed pulsation and increase the estimation accuracy, the operation may be performed with the gain of the current control unit 43 shown in FIGS. In the case of PID control, the proportional gain, the integral gain, and the differential gain correspond to the gain of the control device.

  The torque pulsation estimation result is recorded as a torque pulsation corresponding to the magnetic pole position of the hoisting machine (1), for example, in a storage medium including a nonvolatile memory. During normal operation, an estimated torque pulsation value corresponding to the output of the position detector 2 is read from this storage medium and corrected. The information on the torque pulsation to be recorded in the storage medium is obtained by calculating the torque pulsation from the same equation as the above equation (1) as the amplitude and the phase shift of the torque pulsation.

  In the elevator, the dynamic characteristics of the elevator system change according to the position of the car 7 and the load weight. Therefore, the transfer characteristic TCH shown in FIG. 5 also changes according to the position of the car 7 and the load weight. Therefore, it is desirable that the operation without adding the correction signal and the operation with the addition of the correction signal when performing the torque pulsation estimation be performed under the condition that the car position and the loaded weight are equal or nearly equal.

  Further, in the elevator, the dynamic characteristics of the elevator system change when the specifications such as the elevating length and the rated load capacity change, but in the present invention, the transfer characteristic TCH of the control system of the electric motor is obtained by the operation based on the test signal TS. Torque pulsation can be estimated irrespective of the specification. Of course, the torque pulsation can be estimated by using the present invention not only in the elevator but also in a system in which the characteristics of the load of the electric motor change every moment.

  Further, in the present invention, in estimating the torque pulsation, it is only necessary to perform at least four types of frequency analysis consisting of two current conditions × two presence / absence of a test signal, and the torque pulsation can be estimated in a short time. It is possible. Further, when the estimation is started, the estimation can be continuously performed without stopping the electric motor 1, so that the torque pulsation can be estimated in a short time. Therefore, for example, the torque pulsation can be estimated in a short time during the test operation after the installation of the elevator, so that the adjustment time at the time of installation can be shortened.

  Next, a case where estimation is performed while changing the position of the car 7 will be described. For example, when the car 7 is estimated while operating the car 7 from the lowest floor to the highest floor or from the highest floor to the lowest floor at the time of installation, the torque pulsation can be accurately estimated by performing the estimation in the following procedure.

  In the elevator, a resonance point due to the elastic characteristics of the rope 8 exists between the car 7 and the rope 8 or between the counterweight 9 and the rope 8. Further, the resonance point changes according to the position of the car 7 and the loaded mass of the car. Therefore, the cycle of the torque pulsation and the frequency of the test signal TS when estimating the torque pulsation may coincide with these resonance frequencies. Here, when the frequency of the torque pulsation or the frequency of the test signal coincides with the resonance frequency of the elevator, the amplitude and phase of the speed used for the frequency analysis change suddenly, and the frequency analysis result is not stable. It gets worse.

  Therefore, before estimating the torque pulsation, the elevator car 7 is operated from the lowest floor to the highest floor or from the highest floor to the lowest floor, and the frequency analysis of the motor speed is performed at a frequency corresponding to the torque pulsation. At this time, when the frequency of the torque pulsation is near the resonance frequency, the amplitude of the corresponding speed pulsation sharply increases or decreases, or the phase rapidly changes by nearly 180 degrees.

  Therefore, it is checked whether or not the change amount of the speed pulsation amplitude or the phase obtained by the frequency analysis exceeds a predetermined value, and if it exceeds the predetermined value, it is determined that the vicinity thereof is close to the resonance frequency. Further, based on the determination result, the torque pulsation is estimated at a position different from the position determined to be close to the resonance frequency. The operating speed at the time of torque pulsation estimation may be changed so as not to be near the resonance frequency. Further, the above method can be applied not only to the elevator but also to a case where the resonance frequency changes depending on the rotational position of the electric motor 1.

