JP6682313B2 - Motor control device - Google Patents

Description

  The present invention relates to a motor control device that controls an AC motor.

  Conventionally, there is known a motor control device that vector-controls an AC motor with d-axis and q-axis. This motor control device generates a current command (d-axis current command id * and q-axis current command iq *), current-controls the current command by a PI controller, and voltage commands (d-axis voltage command vd * and q-axis). The voltage command vq *) is generated.

  The motor control device performs coordinate conversion of the voltage command, and U-phase, V-phase, and W-phase three-phase AC voltage commands (U-phase AC voltage command Vu *, V-phase AC voltage command Vv *, and W-phase AC voltage command Vw *). ) Is generated. Then, the motor control device controls the AC motor by outputting the three-phase AC voltage command to the power amplifier.

  Further, the motor control device includes a three-phase AC current feedback (U-phase AC current feedback iu, V-phase) of U-phase, V-phase and W-phase detected by a current detector provided between the power amplifier and the AC motor. The alternating current feedback iv and the W-phase alternating current feedback iw) are input. Then, the motor control device performs coordinate conversion on the three-phase AC current feedback to generate current feedback (d-axis current feedback id and q-axis current feedback iq).

  In the AC motor controlled by such a motor control device, a voltage is generated on the q-axis in the direction in which the phase advances by 90 ° by the d-axis current, and a d-direction in the direction by 90 ° in the phase is generated by the q-axis current. A voltage is generated on the shaft. These voltages become interference voltages on the q-axis and the d-axis, respectively. Therefore, the motor control device needs to control the AC motor in consideration of these interference voltages.

  The control for canceling the interference voltage is called non-interference control, and various methods have been proposed (for example, refer to Patent Document 1). In Patent Document 1, the motor control device generates a d-axis non-interference voltage and a q-axis non-interference voltage for eliminating the influence of these interference voltages based on the d-axis current feedback id, the q-axis current feedback iq, and the like. To do. Then, the motor controller adds the d-axis non-interference voltage to the d-axis voltage command vd * to obtain a new d-axis voltage command vd *, and adds the q-axis non-interference voltage to the q-axis voltage command vq *. A new q-axis voltage command vq * is obtained. The AC motor is controlled by the new d-axis voltage command vd * and the new q-axis voltage command vq * thus obtained, and the interference voltage can be canceled.

  There is also a method of realizing non-interference control with a PI controller. Specifically, in order to generate the command corresponding to the interference voltage, the PI controller performs control by adding a gain corresponding to this to the normal gain.

JP, 2008-99472, A

  However, the above-mentioned Patent Document 1 does not describe the specific processing content for generating the d-axis non-interference voltage and the q-axis non-interference voltage for canceling the interference voltage. Moreover, this method is not necessarily applicable to all AC motors. In order to apply to a plurality of types of AC motors, it is necessary to provide a circuit that realizes non-interference control for each type of AC motor, which causes a problem that the circuit scale becomes large.

  Further, when the PI controller described above is used, the gain needs to be set higher than usual, resulting in overcompensation, and there is a problem that the AC motor may not be appropriately controlled.

  Therefore, the present invention has been made to solve the above problems, and its object is to apply these alternating-current motors when controlling a synchronous reluctance motor (SynRM) or an IPM synchronous motor (IPMSM). It is to provide a motor control device that can realize non-interference control with a common circuit.

In order to solve the problem, the motor control device according to claim 1 generates a d-axis voltage command from a d-axis current command, generates a q-axis voltage command from a q-axis current command, and outputs the d-axis voltage command and the d-axis voltage command. In a motor control device for controlling an AC motor by generating a 3-phase AC voltage command from a q-axis voltage command and outputting the 3-phase AC voltage command to a power amplifier, a d-axis generated by a q-axis current in the AC motor. Non-interference voltage for calculating d-axis non-interference voltage compensation for canceling the above interference voltage and q-axis non-interference voltage compensation for canceling the interference voltage on the q-axis generated by the d-axis current in the AC motor. A compensation unit and the d-axis voltage command are added with the d-axis non-interference voltage compensation calculated by the non-interference voltage compensating unit to obtain a new d-axis voltage command, and the q-axis voltage command includes the non- Dried A first adder that adds the q-axis non-interference voltage compensation calculated by the voltage compensator and obtains a new q-axis voltage command, and the new d-axis voltage command obtained by the first adder And a coordinate conversion unit that performs coordinate conversion of the new q-axis voltage command into the three-phase AC voltage command, wherein the non-interference voltage compensating unit converts the q-axis current command into a rotor electrical angular velocity of the AC motor. A first multiplier for obtaining a first multiplication result, multiplying the first multiplication result by a preset q-axis reactance identification value, and obtaining a second multiplication result; A first inverter that inverts the second multiplication result obtained by the multiplier to obtain the d-axis non-interference voltage compensation, and a rotor electrical angular velocity of the AC motor are multiplied by the d-axis current command to obtain a first 3 multiplication result is obtained and is preset to the third multiplication result. A second multiplier for multiplying the d-axis reactance identification value to obtain a fourth multiplication result, and a rotor electro-angular velocity of the AC motor are multiplied by a preset back electromotive force constant to obtain a fifth multiplication result. The q-axis non-interference voltage is obtained by adding the fifth multiplication result obtained by the third multiplier to the fourth multiplication result obtained by the third multiplication device and the second multiplication device. A second adder for obtaining compensation, 0 is used as the preset back electromotive force constant when the AC motor is a synchronous reluctance motor, and when the AC motor is an IPM synchronous motor. , A predetermined value is used, the motor control device further includes a current command generation unit that generates the d-axis current command and the q-axis current command, and the current command generation unit uses the first adder. Sought the new Based on the axis voltage command and the new q-axis voltage command, a voltage command FB (feedback) generator that calculates a voltage command feedback, and a terminal voltage command that indicates a set value of the DC bus voltage of the power amplifier, A first subtractor that subtracts the voltage command feedback calculated by the command FB generation unit to obtain a terminal voltage deviation, and a terminal current so that the terminal voltage deviation obtained by the first subtractor becomes zero. A terminal voltage control unit that calculates a command, limits the terminal current command within a range from 0 to a predetermined negative value, and outputs the terminal current command within a range from the zero to a predetermined negative value; The speed feedback indicating the speed of the AC motor is subtracted from the preset speed command to obtain the speed deviation by the second subtractor and the second subtractor. The speed deviation current command is calculated so that the speed deviation becomes 0, and the speed deviation current command is added to a preset external current command to obtain a current command. The current command and the preset current Based on the phase angle command, a d-axis shared current command and a q-axis shared current command are obtained, and a speed control unit that uses the q-axis shared current command as the q-axis current command, and the d-axis obtained by the speed control unit A third adder for adding the terminal current command output by the terminal voltage control unit to the shared current command to obtain the d-axis current command, wherein the preset current phase angle command is When the AC motor is a synchronous reluctance motor, a first predetermined value is used, and when the AC motor is an IPM synchronous motor, a second predetermined value is used.

