JP6695497B2 - Motor controller - Google Patents

Description

  The present invention relates to a motor control device that controls driving of a motor.

  Patent Document 1 discloses an example of a conventional motor control device. The motor control device disclosed in Patent Literature 1 applies a plurality of parameters including a d-axis current command value, a q-axis current command value, a winding inductance of a permanent magnet motor, and an induced voltage constant to a permanent magnet motor. It is provided with a voltage command value generator that calculates a voltage command value. Patent Document 1 discloses the following as a procedure for starting a permanent magnet motor.

(1) In the positioning mode, the motor control device controls the permanent magnet motor based on the voltage command value determined by the voltage command value generator based on the d-axis current command value and the q-axis current command value given from the host controller. Apply voltage.
(2) Next, in the synchronous operation mode, the motor control device increases the frequency command value of the inverter while keeping the d-axis current command value at a constant value, and accelerates to a certain rotation speed.
(3) Next, in the position sensorless mode, the motor control device operates using the estimated value of the magnetic pole position or the information of the rotational angle position obtained by the magnetic pole position sensor or the like.

  In Patent Document 1, the inverter frequency command value is integrated in the modes (1) and (2), and the detection frequency is integrated in the mode (3) to estimate the magnetic pole position of the permanent magnet motor. ing. In all the modes (1) to (3), the motor control device operates the permanent magnet motor with the magnetic pole position or the estimated magnetic pole position as the control axis.

Japanese Patent No. 4729356

  In the method disclosed in Patent Document 1, when setting the voltage applied to the permanent magnet motor, the values of the winding inductance and the induced voltage constant of the permanent magnet motor are required. The winding inductance changes the possible value due to magnetic saturation. Further, the winding inductance and the induced voltage constant have different possible values due to temperature and manufacturing variations. In addition, the winding inductance and the induced voltage constant may include harmonics depending on the rotational position. As a result, the permanent magnet motor cannot be driven stably.

  The present invention has been made to solve the above problems, and provides a motor control device for stably driving a motor.

  A motor control device according to the present invention outputs a power conversion circuit that applies a voltage to a motor corresponding to a voltage command value, and a current detection value that is a value obtained by detecting a current supplied to the motor from the power conversion circuit. And a controller for adjusting the voltage command value, wherein the controller calculates the voltage command value corresponding to the current command value that is the basis of the voltage applied to the motor. And an estimated magnetic flux that is a value that estimates the magnetic flux generated in the motor based on the voltage command value and the detected current value, and an estimated angular velocity that is a value that estimates the angular velocity of the motor. A magnetic flux estimator, a magnetic flux controller that adjusts the current command value so that the estimated magnetic flux has a magnetic flux command value, and a speed controller that adjusts the current command value so that the estimated angular velocity has an angular velocity command value. The control unit switches the combination of the application of the speed controller and the application of the magnetic flux controller as a controller applied to the adjustment of the current command value, and the speed control The synchronous current mode in which neither the controller nor the magnetic flux controller is applied to the synchronous magnetic flux mode in which the speed controller is not applied but the magnetic flux controller is applied, and then the speed controller and the magnetic flux controller are applied. It is to switch to the mode.

  According to the present invention, after the synchronous magnetic flux mode, the current command value is changed to a mode in which the speed control and the magnetic flux control are performed for adjustment, so that the values of the winding inductance and the induced voltage constant are unnecessary for calculating the applied voltage. Therefore, it is possible to suppress the change of these values and the influence of harmonics, and to stably drive the motor.

It is a block diagram showing an example of 1 composition of a motor control device concerning Embodiment 1 of the present invention. FIG. 2 is a circuit diagram showing a configuration example of a power conversion circuit shown in FIG. 1. It is a figure which shows one structural example of a magnetic flux estimator in case a control mode is a synchronous current mode and a synchronous magnetic flux mode. It is a figure which shows one structural example of a magnetic flux estimator in case a control mode is a position sensorless 1st mode and a position sensorless 2nd mode. It is a figure which shows one structural example of the current controller of the d-axis side shown in FIG. It is a figure which shows one structural example of the current controller by the side of the q-axis shown in FIG. It is a figure which shows one structural example of the speed controller shown in FIG. It is a figure which shows one structural example of the magnetic flux controller shown in FIG. It is a simplified diagram which shows the transition of each control mode when the motor control device shown in FIG. 1 starts a permanent magnet motor, and after that. 6 is a flowchart showing a procedure of a switching operation by the mode changeover switch shown in FIG. 1.

