JP6237798B2 - Load angle estimation device - Google Patents

Description

  The present invention relates to a technique for controlling a synchronous motor including a field and an armature. In particular, the present invention relates to a technique for controlling a synchronous motor based on a so-called primary magnetic flux.

  Conventionally, various types of so-called primary magnetic flux control have been proposed for synchronous motor control based on primary magnetic flux. Simply speaking, the primary magnetic flux control is a technique for stably controlling the synchronous motor by controlling the primary magnetic flux of the synchronous motor according to the command value.

  The phase difference between the phase of the field magnetic flux and the phase of the primary magnetic flux is called a load angle. For example, in Patent Document 1, it is used for estimating the primary magnetic flux. A technique for estimating the load angle is introduced in Patent Document 1 below. In Patent Document 1, a load angle is estimated based on design device constants such as an inductance component and a resistance component of an armature, and an observable amount such as a voltage applied to the synchronous motor and a current flowing through the synchronous motor.

Japanese Patent No. 5494760

  However, the estimation of the load angle involves an error when the device constant is different between the actual machine and the set value, or due to an error in the observable amount.

  Therefore, an object of the present invention is to improve the accuracy of the estimated value of the load angle.

  The load angle estimation device according to the present invention includes an armature reaction magnetic flux ([λa]) generated by a current ([I]) flowing through a synchronous motor (3) and a field magnetic flux ([Λf]) of the synchronous motor. Is a device that estimates a load angle (δ) that is a phase difference of the primary magnetic flux ([λ0]), which is a combination of the above and the field magnetic flux.

The first mode (100B) includes a rough load angle estimator (101) for obtaining a first estimated value (δc) of the load angle, and an estimated value of an error between the first estimated value and the load angle. A load angle error estimator ( 107 ) for obtaining an estimated error value ( Δδ2 ) as an arctangent function value of the magnetic flux ratio, a compensation value ( K2 · Δδ2 ) based on the error estimate value, and the first estimated value. And a combining unit ( 108, 105) for combining and obtaining a second estimated value (δcc) of the load angle .

However, the magnetic flux ratio is a component in phase with the primary magnetic flux command ([λ0 *]) that is the command value of the primary magnetic flux ([λ0]) of the estimated value ([λ0 ^]) of the primary magnetic flux ([λ0]). for the ratio of the component 90 DoSusumusho to the primary magnetic flux command of the estimated value of the primary flux.

A second aspect (100A) of the load angle estimation device according to the present invention includes a load angle rough estimation unit (101) for obtaining a first estimated value (δc) of the load angle, the first estimated value, and the A load angle error estimator (102) for obtaining an error estimated value (Δδ1) as an estimated value of an error from the load angle as an arctangent function value of the magnetic flux ratio, a compensation value (K1 · Δδ1) based on the error estimated value, and And a combining unit (103, 104) that combines the first estimated value to obtain a second estimated value (δcc) of the load angle. The magnetic flux ratio is obtained as a value obtained by dividing the first value by the second value. With respect to the primary magnetic flux command ([λ0 *]) that is the command value of the primary magnetic flux ([λ0]) of the current ([I]), the Mc axis current iMc that is in phase with the primary magnetic flux command ([λ0 *]), and the primary magnetic flux command of the current The Tc axis current iTc, which is a component advanced by 90 degrees, the Mc axis voltage command vMc *, which is a component in phase with the primary magnetic flux command of the voltage command value applied to the synchronous motor (3), and the command of the voltage The first value is (R · iMc−vMc *) by introducing the Tc-axis voltage command vTc *, which is a component advanced by 90 degrees with respect to the primary magnetic flux command, and the resistance component R of the synchronous motor. And the second value is (vTc * −R · iTc).

