JP2010041748A - Motor control device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor control device and method capable of performing continuous normal operation without making an overcurrent flow to a motor, even if the motor is rotated at high speed. <P>SOLUTION: A d-axis current command generator 16 inputs a bus voltage Ebus from a bus voltage detector 4, inputs a d-axis voltage command vd* and a q-axis voltage command vq* from a current controller 12, generates an output voltage command of an inverter 5 from the bus voltage Ebus, calculates an output voltage of an inverter 5 from the d-axis voltage command vd* and the q-axis voltage command vq*, performs PI-control so that a difference of the output voltage of the inverter 5 becomes zero, generates a negative d-axis current command id* so that the output voltage of the inverter 5 is not brought into a saturated state, and then outputs the generated d-axis current command id* to the current controller 12. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a motor control device and a control method, and more particularly to a technique for preventing an output voltage of an inverter from being saturated and realizing continuous normal operation.

  FIG. 6 is a block diagram showing a configuration of a conventional motor control device. This conventional motor control device 200 is for suppressing an increase in the output voltage and current of the inverter 66 and also for suppressing an increase in the capacity of the inverter 66. The speed command generator 61, the speed controller 62, q A shaft current command generator 63, a d-axis current command generator 64, a current controller 65, an inverter 66, a subtractor 67, a counter 52, and a differentiator 53 are provided (see FIG. 1 of Patent Document 1).

  The subtracter 67 inputs the speed command ω * of the motor 51 from the speed command generator 61 and also inputs the rotational speed ω of the motor 51 from the differentiator 53, and the speed between the speed command ω * and the rotational speed ω. The deviation is calculated and output to the speed controller 62.

  The speed controller 62 receives the speed deviation from the subtractor 67, calculates the torque command T * so that the speed deviation becomes zero by PI control, and outputs it to the q-axis current command generator 63. The q-axis current command generator 63 receives the torque command T * from the speed controller 62, calculates the q-axis current command iq * corresponding to the torque command T *, for example, so as to have a proportional relationship, and the current controller Output to 65.

  The d-axis current command generator 64 calculates the d-axis current command id * so that the output voltage of the inverter 66 is equal to or lower than a predetermined value, and outputs it to the current controller 65. For example, the d-axis current command generator 64 receives the q-axis current command iq * from the q-axis current command generator 63 (not shown), and the output voltage of the inverter 66 is based on the q-axis current command iq *. The d-axis current command id * is calculated so as to be equal to or less than a predetermined value (see FIG. 3 and paragraphs 0007 and 0008 of Patent Document 1). Thus, since the d-axis current command id * is calculated so as to be a suppressed value under a predetermined condition, not only an increase in torque but also an increase in output voltage of the inverter 66 is suppressed. Can do.

  The current controller 65 receives the q-axis current command iq * from the q-axis current command generator 63, the d-axis current command id * from the d-axis current command generator 64, the rotational speed ω from the differentiator 53, and the counter 52. The phase angle θ is input, an output voltage command signal is calculated, and output to the inverter 66. The inverter 66 receives the output voltage command signal from the current controller 65, performs PWM (Pulse Width Modulation) control, the output voltage and the output frequency are controlled, and supplies AC power to the motor 51. Thus, the output voltage of the inverter 66 is controlled to be equal to or lower than a predetermined value, and the speed control of the motor 51 is performed.

JP 11-178399 A

  In the conventional motor control apparatus 200 shown in FIG. 6, when the motor 51 is rotated at a high speed, the induced voltage of the motor 51 becomes high. For this reason, it is necessary to increase the output voltage of the inverter 66, and accordingly, it is also necessary to increase the bus voltage that is the input voltage of the inverter 66.

  However, since the bus voltage supplied to the inverter 66 is determined by the voltage of the converter and the original power supply installed in the previous stage of the inverter 66, the upper limit value has a limit. That is, when the motor 51 is rotated at a high speed, when the bus voltage of the inverter 66 is low, the output voltage of the inverter 66 corresponding to the high speed rotation of the motor 51 cannot be supplied to the motor 51. Becomes saturated (oversaturation). When the output voltage of the inverter 66 becomes saturated, the terminal voltage of the motor 51 does not reach the required voltage, so an overcurrent flows through the motor 51 and an abnormality occurs, and it is impossible to continue normal operation. .