Embodiment 1.
The configuration of the motor control device according to the first embodiment will be described. FIG. 1 is a block diagram showing a configuration example of a motor control device according to the first embodiment of the present invention. The motor control device 1 applies a voltage to a permanent magnet motor (PM (Permanent Magnet) motor) 6 according to a three-phase voltage command value (Vu ^* , Vv ^* , Vw ^* ), and a power conversion circuit 5. From the current supplied to the permanent magnet motor 6 from the d-axis current detection value Idc and the q-axis current detection value Iqc, the three-phase voltage command value (Vu ^* , Vv ^* , Vw ^* ) is output to the power conversion circuit 5. Motor current detection means 7a for detecting the U-phase current Iu out of the three-phase alternating currents supplied from the power conversion circuit 5 to the permanent magnet motor 6 is provided. Further, motor current detecting means 7b for detecting the W-phase current Iw among the three-phase alternating currents supplied to the permanent magnet motor 6 is provided. Note that any two phases or all three phases may be detected from the three-phase alternating current.

  FIG. 2 is a circuit diagram showing a configuration example of the power conversion circuit 5 shown in FIG. As shown in FIG. 2, the power conversion circuit 5 has a configuration including an inverter 21, a DC voltage source 20, and a driver circuit 23. The inverter 21 is configured to include a plurality of semiconductor elements such as an IGBT (Insulated Gate Bipolar Transistor) and a power MOSFET (Metal Oxide Semiconductor Field Effect Transistor). A semiconductor element is used for each of the U-phase, V-phase, and W-phase upper and lower arms. The connection points of the upper and lower arms of each phase are wired to the permanent magnet motor 6. The inverter 21 performs a switching operation according to pulse-shaped PWM (Pulse Width Modulation) pulse signals 22a, 22b, 22c output from the driver circuit 23. The power conversion circuit 5 switches the DC voltage source 20 to apply an AC voltage of an arbitrary frequency to the permanent magnet motor 6 to drive the motor.

  The control unit 2 includes a 3φ / dq converter 8, a magnetic flux estimator 10, mode changeover switches 16a to 16c, a speed controller (ASR (Automatic Speed Regulator)) 14, a magnetic flux controller 15, and a current controller. 42, 43, a dq / 3φ converter 4, and an integrator 9. The 3φ / dq converter 8 uses the control axis phase θdc that is the direction of the estimated magnetic flux with respect to the U-phase current Iu and the W-phase current Iw detected by the motor current detection means 7a and 7b to control the axis from the three-phase axis. Coordinate conversion is performed to obtain the d-axis current detection value Idc and the q-axis current detection value Iqc.

  The current controller 42 is a d-axis side current controller, and the current controller 43 is a q-axis side current controller. The current controllers 42 and 43 calculate the voltage command value corresponding to the input current command value. The current command value is a value that is the basis of the voltage applied to the permanent magnet motor 6. Details of the configurations of the current controllers 42 and 43 will be described later. The control unit 2 is a semiconductor integrated circuit having a memory that stores a program and an arithmetic processing unit having an arithmetic control function such as a CPU (Central Processing Unit) and a DSP (Digital Signal Processor) that executes processing according to the program. Composed. The control unit 2 is, for example, a microcomputer.

  The motor control device 1 according to the first embodiment has a plurality of modes for controlling the permanent magnet motor 6. For example, the control unit 2 applies the mode in which the magnetic flux controller 15 is not applied, the mode in which the magnetic flux controller 15 is applied, and the speed controller 14 to the adjustment of the current command value input to the current controllers 42 and 43. There are modes and modes to which the speed controller 14 is not applied. The control unit 2 switches the combination of the application of the speed controller 14 and the application of the magnetic flux controller 15 using these plural kinds of modes. Hereinafter, a mode in which the presence or absence of speed control and the presence or absence of magnetic flux control are combined is referred to as a control mode. The control modes include a mode in which position feedback is not performed and a mode in which position feedback is performed. The modes that do not perform position feedback include a synchronous current mode and a synchronous magnetic flux mode. The synchronous current mode is a mode in which neither the speed controller 14 nor the magnetic flux controller 15 is applied to the adjustment of the current command value. The synchronous magnetic flux mode is a mode in which the speed controller 14 is not applied but the magnetic flux controller 15 is applied to the adjustment of the current command value. The position feedback mode includes a position sensorless first mode and a position sensorless second mode. The position sensorless first mode is a mode in which the speed controller 14 is applied but the magnetic flux controller 15 is not applied to the adjustment of the current command value. The position sensorless second mode is a mode in which the speed controller 14 and the magnetic flux controller 15 are applied to the adjustment of the current command value. The control unit 2 switches the mode changeover switches 16a to 16c according to the control mode.