A third aspect of the load angle estimating device according to the present invention is the first aspect, wherein the first estimated value (δc) of the load angle is used as a command value ω * for the rotational angular velocity of the synchronous motor. A q-axis inductance Lq which is a component advanced by 90 degrees with respect to the field magnetic flux of the inductance of the synchronous motor, and an Mc-axis current iMc which is a component in phase with the primary magnetic flux command ([λ0 *]) of the current. A Tc-axis current iTc that is a component advanced by 90 degrees with respect to the primary magnetic flux command of the current, and an Mc-axis voltage command that is a component in phase with the primary magnetic flux command of the command value of the voltage applied to the synchronous motor vMc *, a Tc-axis voltage command vTc * that is a component advanced by 90 degrees with respect to the primary magnetic flux command of the command value of the voltage, and a resistance component R of the synchronous motor are introduced, and (vMc * -R・ IMc + ω * ・ Lq ・Tc) / (determined by inverse tangent function of the value represented by vTc * -R · iTc-ω * · Lq · iMc).
A fourth aspect of the load angle estimation device according to the present invention is the second aspect thereof, wherein the load angle rough estimation unit (101) calculates the first estimated value (δc) of the load angle, A command value ω * of the rotational angular velocity of the synchronous motor and a q-axis inductance Lq that is a component advanced by 90 degrees with respect to the field magnetic flux of the inductance of the synchronous motor are further introduced, and (vMc * −R · iMc + ω * · Lq · iTc) / (vTc * −R · iTc−ω * · Lq · iMc).

  Preferably, the combining unit performs proportional control on the error estimated value (Δδ1; Δδ2) to obtain the compensation value (K1 · Δδ1; K2 · Δδ2), and the compensation value. And an adder (104; 105) for adding to the first estimated value (δc).

  According to the load angle estimating device of the present invention, the load angle is estimated with high accuracy.

It is a vector diagram which shows the relationship between a field magnetic flux, a primary magnetic flux, and a voltage. It is a vector diagram which shows the relationship between a field magnetic flux, a primary magnetic flux, and a voltage. It is a block diagram which shows the structure of the load angle estimation apparatus concerning 1st Embodiment. It is a block diagram which shows the technique which controls the drive of a synchronous motor. It is a block diagram which shows the structure of the load angle estimation apparatus concerning 2nd Embodiment. It is a block diagram which shows the structure of the load angle estimation apparatus concerning a deformation | transformation.

First embodiment.
Hereinafter, the phase of the field magnetic flux [Λf] ([] and the symbol between them indicates that the indicated quantity is a vector: the same applies hereinafter) is adopted for the d-axis of the rotating coordinate system, and the primary magnetic flux [ The phase of [lambda] 0] is adopted for the M-axis of another rotating coordinate system. In such a setting, the phase difference between the M axis and the d axis is considered as the load angle δ. A T-axis that is advanced by 90 degrees with respect to the M-axis is also assumed.

  The primary magnetic flux [λ0] is a combination of the field magnetic flux [Λf] and the armature reaction magnetic flux [λa] generated by the armature current flowing in the armature winding.

  The Mc axis and the Tc axis are employed as the coordinate axes of the rotating coordinate system employed in the control of the primary magnetic flux. The Mc axis and the Tc axis correspond to the M axis and the T axis, respectively, and the phase difference of the Mc axis with respect to the d axis is δc. The Mc axis is set in phase with the command value of primary magnetic flux [λ0] (hereinafter referred to as “primary magnetic flux command”) [λ0 *]. It is assumed that the Mc-axis component of the primary magnetic flux command [λ0 *] has a value λ0 * and the Tc-axis component is zero.

  If the primary magnetic flux [λ0] matches the primary magnetic flux command [λ0 *], the Mc axis component λ0Mc of the primary magnetic flux [λ0] is equal to the value λ0 *, the phase difference δc is equal to the load angle δ, and the Mc axis is the M axis. Matches.

  FIG. 1 is a vector diagram showing the relationship between field magnetic flux [Λf], primary magnetic flux [λ0], and voltage [V0]. In FIG. 1, the primary magnetic flux [λ0] coincides with the primary magnetic flux command [λ0 *]. Therefore, the phase difference δc is equal to the load angle δ, the Mc axis coincides with the M axis, and the Tc axis coincides with the T axis.

  The voltage [V0] is an induced voltage induced by the rotation of the synchronous motor. The magnitude | V0 | is represented by the product ω · | λ0 | where the rotational angular velocity of the synchronous motor is ω (the magnitude | λ0 | of the primary magnetic flux [λ0] is introduced: if δ = δc, | λ0 | = λ0Mc ), It is known that the electrical angle is advanced by 90 degrees with respect to the primary magnetic flux [λ0], and the direction thereof coincides with the T-axis. In FIG. 1, the magnitude | Λf | of the field magnetic flux [Λf] is also introduced and illustrated. Similarly, the symbol | G | is used as the magnitude of the vector [G].