  Therefore, the present invention has been made to solve the above-described problems, and the object thereof is to perform continuous normal operation without overcurrent flowing through the motor even when the motor rotates at high speed. It is an object of the present invention to provide a motor control device and a control method that can be used.

  In order to achieve the above object, a motor control device according to the present invention generates a d-axis current command by a predetermined calculation, generates a q-axis current command so that the rotational speed of the motor becomes a predetermined speed, The output current is coordinate-transformed to generate a d-axis current and a q-axis current, a d-axis voltage command is generated based on the d-axis current command and the d-axis current, and based on the q-axis current command and the q-axis current. In a motor control device that generates a q-axis voltage command, performs PWM control of the inverter based on the d-axis voltage command and the q-axis voltage command, converts bus voltage by the inverter and supplies AC power to the motor. Bus voltage detection means for detecting the bus voltage of the inverter, and the output voltage of the inverter is lower than an output voltage that can be generated based on the bus voltage detected by the bus voltage detector. As such, characterized by comprising a d-axis current command generating means for generating a d-axis current command.

  In the motor control device according to the present invention, the d-axis current command generation means generates an output voltage command of the inverter based on the bus voltage detected by the bus voltage detector, and the output voltage of the inverter is an output voltage. A d-axis current command is generated so as to match the command.

  In the motor control device according to the present invention, the d-axis current command generation unit generates an output voltage command of the inverter based on the bus voltage detected by the bus voltage detector, and the d-axis voltage command and the q-axis An output voltage of the inverter is generated based on the voltage command, PI control is performed so that a deviation between the output voltage command of the inverter and the output voltage becomes zero, and a negative d-axis current command is generated. And

  Further, the motor control method according to the present invention generates a d-axis current command by a predetermined calculation, generates a q-axis current command so that the rotational speed of the motor becomes a predetermined speed, and converts the inverter output current to coordinates. Generates a d-axis current and a q-axis current, generates a d-axis voltage command based on the d-axis current command and the d-axis current, and generates a q-axis voltage command based on the q-axis current command and the q-axis current. In the motor control method in which the inverter is PWM-controlled based on the d-axis voltage command and the q-axis voltage command, the bus voltage is converted by the inverter and AC power is supplied to the motor, the bus voltage of the inverter is And a step of generating a d-axis current command so that an output voltage of the inverter is lower than an output voltage that can be generated based on the detected bus voltage. It is characterized in.

  The motor control method according to the present invention includes a step of generating an inverter output voltage command based on the detected bus voltage, and a d-axis current command so that the inverter output voltage matches the output voltage command. And a step of performing.

  The motor control method according to the present invention includes a step of generating an inverter output voltage command based on the detected bus voltage, and a step of generating an inverter output voltage based on the d-axis voltage command and the q-axis voltage command. And calculating a deviation between the output voltage command and the output voltage of the inverter, performing a PI control so that the calculated deviation becomes zero, and generating a negative d-axis current command. It is characterized by having.

  As described above, according to the present invention, the d-axis current command is generated so that the output voltage of the inverter becomes a predetermined voltage value even when the motor rotates at high speed. As a result, the output voltage of the inverter is controlled to be a predetermined voltage value that does not reach the saturation state, so the output voltage of the inverter does not become the saturation state, and no overcurrent flows through the motor. . Therefore, it is possible to perform continuous normal operation.