A motor control device according to a second aspect is the motor control device according to the first aspect , wherein the speed deviation is such that the speed deviation obtained by the second subtractor is zero by the speed control unit. A speed controller that calculates a current command, a preset speed limit command that indicates a limit value of the rotation speed of the AC motor, and based on the speed feedback, the preset speed limit command and the speed feedback Between the speed limit current generator that calculates a speed limit current corresponding to the deviation between the speed limit current generator and the predetermined external current command, and the speed deviation current command calculated by the speed controller and the speed limit current generator. The absolute value of the fourth adder for obtaining the current command and the current command obtained by the fourth adder is calculated by adding the speed limiting currents thus obtained. An absolute value calculator and an absolute value of the current command calculated by the absolute value calculator are multiplied by a cosine function whose angle is the preset current phase angle command to obtain the d-axis shared current command. The cosine arithmetic unit to be obtained and the current command obtained by the fourth adder are multiplied by a sine function whose angle is the preset current phase angle command, and the q-axis shared current command is given to the q-axis. And a sine calculator that obtains a current command.

According to a third aspect of the present invention, there is provided the motor control device of the second aspect , wherein the speed limiting current generator subtracts the speed feedback from the preset speed limiting command to obtain a speed limiting deviation. A third subtractor, a fourth multiplier that multiplies the speed limit deviation obtained by the third subtractor by a preset coefficient, and obtains a speed limit deviation as a multiplication result, and the fourth multiplication A limit value is added to the speed limit deviation of the multiplication result obtained by a multiplier in the range of 0 to a predetermined negative value, and the speed limit deviation of the multiplication result of the range of 0 to a predetermined negative value is output. 1 limiter, a second inverter that inverts the preset speed limit command, and the speed feedback from the preset speed limit command that is inverted by the second inverter. A fourth subtracter that subtracts and obtains a reverse speed limit deviation, and the reverse speed limit deviation obtained by the fourth subtractor is multiplied by a preset coefficient to obtain a reverse speed limit deviation as a result of the multiplication. A fifth multiplier and the inversion speed limit deviation of the multiplication result obtained by the fifth multiplier are limited within a range from a predetermined plus value to 0 to obtain a value from the plus predetermined value to 0. A second limiter for outputting the inversion speed limit deviation of the multiplication result of the range; and a speed limit deviation of the multiplication result output by the first limiter for the multiplication result output by the second limiter. A fifth adder for adding the inversion limit speed deviation to obtain the speed limit current.

  As described above, according to the present invention, when controlling the synchronous reluctance motor and the IPM synchronous motor, non-interference control can be realized by the common circuit applied to these AC motors.

1 is an overall view showing a configuration example of a motor control system including a motor control device according to an embodiment of the present invention. It is a block diagram which shows the structural example of a current command generation part. It is a block diagram which shows the structural example of a terminal voltage control part. It is a block diagram which shows the structural example of a speed control part. It is a block diagram which shows the structural example of a speed limiting current generator. It is a block diagram which shows the structural example of a non-interference voltage FF compensation part. It is a graph which shows the measurement result by an actual machine at the time of using a synchronous reluctance motor. It is a graph which shows the measurement result by an actual machine when using an IPM synchronous motor.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.
[Motor control system]
FIG. 1 is an overall view showing a configuration example of a motor control system including a motor control device according to an embodiment of the present invention. This motor control system includes a motor control device 1, a power amplifier 2, an AC motor 3, and a PG (pulse generator) 4. It should be noted that FIG. 1 shows only the components directly related to the present invention, and the components not directly related to the present invention are omitted. The AC motor 3 is either a synchronous reluctance motor or an IPM synchronous motor.

  The motor control device 1 is a device that vector-controls the AC motor 3 with d-axis and q-axis. Motor control device 1 generates a current command (d-axis current command id * and q-axis current command iq *) for controlling the rotation speed of AC motor 3. This current command is also a command to set the rotation speed of AC motor 3 to a predetermined speed limit or less.

  The motor control device 1 current-controls the current command and adds the non-interference voltage to generate the voltage command (d-axis voltage command vd * and q-axis voltage command vq *). This voltage command is also a command for canceling the interference voltage generated in AC motor 3.

  The motor control device 1 determines a voltage command based on the electrical angle θe as a three-phase AC voltage command of U phase, V phase, and W phase (U phase AC voltage command Vu *, V phase AC voltage command Vv *, and W phase AC). The voltage command Vw *) is converted and the three-phase AC voltage command is output to the power amplifier 2.

  The motor control device 1 includes a U-phase, V-phase, and W-phase three-phase AC current feedback (U-phase AC current feedback iu, V) detected by a current detector provided between the power amplifier 2 and the AC motor 3. The phase alternating current feedback iv and the W phase alternating current feedback iw) are input. Further, the motor control device 1 inputs the speed feedback ω indicating the speed of the AC motor 3 from the PG 4.