  The mode changeover switches 16a to 16c switch connection in accordance with the control modes of the synchronous current mode, the synchronous magnetic flux mode, the position sensorless first mode and the position sensorless second mode. Specifically, when the control mode is the synchronous current mode, the mode changeover switches 16a to 16c connect the connection destinations to the A terminal shown in FIG. When the control mode is the synchronous magnetic flux mode, the mode changeover switches 16a to 16c connect the connection destinations to the B terminal shown in FIG. When the control mode is the position sensorless first mode, the mode changeover switches 16a to 16c connect the connection destinations to the C terminal shown in FIG. When the control mode is the position sensorless second mode, the mode changeover switches 16a to 16c connect the connection destinations to the D terminal shown in FIG.

  In addition, in FIG. 1, in the mode changeover switches 16a and 16b, the A terminal and the B terminal are common terminals, and the C terminal and the D terminal are common terminals. Further, in the mode changeover switch 16c, the A terminal and the C terminal are common terminals. For the sake of explanation, FIG. 1 schematically shows the mode changeover switches 16a to 16c as mechanical switches. The mode changeover switches 16a to 16c are configured in the motor control device 1 by the arithmetic processing unit of the control unit 2 executing a program. In addition, the arithmetic processing unit of the control unit 2 executes the program so that the 3φ / dq converter 8, the dq / 3φ converter 4, the integrator 9, the magnetic flux estimator 10, the speed controller 14, the magnetic flux controller 15, and the The current controllers 42 and 43 may be included in the motor control device 1. Furthermore, a part of these configurations may be a dedicated circuit such as an ASIC (Application Specific Integrated Circuit). For example, each of the 3φ / dq converter 8, the dq / 3φ converter 4, the integrator 9, the magnetic flux estimator 10, the speed controller 14, the magnetic flux controller 15, and the current controllers 42 and 43 is configured by a dedicated circuit. , And may be provided separately from the control unit 2. However, it is desirable that these components are provided on the same printed circuit board as the control unit 2.

  As shown in FIG. 1, in the magnetic flux controller 15, a subtractor 11e is provided on the input side and a mode changeover switch 16c is connected on the output side. The B terminal of the mode changeover switch 16c is connected to the A terminal and the B terminal of the mode changeover switch 16b. A subtractor 11d is provided on the output side of the mode changeover switch 16a. In the speed controller 14, the subtractor 11d is connected to the input side, and the C terminal and the D terminal of the mode changeover switch 16b are connected to the output side. The mode changeover switch 16b is connected to the current controller 43 via the subtractor 11c. The D terminal of the mode changeover switch 16c is connected to the current controller 42 via the subtractor 11b.

The magnetic flux estimator 10 receives the d-axis current detection value Idc and the q-axis current detection value Iqc, and the d-axis voltage command value Vd ^* and the q-axis voltage command value Vq ^*, and estimates the magnetic flux Φ1 of the permanent magnet motor 6 and The estimated angular velocity ω1 is calculated. The speed controller 14 obtains the difference between the angular velocity command value ω ^* and the estimated angular velocity ω1 by the subtractor 11d in the position sensorless first mode and the position sensorless second mode, and the q-axis is set so that the value of this difference becomes zero. Adjust the current command value Iq ^* .

When the difference value between the magnetic flux command value Φ ^* and the estimated magnetic flux Φ1 is input from the subtractor 11e in the synchronous magnetic flux mode, the magnetic flux controller 15 sets the q-axis current command value so that the difference value becomes zero. Adjust Iq ^* . When the value of the difference between the magnetic flux command value Φ ^* and the estimated magnetic flux Φ1 is input from the subtractor 11e in the position sensorless second mode, the magnetic flux controller 15 adjusts the d-axis current so that the value of the difference becomes zero. Adjust the command value Id ^* .