  For example, when estimating torque pulsation at the time of installing an elevator, the following may be performed. First, the elevator car 7 is operated from the bottom floor to the top floor or from the top floor to the bottom floor, and a frequency analysis of the motor speed is performed at a frequency corresponding to the torque pulsation, and a change amount of the speed pulsation amplitude and phase is calculated. I do.

  At this time, the car position is stored together with the speed pulsation amplitude and the amount of change in the phase. Subsequently, when the operation from the lowest floor to the top floor or from the top floor to the lowest floor is finished, it is checked whether or not the amount of change in the amplitude and phase of the speed pulsation exceeds a predetermined value, and does not exceed the predetermined value. Extract location. Next, the velocity pulsation is moved to a position where the amplitude and phase change amounts do not exceed predetermined values, and torque pulsation estimation is performed.

  If the operation to check whether the amplitude and phase variation of the speed pulsation exceeds a predetermined value is the operation from the lowest floor to the top floor, the operation to estimate the torque pulsation is the opposite top operation. When the operation is performed from the floor to the lowest floor, the torque pulsation can be estimated by one reciprocating operation, so that the time required for the torque pulsation estimation can be reduced.

  On the other hand, when the operation for checking whether the amplitude and the phase change of the speed pulsation exceed a predetermined value is the operation from the top floor to the bottom floor, the operation for estimating the torque pulsation is the opposite. It can be implemented by driving from the lowest floor to the highest floor. According to such an estimation method, it is possible to estimate torque pulsation while avoiding deterioration of estimation accuracy due to resonance, so that torque pulsation can be accurately corrected. Further, since the torque pulsation can be accurately estimated by one reciprocating operation, the adjustment time during installation can be shortened.

  The layout and roping method of the entire equipment of the elevator are not limited to the example of FIG. For example, the present invention can be applied to a 2: 1 roping elevator. Further, for example, the position of the hoist including the electric motor 1 is not limited to the example in FIG. 12. Further, the present invention can be applied to various types of elevators such as a machine room-less elevator, a double deck elevator, a one-shaft multi-car type elevator, and a skew elevator.

  In the configuration of FIGS. 1-3, 11 and 12, even if the torque pulsation correction devices 5 and 5A are dedicated hardware, a CPU (Central Processing Unit) that executes a program stored in a memory is used. , A processing device, an arithmetic device, a microprocessor, a microcomputer, a processor, and a DSP).

FIG. 13A schematically illustrates a hardware configuration when the functions of the torque pulsation correction devices 5 and 5A are configured by hardware, and FIG. 13B schematically illustrates a case where the functions are configured by software.
When the torque pulsation correction devices 5 and 5A are configured by the hardware illustrated in FIG. 13A, the processing circuit 1000 includes, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC, An FPGA or a combination thereof is applicable. Each function of the torque pulsation correction devices 5 and 5A may be realized by a processing circuit, or the function of each unit may be realized by a processing circuit.

  When the above functions are configured by the CPU shown in FIG. 13B, each function is realized by software, firmware, or a combination of software and firmware. Software and firmware are described as programs and stored in the memory 2100. The processor 2000, which is a processing circuit, implements each function by reading and executing a program stored in the memory 2100. It can be said that these programs cause a computer to execute the procedures and methods of the above functions. Here, the memory 2100 includes, for example, a nonvolatile or volatile semiconductor memory such as a RAM, a ROM, a flash memory, an EPROM, and an EEPROM, a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, and a DVD. Applicable.

  A part of each of the above functions may be realized by dedicated hardware, and a part may be realized by software or firmware.

As described above, the processing circuit can realize each of the above functions by hardware, software, firmware, or a combination thereof.
Various kinds of information required for processing are set in advance in a circuit in the case of a hardware configuration, and are stored in a memory in advance in a case of a software configuration.

  Further, the torque pulsation correction devices 5 and 5A can be configured as described above together with the portion of the electric motor control device 4 shown in FIGS.