  The resistance component R of the synchronous motor, the q-axis component Lq (hereinafter referred to as “q-axis inductance”) and the d-axis component Ld (hereinafter referred to as “d-axis inductance”) of the inductance of the synchronous motor, and the current [ I] T-axis component iT (hereinafter referred to as “T-axis current”) and M-axis component iM (hereinafter referred to as “M-axis current”), and T-axis component vT (Va) applied to the synchronous motor. Introducing an M-axis component vM (hereinafter referred to as “M-axis voltage”) and a load angle δ between these and the load angle δ (especially, the equation (8)). In view of the above, there is a relationship of the formula (1).

  Based on such a relationship, it is considered to estimate the load angle δ using various quantities on the right side. Since the estimation is performed in the primary magnetic flux control, various amounts in the control are adopted. That is, since the estimated value of the load angle δ is estimated using various quantities in the rotating coordinate system having the Mc axis and the Tc axis, it is obtained as the phase difference δc. Therefore, hereinafter, the phase difference δc is referred to as a first estimated value δc.

  As exemplified in Patent Document 1, the observed amount in the primary magnetic flux control is the current [I] flowing through the synchronous motor. Therefore, when obtaining the first estimated value δc, instead of the T-axis current iT and the M-axis current iM in the equation (1), the Tc-axis component iTc (hereinafter referred to as “Tc-axis current”) of the observed value of the current [I] And Mc axis component iMc (hereinafter referred to as “Mc axis current”).

  On the other hand, since the voltage [Va] applied to the synchronous motor is not normally measured, instead of the T-axis voltage vT and the M-axis voltage vM when obtaining the first estimated value δc from the equation (1), Tc Voltage command values vTc * and vMc * (hereinafter referred to as “Tc-axis voltage command vTc *” and “Mc-axis voltage command vMc *”, respectively) on the axis and the Mc axis are employed. Hereinafter, since the rotational angular velocity ω cannot be observed directly, the velocity command ω * as the command value is adopted. As the speed command ω *, a value obtained by removing a high frequency component of the Tc-axis current iTc may be adopted as disclosed in Patent Document 1.

  From the above, following the equation (1), the first estimated value δc is obtained by the equation (2). Usually, the synchronous motor 3 is a balanced load, and it can be considered that the resistance component R does not depend on the coordinate system.

  Now, assume that an error occurs in the observable amount. For example, there is an error in the current sensor itself that measures the current [I]. Alternatively, even if there is no error in the current sensor, the current [I] itself may fluctuate due to malfunction of the inverter that supplies power to the synchronous motor. An example of the latter is a case where the followability of the inverter with respect to the Tc axis voltage command vTc * and the Mc axis voltage command vMc * is poor. Such deterioration in follow-up performance may be caused by, for example, a defective voltage sensor inside the inverter.

  Further, due to variations in the synchronous motor, the q-axis inductance Lq, the d-axis inductance Ld, and the resistance component R, which are device constants, may have values different from the design values.

  Thus, there is a possibility that the load angle δ actually generated as in equation (1) and the first estimated value δc obtained in equation (2) are different.

  FIG. 2 is a vector diagram showing a case where the Mc axis component λ0Mc is different from the value λ0 *, and therefore the first estimated value δc is different from the load angle δ, and the Mc axis is different from the M axis.

  In Patent Document 1, an estimated value χ ^ of the angle χ obtained by subtracting the first estimated value δc from the load angle δ is shown by the expression (3) (the symbols are shown in conformity with the present case).

  Therefore, in order to obtain the second estimated value δcc closer to the load angle δ than the first estimated value δc, the calculation of Expression (4) may be performed. Here, an error estimated value Δδ1 corresponding to the estimated value χ ^ and a proportional gain K1 (> 0) were introduced.

  FIG. 3 is a block diagram showing a configuration of the load angle estimation apparatus 100A according to the present embodiment. The load angle estimation device 100A obtains the second estimated value δcc according to the equations (2) and (4).