The current controller 42 obtains the difference between the d-axis current command value Id ^* and the d-axis current detection value Idc, and outputs the d-axis voltage command value Vd ^* so that the value of this difference becomes zero. The current controller 43 obtains the difference between the q-axis current command value Iq ^* and the q-axis current detection value Iqc, and outputs the q-axis voltage command value Vq ^* so that the difference value becomes zero. The dq / 3φ converter 4 performs coordinate conversion from the control axis of the d-axis voltage command value Vd ^* and the q-axis voltage command value Vq ^* to a three-phase axis and applies the three-phase voltage command value (Vu ^*) to the permanent magnet motor 6 ^. , Vv ^* , Vw ^* ) is output.

  Next, of the configurations included in the control unit 2, the main configuration will be described in detail.

[Magnetic flux estimator 10]
The configuration of the magnetic flux estimator 10 shown in FIG. 1 will be described.
The magnetic flux estimator 10 receives the d-axis current detection value Idc and the q-axis current detection value Iqc from the 3φ / dq converter 8 and outputs the d-axis voltage command value Vd ^* and the q-axis voltage command value Vq ^* to the current controller 42, Receive from 43. The magnetic flux estimator 10 uses the d-axis current detection value Idc and the q-axis current detection value Iqc and the d-axis voltage command value Vd ^* and the q-axis voltage command value Vq ^* to generate a magnetic flux and a permanent magnet in the permanent magnet motor 6. The angular velocity of the motor 6 is estimated. The magnetic flux estimator 10 outputs the estimated magnetic flux Φ1 that is the estimated magnetic flux and the estimated angular velocity ω1 that is the estimated angular velocity.

  In the position sensorless first mode and the position sensorless second mode, the integrator 9 integrates the estimated angular velocity ω1 to estimate the control axis phase θdc, which is the direction of the estimated magnetic flux of the permanent magnet motor 6. The control axis phase θdc is input to the dq / 3φ converter 4 and the 3φ / dq converter 8 and used for calculation of each block.

FIG. 3 is a diagram showing a configuration example of the magnetic flux estimator when the control modes are the synchronous current mode and the synchronous magnetic flux mode. When the control modes are the synchronous current mode and the synchronous magnetic flux mode, the mode changeover switch 16a is connected to the A terminal and the B terminal. The angular velocity command value ω ^* is input to the magnetic flux estimator 10 via the mode changeover switch 16a.

The magnetic flux estimator 10 calculates the d-axis estimated magnetic flux Φd1 which is the estimated magnetic flux on the d-axis according to the equation (1). Specifically, the magnetic flux estimator 10 outputs the value of the result obtained by multiplying the d-axis current detection value Idc by the resistance value R of the primary winding of the permanent magnet motor 6 as the output of the d-axis side current controller 42. Subtract from the d-axis voltage command value Vd ^* . Then, the magnetic flux estimator 10 adds, to the result of the subtraction, a product of the q-axis estimated magnetic flux Φq1, which is the estimated magnetic flux on the q-axis, and the angular velocity command value ω ^* . Further, the magnetic flux estimator 10 calculates the d-axis estimated magnetic flux Φd1 by performing the first-order lag filter processing of the cutoff frequency ωc using the variable s as the addition result.

Further, the magnetic flux estimator 10 calculates the q-axis estimated magnetic flux Φq1 according to the equation (2). Specifically, the magnetic flux estimator 10 outputs the value obtained by multiplying the q-axis current detection value Iqc by the resistance value R of the primary winding of the permanent magnet motor 6 as the output of the q-axis side current controller 43. Subtract from the q-axis voltage command value Vq ^* . Then, the magnetic flux estimator 10 subtracts the product of the angular velocity command value ω ^* and the d-axis estimated magnetic flux Φd1 from the result of the subtraction. Further, the magnetic flux estimator 10 calculates the q-axis estimated magnetic flux Φq1 by subjecting the result of the subtraction to first-order lag filter processing of the cutoff frequency ωc. By performing the first-order lag filter process, the permanent magnet motor 6 can be stably driven in the low speed rotation range. Then, the magnetic flux estimator 10 outputs the q-axis estimated magnetic flux Φq1 to the subtractor 11e as the estimated magnetic flux Φ1.