As described above, in the motor torque pulsation correction device of the present invention, the periodic torque pulsation included in the motor torque is corrected for the current command value (ic, tc) for controlling the motor (1) in the motor control device (4). A torque pulsation correction device (5) for an electric motor,
When the electric motor is rotated, the rotational speed (MRS) of the electric motor is calculated from the rotational position (MRP) of the electric motor from the position detector (2), the rotational speed is frequency-analyzed, and the amplitude of the specific frequency (A1 ) And a phase (φ1), and outputs a frequency analysis result (FAR) as a frequency analysis unit (51);
A motor operation command (MDC) is input to the motor control device (4) to rotate the motor, and the amplitude (A2) and phase (φ2) of torque pulsation generated in the motor are obtained from the frequency analysis result (FAR). A torque pulsation estimator (52) for estimating and outputting as a torque pulsation estimated value (TPE);
The torque pulsation correction current value (Itpc) is calculated based on the torque pulsation estimated value (TPE), the motor current (Im) detected by the current detector (3), and the position detection signal (MRP), and the motor control device ( 4) a torque pulsation corrector (53) for correcting the current command value (ic, tc) of
With
The torque pulsation estimation unit (52) causes the frequency analysis unit (51) to calculate the frequency analysis result (FAR) for a plurality of conditions where the electric current of the electric motor is different, and obtains the obtained plurality of frequency analysis results (FAR). , The amplitude (A2) or phase (φ2) of the torque pulsation is obtained as a function of the current.
Thus, by obtaining the correction value of the torque pulsation as a function of the current, table data and the like become unnecessary, and the correction can be performed with a simple configuration.

Further, the torque pulsation estimation unit (52)
A first control process for operating the electric motor in a state where the torque pulsation correction unit (53) does not perform the torque pulsation correction;
By the frequency analysis unit (51), the rotation speed (MRS) of the electric motor obtained by the first control process is subjected to frequency analysis for a frequency corresponding to the torque pulsation, and an amplitude (A1a) and a phase (φ1a) are obtained. A second control process to obtain;
A test signal (TS) having a known amplitude, phase, and frequency is set in the torque pulsation correction unit (53), and the electric motor is supplied with the test signal (TS) added by the torque pulsation correction unit (53). A third control process for driving,
An amplitude (A1b) and a phase (φ1b) obtained by subjecting the rotational speed (MRS) of the electric motor obtained by the third control process to frequency analysis for the frequency of the test signal (TS) by the frequency analysis unit (51). And a fourth control process for obtaining
Based on the amplitude (A1a) and phase (φ1a) obtained in the second control process, and the amplitude (A1b) and phase (φ1b) obtained in the fourth control process, the amplitude (A2) of the torque pulsation And the phase (φ2) are calculated.
Thus, the current value for correcting the torque pulsation from the speed can be obtained by inputting the test signal.

Further, the torque pulsation estimating unit (52) calculates a transfer characteristic (TCH) at a specific frequency corresponding to the torque pulsation from the current of the motor to the rotation speed of the motor, and based on the transfer characteristic (TCH). An estimated value of the amplitude (A2) and the phase (φ2) of the torque pulsation is estimated.
This makes it possible to estimate torque pulsation even when the load is connected.
The transfer characteristic is a gain and a phase from a current (Im) of the electric motor to a rotation speed (MRS) of the electric motor.

Further, the frequency of the test signal (TS) is set to a specific frequency corresponding to the torque pulsation,
The torque pulsation estimating unit (52) performs a calculation to separate a speed pulsation component due to the torque pulsation and a speed pulsation component due to the test signal from a plurality of frequency analysis, and a speed pulsation component due to the torque pulsation. And the torque pulsation is estimated based on the transmission characteristic (TCH).
Thus, the frequency of the test signal is made to coincide with the frequency of the torque pulsation, so that accurate estimation can be performed.