The best mode for carrying out the present invention will be described below with reference to the drawings.
A feature of the present invention is that d-axis current command (excitation current command) id * is generated so that the output voltage (motor terminal voltage) of the inverter becomes a predetermined voltage value even when the motor rotates at high speed. There is to do. In the embodiment of the present invention, an output voltage command for making the output voltage of the inverter P times the bus voltage Ebus is calculated, the output voltage current value is calculated based on the inverter output current I, and the output voltage command and the output voltage are calculated. A negative d-axis current command id * is generated using the current value. Here, the voltage value P times the bus voltage Ebus (output voltage command, maximum motor terminal voltage command) is an upper limit value set in order to prevent the output voltage of the inverter from being saturated. That is, the voltage value P times the bus voltage Ebus is an upper limit value for making the output voltage of the inverter lower than the output voltage that can be generated based on the bus voltage Ebus. As long as the output voltage of the inverter is controlled to be P times the bus voltage Ebus, the output voltage of the inverter does not become saturated. In addition, when the inverter output voltage is in a saturated state, AC power necessary for controlling the motor cannot be supplied from the inverter due to insufficient capacity of the inverter, and the output voltage cannot be increased. Say. In other words, a voltage exceeding the output voltage that can be generated from the bus voltage Ebus on the input side is required, but only an output voltage that can be generated from the bus voltage Ebus on the input side can be supplied. On the other hand, the q-axis current command iq * is generated based on the torque command T *. Using the d-axis current command id * and the q-axis current command iq * thus generated, a d-axis voltage command vd * and a q-axis voltage command vq * are generated, and the inverter is PWM controlled to speed the motor. Control.

[Configuration of motor controller]
First, the configuration of the motor control device will be described. FIG. 1 is a block diagram showing a configuration of a motor control system including a motor control device according to an embodiment of the present invention. This motor control system uses a power source 1 for supplying three-phase AC power and an AC for driving the motor so that a motor 7 described later rotates at a predetermined speed using the three-phase AC power supplied from the power source 1. A motor control device 20 that supplies electric power, a motor 7 that rotates by AC power supplied from the motor control device 20, and a pulse generator 8 that outputs a pulse signal as the motor 7 rotates are configured. . The motor 7 is, for example, a permanent magnet synchronous motor.

  The motor control device 20 includes a converter 2, a smoothing capacitor 3, a bus voltage detector 4, an inverter 5, a current detector 6, a counter 9, a PWM pulse generator 10, a differentiator 11, a current controller 12, and a q-axis current command. A generator 13, a speed controller 14, a speed command generator 15, a d-axis current command generator 16 and a subtracter 17 are provided. Hereinafter, the configuration of the motor control device 20 will be described in detail.

  Converter 2 receives AC power from power supply 1 and converts AC power into DC power. Smoothing capacitor 3 smoothes the DC power converted by converter 2. Here, one end of the smoothing capacitor 3 is connected to the output positive terminal of the converter 2 and the input positive terminal of the inverter 5, and the other end is connected to the output negative terminal of the converter 2 and the input negative terminal of the inverter 5. The bus voltage detector 4 detects the voltage between the smoothing capacitor 3 and the inverter 5. The voltage detected by the bus voltage detector 4 is the input voltage (bus voltage Ebus) of the inverter 5 and is output to the d-axis current command generator 16.

  The inverter 5 receives DC power from the converter 2 via the smoothing capacitor 3 and also receives a gate signal from the PWM pulse generator 10 and converts the DC power into AC power based on the gate signal. Supply to the motor 7. That is, the inverter 5 includes a PWM inverter circuit that performs DC-AC power conversion, and conducts / cuts off between the collector and the emitter by a gate signal input to a gate of a semiconductor switching element such as an IGBT (Insulated Gate Bipolar Transistor). Control. In other words, the AC power is generated by turning on / off the gate of the switching element by the gate signal and supplied to the motor 7.

  The current detector 6 detects the output current (inverter output current I) of the inverter 5. The inverter output current I detected by the current detector 6 is output to the current controller 12.

  The counter 9 receives a pulse signal accompanying the rotation of the motor 7 from the pulse generator 8, counts the pulse signal, calculates the phase angle θ from the count value, and calculates the phase angle θ from the PWM pulse generator 10, the differentiator 11, and Output to the current controller 12.