FIG. 4 is a diagram showing a configuration example of the magnetic flux estimator when the control modes are the position sensorless first mode and the position sensorless second mode. When the control modes are the position sensorless first mode and the position sensorless second mode, the mode changeover switch 16a is connected to the C terminal and the D terminal. The angular velocity command value ω ^* is not input to the magnetic flux estimator 10.

The magnetic flux estimator 10 calculates the d-axis estimated magnetic flux Φd1 according to the equation (3). Specifically, the magnetic flux estimator 10 outputs the value of the result obtained by multiplying the d-axis current detection value Idc by the resistance value R of the primary winding of the permanent magnet motor 6 as the output of the d-axis side current controller 42. Subtract from the d-axis voltage command value Vd ^* . Then, the magnetic flux estimator 10 calculates the d-axis estimated magnetic flux Φd1 by subjecting the result of this subtraction to the first-order lag filter processing of the cutoff frequency ωc. Then, the magnetic flux estimator 10 outputs the d-axis estimated magnetic flux Φd1 to the subtractor 11e as the estimated magnetic flux Φ1.

Further, the magnetic flux estimator 10 calculates the estimated angular velocity ω1 according to the equation (4). Specifically, the magnetic flux estimator 10 outputs the value obtained by multiplying the q-axis current detection value Iqc by the resistance value R of the primary winding of the permanent magnet motor 6 as the output of the q-axis side current controller 43. Subtract from the q-axis voltage command value Vq ^* . Then, the magnetic flux estimator 10 calculates the estimated angular velocity ω1 by dividing the result of the subtraction by the d-axis estimated magnetic flux Φd1. Then, the magnetic flux estimator 10 outputs the estimated angular velocity ω1 to the mode changeover switch 16a.

[Current controller 42, 43]
Next, the configuration of the current controllers 42 and 43 shown in FIG. 1 will be described. FIG. 5 is a diagram showing a configuration example of the d-axis side current controller shown in FIG. The current controller 42 has a proportional calculator 42A, an integral calculator 42B, and an adder 42C. The current controller 42 calculates the d-axis voltage command value Vd ^* according to the equation (5). Specifically, the subtractor 11b calculates a deviation between the d-axis current command value Id ^* and the d-axis current detection value Idc input from a host device (not shown) including a host controller or the magnetic flux controller 15. Output. In the current controller 42, the result of the proportional calculation unit 42A multiplying the output value of the subtractor 11b by the proportional gain Kpd and the integral calculation unit 42B multiplying the output value of the subtractor 11b by the integral gain Kid to perform integration processing. The result is added to calculate the d-axis voltage command value Vd ^* . Then, the current controller 42 outputs the d-axis voltage command value Vd ^* to the dq / 3φ converter 4.

FIG. 6 is a diagram showing a configuration example of the q-axis side current controller shown in FIG. The current controller 43 has a proportional calculator 43A, an integral calculator 43B, and an adder 43C. The current controller 43 calculates the q-axis voltage command value Vq ^* according to the equation (6). Specifically, the subtractor 11c calculates the deviation between the q-axis current command value Iq ^* and the q-axis current detection value Iqc input from the host device (not shown), the speed controller 14 or the magnetic flux controller 15. Output. In the current controller 43, the proportional calculation unit 43A multiplies the output value of the subtractor 11c by the proportional gain Kpq, and the integral calculation unit 43B multiplies the output value of the subtractor 11c by the integral gain Kiq to perform integration processing. The result is added to calculate the q-axis voltage command value Vq ^* . Then, the current controller 43 outputs the q-axis voltage command value Vq ^* to the dq / 3φ converter 4.

[Speed controller 14]
Next, the configuration of the speed controller 14 shown in FIG. 1 will be described. FIG. 7 is a diagram showing a configuration example of the speed controller shown in FIG. The speed controller 14 has a proportional calculator 14A, an integral calculator 14B, and an adder 14C. When the control modes are the position sensorless first mode and the position sensorless second mode, the speed controller 14 calculates the q-axis current command value Iq ^* according to the equation (7).