Further, the torque pulsation estimating unit (52) includes an electric motor including the electric motor control device (4), the position detector (2), the current detector (3), and the torque pulsation correction device (5). The torque pulsation is estimated at the time of installation adjustment of the control system.
This makes it possible to easily estimate torque pulsation even after installation.

Further, the specific frequency corresponding to the torque pulsation is an electric motor constituted by the motor control device (4), the position detector (2), the current detector (3), and the torque pulsation correction device (5). Further comprising a resonance determination unit (54a) for determining whether the resonance frequency matches the resonance frequency of the control system of
The torque pulsation estimating unit (52A) is configured to determine, when the resonance determining unit (54a) determines that the specific frequency corresponding to the torque pulsation matches the resonance frequency of the control system of the electric motor, the rotational speed of the electric motor. Alternatively, the torque pulsation is estimated by changing the rotational position.
As a result, an estimation error occurs at the time of resonance, and therefore, by performing the resonance determination, the estimation accuracy is increased.
Further, the resonance determination unit (54A) determines that resonance occurs when at least one of the change amount of the amplitude and the change amount of the phase of the speed pulsation of the electric motor corresponding to the torque pulsation exceeds a set value. judge.

The torque pulsation estimating unit (52, 52A) includes a first amplitude that is an amplitude obtained by the second control process, a second amplitude that is an amplitude obtained by the fourth control process, and the test signal. And the amplitude of the torque pulsation is estimated by multiplying the ratio of the first amplitude to the second amplitude by the amplitude of the test signal.
The torque pulsation correction unit (53) performs the third control processing and the fourth control processing a plurality of times using the test signal having the same amplitude, phase, and frequency,
The torque pulsation estimating unit (52, 52A) estimates the amplitude of the torque pulsation a plurality of times, and sets an average value of the estimated values of the amplitude of the torque pulsation a plurality of times as the estimated value of the amplitude of the torque pulsation.
As a result, the reliability is improved by performing estimation multiple times with the same test signal.
The torque pulsation correction unit (53) performs the third control processing and the fourth control processing a plurality of times using the test signals having different amplitudes, phases, and frequencies,
The torque pulsation estimating unit (52, 52A) estimates the amplitude of the torque pulsation a plurality of times, and sets an average value of the estimated values of the amplitude of the torque pulsation a plurality of times as the estimated value of the amplitude of the torque pulsation.
As a result, the reliability is improved by performing the estimation a plurality of times with different test signals.

The torque pulsation estimating unit (52, 52A) is configured to calculate a difference between a first phase obtained by the second control processing and a phase obtained by the fourth control processing and a phase of the test signal. And the second phase is used to estimate the phase of the torque pulsation from the difference between the first phase and the second phase.
The torque pulsation correction unit (53) performs the third control processing and the fourth control processing a plurality of times using the test signal having the same amplitude, phase, and frequency,
The torque pulsation estimating unit (52, 52A) estimates the phase of the torque pulsation a plurality of times, and sets an average value of the estimated values of the phases of the torque pulsation a plurality of times as the estimated value of the phase of the torque pulsation.
As a result, the reliability is improved by performing estimation multiple times with the same test signal.
The torque pulsation correction unit (53) performs the third control processing and the fourth control processing a plurality of times using the test signals having different amplitudes, phases, and frequencies,
The torque pulsation estimating unit (52, 52A) estimates the phase of the torque pulsation a plurality of times, and sets an average value of the estimated values of the phases of the torque pulsation a plurality of times as the estimated value of the phase of the torque pulsation.
As a result, the reliability is improved by performing the estimation a plurality of times with different test signals.

