JP2934898B2 - Magnetic pole position detection device, synchronous motor control device, and induction motor control device - Google Patents

Description

The present invention relates to a magnetic pole position detection device, a synchronous motor control device, an induction motor control device, and a method for extracting numerical data, and more particularly, to generating a pulse for driving a motor. The present invention relates to a magnetic pole position detection device, a synchronous motor control device, an induction motor control device, and a numerical data extraction method suitable for extracting numerical data from a memory.

[Conventional technology]

When operating a rotating field type synchronous motor, the magnitude of the generated torque is determined by the induced voltage induced in the stator winding when the rotor rotates and the phase of the current supplied to the motor. Has become.

For example, in a three-phase synchronous motor, the relationship between each induced voltage, current, and torque T is as follows.

ω · T = EuIu + EvIv + EwIw (1) where ω: rotational angular velocity And the induced voltages Eu, Ev, Ew of each phase are as follows.

The currents Iu, Iv, Iw of each phase are as follows.

Here, E ₀ is the effective value of the induced voltage of the phase, and I ₀ is the effective value of the current of one phase.

The above equations (1) to (7) are summarized as follows.

ω · T = 3E ₀ I ₀ cos θ (8) From the expression (8), if cos θ = 1, that is, if the phase of the induced voltage and the phase of the current are matched, the motor can be operated at the maximum torque. Therefore, when the motor is operated, the phase of the induced voltage is accurately detected as described in JP-A-58-15114 and JP-A-60-62894.

[Problems to be solved by the invention]

In the prior art, the U phase, the V phase, and the 12
A method is used to generate a current phase that matches the induced voltage using a sine wave ROM, U / D counter, encoder, etc. with a phase difference of 0 degrees, but if the pulse number changes due to the encoder specifications, However, if the number of bits of the U / D counter is not changed, the numerical data stored in the ROM cannot be effectively used, and there is a problem that compatibility is not achieved.

An object of the present invention is to provide a magnetic pole position detection device, a synchronous motor control device, and an induction motor control device that can effectively use numerical data in a memory for various types of encoders having different pulse numbers. .

Means for Solving the Problems To achieve the above object, the present invention provides a magnetic pole position detector that generates a magnetic pole position signal synchronized with the phase of an induced voltage of a synchronous motor, and a magnetic pole position detector that is proportional to the rotation speed of the synchronous motor. An encoder that generates a pulse, a pulse generator that counts the output pulse of the encoder using the magnetic pole position signal as an initial value of a counting pulse at the time of starting, and generates a pulse corresponding to the counted value, and numerical data of a function. A memory for storing a group, a constant generator for generating a plurality of constants for matching the number of output pulses per rotation of the encoder with the numerical data storage capacity of the memory, and a constant generator designated from among the constant group of the constant generator. A constant selector for selecting a constant, a multiplier circuit for multiplying the output pulse of the counting pulse generator by the constant selected by the constant selector, And a numerical data output circuit for selecting and outputting specified numerical data.

Also, the present invention provides a magnetic pole position detector that generates a magnetic pole position signal synchronized with the phase of the induced voltage of the synchronous motor, an encoder that generates a pulse proportional to the rotation speed of the synchronous motor, A counting pulse generator that counts the output pulse of the encoder as an initial value of the counting pulse and generates a pulse corresponding to the counting value, an inverter that drives a synchronous motor by a pulse signal, and a current that detects the output current of the inverter A detector, a memory for storing a numerical data group of functions, a constant generator for generating a plurality of constants for matching the number of output pulses per encoder rotation and the numerical data storage capacity of the memory, and a constant generator And a multiplier for multiplying the output pulse of the counting pulse generator by the constant selected by the constant selector. Circuit, a numerical data output circuit that selects and outputs specified numerical data from a memory according to an output signal of the multiplying circuit, and a pulse according to a current command based on a detection output of the current detector and output data of the numerical data output circuit. A synchronous motor control device comprising a signal generator and an inverter controller for controlling the inverter with the pulse signal.