Specifically, since the mode changeover switch 16a is connected to the C terminal and the D terminal, the estimated angular velocity ω1 is input to the subtractor 11d from the magnetic flux estimator 10 via the mode changeover switch 16a. The subtractor 11d subtracts the estimated angular velocity ω1 from the angular velocity command value ω ^* input from a higher-level device (not shown), and outputs the result of the subtraction to the velocity controller 14. In the speed controller 14, the proportional calculation unit 14A multiplies the output value of the subtractor 11d by the proportional gain Kpa, and the integral calculation unit 14B multiplies the output value of the subtractor 11d by the integral gain Kia to perform integration processing. The result is added to calculate the q-axis current command value Iq ^* . Then, the speed controller 14 outputs the q-axis current command value Iq ^* to the subtractor 11c.

[Magnetic flux controller 15]
Next, the configuration of the magnetic flux controller 15 shown in FIG. 1 will be described. FIG. 8 is a diagram showing a configuration example of the magnetic flux controller shown in FIG. The magnetic flux controller 15 has a proportional calculator 15A, an integral calculator 15B, and an adder 15C. When the control modes are the synchronous magnetic flux mode and the position sensorless second mode, the magnetic flux controller 15 calculates the current command value I0 ^* according to the equation (8). Specifically, the subtractor 11e calculates and outputs a deviation between the magnetic flux command value Φ ^* input from a higher-level device (not shown) and the estimated magnetic flux Φ1. In the magnetic flux controller 15, the proportional calculation unit 15A multiplies the output value of the subtractor 11e by the proportional gain Kpf, and the integral calculation unit 15B multiplies the output value of the subtractor 11e by the integral gain Kif to perform integration processing. The current command value I0 ^* is calculated by adding the result and the result.

When the control mode is the synchronous magnetic flux mode, the mode changeover switch 16c connects the output side of the magnetic flux controller 15 to the B terminal. In this case, the magnetic flux controller 15 outputs the current command value I0 ^* as the q-axis current command value Iq ^* to the subtractor 11c via the mode changeover switch 16b. When the control mode is the position sensorless second mode, the mode changeover switch 16c connects the output side of the magnetic flux controller 15 to the D terminal. In this case, the magnetic flux controller 15 outputs the current command value I0 ^* to the subtractor 11b as the d-axis current command value Id ^* .

[Control Method of Motor Control Device 1 for Permanent Magnet Motor 6]
Next, the operation of the motor control device 1 when starting the permanent magnet motor 6 will be described. FIG. 9 is a simplified diagram showing the transition of each control mode when the motor control device shown in FIG. 1 starts the permanent magnet motor and thereafter. FIG. 10 is a flowchart showing the procedure of the switching operation by the mode changeover switch shown in FIG.

As described above, the control modes in the first embodiment include the four modes of the synchronous current mode, the synchronous magnetic flux mode, the position sensorless first mode, and the position sensorless second mode. The synchronous current mode is a mode in which the voltage applied to the permanent magnet motor 6 is determined according to the d-axis current command value Id ^* and the q-axis current command value Iq ^* . The synchronous magnetic flux mode is a mode in which the voltage applied to the permanent magnet motor 6 is determined according to the d-axis current command value Id ^* and the magnetic flux command value Φ ^* . The position sensorless first mode is a mode in which the voltage applied to the permanent magnet motor 6 is determined according to the d-axis current command value Id ^* and the angular velocity command value ω ^* . The second position sensorless mode is a mode in which the voltage applied to the permanent magnet motor 6 is determined according to the magnetic flux command value Φ ^* and the angular velocity command value ω ^* .

In these control modes, any one of the d-axis current command value Id ^* , the q-axis current command value Iq ^* , the angular velocity command value ω ^*, and the magnetic flux command value Φ ^* is changed, or the mode change switch is used. By switching 16a to 16c, a transition is made to another control mode. It should be noted that all of the mode changeover switches 16a to 16c are switched at the same timing unless otherwise specified.

As shown in FIG. 9, after the power conversion circuit 5 starts applying the voltage to the permanent magnet motor 6, the control unit 2 sets the connection destination of the mode changeover switches 16a to 16c to the A terminal. As a result, the control mode becomes the synchronous current mode. As shown in FIG. 10, until the time t reaches the time T1, the control unit 2 maintains the connection destination of the mode changeover switches 16a to 16c at the A terminal (steps S1 and S2). Time T1 is the time when the angular velocity command value ω ^* reaches the angular velocity command value in the synchronous magnetic flux mode.