  The load angle estimation device 100A includes a load angle rough estimation unit 101, a load angle error estimation unit 102, a proportional control unit 103 (denoted as “P control unit” in the drawing), and an adder 104. The rough load angle estimation unit 101 generates a speed command ω *, a Tc-axis voltage command vTc *, an Mc-axis voltage command vMc *, a q-axis inductance Lq, a resistance component R, a Tc-axis current iTc, and an Mc-axis current iMc. The first estimated value δc is obtained according to the equation (2).

  More specifically, the load angle rough estimation unit 101 obtains an arctangent function value obtained by dividing the first value by the second value as the first estimated value δc. The first value is a value obtained by subtracting the product of the Mc-axis current iMc and the resistance component R from the sum of the product of the speed command ω *, the q-axis inductance Lq, and the Tc-axis current iTc and the Mc-axis voltage command vMc *. It is. The second value is a value obtained by subtracting the sum of the product of the speed command ω *, the q-axis inductance Lq, and the Mc-axis current iMc and the product of the Tc-axis current iTc and the resistance component R from the Tc-axis voltage command vTc *. It is.

  The load angle error estimation unit 102 uses the Tc-axis voltage command vTc *, the Mc-axis voltage command vMc *, the resistance component R, the Tc-axis current iTc, and the Mc-axis current iMc, and estimates the error according to Equation (4). The value Δδ1 is obtained.

  More specifically, the load angle error estimating unit 102 obtains an arc tangent function value obtained by dividing the third value by the fourth value as the error estimated value Δδ1. The third value is a value obtained by subtracting the Mc-axis voltage command vMc * from the product of the Mc-axis current iMc and the resistance component R. The fourth value is a value obtained by subtracting the product of the Tc-axis current iTc and the resistance component R from the Tc-axis voltage command vTc *.

  The proportional control unit 103 performs proportional control on the error estimated value Δδ1 using the proportional gain K1 to obtain a value K1 · Δδ1. The adder 104 adds the value K1 · Δδ1 to the first estimated value δc to obtain a second estimated value δcc. That is, the value K1 · Δδ1 can be considered as a compensation value for compensating the first estimated value δc. The proportional control unit 103 and the adder 104 can be combined to be a combining unit that combines the compensation value K1 · Δδ1 based on the error estimated value Δδ1 and the first estimated value δc.

  Thus, by obtaining the compensation value K1 · Δδ1 using the estimated error value Δδ1 of the load angle, the load angle is accurately estimated.

  FIG. 4 is a block diagram illustrating a technique for controlling the driving of the synchronous motor 3 using the load angle estimation device 100A.

  The synchronous motor 3 is, for example, a three-phase motor, and includes an armature (not shown) and a rotor that is a field. As technical common sense, the armature has an armature winding, and the rotor rotates relative to the armature. The field includes, for example, a magnet that generates a field magnetic flux.

  The voltage supply source 2 includes, for example, a voltage control type inverter and its control unit, and applies a three-phase voltage to the synchronous motor 3 based on a three-phase voltage command value [V *]. As a result, the three-phase current [I] flows through the synchronous motor 3.

  The motor control device 1 is a device that controls the primary magnetic flux [λ0] and the rotational angular velocity ω with respect to the synchronous motor 3. The motor control device 1 includes a load angle estimation device 100, a primary magnetic flux estimation unit 110, a voltage command calculation unit 120, a first coordinate conversion unit 130, a second coordinate conversion unit 140, and an integrator 150. Yes.

  The first coordinate conversion unit 130 converts the Mc-axis voltage command vMc * and the Tc-axis voltage command vTc * into a voltage command value [V *]. The second coordinate conversion unit 140 converts the three-phase current [I] into the Mc-axis current iMc and the Tc-axis current iTc in the Mc-Tc rotating coordinate system that performs primary magnetic flux control.

  The integrator 150 integrates a speed command ω *, which is a command value of the rotational angular velocity ω, and calculates a fixed axis coordinate, for example, the phase θ of the Mc axis with respect to the α axis in phase with the U phase voltage. Based on the phase θ, the first coordinate conversion unit 130 and the second coordinate conversion unit 140 can perform the coordinate conversion described above.