Further, the present invention provides an inverter for driving an induction motor by a pulse signal, an encoder for generating a pulse proportional to the rotation speed of the induction motor, and a torque current command generation for generating a torque current command from an output pulse of the encoder and a speed command. Encoder, a slip angle frequency signal generator for generating a slip angle frequency signal from an excitation current command and a torque current command, and a primary angle for generating a primary angle frequency command signal from an encoder output pulse and a slip angle frequency signal A frequency command signal generator, an integrator that integrates a primary angular frequency command signal to generate a phase angle signal, a memory that stores a group of numerical data of functions, the number of output pulses per encoder rotation, and a numerical value of the memory A constant generator that generates multiple constants to match the data storage capacity, and a specified constant selected from a group of constant generator constants A constant selector, a multiplier for multiplying the output signal of the integrator by the constant selected by the constant selector, and a numerical data output circuit for selecting and outputting specified numerical data from the memory based on the output signal of the multiplier. An induction motor controller includes an inverter controller that generates a pulse signal based on an excitation current command, a torque current command, and numerical data, and controls an inverter based on the pulse signal.

[Action]

When extracting numerical data from the memory based on the output pulse of the encoder, if the encoder output pulse in the range of En _{1 to} Enn is used depending on the specifications of the encoder, a constant K ₁ is used for the pulse number En _{1 to} Enn. KKn, and the result of the multiplication is always set to a constant value N (the numerical data storage capacity of the memory) as shown in the following equation (9).

N = Enn × Kn (9) When the pulse number E _ii is large, the pulse number E _ii is multiplied by a small multiplication coefficient K _i.
By multiplying a small value of _{ii by} a large value as the multiplication coefficient K _i , the number N of numerical data is always constant, and the numerical data in the memory is effectively used even when the number of output pulses changes according to the specifications of the encoder. It becomes possible.

〔Example〕

 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, an inverter 2 has a plurality of switching elements constituting an arm, receives power from an AC power supply 1, rectifies this power with a pulse signal from a PWM control circuit 13, and converts the rectified signal to an arbitrary frequency. And drives the synchronous motor 3. The synchronous motor 3 drives, for example, an XY table, a robot welding machine, or the like as a load. An encoder 4 and a magnetic pole position detector 5 are provided on a drive shaft of the synchronous motor 3. The encoder 4 generates a pulse proportional to the rotation speed of the synchronous motor 3, and the magnetic pole position detector 5 generates a magnetic pole position signal synchronized with the phase of the induced voltage of the synchronous motor 3. The output signals of the encoder 4 and the magnetic pole position detector 5 are supplied to a counting pulse generator 6. The counting pulse generator counts the output pulse of the encoder 4 using the magnetic pole position signal as an initial value of the counting pulse at the time of starting, and outputs a pulse corresponding to the counted value to the numerical data output circuit 9 via the multiplying circuit 7. It has become. A numerical data output circuit 9 extracts specified numerical data from a table 8 as a memory based on an output signal from the multiplying circuit 7 and converts the extracted numerical data into a 3 / 2-phase converter 10 and a vector operation circuit 1.
Output to 1

The output signals of the current transformers 14 and 15 as current detectors for detecting the output current of the inverter 2 are input to the 3 / 2-phase converter 10, and the input signals are converted into 3 / 2-phase signals. converted signal I _a, and outputs the I _B to the vector computing circuit 11. Vector computing circuit 11, the numerical data output is input from the circuit 9 as numerical data the sin [theta, cos [theta] and the signal I _A inputted from the 3/2 phase converter 10, the current Q-axis from the I _B I _Q,
A D-axis current _ID is generated.

That is, in the 3-2 phase converter 10 and the vector operation circuit 11, as shown in the vector diagram of FIG.
The coordinates are transformed from v and Iw using the following equations (10) to (12) to obtain _IQ and _ID .

Here, I _A is α-axis current, I _B is β-axis current, theta is α-axis and d
Phase difference of the shaft, omega ₁ is the rotational speed of the motor 3.

Current control circuit (ACR circuit) 12 is current I _Q, I _D and the current command I
_QN, and a I _DN using the following equation (13) and (14) d-q
-Axis voltage V _Q, is adapted to generate the V _D.