The power amplifier 2 includes an inverter. The power amplifier 2 inputs a three-phase AC voltage command from the motor control device 1, generates a PWM signal from the three-phase AC voltage command, turns on / off a gate of a switching element of the inverter by the PWM signal, and inputs a DC signal to the inverter. The bus voltage e _bus is switched and converted into an AC voltage. Then, the power amplifier 2 supplies an AC voltage to the AC motor 3.

  PG4 generates a pulse signal according to the rotation of AC motor 3. From the count value of this pulse signal, the speed feedback ω that is the rotation speed of the AC motor 3 is obtained, and the speed feedback ω is input to the motor control device 1. In FIG. 1, the speed feedback ω is schematically illustrated as being input from the PG 4 to the motor control device 1.

[Motor control device 1]
Next, the motor control device 1 shown in FIG. 1 will be described in detail. As shown in FIG. 1, the motor control device 1 includes a current command generation unit 10, subtractors 11 and 12, current control units 13 and 14, adders 15 and 16, coordinate conversion units 17 and 18, a converter 19, and an integration unit. And a non-interference voltage FF (feedforward) compensator 21.

The current command generator 10 inputs the preset terminal voltage command v * and speed command ω *, and also inputs the speed feedback ω from PG4, the d-axis voltage command vd * from the adder 15, and the q-axis from the adder 16. Input the voltage command vq *. The terminal voltage command v * indicates the set value of the DC bus voltage e _bus of the power amplifier 2. Then, the current command generation unit 10 generates the d-axis current command id * and the q-axis current command iq * based on these data. As a result, the d-axis current command id * and the q-axis current command iq * that set the rotation speed of the AC motor 3 to the preset speed limit command ω _MAX or less are generated.

  The current command generator 10 outputs the d-axis current command id * to the subtractor 11 and the non-interference voltage FF compensator 21, and outputs the q-axis current command iq * to the subtractor 12 and the non-interference voltage FF compensator 21. To do. The details of the current command generator 10 will be described later.

  The subtractor 11 inputs the d-axis current command id * from the current command generation unit 10 and also inputs the d-axis current feedback id from the coordinate conversion unit 18 described later. Then, the subtractor 11 subtracts the d-axis current feedback id from the d-axis current command id * and outputs the subtraction result to the current control unit 13 as a d-axis current deviation.

  The subtractor 12 inputs the q-axis current command iq * from the current command generation unit 10 and inputs the q-axis current feedback iq from the coordinate conversion unit 18 described later. Then, the subtractor 12 subtracts the q-axis current feedback iq from the q-axis current command iq * and outputs the subtraction result to the current control unit 14 as a q-axis current deviation.

  The current control unit 13 inputs the d-axis current deviation from the subtractor 11, and performs current control by the PI controller using the preset proportional gain and integral gain so that the d-axis current deviation becomes 0, Calculate the d-axis voltage command. Then, the current control unit 13 outputs the d-axis voltage command to the adder 15.

  The current control unit 14 inputs the q-axis current deviation from the subtractor 12, and performs current control by the PI controller using the preset proportional gain and integral gain so that the q-axis current deviation becomes 0, Calculate the q-axis voltage command. Then, the current control unit 14 outputs the q-axis voltage command to the adder 16.

  The adder 15 inputs the d-axis voltage command from the current control unit 13, and also inputs the d-axis non-interference voltage FF (feedforward) compensation Δvd * from the non-interference voltage FF compensation unit 21 described later. Then, the adder 15 adds the d-axis non-interference voltage FF compensation Δvd * to the d-axis voltage command, and outputs the addition result to the coordinate conversion unit 17 and the current command generation unit 10 as the d-axis voltage command vd *. As a result, a d-axis voltage command vd * for canceling the interference voltage generated on the d-axis of AC motor 3 is calculated.

  The adder 16 inputs the q-axis voltage command from the current control unit 14 and also inputs the q-axis non-interference voltage FF compensation Δvq * from the non-interference voltage FF compensation unit 21 described later. Then, the adder 16 adds the q-axis non-interference voltage FF compensation Δvq * to the q-axis voltage command, and outputs the addition result as the q-axis voltage command vq * to the coordinate conversion unit 17 and the current command generation unit 10. Thereby, q-axis voltage command vq * for canceling the interference voltage generated on the q-axis of AC motor 3 is calculated.

  Here, the feedforwards of the d-axis non-interference voltage FF compensation Δvd * and the q-axis non-interference voltage FF compensation Δvq * are generated in the non-interference voltage FF compensating unit 21, which will be described later, by feedforward control instead of feedback control. Means that.

  The coordinate conversion unit 17 inputs the d-axis voltage command vd * from the adder 15, inputs the q-axis voltage command vq * from the adder 16, and further inputs the electrical angle θe from the integrator 20 described later. Then, the coordinate conversion unit 17 converts the d-axis voltage command vd * and the q-axis voltage command vq * of the rotating coordinate system into the U-phase AC voltage command Vu *, the V-phase AC voltage command Vv *, and W based on the electrical angle θe. The coordinates are converted into the phase AC voltage command Vw *. The coordinate conversion unit 17 outputs the U-phase AC voltage command Vu *, the V-phase AC voltage command Vv *, and the W-phase AC voltage command Vw * to the power amplifier 2.

The converter 19 receives the velocity feedback ω from the PG 4, inputs the velocity feedback ω, and the preset number of counter poles N _p (= number of poles / 2), the rated angular velocity ω ₀ (rad / s), and the base angular velocity ω _base ( The rotor electrical angular velocity ω1 is calculated based on rad / s). Specifically, the converter 19 calculates (N _p × ω ₀ ) / (N _p × ω _base ), and obtains the rotor electrical angular velocity ω1. Then, the converter 19 outputs the rotor electrical angular velocity ω1 to the integrator 20 and the non-interference voltage FF compensator 21.

  The integrator 20 receives the rotor electrical angular velocity ω1 from the converter 19 and integrates the rotor electrical angular velocity ω1 to obtain the electrical angle θe. Then, the integrator 20 outputs the electrical angle θe to the coordinate conversion units 17 and 18.