  Further, in the elevator control device according to the present invention, an electric motor (1) as a hoist of the elevator, an electric motor control device (4) controlled by the electric motor (1), and a rotational position (MRP) of the electric motor (1). , A current detector (3) for detecting a motor current (Im) flowing through the motor (1), a rotational position (MRP) and a motor current (Im) of the motor (1). ), A torque pulsation correction current for correcting a periodic torque pulsation included in the torque of the electric motor with respect to a current command value (ic, tc) for controlling the electric motor (1) in the electric motor control device (4). The torque pulsation correction device (5) according to any one of claims 1 to 14, which performs correction with a value (Itpc).

In the method for correcting torque pulsation of a motor according to the present invention, a periodic torque pulsation included in the torque of the motor is controlled with respect to a current command value (ic, tc) of a motor control device (4) for controlling the motor (1). A method for correcting torque pulsation of a motor to be corrected (5),
When the electric motor is rotated, the rotational speed (MRS) of the electric motor is calculated from the rotational position (MRP) of the electric motor from the position detector (2), the rotational speed is frequency-analyzed, and the amplitude of the specific frequency (A1 ) And phase (φ1) to obtain a frequency analysis result (FAR) (51),
From the frequency analysis result (FAR), the amplitude (A2) and phase (φ2) of the torque pulsation generated in the electric motor are estimated to obtain a torque pulsation estimated value (TPE) (52),
The torque pulsation correction current value (Itpc) is calculated based on the torque pulsation estimated value (TPE), the motor current (Im) detected by the current detector (3), and the position detection signal (MRP), and the motor control device ( The current command value (ic, tc) of 4) is corrected (53),
When obtaining the torque pulsation estimated value (TPE), the frequency analysis result (FAR) is calculated for a plurality of conditions where the electric current of the electric motor is different, and the amplitude of the torque pulsation is calculated from the obtained plurality of frequency analysis results (FAR). Determine (A2) or phase (φ2) as a function of current.
Thus, by obtaining the correction value of the torque pulsation as a function of the current, table data and the like become unnecessary, and the correction can be performed with a simple configuration.

ADVANTAGE OF THE INVENTION According to the torque pulsation correction apparatus and the torque pulsation correction method for a motor according to the present invention, it is possible to perform frequency analysis of a specific frequency component of the rotation speed of the motor and estimate torque pulsation of the motor based on the frequency analysis result. At this time, the amplitude or the phase of the torque pulsation is estimated as a function of the current based on the frequency analysis results obtained under a plurality of conditions under different current conditions.
Therefore, it is possible to obtain a torque pulsation correction device and a torque pulsation correction method that can estimate and correct torque pulsation with a simple configuration.
Further, according to the elevator control apparatus of the present invention, it is possible to perform frequency analysis of a specific frequency component of the rotation speed of the electric motor and estimate torque pulsation of the electric motor based on the frequency analysis result. At this time, the amplitude or the phase of the torque pulsation is estimated as a function of the current based on the frequency analysis results obtained under a plurality of conditions under different current conditions.
Therefore, it is possible to obtain a torque pulsation correction device and a torque pulsation correction method that can estimate and correct torque pulsation with a simple configuration in an elevator.

  The present invention is not limited to the above embodiments, but includes all possible combinations.

Industrial applicability

  The motor torque pulsation correction device and correction method according to the present invention can be applied to motors used in various fields. Further, the elevator control device according to the present invention can be applied to many types of elevator systems.

  REFERENCE SIGNS LIST 1 motor, 2 position detector, 3 current detector, 4 motor control device, 5, 5 A torque pulsation correction device, 6 sheave, 8 rope, 9 counterweight, 41 speed calculation unit, 42 speed control unit, 42 a position Control section, 43 current control section, 44 power converter, 51 frequency analysis section, 52, 52A torque pulsation estimation section, 53 torque pulsation correction section, 54A resonance determination section, 1000 processing circuits, 2000 processor, 2100 memory, AD1 addition section

Claims (16)