V _Q = (IQN−IQ) Kpc + Σ (IQN−IQ) Kic… (13) V _D = (IDN−ID) Kpc + Σ (IDN−ID) Kic… (14) Voltage commands V _Q and V _D are PWM control circuits 13 And converted into a pulse signal. PWM control circuit 13 is the voltage command V _Q, the switching elements forming the inverter 2 on the basis of V _D, a pulse signal for supplying a current that matches example, flowing the induced voltage of the width determined by the synchronous motor 3 of the transistor Is to be generated. When this pulse signal is supplied to each transistor of the inverter 2, the current of the inverter 2 is controlled. That is, the 3 / 2-phase converter 10, the vector operation circuit 11, the current control circuit 12, and the PWM control circuit 13 constitute an inverter controller.
When the inverter 2 is controlled by the inverter controller, the states of the respective components have a relationship as shown in FIG.

That is, the relationship between the induced voltage e _ou (e _ov , e _ow ), the magnetic flux φ, and the terminal voltage V ₁ is as shown in FIG. 3A, and the dq axis voltage command V _Q relationship between V _D and the motor terminal voltages V ₁ is as shown in the third view of (b).

Now the phase difference between V _Q and V _D and [delta], the [delta] is expressed by the following equation (15).

the effective value V ₁ of the terminal voltage of the u phase is determined by the following equation (16).

Then, the PWM control circuit 13 can determine the width of current flowing through each transistor of the inverter 2 according to the equation (16).

As shown in FIG. 4, the counting pulse generator 6 includes a memory 29, a magnetic pole position data generating circuit 33, a memory 25, and a comparator.
28,31, up / down counter 20, AND gate 21,22,23,2
4, an OR gate 34, an inverter 32, a memory 29 is connected to a comparator 31 via a zero value bus 30, a magnetic pole position data generation circuit 33, a memory 25, a comparator 28,
The up / down counter 20 is connected to each other via an En bus 27, and the up / down counter 20 and the comparators 31, 28 are connected via an up / down counter bus 26. memory
29 stores zero value data, and the memory 25 stores En value data. This En next (18)
It is represented by an equation.

Here, En: the number of encoder pulses during one cycle of the induced voltage E _N : the number of output pulses per encoder rotation (p / r) P: the number of poles of the electric motor 3

The magnetic pole position data generation circuit 33 takes in the output signal of the magnetic pole position detector 5 and converts this signal into rectangular wave signals U, V, W as shown in FIG. Magnetic pole position data is generated. The magnetic pole position data is set in the up / down counter 20 as an initial value of a counting pulse at the time of starting by a starting signal. That is, when the mode in this stopped state is measured while the electric motor 3 is stopped at the time of starting, an address value in the middle of the mode is written into the up / down counter 20 by a command from the CPU. When the start signal is input to the LOAD terminal via the OR gate 34, the magnetic pole position data is set in the up / down counter 20.

The AND gates 21 and 23 and the inverter 32 have the A of the encoder 4
A normal rotation signal or a reverse rotation signal determined from the phase and the phase B is input. The forward rotation signal is at the “H” level, and the reverse rotation signal is at the “L” level. further
Output pulses of the encoder 4 are input to the AND gates 21 and 22. And when the motor 3 rotates forward,
The output pulses of the encoder 4 are sequentially input to the up / down counter 20 via the AND gate 21, and the input pulses are counted. The output pulse of the up / down counter 20 is supplied to comparators 31 and 28. When the output pulse of the up / down counter 20 matches En at the comparator 28, the output of the comparator 28 becomes "H", and this signal is output to the AND gate 23. Supplied to As a result, an “H” signal is output from the AND gate 23, and the count value of the up / down counter 20 is cleared.
That is, the count value is cleared when the count value of the up / down counter 20 becomes equal to En, as shown in FIG. Thereafter, the same operation is repeated, and each time the count value of the up / down counter 20 becomes equal to En, the count value is cleared, and a pulse corresponding to the count value of the up / down counter 20 is supplied to the multiplier circuit via the up / down counter bus 26. 7. Next, when the motor 3 rotates in the reverse direction, the output of the inverter 32 becomes “H”, and the output pulse of the encoder 4 is input to the up / down counter 20 via the AND gate 22. This causes the up / down counter 20 to start counting down, and the count value is changed to the up / down counter bus.
The signal is supplied to comparators 31 and 28 and the multiplying circuit 7 through 26.
Then, in the comparator 31, the count value of the counter 20 and the memory 29
Are compared with each other, and when they match, the comparator 31
Outputs an “H” signal, and the AND gate 24 and the OR gate 34
The value of En is set in the up / down counter 20 via. By repeating such an operation, the value of the counter 20 is sequentially supplied to the multiplying circuit 7 even when the motor 3 rotates in the reverse direction.