  The coordinate conversion unit 18 inputs the U-phase AC current feedback iu, the V-phase AC current feedback iv, and the W-phase AC current feedback iw detected by the current detector provided between the power amplifier 2 and the AC motor 3. At the same time, the electrical angle θe is input from the integrator 20. Then, the coordinate conversion unit 18 outputs the U-phase AC current feedback iu, the V-phase AC current feedback iv, and the W-phase AC current feedback iw based on the electrical angle θe to the d-axis current feedback id and the q-axis current feedback of the rotating coordinate system. Convert the coordinates to iq. The coordinate conversion unit 18 outputs the d-axis current feedback id to the subtractor 11 and the q-axis current feedback iq to the subtractor 12.

  The non-interference voltage FF compensator 21 inputs the preset back electromotive force constant ec ^, the d-axis reactance identification value Xd ^, and the q-axis reactance identification value Xq ^, and at the same time, outputs the rotor electrical angular velocity ω1 from the converter 19. The d-axis current command id * and the q-axis current command iq * are input from the current command generation unit 10. Then, the non-interference voltage FF compensation unit 21 calculates the d-axis non-interference voltage FF compensation Δvd * and the q-axis non-interference voltage FF compensation Δvq * based on these data.

  Thus, d-axis non-interference voltage FF compensation Δvd * for canceling the interference voltage generated on the d-axis of AC motor 3 is calculated. Further, q-axis non-interference voltage FF compensation Δvq * for canceling the interference voltage generated on the q-axis of AC motor 3 is calculated.

  The non-interference voltage FF compensation unit 21 outputs the d-axis non-interference voltage FF compensation Δvd * to the adder 15 and outputs the q-axis non-interference voltage FF compensation Δvq * to the adder 16. Details of the non-interference voltage FF compensation unit 21 will be described later.

(Current command generator 10)
Next, the current command generator 10 shown in FIG. 1 will be described in detail. As described above, the current command generation unit 10 uses the preset terminal voltage command v *, speed command ω *, speed limit command ω _MAX, etc., and the input speed feedback ω, d-axis voltage command vd *, and q-axis voltage. A d-axis current command id * and a q-axis current command iq * are generated based on the command vq *.

  FIG. 2 is a block diagram showing a configuration example of the current command generation unit 10. The current command generator 10 includes a voltage command FB (feedback) generator 30, subtractors 31, 32, a terminal voltage controller 33, a speed controller 34, and an adder 35.

The voltage command FB generation unit 30 inputs the d-axis voltage command vd * from the adder 15 and the q-axis voltage command vq * from the adder 16, and the d-axis voltage command vd * and the q-axis voltage command vq *. Based on, the voltage command feedback v1 * is calculated by the following formula.
v1 * = √ (vd * ² + vq * ² )
Then, the voltage command FB generation unit 30 outputs the voltage command feedback v1 * to the subtractor 31.

  The subtractor 31 inputs the preset terminal voltage command v *, inputs the voltage command feedback v1 * from the voltage command FB generator 30, and subtracts the voltage command feedback v1 * from the terminal voltage command v *. Then, the subtractor 31 outputs the subtraction result as the terminal voltage deviation Δv1 to the terminal voltage control unit 33.

  The terminal voltage control unit 33 inputs the terminal voltage deviation Δv1 from the subtractor 31, performs voltage control so that the terminal voltage deviation Δv1 becomes 0, and calculates a terminal current command. Then, the terminal voltage control unit 33 outputs the terminal current command in the range of 0 to −1 to the adder 35 as the terminal current command id1 *.

  FIG. 3 is a block diagram showing a configuration example of the terminal voltage control unit 33. The terminal voltage control unit 33 includes a voltage controller 40 and a limiter 41. The voltage controller 40 receives the terminal voltage deviation Δv1 from the subtractor 31 and performs voltage control by the PI controller using the preset proportional gain and integral gain so that the terminal voltage deviation Δv1 becomes 0, Calculate the terminal current command. Then, the terminal voltage control unit 33 outputs the terminal current command to the limiter 41.

  The limiter 41 inputs the terminal current command from the voltage controller 40, limits the terminal current command in the range of 0 to -1, and adds the terminal current command id1 * in the range of 0 to -1. To 35.

  Accordingly, when the voltage command feedback v1 * is larger than the terminal voltage command v *, the terminal current command id1 * in the range of 0 to −1 is output to the adder 35, and the adder 35 d-axis current command id. * Can be reduced. Then, as the d-axis current command id * becomes smaller, the d-axis voltage command vd * also becomes smaller. As a result, the voltage command feedback v1 * can be made smaller to bring the voltage command feedback v1 * closer to the terminal voltage command v *. it can.

  Returning to FIG. 2, the subtractor 32 inputs the speed command ω * set in advance, inputs the speed feedback ω from PG4, subtracts the speed feedback ω from the speed command ω *, and subtracts the subtraction result into the speed deviation. It is output to the speed control unit 34 as Δω.

The speed control unit 34 inputs the speed deviation Δω from the subtractor 32, performs speed control so that the speed deviation Δω becomes 0, and calculates the speed deviation current command Δi1 *. Then, the speed control unit 34, based on the speed deviation current command Δi1 *, the speed limiting current i1 _LMT described later, the external current command i * described later, and the current phase angle command β, the d-axis shared current command id * ′ and The q-axis shared current command iq * 'is calculated.

  The speed control unit 34 outputs the d-axis shared current command id * ′ to the adder 35, and the q-axis shared current command iq * ′ as the q-axis current command iq * to the subtracter 12 and the non-interference voltage FF compensator 21. Output. Details of the speed control unit 34 will be described later.

  The adder 35 inputs the terminal current command id1 * in the range of 0 to −1 from the terminal voltage control unit 33, and also inputs the d-axis shared current command id * ′ from the speed control unit 34. Then, the adder 35 adds the terminal current command id1 * in the range of 0 to −1 to the d-axis shared current command id * ′, and the addition result is used as the d-axis current command id * and the subtracter 11 and the non-interference voltage. It is output to the FF compensation unit 21.