  The differentiator 11 receives the phase angle θ of the motor 7 from the counter 9, calculates the rotational speed ω by time differentiation of the phase angle θ, and outputs the rotational speed ω to the subtractor 17. The speed command generator 15 generates a speed command ω * and outputs it to the subtracter 17. The speed command ω * may be set in advance. The subtracter 17 inputs the speed command ω * from the speed command generator 15 and also inputs the rotational speed ω from the differentiator 11, subtracts the rotational speed ω from the speed command ω *, and uses the result as a speed deviation for speed. Output to the controller 14.

  The speed controller 14 receives the speed deviation from the subtractor 17, calculates the torque command T * by, for example, PI control so that the speed deviation becomes zero, and converts the torque command T * into the q-axis current command generator 13. Output to.

  The q-axis current command generator 13 receives the torque command T * from the speed controller 14, calculates the q-axis current command iq * corresponding to the torque command T *, for example, so as to have a proportional relationship, and the q-axis current command Command iq * is output to current controller 12.

  The current controller 12 receives the inverter output current I from the current detector 6, the phase angle θ from the counter 9, and the d-axis current command id * from the d-axis current command generator 16 to generate the q-axis current command. The q-axis current command iq * is input from the generator 13, the d-axis voltage command vd * and the q-axis voltage command vq * are generated by current control, and output to the PWM pulse generator 10 and the d-axis current command generator 16. . Specifically, the current controller 12 inputs the U-phase current and the W-phase current as the inverter output current I from the current detector 6, inputs the phase angle θ from the counter 9, and uses the phase angle θ for three-phase Coordinate conversion from the axis to the d-axis and the q-axis is performed to calculate the d-axis current id and the q-axis current iq. Then, the current controller 12 subtracts the d-axis current id from the d-axis current command id *, performs PI control so that the obtained d-axis current deviation becomes zero, and calculates the d-axis voltage command vd *. Output. Further, the current controller 12 subtracts the q-axis current command iq from the q-axis current command iq *, performs PI control so that the obtained q-axis current deviation becomes zero, and calculates the q-axis voltage command vq *. Output.

  The PWM pulse generator 10 receives the d-axis voltage command vd * and the q-axis voltage command vq * from the current controller 12, inputs the phase angle θ from the counter 9, generates a gate signal, and outputs it to the inverter 5. To do. Specifically, the PWM pulse generator 10 receives the d-axis voltage command vd * and the q-axis voltage command vq * from the current controller 12, receives the phase angle θ from the counter 9, and uses the phase angle θ. Coordinate conversion from the d-axis and q-axis to the three-phase axis is performed, and voltage commands (U-phase voltage command, V-phase voltage command, and W-phase voltage command) are calculated. Then, the PWM pulse generator 10 generates six gate signals based on the calculated voltage commands (U-phase voltage command, V-phase voltage command, and W-phase voltage command), and outputs them to the inverter 5. Based on the gate signal generated in this way, the inverter 5 supplies AC power to the motor 7 and the speed control of the motor 7 is performed.

  The d-axis current command generator 16 receives the d-axis voltage command vd * and the q-axis voltage command vq * from the current controller 12, and also receives the bus voltage Ebus from the bus voltage detector 4, and receives the d-axis voltage command vd. A negative d-axis current command id * is generated and supplied to the current controller 12 so that the output voltage of the inverter 5 calculated from the * and q-axis voltage command vq * becomes a predetermined voltage value calculated from the bus voltage Ebus. Output. Details of the d-axis current command generator 16 will be described later.

[D-axis current command generator]
Next, the d-axis current command generator 16 shown in FIG. 1 will be described in detail. FIG. 2 is a block diagram showing a configuration of the d-axis current command generator 16. The d-axis current command generator 16 includes calculators 161 to 165. The arithmetic units 161 and 164 are arithmetic units for calculating an inverter output voltage command, and the arithmetic units 162 and 163 are arithmetic units for calculating a current value of the inverter output voltage. Is a calculator for calculating the d-axis current command id * so that the deviation of the inverter output voltage becomes zero. Further, a maximum motor terminal voltage command unit is configured by a part of the calculator 161 and the calculator 164.