As shown in FIG. 6, the multiplier 7 is provided with a constant generator 16 and a constant selector 17. Constant generator 16 is adapted to generate a plurality of constants K1~Kn for matching the numerical data storage capacity N of the number of output pulses En ₁ ~En _n memory 8 per revolution encoder 1. That is, (9)
The constants K1 to Kn satisfying the expression are generated. The constant selector 17 is constituted by a switch, selects a specified constant from the constants K1 to Kn, and connects the selected constant to the output side of the counting pulse generator 6 and the input side of the numerical data output circuit 9. It is designed to be inserted inside. That is, the output pulse of the counting pulse generator 6 is multiplied by a specified constant,
The multiplied signal is supplied to the numerical data output circuit 9.

The numerical data output circuit 9 has a table 8 as a memory.
The table 8 is composed of N sine wave tables and N cosine wave tables. The value of the number N of tables may be arbitrary, but it is convenient to select 2 ^m when calculating with a microcomputer.

N = 2 ^m (19) At this time, m represents the number of table bits and is a value related to the resolution of the table.

The sine wave table and the cosine wave table store sine wave numerical data and cosine wave numerical data, respectively. When an output pulse of the multiplying circuit 7 is input to the numerical data output circuit 9, it is designated according to the pulse. Is extracted from each table. In this case, when the number of pulses per revolution encoder 1 is changed En ₁ ~En _n and type obtains a En ₁ ~En _n from equation (18), En ₁ × K1
The constant Kn is selected so that ~ En _n × Kn always becomes N. Therefore, the output pulse of the multiplication circuit 7
When extracting the numerical data of, the numerical data of Table 8 can be effectively used.

Here, if En _n and Kn are m bits, N is 2m bits. At this time, if the upper m bits of N are selected again as N, the microcomputer can extract numerical data satisfying the expression (9).
In this case, a process of cutting off lower m bits is performed.

For example, the number of pulses per rotation of the encoder 3 is E _n =
1500, when the magnetic poles of the motor 3 4-pole, E _n = 750 = $ 2
EE. Further, the number of sine wave tables is set to N = 512 = ＄ 200
Then, Kn is obtained by the following equation (20).

The actual calculation is performed by substituting the value of equation (20) into equation (9).

N = ＄ 2EE × ＄ AEC = ＄ 1FF F68 N = 12200 is obtained by rounding off the 12th bit of the above equation to 0 and validating the upper 12 bits.

With the above configuration, the induced voltage E as shown in FIG.
_VO, the magnetic flux phi, 3-phase reference voltages U, V, and generates numerical data from a table 8 on the basis of the W d-q-axis voltage, V _Q, by controlling the inverter seeking V _D, the output voltage of the inverter 2 V ₁ and output current I ₁ are obtained.

Next, when storing the numerical data of the sine value and the cosine value in the table 8, the table 8 is composed of only the sine wave table, and when the Nn-th sine wave table is required, the Nn-th sine wave table is obtained from the following equation (21). Table values can be read.

On the other hand, the Nn-th cosine value is represented by the following equation (22) from the relationship cos θ = sin (θ + 90 °).

From equation (22) You can read the values in the table.

Here, N is the total number of sine wave tables, and Nn is the nth value in the sine wave table.

Thus, when storing numerical data in the table 8,
If the sine value and the cosine value table are shared, the number of tables can be increased and the calculation accuracy can be improved.