  FIG. 4 is a block diagram showing a configuration example of the speed control unit 34. The speed control unit 34 includes a speed controller 42, a speed limiting current generator 43, an adder 44, an absolute value calculator 45, a cosine calculator 46, and a sine calculator 47.

  The speed controller 42 inputs the speed deviation Δω from the subtractor 32, performs speed control by the PI controller using the preset proportional gain and integral gain so that the speed deviation Δω becomes 0, and Calculate the current command Δi1 *. Then, the speed controller 42 outputs the speed deviation current command Δi1 * to the adder 44.

The speed limit current generator 43 calculates the speed limit current i1 _LMT based on the preset speed limit command ω _MAX and the speed feedback ω, and outputs the speed limit current i1 _LMT to the adder 44. The speed limit command ω _MAX indicates a limit value of the rotation speed of the AC motor 3, and the maximum speed of the AC motor 3 is set. Details of the speed limiting current generator 43 will be described later.

The adder 44 inputs the speed deviation current command Δi1 * from the speed controller 42, inputs the speed limit current i1 _LMT from the speed limit current generator 43, and further inputs the preset external current command i *. To do. The adder 44 adds the speed limit current i1 _LMT and the external current command i * to the speed deviation current command Δi1 *, and outputs the addition result to the absolute value calculator 45 and the sine calculator 47 as the current command i1 *.

  The absolute value calculator 45 receives the current command i1 * from the adder 44, calculates the absolute value | i1 * | of the current command i1 *, and calculates the absolute value | i1 * | of the current command i1 * by the cosine calculator 46. Output to.

  The cosine calculator 46 inputs the absolute value | i1 * | of the current command i1 * from the absolute value calculator 45, and also inputs the preset current phase angle command β, and the absolute value | i1 of the current command i1 *. * | Is multiplied by cos β (cosine function whose current phase angle command β is an angle). Then, the cosine calculator 46 outputs the multiplication result to the adder 35 as a d-axis shared current command id * '.

  Here, the current phase angle command β is preset with a different value for each type of the AC motor 3 according to the purpose of realizing the maximum torque or the maximum efficiency of the AC motor 3. For example, in the case of a synchronous reluctance motor, the current phase angle command β = 45 ° is set, and in the case of the IPM synchronous motor, the current phase angle command β = 90 ° is set.

  The sine calculator 47 inputs the current command i1 * from the adder 44 and also inputs a preset current phase angle command β, and sin β (sine function with the current phase angle command β as an angle to the current command i1 *. ). Then, the sine calculator 47 outputs the q-axis shared current command iq * ′, which is the multiplication result, to the subtractor 12 as the q-axis current command iq *.

  FIG. 5 is a block diagram showing a configuration example of the speed limiting current generator 43. The speed limiting current generator 43 includes subtractors 50 and 52, an inverter 51, multipliers 53 and 54, limiters 55 and 56, and an adder 57.

The subtractor 50 inputs the preset speed limit command ω _MAX , inputs the speed feedback ω from PG4, subtracts the speed feedback ω from the speed limit command ω _MAX, and multiplies the subtraction result as the speed limit deviation. Output to 53.

The multiplier 53 receives the speed limit deviation from the subtractor 50, multiplies the speed limit deviation by a preset coefficient K _DROOP , and outputs the speed limit deviation resulting from the multiplication to the limiter 55.

  The limiter 55 inputs the speed limit deviation of the multiplication result from the multiplier 53, limits the speed limit deviation of the multiplication result in the range from 0 to a preset negative value (−η), and The speed limiting current in the range up to −η is output to the adder 57.

  As a result, during the normal rotation operation of the AC motor 3, the speed limiting current in the range of 0 to −η is calculated.

Inverter 51 inputs the speed limit command omega _MAX set in advance is multiplied by -1 speed limit command omega _MAX, by reversing the sign of the speed limit command omega _MAX, inverted speed limit command omega _MAX Is output to the subtractor 52.

The subtractor 52 inputs the inverted speed limit command ω _MAX from the inverter 51, inputs the speed feedback ω from PG4, subtracts the speed feedback ω from the inverted speed limit command ω _MAX , and inverts the subtraction result. The speed deviation is output to the multiplier 54.

The multiplier 54 receives the inversion speed limit deviation from the subtractor 52, multiplies the inversion speed limit deviation by a preset coefficient K _DROOP , and outputs the multiplication result inversion speed limit deviation to the limiter 56.

  The limiter 56 inputs the inversion limit speed deviation of the multiplication result from the multiplier 54, limits the variation limit speed deviation of the multiplication result in a range from a preset positive value (+ η) to 0, The speed limiting current in the range from + η to 0 is output to the adder 57.

  Accordingly, the speed limiting current in the range from + η to 0 is calculated during the reverse rotation operation of the AC motor 3.

The adder 57 inputs the speed limiting current in the range of 0 to −η from the limiter 55 and inputs the speed limiting current in the range of + η to 0 from the limiter 56. Then, the adder 57 adds the two input speed limiting currents and outputs the addition result to the adder 44 as the speed limiting current i1 _LMT . In this case, the adder 57 inputs the speed limiting current of 0 from the limiter 56 when the speed limiting current in the range of 0 to −η is input from the limiter 55. Further, when the speed limit current in the range of + η to 0 is input from the limiter 56, the adder 57 inputs the speed limit current of 0 from the limiter 55. That is, the adder 57 outputs the speed limiting current in the range of 0 to −η input from the limiter 55 or the speed limiting current in the range of + η to 0 input from the limiter 56.

As a result, when the AC motor 3 is operating in the forward direction, the speed limiting current i1 _{LMT in} the range from 0 to −η is output to the adder 44, and when the AC motor 3 is operating in the reverse direction, + η The speed limiting current i1 _{LMT in} the range from 0 to 0 is output to the adder 44. Then, as described above, in the adder 44, the speed limiting current i1 _LMT is added to the external current command i * and the speed deviation current command Δi1 * to obtain the current command i1 *.