  When obtaining the phase θ, instead of the speed command ω *, a rotational angular speed ω in consideration of the variation of the Tc-axis current iTc may be employed as in Patent Document 1.

  The load angle estimation device 100 receives the Mc axis voltage command vMc *, the Tc axis voltage command vTc *, the speed command ω *, the resistance component R, the q axis inductance Lq, and the d axis inductance Ld, and performs the second estimation of the load angle. The value δcc is output. Specifically, the load angle estimation device 100A described above can be employed as the load angle estimation device 100.

  The primary magnetic flux estimation unit 110 receives the second estimated value δcc, the resistance component R, the q-axis inductance Lq, and the d-axis inductance Ld and obtains an estimated value [λ0 ^] of the primary magnetic flux. The configuration of the primary magnetic flux estimation unit 110 can be realized by employing a known technique (for example, introduced in Patent Document 1).

  When the load angle estimating device 100A is adopted as the load angle estimating device 100, the load angle estimating device 100 and the primary magnetic flux estimating unit 110 as a whole are Mc axis voltage command vMc *, Tc axis voltage command vTc *, speed command ω *. Also, it can be considered as an estimated primary magnetic flux value obtained by inputting the resistance component R, the q-axis inductance Lq, and the d-axis inductance Ld to obtain the estimated value [λ0 ^].

  The voltage command calculation unit 120 inputs the estimated value [λ0 ^] of the primary magnetic flux, the primary magnetic flux command [λ0 *], the Mc-axis current iMc, the Tc-axis current iTc, and the speed command ω *, and the Mc-axis voltage. Calculation to obtain the command vMc * and the Tc axis voltage command vTc * is performed. Such a calculation is disclosed in Patent Document 1 as a calculation for obtaining a feedforward term and a feedback term and the sum of the two, and is a known technique, and thus detailed description thereof is omitted here.

Second embodiment.
As shown in Patent Document 1, the numerator of Expression (3) is equal to the Tc axis component of the internal induced voltage of the synchronous motor 3, and the denominator is equal to the Mc axis component of the internal induced voltage. The internal induced voltage is a product of the rotational angular velocity ω and the primary magnetic flux [λ0]. Therefore, by introducing the Mc axis component λ0Mc ^ and the Tc axis component λ0Tc ^ of the estimated value [λ0 ^] of the primary magnetic flux, the second estimated value δcc is expressed by the expression (5) in the same manner as the expression (4). Can be obtained by:

  That is, the error estimated value Δδ2 and the proportional gain K2 are introduced to obtain the compensation value K2 · Δδ2, and this is added to the first estimated value δc to obtain the second estimated value δcc.

  FIG. 5 is a block diagram showing a configuration of the load angle estimating apparatus 100B according to the present embodiment. The load angle estimation device 100B obtains the second estimated value δcc according to the equations (2) and (5).

  The load angle estimation device 100B includes a load angle rough estimation unit 101, a load angle error estimation unit 107, a proportional control unit 108 (denoted as “P control unit” in the figure), an adder 105, and a primary magnetic flux estimation unit 106. . The rough load angle estimation unit 101 performs the same function as the rough load angle estimation unit 101 shown in the first embodiment.

  The load angle error estimation unit 107 uses the Mc axis component λ0Mc ^ and the Tc axis component λ0Tc ^ of the estimated value [λ0 ^] of the primary magnetic flux obtained as described later from the primary magnetic flux estimation unit 106, and the equation (5). The error estimated value Δδ2 is obtained according to

  More specifically, the load angle error estimation unit 107 obtains an arc tangent function value obtained by dividing the Tc axis component λ0Tc ^ by the Mc axis component λ0Mc ^ as the error estimated value Δδ2.

  The proportional control unit 108 performs proportional control on the error estimated value Δδ2 using the proportional gain K2 to obtain the value K2 · Δδ2. The adder 105 adds the value K2 · Δδ2 to the first estimated value δc to obtain a second estimated value δcc. The proportional control unit 108 and the adder 105 can be combined to be considered as a combining unit that combines the compensation value K2 · Δδ2 based on the error estimated value Δδ2 and the first estimated value δc.