A torque pulsation correction device for a motor for correcting a periodic torque pulsation included in the torque of the motor with respect to a current command value for controlling the motor in the motor control device,
When the electric motor is rotated, the rotational speed of the electric motor is calculated from the rotational position of the electric motor from the position detector to analyze the rotational speed, and the amplitude and phase of a specific frequency are calculated and output as a frequency analysis result. Frequency analysis unit to perform,
A torque pulsation estimating unit that inputs a motor operation command to the motor control device and rotates the motor, estimates the amplitude and phase of the torque pulsation generated in the motor from the frequency analysis result, and outputs the estimated value as a torque pulsation estimation value. ,
A torque pulsation correction unit that calculates a torque pulsation correction current value based on the torque pulsation estimated value and the motor current detected by the current detector and the position detection signal to correct a current command value of the motor control device,
With
The torque pulsation estimation unit causes the frequency analysis unit to calculate the frequency analysis result for a plurality of conditions where the current of the electric motor is different, and obtains the amplitude or phase of the torque pulsation from the obtained plurality of frequency analysis results as a function of the current. The required motor torque pulsation correction device. The torque pulsation estimator,
A first control process for operating the electric motor in a state where the torque pulsation correction unit does not perform the torque pulsation correction;
A second control process of obtaining, by the frequency analysis unit, an amplitude and a phase obtained by frequency-analyzing the rotation speed of the electric motor obtained by the first control process with respect to a frequency corresponding to the torque pulsation;
A third control process for setting a test signal having a known amplitude, phase, and frequency in the torque pulsation correction unit, and operating the motor with the torque pulsation correction unit applying the test signal;
A fourth control process of obtaining, by the frequency analysis unit, an amplitude and a phase obtained by performing a frequency analysis on the rotation speed of the electric motor obtained by the third control process with respect to the frequency of the test signal;
Calculating the amplitude and the phase of the torque pulsation based on the amplitude and the phase obtained in the second control process and the amplitude and the phase obtained in the fourth control process;
The torque pulsation correction device for an electric motor according to claim 1.   The torque pulsation estimating unit calculates a transfer characteristic at a specific frequency corresponding to the torque pulsation from the current of the motor to the rotation speed of the motor, and estimates an amplitude and a phase of the torque pulsation based on the transfer characteristic. 3. The torque pulsation correction device for an electric motor according to claim 2, wherein the estimation is performed.   4. The torque pulsation correction device for an electric motor according to claim 3, wherein the transfer characteristic is a gain and a phase from a current of the electric motor to a rotation speed of the electric motor. The frequency of the test signal is set to a specific frequency corresponding to the torque pulsation,
The torque pulsation estimating unit performs a calculation for separating a speed pulsation component due to a torque pulsation and a speed pulsation component due to a test signal from a plurality of frequency analysis, and calculates a speed pulsation component due to the torque pulsation and the transmission. The torque pulsation correction device for an electric motor according to claim 3, wherein the torque pulsation is estimated based on characteristics.   The said torque pulsation estimation part estimates the said torque pulsation at the time of installation adjustment of the control system of the electric motor which consists of the said motor control apparatus, the said position detector, the said current detector, and the said torque pulsation correction apparatus. The torque pulsation correction device for a position detector according to any one of 2 to 5. It is determined whether or not a specific frequency corresponding to the torque pulsation coincides with a resonance frequency of a control system of a motor including the motor control device, the position detector, the current detector, and the torque pulsation correction device. Further comprising a resonance determination unit