  The calculator 161 receives the bus voltage Ebus from the bus voltage detector 4, multiplies the bus voltage Ebus by P, and outputs the obtained voltage command E * to the calculator 164. This voltage command E * is used to calculate the inverter output voltage command, that is, the maximum value of the motor terminal voltage.

The calculator 162 receives the d-axis voltage command vd * and the q-axis voltage command vq * from the current controller 12, and calculates (I1 × G1 + I2 × G2), ie, (vd * ² + vq * ² ). The calculation result is output to the calculator 163.

The calculator 163 receives the calculation result (vd * ² + vq * ² ) from the calculator 162, calculates √ (vd * ² + vq * ² ), and outputs the calculation result to the calculator 161 as voltage feedback v *. To do. The value of √ (vd * ² + vq * ² ) that is this voltage feedback v * is a combination of the d-axis d-axis voltage command vd * and the q-axis q-axis voltage command vq * that is the axis perpendicular to the d-axis. Therefore, it can be said that the value corresponds to the voltage command (inverter output voltage command) on the three-phase axis. That is, the voltage feedback v * is a current value of the inverter output voltage because the d-axis voltage command vd * and the q-axis voltage command vq * are values calculated from the inverter output current I.

  The computing unit 164 receives the voltage command E * from the computing unit 161 and also receives the voltage feedback v * (current value of the inverter output voltage) from the computing unit 163 and performs the computation of (E * −v *). The deviation of the inverter output voltage, which is the calculation result, is output to the calculator 165. The value of the voltage command E * is a command for the inverter output voltage and is the maximum value of the motor terminal voltage. That is, this value is a predetermined voltage value. Here, P is a preset parameter, and P <1. In this case, the inverter output voltage is controlled to a voltage value P times the bus voltage. By setting P to a value smaller than 1, even if the inverter output voltage fluctuates, the output voltage of the inverter 5 is not saturated (exceeds the output voltage that can be generated based on the bus voltage Ebus of the inverter 5). Can afford). That is, the value of P is a margin value considering the response of the inverter output voltage.

  The maximum motor terminal voltage command unit receives the bus voltage Ebus from the bus voltage detector 4, multiplies the bus voltage Ebus by P, and generates an inverter output voltage command (maximum motor terminal voltage command).

  The calculator 165 receives the deviation of the inverter output voltage from the calculator 164, performs PI control so that this deviation becomes zero, and calculates and outputs the d-axis current command id *. In this case, when the d-axis current command id * is larger than 0, 0 is output instead of the calculated d-axis current command id *, and when the d-axis current command id * is smaller than −1, the calculation is performed. -1 is output instead of the d-axis current command id *. Here, Kp is a proportional constant, Ti is an integral constant, and these parameters are set in advance.

[Control system when vq * = 0]
Next, the control system when the q-axis voltage command vq * is 0 (vq * = 0) will be described. FIG. 3 is a diagram for explaining the control system when vq * = 0. 1 and 2, when the q-axis voltage command vq * is set to 0, the control system of the d-axis current command id * and the d-axis voltage command vd * can be expressed by a feedback control system as shown in FIG. . In FIG. 3, the d-axis current command generator 16 feeds back a d-axis voltage command vd * in which the current value of the inverter output voltage is reflected via the d-axis current id, and the voltage command E * and the d-axis voltage command vd * are fed back. PI control is performed so that the deviation from * is zero, that is, feedback control is performed so that the deviation between the inverter output voltage command and the current value of the inverter output voltage is zero, and the d-axis current command id * is Calculate.

  The current controller 12 feeds back the d-axis current id, performs PI control so that the deviation between the d-axis current command id * and the d-axis current id becomes zero, and calculates the d-axis voltage command vd *. Here, Ki is a proportionality constant, Te is an integration constant, and these parameters are set in advance. Then, a d-axis current id is generated via the motor 7 and the like. Here, r represents the resistance value of the motor winding.