  Thus, the estimated value of the load angle is accurately estimated by obtaining the compensation value K2 · Δδ2 using the estimated error value Δδ2 of the load angle.

  The primary magnetic flux estimator 106 includes the second estimated value δcc, the q-axis inductance Lq, the d-axis inductance Ld, the Mc-axis current iMc, the Tc-axis current iTc, and the magnitude of the field magnetic flux [Λf] | Λf. |, The estimated value [λ0 ^] of the primary magnetic flux is calculated. Since such calculation is well known and has been introduced in, for example, Patent Document 1, detailed description thereof is omitted here.

  The load angle estimation device 100B can be replaced with the load angle estimation device 100 and the primary magnetic flux estimation unit 110 shown in FIG. Or conversely, the primary magnetic flux estimation unit 110 may be employed instead of the primary magnetic flux estimation unit 106 of the load angle estimation device 100B.

Deformation.
As described above, the estimated error value Δδ1 is the product of the Mc axis component λ0Mc ^ and the rotational angular velocity ω (or speed command ω *), and the product of the Tc axis component λ0Tc ^ and the rotational angular velocity ω (or speed command ω *). The value of the arctangent function of the value divided by. The estimated error value Δδ2 is a value of an arctangent function obtained by dividing the Mc axis component λ0Mc ^ by the Tc axis component λ0Tc ^.

  Therefore, the error estimated values Δδ1 and Δδ2 can be considered as values of arctangent functions with respect to the magnetic flux ratio that is the ratio of the Tc-axis component λ0Tc ^ to the Mc-axis component λ0Mc ^ of the estimated value [λ0 ^] of the primary magnetic flux. it can.

  However, the values used as parameters for obtaining the arc tangent function are different. Therefore, the second estimated value δcc may be obtained using both the compensation values K1 · Δδ1, K2 · Δδ2.

  FIG. 6 is a block diagram showing a configuration of a load angle estimation device 100C according to a modification between the first embodiment and the second embodiment. The load angle estimation device 100C includes a load angle rough estimation unit 101, a load angle error estimation unit 102, and a proportional control unit 103 included in the load angle estimation device 100A, and a load angle error estimation unit 107 and proportional control included in the load angle estimation device 100B. Unit 108 and an adder 109.

  Since the operations of the load angle rough estimation unit 101 and the load angle error estimation units 102 and 107 have already been described, illustration of inputs to these is omitted. As described in the first embodiment and the second embodiment, the proportional control units 103 and 108 perform proportional control using the proportional gains K1 and K2 on the error estimated values Δδ1 and Δδ2, respectively.

  The adder 109 takes the sum of the compensation values K1 · Δδ1, K2 · Δδ2 and the first estimated value δc, and outputs the sum as the second estimated value δcc. The proportional control units 103 and 108 and the adder 109 can be combined to be a combining unit that combines the compensation values K1 · Δδ1, K2 · Δδ2 based on the error estimated values Δδ1 and Δδ2 and the first estimated value δc. .

  Thus, even if the two estimated values δcc are obtained by using the two compensation values together, the values that serve as parameters for obtaining these compensation values (the compensation values K1 · Δδ1 are the Mc-axis voltage command vMc * , Tc-axis voltage command vTc *, Mc-axis current iMc, Tc-axis current iTc and resistance component R; the compensation value K2 · Δδ2 is Mc-axis component λ0Mc ^ and Tc-axis component λ0Tc ^), so the second An estimated value δcc can be obtained.

DESCRIPTION OF SYMBOLS 3 Synchronous motor 100,100A, 100B, 100C Load angle estimation apparatus 101 Load angle rough estimation part 102,107 Load angle error estimation part 103,108 Proportional control part 104,105 Adder

Claims (5)