The torque pulsation estimating unit, when it is determined in the resonance determination unit that the specific frequency corresponding to the torque pulsation matches the resonance frequency of the control system of the electric motor, changes the rotational speed or rotational position of the electric motor. The torque pulsation correction device for an electric motor according to any one of claims 2 to 6, wherein the torque pulsation is estimated by performing the estimation.   The said resonance determination part determines that it is a resonance, when at least one of the amount of change of the amplitude and the amount of change of the phase of the speed pulsation of the electric motor of the specific frequency component corresponding to the torque pulsation exceeds a set value. 8. The torque pulsation correction device for an electric motor according to claim 7.   The torque pulsation estimating unit uses the first amplitude that is the amplitude obtained by the second control process, the second amplitude that is the amplitude obtained by the fourth control process, and the amplitude of the test signal. The torque pulsation of an electric motor according to any one of claims 2 to 8, wherein an amplitude of the torque pulsation is estimated by multiplying a ratio of the first amplitude and the second amplitude by an amplitude of the test signal. Correction device. The torque pulsation correction unit performs the third control process and the fourth control process a plurality of times with the test signal having the same amplitude, phase, and frequency,
The torque pulsation estimation unit estimates the amplitude of the torque pulsation a plurality of times, and sets an average value of the estimated values of the amplitude of the torque pulsation a plurality of times as the estimated value of the amplitude of the torque pulsation.
The torque pulsation correction device for an electric motor according to claim 9. The torque pulsation correction unit performs the third control processing and the fourth control processing a plurality of times using the test signals having different amplitudes, phases, and frequencies,
The torque pulsation estimation unit estimates the amplitude of the torque pulsation a plurality of times, and sets an average value of the estimated values of the amplitude of the torque pulsation a plurality of times as the estimated value of the amplitude of the torque pulsation.
The torque pulsation correction device for an electric motor according to claim 9.   The torque pulsation estimating unit includes: a first phase that is a phase obtained by the second control process; a second phase that is a difference between a phase obtained by the fourth control process and a phase of the test signal; The torque pulsation correction device for an electric motor according to any one of claims 2 to 8, wherein a phase of the torque pulsation is estimated based on a difference between the first phase and the second phase by using the following. The torque pulsation correction unit performs the third control process and the fourth control process a plurality of times with the test signal having the same amplitude, phase, and frequency,
The torque pulsation estimating unit performs the estimation of the phase of the torque pulsation a plurality of times, and sets an average value of the estimated values of the phases of the plurality of the torque pulsations as the estimated value of the phase of the torque pulsation.
The torque pulsation correction device for an electric motor according to claim 12. The torque pulsation correction unit performs the third control processing and the fourth control processing a plurality of times using the test signals having different amplitudes, phases, and frequencies,
The torque pulsation estimating unit performs the estimation of the phase of the torque pulsation a plurality of times, and sets an average value of the estimated values of the phases of the plurality of the torque pulsations as the estimated value of the phase of the torque pulsation.
The torque pulsation correction device for an electric motor according to claim 12. An electric motor, which is the hoist of the elevator,
A motor control device that controls the motor,
A position detector for detecting a rotational position of the electric motor,
A current detector for detecting a motor current flowing through the motor,
Based on the rotation position and the motor current of the motor, a correction is made with a torque pulsation correction current value for correcting a periodic torque pulsation included in the torque of the motor with respect to a current command value for controlling the motor in the motor control device. A torque pulsation correction device according to any one of claims 1 to 14, wherein
Elevator control device with A torque pulsation correction method for an electric motor that corrects a periodic torque pulsation included in a torque of the electric motor with respect to a current command value of an electric motor control device that controls the electric motor,
When the electric motor is rotated, the rotational speed of the electric motor is calculated from the rotational position of the electric motor from the position detector, the rotational speed is frequency-analyzed, and the amplitude and phase of a specific frequency are calculated to obtain a frequency analysis result. ,
Estimating the amplitude and phase of torque pulsation generated in the electric motor from the frequency analysis result to obtain a torque pulsation estimated value,
Correcting the current command value of the motor control device by calculating a torque pulsation correction current value based on the torque pulsation estimated value and the motor current detected by the current detector and the position detection signal,
When obtaining the torque pulsation estimated value, the frequency analysis result is calculated for a plurality of conditions where the current of the electric motor is different, and the amplitude or phase of the torque pulsation is obtained as a function of the current from the obtained plurality of frequency analysis results. A method for correcting torque pulsation of an electric motor.

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