For example, assume that the AC motor 3 is operating in the normal direction, the speed feedback ω becomes larger than the speed limit command ω _MAX , and the external current command i * is positive. In this case, the speed limit current generator 43 calculates the speed limit current i1 _{LMT in} the range from 0 to −η. Then, in the adder 44 of FIG. 4, the speed limit current i1 _{LMT in} the range from 0 to −η is added to the positive external current command i * and the speed deviation current command Δi1 *, so that the current command i1 * becomes It approaches 0. On the other hand, assume that, for example, the AC motor 3 is operating in reverse, the absolute value of the negative speed feedback ω becomes larger than the speed limit command ω _MAX , and the external current command i * is negative. In this case, the speed limiting current generator 43 calculates the speed limiting current i1 _{LMT in} the range from + η to 0. Then, in the adder 44 of FIG. 4, the speed limit current i1 _{LMT in} the range from + η to 0 is added to the negative external current command i * and the speed deviation current command Δi1 *, so that the current command i1 * becomes 0. Approach. In this way, by canceling the current command i1 * to 0, the rotation speed of the AC motor 3 can be set to the speed limit command ω _MAX or less in the current control.

As described above, the current command generation unit 10 sets the preset terminal voltage command v *, speed command ω *, speed limit command ω _MAX, etc., and the input speed feedback ω, d-axis voltage command vd *, and q-axis voltage. Based on the command vq *, the d-axis current command id * and the q-axis current command iq * that set the rotation speed of the AC motor 3 to a preset speed limit command ω _MAX or less are generated. The processing of the current command generation unit 10 can be applied to the synchronous reluctance motor or the IPM synchronous motor according to the preset current phase angle command β.

(Non-interference voltage FF compensator 21)
Next, the non-interference voltage FF compensator 21 shown in FIG. 1 will be described in detail. As described above, the non-interference voltage FF compensation unit 21 sets the preset counter electromotive force constant ec ^, the d-axis reactance identification value Xd ^ and the q-axis reactance identification value Xq ^, and the input rotor electrical angular velocities ω1, d. The d-axis non-interference voltage FF compensation Δvd * and the q-axis non-interference voltage FF compensation Δvq * are calculated based on the axis current command id * and the q-axis current command iq *.

  FIG. 6 is a block diagram showing a configuration example of the non-interference voltage FF compensation unit 21. The non-interference voltage FF compensator 21 includes multipliers 60, 61, 62, 63, 64, an inverter 65 and an adder 66.

  The multiplier 60 inputs the rotor electrical angular velocity ω1 from the converter 19 and also inputs the q-axis current command iq * from the current command generation unit 10 to multiply the rotor electrical angular velocity ω1 by the q-axis current command iq *. , And outputs the multiplication result to the multiplier 62.

  The multiplier 62 receives the multiplication result from the multiplier 60, multiplies the multiplication result by a preset q-axis reactance identification value Xq ^, and inverts the multiplication result (ω1 × iq * × Xq ^). Output to.

  The inverter 65 inputs the multiplication result (ω1 × iq * × Xq ^) from the multiplier 62 and multiplies the multiplication result (ω1 × iq * × Xq ^) by −1 to obtain the multiplication result (ω1 × iq). The sign of * × Xq ^) is inverted. Then, the inverter 65 outputs the inverted multiplication result (−ω1 × iq * × Xq ^) to the adder 15 as the d-axis non-interference voltage FF compensation Δvd *.

  The multiplier 61 inputs the rotor electrical angular velocity ω1 from the converter 19 and also inputs the d-axis current command id * from the current command generator 10 to multiply the rotor electrical angular velocity ω1 by the d-axis current command id *. , And outputs the multiplication result to the multiplier 63.

  The multiplier 63 receives the multiplication result from the multiplier 61, multiplies the multiplication result by a preset d-axis reactance identification value Xd ^, and adds the multiplication result (ω1 × id * × Xd ^) to the adder 66. Output to.

  The multiplier 64 receives the rotor electrical angular velocity ω1 from the converter 19, multiplies the rotor electrical angular velocity ω1 by a preset back electromotive force constant ec ^, and adds the multiplication result (ω1 × ec ^). Output to the device 66.

  Here, the back electromotive force constant ec ^ is preset with a different value for each type of the AC motor 3. For example, in the case of a synchronous reluctance motor, a counter electromotive voltage constant ec ^ = 0 is set, and in the case of an IPM synchronous motor, a predetermined counterelectromotive voltage constant ec ^ is set.

  The adder 66 inputs the multiplication result (ω1 × id * × Xd ^) from the multiplier 63 and inputs the multiplication result (ω1 × ec ^) from the multiplier 64, and outputs the multiplication result (ω1 × id * × Xd). The multiplication result (ω1 × ec ^) is added to ^). Then, the adder 66 outputs the addition result (ω1 × id * × Xd ^ + ω1 × ec ^) to the adder 16 as the q-axis non-interference voltage FF compensation Δvq *.

  As described above, the non-interference voltage FF compensator 21 sets the back electromotive force constant ec ^, the d-axis reactance identification value Xd ^ and the q-axis reactance identification value Xq ^ that are set in advance, and the input rotor electrical angular velocities ω1, d. Based on the axis current command id * and the q-axis current command iq *, the d-axis non-interference voltage FF compensation Δvd * (− ω1 × iq * × Xq ^) for canceling the interference voltage generated in the AC motor 3 and The q-axis non-interference voltage FF compensation Δvq * (ω1 × id * × Xd ^ + ω1 × ec ^) is calculated.

  That is, when the d-axis current flows in the AC motor 3, an interference voltage (ω1 × id * × Xd ^ + ω1 × ec ^) having the same polarity as the q-axis current is generated on the q-axis, and this interference voltage is q. It is calculated as the axis non-interference voltage FF compensation Δvq *. Further, as the q-axis current flows through the AC motor 3, an interference voltage (−ω1 × iq * × Xq ^) having a polarity opposite to that of the d-axis current is generated on the d-axis, and this interference voltage is generated on the d-axis. It is calculated as the non-interference voltage FF compensation Δvd *.