Next, when storing the numerical data of the sine values in the table 8, instead of storing all the numerical data of 360 degrees in the table 8, the numerical data is associated with the period obtained by dividing one period of the induced voltage by a predetermined number. Can be subdivided.
That is, the value of the value NN obtained by dividing the address N by an arbitrary even number 1 is set as the number of the table.

When dividing the area of the table 8 by the equation (23), the accuracy can be improved by dividing, for example, 360 degrees into l = 4 and using NN sine wave tables for 90 degrees. In this case, 360 degrees can be divided into four quadrants with respect to the set value En of the up / down counter 20, and positive and negative signs can be selected by using equations (21) and (22) to obtain continuity.

In this case, the numerical data is divided according to the following equations (24) to (27).

Here, Nn is the n-th table value for 90 degrees.

The cosine value table can be obtained in the same manner.

Next, when the induction motor is controlled by the inverter 2, the counting pulse generator 6 includes a microcomputer 51 and a memory for storing the value of En, as shown in FIG.
53, a counter 52, and an adder 54.

When the induction motor is driven by the inverter 2, in addition to the encoder, a torque current command generator that generates a torque current command from the output pulse and the speed command of the encoder 4, and a slip angular frequency based on the excitation current command and the torque current command. A slip angular frequency signal generator for generating a signal, a primary angular frequency command signal generator for generating a primary angular frequency command signal from an output pulse of the encoder 4 and the slip angular frequency signal, and integrating the primary angular frequency command signal. Although an integrator for generating a phase angle signal is required, the microcomputer 51 determines the speed ω1 of the induction motor based on the output signal of the encoder 4 and calculates the slippage from the q-axis current component _IQ and the d-axis current component _ID . Can be obtained by the following equation (28).

Where K _{S is a} constant. On the other hand, the phase angle θ corresponding to the magnetic pole position of the synchronous motor can be obtained by equation (29).

θ = ∫ (ω ₁ + ωs) dt (29) When calculating the phase angle according to the equation (29), the calculation of ω ₁ + ωs is performed for each sampling time, and the value is added to the soft counter 52 to obtain the angle. it can. Then, when the value of θ becomes equal to En or becomes equal to or more than En, a process of newly writing θn to the soft counter 52 according to the equation (30) is executed.

θ = En value = θn (30) On the other hand, at the time of the reverse rotation of the induction motor, the values of the soft counter 52 can be obtained by calculating ω ₁ and ωs by the sign and executing the equation (29). By outputting the count value of the soft counter 52 to the multiplication circuit 7, the numerical data of the table 8 can be effectively used even if the specifications of the encoder 4 change as in the above embodiment.

Next, as shown in FIG. 9, an external setting device 18 is connected to the multiplying circuit 7, and the external setting device 18 is constituted by a programmable touch panel, a dip switch, and the like. In addition to setting initial data such as positioning, and setting Enn and constant Kn based on the pulse per rotation of the encoder 4, various encoders can be supported without providing the constant generator 16 and the constant selector 17. be able to.

Further, the storage area of the table 8 is divided into a plurality of areas,
Numerical data can be subdivided to improve the accuracy of the numerical data. In this case, an XY table, a robot, a welding machine, or the like is used as the load 19, and when these are positioned, it is possible to improve the positioning accuracy of the load and shorten the establishment time to the target position.