  Thus, the d-axis current command generator 16 sets a value P times the bus voltage Ebus as the output voltage command of the inverter 5 and feeds back the inverter output current I to calculate the d-axis voltage commands vd * and q The current output voltage value of the inverter 5 is calculated from the shaft voltage command vq *, and the negative d-axis current command id * is generated and output so that the current output voltage value of the inverter 5 becomes the output voltage command. . In other words, in the feedback control calculation process, the d-axis current command id * is generated to a negative value. As a result, the output voltage of the inverter 5 can be suppressed to about P times the bus voltage Ebus. Therefore, even when a high-speed rotation operation exceeding the base rotation speed of the motor 7 is performed, the motor does not become saturated, and the motor No overcurrent flows through 7. Even if the bus voltage Ebus of the inverter 5 is lowered due to an unexpected situation, the d-axis current command id * is determined based on the output voltage command of the inverter 5 based on the bus voltage Ebus and the current value of the output voltage of the inverter 5. Is generated according to the reduced bus voltage Ebus so that the deviation between is zero. As a result, the output voltage of the inverter 5 is not saturated and no overcurrent flows through the motor 7. Therefore, it is possible to perform normal operation without any abnormality.

[Processing of motor controller]
Next, processing of the motor control device 20 shown in FIG. 1 will be described. First, calculation processing of the d-axis current command id * will be described. FIG. 4 is a flowchart showing the calculation process of the d-axis current command id *. The calculation process of the d-axis current command id * is performed by the d-axis current command generator 16 in FIG.

  The d-axis current command generator 16 receives the bus voltage Ebus from the bus voltage detector 4, and calculates an inverter output voltage command from the bus voltage Ebus (step S501). Specifically, in FIG. 2, the voltage command E * becomes the inverter output voltage command by the calculator 161 and the calculator 164 of the d-axis current command generator 16.

  The d-axis current command generator 16 calculates the current value of the inverter output voltage from the d-axis voltage command vd * and the q-axis voltage command vq * reflecting the inverter output current I (step S502). Specifically, in FIG. 2, the voltage feedback v * becomes the current value of the inverter output voltage by the calculators 162 to 164 of the d-axis current command generator 16.

  The d-axis current command generator 16 calculates the deviation of the inverter output voltage (step S503). In FIG. 2, the calculator 164 calculates (E * -v *) to calculate the deviation of the inverter output voltage.

  The d-axis current command generator 16 calculates a negative d-axis current command id * by PI control so that the deviation of the inverter output voltage becomes zero (step S504). In FIG. 2, the calculator 165 calculates a negative d-axis current command id *.

  In this way, the d-axis current command id * is calculated by the d-axis current command generator 16 so that the inverter output voltage is about P times the bus voltage that is the input voltage.

  Next, calculation processing of the q-axis current command iq * will be described. FIG. 5 is a flowchart showing a calculation process of the q-axis current command iq *. The calculation process of the q-axis current command iq * is performed by the speed command generator 15, the subtracter 17, the speed controller 14, and the q-axis current command generator 13 in FIG.

  The subtracter 17 inputs the speed command ω * from the speed command generator 15 and the rotational speed ω from the differentiator 11, and calculates the speed deviation of the motor 7 (step S601). The speed controller 14 calculates a torque command T * by PI control so that the speed deviation of the motor 7 becomes zero (step S602).

  The q-axis current command generator 13 calculates a q-axis current command iq * corresponding to the torque command T * from the torque command T * calculated by the speed controller 14 so as to have a proportional relationship, for example (step S603). ).

  The present invention has been described with reference to the embodiment. However, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the technical idea thereof. For example, in the embodiment, the d-axis current command generator 16 shown in FIGS. 1 and 2 outputs the output of the inverter 5 via the d-axis voltage command vd * and the q-axis voltage command vq * by the inverter output current I. Although the voltage is calculated, the present invention is not limited to this. The output voltage of the inverter 5 may be directly measured by a voltage detector.