  Further, the process of the non-interference voltage FF compensation unit 21 can be applied to the synchronous reluctance motor or the IPM synchronous motor according to the preset counter electromotive voltage constant ec ^. When the AC motor 3 is a synchronous reluctance motor, a counter electromotive voltage constant ec ^ = 0 is set, and the non-interference voltage FF compensating unit 21 d-axis non-interference voltage FF compensation Δvd * (-ω1 × iq * × Xq ^. ) And q-axis non-interference voltage FF compensation Δvq * (ω1 × id * × Xd ^) are calculated. When the AC motor 3 is an IPM synchronous motor, a predetermined back electromotive force constant ec ^ is set, and the non-interference voltage FF compensating unit 21 d-axis non-interference voltage FF compensation Δvd * (-ω1 × iq * ×). Xq ^) and q-axis non-interference voltage FF compensation Δvq * (ω1 × id * × Xd ^ + ω1 × ec ^) are calculated.

As described above, according to the motor control device 1 of the embodiment of the present invention, the current command generation unit 10 inputs the preset terminal voltage command v *, the speed command ω *, the speed limit command ω _{MAX, and the} like, and the input. Based on the speed feedback ω, the d-axis voltage command vd *, and the q-axis voltage command vq *, the d-axis current command id * and the q-axis current command iq * are set so that the rotation speed of the AC motor 3 is equal to or less than the speed limit command ω _MAX . To generate. Here, the current command generation unit 10 applies the d-axis current command id * and the q-axis current command iq applied to either the synchronous reluctance motor or the IPM synchronous motor according to the preset current phase angle command β. Generate *.

As a result, when controlling the two types of AC motors 3 of the synchronous reluctance motor and the IPM synchronous motor, it is possible to realize the control in which the rotation speed of the AC motor 3 is equal to or lower than the speed limit command ω _MAX by the common circuit. it can.

  Further, the non-interference voltage FF compensating unit 21 sets the back electromotive force constant ec ^, the d-axis reactance identification value Xd ^ and the q-axis reactance identification value Xq ^ set in advance, and the input rotor electrical angular velocity ω1, d-axis current. Based on the command id * and the q-axis current command iq *, the d-axis non-interference voltage FF compensation Δvd * (− ω1 × iq * × Xq ^) for canceling the interference voltage generated in the AC motor 3 and the q-axis The non-interference voltage FF compensation Δvq * (ω1 × id * × Xd ^ + ω1 × ec ^) is calculated. Here, the non-interference voltage FF compensating unit 21 performs processing with a preset counter electromotive voltage constant ec ^ = 0 in the case of a synchronous reluctance motor, and in the case of an IPM synchronous motor, a preset predetermined value. Processing is performed with the back electromotive force constant ec ^.

  As a result, when controlling the synchronous reluctance motor and the IPM synchronous motor, non-interference control can be realized by the common circuit applied to these AC motors 3.

〔Measurement result〕
Next, the measurement result by the motor control device 1 will be described. FIG. 7 is a graph showing the measurement results of the actual machine when the synchronous reluctance motor is used, and FIG. 8 is a graph showing the measurement results of the actual machine when the IPM synchronous motor is used.

7 and 8, from the top of the graph, speed feedback ω, current command i1 *, d-axis current command id *, d-axis current feedback id, q-axis current command iq *, q-axis current feedback iq, DC bus voltage The characteristics of the e _bus and the voltage command feedback v1 * are shown. The horizontal axis is time.

  Referring to FIGS. 7 and 8, when AC motor 3 operates with speed feedback ω having a pattern of forward rotation acceleration, forward rotation deceleration, reverse rotation acceleration and reverse rotation deceleration, d-axis current command id * is applied to d-axis current It can be seen that the feedback id follows. Further, it can be seen that the q-axis current feedback iq follows the q-axis current command iq *. That is, it can be seen that the two circuits of the alternating-current motor 3 of the synchronous reluctance motor and the IPM synchronous motor realize the non-interference control by the common circuit in the motor control device 1.

1 Motor Control Device 2 Power Amplifier 3 AC Motor 4 PG (Pulse Generator)
10 Current command generator 11, 12, 31, 32, 50, 52 Subtractor 13, 14 Current controller 15, 16, 35, 44, 57, 66 Adder 17, 18 Coordinate converter 19 Converter 20 Integrator 21 Non-interference voltage FF (feed forward) compensator 30 Voltage command FB (feedback) generator 33 Terminal voltage controller 34 Speed controller 40 Voltage controllers 41, 55, 56 Limiter 42 Speed controller 43 Speed limiting current generator 45 Absolute Value calculator 46 Cosine calculator 47 Sine calculator 51, 65 Inverter 53, 54, 60, 61, 62, 63, 64 Multiplier id * d-axis current command id * 'd-axis shared current command iq * q-axis current Command iq * 'q-axis shared current command vd * d-axis voltage command vq * q-axis voltage command Δvd * d-axis non-interference voltage FF (feed forward) compensation Δvq * q-axis non-interference Voltage FF (feed forward) compensation v * Terminal voltage command v1 * Voltage command feedback Δi1 * Speed deviation current command Vu * U-phase AC voltage command Vv * V-phase AC voltage command Vw * W-phase AC voltage command id1 * Terminal current command i * External current command i1 * Current command β Current phase angle command ω _max Speed limit command iu U-phase AC current feedback iv V-phase AC current feedback iw W-phase AC current feedback id d-axis current feedback iq q-axis current feedback i1 _LMT speed limit Current ω Velocity feedback ω1 Rotor electrical angular velocity θe Electrical angle N _p Number of pole pairs ω ₀ Rated angular velocity ω _base Base angular velocity Δv1 Terminal voltage deviation Δω Speed deviation Xd ^ d-axis reactance identification value Xq ^ q-axis reactance identification value ec ^ Back electromotive force Constant e _bus DC bus voltage