The primary magnetic flux ([λ0], which is a combination of the magnetic flux ([λa]) of the armature reaction generated by the current ([I]) flowing through the synchronous motor (3) and the field magnetic flux ([Λf]) of the synchronous motor. ]) For estimating a load angle (δ) as a phase difference with respect to the field magnetic flux,
A rough load angle estimator (101) for obtaining a first estimated value (δc) of the load angle;
A load angle error estimator ( 107 ) for obtaining an error estimated value ( Δδ2 ) as an estimated value of an error between the first estimated value and the load angle as an arctangent function value of a magnetic flux ratio;
A combining unit ( 108 , 105 ) that combines the compensation value ( K2 · Δδ2 ) based on the error estimated value and the first estimated value to obtain the second estimated value (δcc) of the load angle ;
The magnetic flux ratio corresponds to a component in phase with the primary magnetic flux command ([λ0 *]), which is the command value of the primary magnetic flux ([λ0]), of the estimated value ([λ0 ^]) of the primary magnetic flux ([λ0]) . the is the ratio of the component 90 DoSusumusho to the primary magnetic flux command of the estimated value of the primary flux, the load angle estimating device (100B). The primary magnetic flux ([λ0], which is a combination of the magnetic flux ([λa]) of the armature reaction generated by the current ([I]) flowing through the synchronous motor (3) and the field magnetic flux ([Λf]) of the synchronous motor. ]) For estimating a load angle (δ) as a phase difference with respect to the field magnetic flux,
A rough load angle estimator (101) for obtaining a first estimated value (δc) of the load angle;
A load angle error estimator (102) for obtaining an error estimated value (Δδ1) as an estimated value of an error between the first estimated value and the load angle as an arctangent function value of a magnetic flux ratio;
A combining unit (103, 104) that combines the compensation value (K1 · Δδ1) based on the error estimated value and the first estimated value to obtain the second estimated value (δcc) of the load angle;
With
The flux ratio was calculated as a value obtained by dividing the first value by the second value,
With respect to the primary magnetic flux command ([λ0 *]) as the command value of the primary magnetic flux ([λ0]) of the current ([I]), the Mc axis current iMc that is a component in phase with the primary magnetic flux command ([λ0 *]), and the primary magnetic flux command of the current The Tc axis current iTc, which is a component advanced by 90 degrees, the Mc axis voltage command vMc *, which is a component in phase with the primary magnetic flux command of the voltage command value applied to the synchronous motor (3), and the command of the voltage The first value is (R · iMc−vMc *) by introducing the Tc-axis voltage command vTc *, which is a component advanced by 90 degrees with respect to the primary magnetic flux command, and the resistance component R of the synchronous motor. and a, the second value is (vTc * -R · iTc), the load angle estimating device (100A).   The rough load angle estimation unit (101) converts the first estimated value (δc) of the load angle into a command value ω * of the rotational angular velocity of the synchronous motor and the field magnetic flux of the inductance of the synchronous motor. The q-axis inductance Lq which is a component advanced by 90 degrees relative to the current, the Mc-axis current iMc which is a component in phase with the primary magnetic flux command ([λ0 *]) of the current, and 90 for the primary magnetic flux command of the current. Tc-axis current iTc that is a component that advances in phase, Mc-axis voltage command vMc * that is a component in phase with the primary magnetic flux command of the voltage command value applied to the synchronous motor, and the primary magnetic flux of the voltage command value By introducing the Tc-axis voltage command vTc *, which is a component advanced by 90 degrees with respect to the command, and the resistance component R of the synchronous motor, (vMc * −R · iMc + ω * · Lq · iTc) / (vTc * − R ・ iTc-ω * ・The load angle estimating device (100B) according to claim 1, wherein the load angle estimating device (100B) is obtained by an arctangent function value of a value represented by Lq · iMc).   The rough load angle estimation unit (101) converts the first estimated value (δc) of the load angle into a command value ω * of the rotational angular velocity of the synchronous motor and the field magnetic flux of the inductance of the synchronous motor. Furthermore, a q-axis inductance Lq, which is a component advanced by 90 degrees, is further introduced, and (vMc * −R · iMc + ω * · Lq · iTc) / (vTc * −R · iTc−ω * · Lq · iMc) The load angle estimating device (100A) according to claim 2, wherein the load angle estimating device (100A) is obtained by an arctangent function value of a value represented. The synthesis unit is
A proportional control unit (103) that performs proportional control on the estimated error value (Δδ1; Δδ2) to obtain the compensation value (K1 · Δδ1; K2 · Δδ2);
The load angle estimating device (100A; 100B) according to any one of claims 1 to 4 , further comprising an adder (104; 105) for adding the compensation value to the first estimated value (δc). ).

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