It is a block diagram which shows the structure of the motor control system containing the motor control apparatus by embodiment of this invention. It is a block diagram which shows the structure of a d-axis current command apparatus. It is a figure explaining a control system in case of vq * = 0. It is a flowchart which shows the calculation process of d-axis current command id *. It is a flowchart which shows the calculation process of q-axis electric current command iq *. It is a block diagram which shows the structure of the conventional motor control apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power supply 2 Converter 3 Smoothing capacitor 4 Bus voltage detector 5,66 Inverter 6 Current detector 7,51 Motor 8 Pulse generator 9,52 Counter 10 PWM pulse generator 11,53 Differentiator 12,65 Current controller 13, 63 q-axis current command generator 14, 62 Speed controller 15, 61 Speed command generator 16, 64 d-axis current command generator 17, 67 Subtractor 20, 200 Motor controller 161-165 Calculator id * d-axis current Command (Excitation current command)
iq * q-axis current command (torque current command)
id d-axis current iq q-axis current vd * d-axis voltage command vq * q-axis voltage command v * voltage feedback vd d-axis voltage vq q-axis voltage E * voltage command Ebus bus voltage I inverter output current θ phase angle ω * speed command ω Rotational speed T * Torque command Kp, Ki Proportional constant Ti, Te Integration constant

Claims (6)

Generates a d-axis current command by a predetermined calculation, generates a q-axis current command so that the rotation speed of the motor becomes a predetermined speed, and converts the output current of the inverter to generate a d-axis current and a q-axis current. A d-axis voltage command is generated based on the d-axis current command and the d-axis current, a q-axis voltage command is generated based on the q-axis current command and the q-axis current, and the d-axis voltage command and the q-axis are generated. In a motor control device that PWM-controls an inverter based on a voltage command, converts bus voltage by the inverter, and supplies AC power to the motor.
Bus voltage detecting means for detecting the bus voltage of the inverter;
D-axis current command generating means for generating a d-axis current command so that an output voltage of the inverter is lower than an output voltage that can be generated based on the bus voltage detected by the bus voltage detector;
A motor control device comprising: The motor control device according to claim 1,
The d-axis current command generation means generates an output voltage command of the inverter based on the bus voltage detected by the bus voltage detector, and the d-axis current command so that the output voltage of the inverter matches the output voltage command. A motor control device that generates a command. The motor control device according to claim 1,
The d-axis current command generation means generates an inverter output voltage command based on the bus voltage detected by the bus voltage detector, and generates an inverter output voltage based on the d-axis voltage command and the q-axis voltage command. And generating a negative d-axis current command by performing PI control so that a deviation between the output voltage command and the output voltage of the inverter becomes zero. Generates a d-axis current command by a predetermined calculation, generates a q-axis current command so that the rotation speed of the motor becomes a predetermined speed, and converts the output current of the inverter to generate a d-axis current and a q-axis current. A d-axis voltage command is generated based on the d-axis current command and the d-axis current, a q-axis voltage command is generated based on the q-axis current command and the q-axis current, and the d-axis voltage command and the q-axis are generated. In the motor control method of performing PWM control of the inverter based on the voltage command, converting the bus voltage by the inverter and supplying AC power to the motor,
Detecting a bus voltage of the inverter;
Generating a d-axis current command so that an output voltage of the inverter is lower than an output voltage that can be generated based on the detected bus voltage;
A motor control method characterized by comprising: The motor control method according to claim 4,
Generating an inverter output voltage command based on the detected bus voltage;
Generating a d-axis current command so that the output voltage of the inverter matches the output voltage command;
A motor control method characterized by comprising: The motor control method according to claim 4,
Generating an inverter output voltage command based on the detected bus voltage;
Generating an output voltage of the inverter based on the d-axis voltage command and the q-axis voltage command;
Calculating a deviation between an output voltage command and an output voltage of the inverter;
Performing PI control so that the calculated deviation becomes zero, and generating a negative d-axis current command;
A motor control method characterized by comprising:

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