Claims (3)

A d-axis voltage command is generated from the d-axis current command, a q-axis voltage command is generated from the q-axis current command, a three-phase AC voltage command is generated from the d-axis voltage command and the q-axis voltage command, and the three-phase is described. In a motor control device that controls an AC motor by outputting an AC voltage command to a power amplifier,
D axis non-interference voltage compensation for canceling the d-axis interference voltage generated by the q-axis current in the AC motor, and canceling the q-axis interference voltage generated by the d-axis current in the AC motor. a non-interference voltage compensator for calculating q-axis non-interference voltage compensation,
The d-axis non-interference voltage compensation calculated by the non-interference voltage compensator is added to the d-axis voltage command to obtain a new d-axis voltage command, and the q-axis voltage command includes the non-interference voltage compensator. A first adder for adding the q-axis non-interference voltage compensation calculated by
A coordinate conversion unit that performs coordinate conversion of the new d-axis voltage command and the new q-axis voltage command obtained by the first adder into the three-phase AC voltage command;
The non-interference voltage compensation unit,
The electric angular velocity of the rotor of the AC motor is multiplied by the q-axis current command to obtain a first multiplication result, and the first multiplication result is multiplied by a preset q-axis reactance identification value and second multiplication is performed. A first multiplier for obtaining the result,
A first inverter that inverts the second multiplication result obtained by the first multiplier to obtain the d-axis non-interference voltage compensation;
The electric angular velocity of the rotor of the AC motor is multiplied by the d-axis current command to obtain a third multiplication result, and the third multiplication result is multiplied by a preset d-axis reactance identification value and fourth multiplication is performed. A second multiplier for finding the result,
A third multiplier for multiplying the rotor electrical angular velocity of the AC motor by a preset back electromotive force constant to obtain a fifth multiplication result;
A second adder for adding the fifth multiplication result obtained by the third multiplier to the fourth multiplication result obtained by the second multiplier to obtain the q-axis non-interference voltage compensation. And
The preset back electromotive force constant is 0 when the AC motor is a synchronous reluctance motor, and a predetermined value is used when the AC motor is an IPM synchronous motor .
The motor control device further includes a current command generation unit that generates the d-axis current command and the q-axis current command,
The current command generator,
A voltage command FB (feedback) generation unit that calculates a voltage command feedback based on the new d-axis voltage command and the new q-axis voltage command obtained by the first adder;
A first subtractor that subtracts the voltage command feedback calculated by the voltage command FB generation unit from a terminal voltage command indicating a set value of the DC bus voltage of the power amplifier to obtain a terminal voltage deviation;
The terminal current command is calculated so that the terminal voltage deviation obtained by the first subtractor becomes 0, and the terminal current command is limited within a range from 0 to a negative predetermined value. To a terminal voltage control unit that outputs the terminal current command in a range from a negative predetermined value,
A second subtractor for subtracting speed feedback indicating the speed of the AC motor from a preset speed command to obtain a speed deviation;
A speed deviation current command is calculated so that the speed deviation obtained by the second subtractor becomes 0, and the speed deviation current command is added to a preset external current command to obtain a current command. A speed control unit that obtains a d-axis shared current command and a q-axis shared current command based on the current command and a preset current phase angle command, and uses the q-axis shared current command as the q-axis current command,
A third adder for adding the terminal current command output by the terminal voltage control unit to the d-axis shared current command obtained by the speed control unit to obtain the d-axis current command,
As the preset current phase angle command, a first predetermined value is used when the AC motor is a synchronous reluctance motor, and a second predetermined value is used when the AC motor is an IPM synchronous motor. A motor control device characterized by the above. The motor control device according to claim 1 ,
The speed control unit,
A speed controller that calculates the speed deviation current command so that the speed deviation obtained by the second subtractor becomes 0;
A speed limit current corresponding to a deviation between the preset speed limit command and the speed feedback, based on a preset speed limit command indicating the limit value of the rotation speed of the AC motor and the speed feedback. A speed limited current generator for calculating
A fourth adder for obtaining the current command by adding the speed deviation current command calculated by the speed controller and the speed limiting current calculated by the speed limiting current generator to the predetermined external current command. When,
An absolute value calculator that calculates an absolute value of the current command obtained by the fourth adder;
A cosine calculator that obtains the d-axis shared current command by multiplying the absolute value of the current command calculated by the absolute value calculator by a cosine function whose angle is the preset current phase angle command;
A sine operation for multiplying the current command obtained by the fourth adder by a sine function having the preset current phase angle command as an angle to obtain the q-axis shared current command as the q-axis current command. And a motor control device. The motor control device according to claim 2 ,
The speed limiting current generator is
A third subtractor for subtracting the speed feedback from the preset speed limit command to obtain a speed limit deviation;
A fourth multiplier that multiplies the speed limit deviation obtained by the third subtractor by a preset coefficient to obtain a speed limit deviation as a result of multiplication;
The speed limit deviation of the multiplication result obtained by the fourth multiplier is limited in the range from 0 to a predetermined negative value, and the speed limit of the multiplication result in the range from 0 to the predetermined negative value is applied. A first limiter that outputs the deviation,
A second inverter for inverting the preset speed limit command;
A fourth subtractor for subtracting the speed feedback from the preset speed limit command inverted by the second inverter to obtain an inversion speed limit deviation;
A fifth multiplier for multiplying the reversal speed limit deviation obtained by the fourth subtractor by a preset coefficient to obtain a reversal speed limit deviation as a result of multiplication;
The reversal speed limit deviation of the multiplication result obtained by the fifth multiplier is limited within a range from a plus predetermined value to 0, and the multiplication result is inverted within the range from the plus predetermined value to 0. A second limiter for outputting the speed limit deviation;
A fifth adder for obtaining the speed limiting current by adding the reversal speed limit deviation of the multiplication result output by the second limiter to the speed limit deviation of the multiplication result output by the first limiter. A motor control device comprising:

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