〔The invention's effect〕

As described above, according to the present invention, the number of output pulses per one rotation of the encoder always matches the numerical data storage capacity of the memory regardless of the number of output pulses of the encoder. The storage area of the memory can be used effectively. Furthermore, since the storage area of the memory can be divided into a plurality of areas and the numerical data can be subdivided to effectively use the storage area of the memory, the numerical data can be improved. Therefore, the rotational pulsation of the electric motor can be reduced, and the gain of the control system can be increased.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention, FIG. 2 is a vector diagram showing a relationship between three-phase currents Iu, Iv, Iw and dq-axis currents Id, Iq, and FIG. Induced voltage and current, magnetic flux and d
FIG. 4 is a specific configuration diagram of the counting pulse generator, FIG. 5 is a time chart for explaining the operation of the circuit shown in FIG. 4, and FIG. 6 is a multiplication diagram. FIG. 7 is a configuration diagram of a circuit and a numerical data output circuit. FIG. 7 is a time chart for explaining the operation of the device shown in FIG.
The figure is a block diagram of a counting pulse generator when an induction motor is used, and FIG. 9 is an overall block diagram showing another embodiment of the present invention. 2 ... Inverter 3 ... Synchronous motor 4 ... Encoder 5 ... Magnetic pole position detector 6 ... Count pulse generator
7 Multiplying circuit, 8 Table, 9 Numerical data output circuit, 10 3 / 2-phase converter, 11 Vector operation circuit, 12 Current control circuit, 13 PWM control circuit, 14,15…
... current transformer, 16 ... constant generator, 17 ... constant selector, 18 ...
... External setting device.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroyuki Tomita 7-1-1 Higashi Narashino Plant, Narashino City, Chiba Prefecture Inside the Hitachi, Ltd. Narashino Plant (72) Inventor Kazuyuki Nakagawa 7-1-1 Higashi Narashino City, Narashino City, Chiba Prefecture Hitachi Keiyo Engineering Co., Ltd. (56) References JP-A-1-243871 (JP, A) JP-A-63-135330 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H02P 5/408-5/412 H02P 7/628-7/632 H02P 21/00

Claims (3)

(57) [Claims] 1. A magnetic pole position detector for generating a magnetic pole position signal synchronized with the phase of an induced voltage of a synchronous motor, an encoder for generating a pulse proportional to the rotation speed of the synchronous motor, A counting pulse generator that counts the output pulses of the encoder as an initial value of the counting pulse and generates a pulse corresponding to the counting value, a memory that stores a group of numerical data of functions, the number of output pulses per rotation of the encoder, A constant generator for generating a plurality of constants for matching the numerical data storage capacity of the memory, a constant selector for selecting a specified constant from a constant group of the constant generator, and a constant selector A multiplying circuit for multiplying the output pulse of the counting pulse generator by a constant, and a numerical data output circuit for selecting and outputting specified numerical data from a memory according to an output signal of the multiplying circuit Magnetic pole position detecting apparatus having a. A magnetic pole position detector for generating a magnetic pole position signal synchronized with the phase of the induced voltage of the synchronous motor; an encoder for generating a pulse proportional to the rotation speed of the synchronous motor; A counting pulse generator that counts an output pulse of an encoder as an initial value of the counting pulse and generates a pulse corresponding to the counting value, an inverter that drives a synchronous motor by a pulse signal, and a current detection that detects an output current of the inverter. A constant generator that generates a plurality of constants for matching the number of output pulses per rotation of the encoder with the numerical data storage capacity of the memory; A constant selector for selecting a specified constant from the constants, and a multiplication cycle for multiplying the output pulse of the counting pulse generator by the constant selected by the constant selector. A numerical data output circuit for selecting and outputting specified numerical data from a memory according to an output signal of the multiplying circuit; and a pulse signal according to a current command based on the detection output of the current detector and the output data of the numerical data output circuit. , And an inverter controller for controlling the inverter with the pulse signal. 3. An inverter for driving an induction motor by a pulse signal, an encoder for generating a pulse proportional to the rotation speed of the induction motor, and a torque current command generator for generating a torque current command from an output pulse of the encoder and a speed command. A slip angular frequency signal generator that generates a slip angular frequency signal from an excitation current command and a torque current command, and a primary angular frequency that generates a primary angular frequency command signal from an encoder output pulse and the slip angular frequency signal A command signal generator, an integrator that integrates a primary angular frequency command signal to generate a phase angle signal, a memory that stores a group of numerical data of functions, the number of output pulses per encoder rotation, and numerical data of the memory A constant generator that generates multiple constants to match the storage capacity, and a constant that selects a specified constant from a constant group of constant generators A selector, a multiplying circuit for multiplying the output signal of the integrator by a constant selected by the constant selector, a numerical data output circuit for selecting and outputting specified numerical data from a memory according to the output signal of the multiplying circuit, An induction motor control device having an inverter controller that generates a pulse signal based on a current command, a torque current command, and numerical data, and controls an inverter based on the pulse signal.