In the synchronous current mode, the control unit 2 increases the d-axis current command value Id ^* so that torque corresponding to the acceleration torque and the load torque is generated, and then sets the d-axis current command value Id ^* to a constant value. .. The control unit 2 also sets the q-axis current command value Iq ^* to zero. The motor control device 1 increases the angular velocity command value ω ^* after the d-axis current command value Id ^* increases to a constant value. As a result, the permanent magnet motor 6 follows the angular velocity command value ω ^* and accelerates.

In FIG. 9, when the time t reaches the time T1, the control unit 2 switches the connection destination of the mode changeover switches 16a to 16c from the A terminal to the B terminal. As a result, the control mode changes from the synchronous current mode to the synchronous magnetic flux mode. In the synchronous magnetic flux mode, the magnetic flux controller 15 adjusts the q-axis current command value Iq ^* so that the difference between the magnetic flux command value Φ ^* and the estimated magnetic flux Φ1 becomes zero. As a result, the d-axis estimated magnetic flux Φd1 becomes a value obtained by estimating the total magnetic flux generated in the motor, which is a combination of the permanent magnet interlinkage magnetic flux and the armature reaction magnetic flux, and the direction of this estimated magnetic flux becomes the control axis.

In the synchronous magnetic flux mode, the motor control device 1 sets the d-axis current command value Id ^* to a constant value and also sets the angular velocity command value ω ^* to a constant value. As a result, the permanent magnet motor 6 operates at a constant rotation speed according to the angular velocity command value ω ^* , and the magnetic flux estimator 10 estimates the magnetic flux. As shown in FIG. 10, until the time t reaches the time T2, the control unit 2 maintains the connection destination of the mode changeover switches 16a to 16c at the B terminal (steps S3 and S4). The time T2 is the time required for the control axis to converge in the direction of the total magnetic flux generated by the motor.

In FIG. 9, when the time t reaches the time T2, the control unit 2 switches the connection destination of the mode changeover switches 16a to 16c from the B terminal to the C terminal (steps S5 and S6). As a result, the control mode changes from the synchronous magnetic flux mode to the position sensorless first mode. In the position sensorless first mode, the speed controller 14 adjusts the q-axis current command value Iq ^* so that the difference between the angular speed command value ω ^* and the estimated angular speed ω1 becomes zero.

The q-axis current command value Iq ^* becomes a value corresponding to the acceleration torque component and the load torque component, and the permanent magnet motor 6 accelerates. After that, when the permanent magnet motor 6 finishes accelerating and reaches a constant speed, the q-axis current command value Iq ^* becomes constant at a value corresponding to the load torque. In the position sensorless first mode, the d-axis current command value Id ^* is input to the control unit 2 from another device (not shown) including a host controller.

In FIG. 9, when the angular velocity command value ω ^* becomes larger than the predetermined threshold value ω2 (step S5 shown in FIG. 10), the control unit 2 switches the connection destination of the mode changeover switches 16a to 16c from the C terminal to the D terminal. (Step S7). As a result, the control mode transitions from the position sensorless first mode to the position sensorless second mode. In the position sensorless second mode, the magnetic flux command value Φ ^* is input to the control unit 2 from another device (not shown) including the host controller. The magnetic flux controller 15 adjusts the d-axis current command value Id ^* so that the difference between the input magnetic flux command value Φ ^* and the estimated magnetic flux Φ1 becomes zero.

  The values in the graph shown in FIG. 9 actually vary depending on the load of the permanent magnet motor 6 and the response frequencies of the magnetic flux estimator 10, the current controllers 42 and 43, the speed controller 14, and the magnetic flux controller 15. However, it is omitted to show the fluctuation in the figure.

Note that, with reference to FIG. 9 and FIG. 10, when the time t becomes the time T2, the control mode is switched from the synchronous magnetic flux mode to the position sensorless first mode, but it is switched to the position sensorless second mode. Good. Further, as shown in FIG. 10, the position sensorless first mode and the position sensorless second mode may be switched based on the threshold value ω2. Further, although the control mode is switched from the position sensorless first mode to the position sensorless second mode when the angular velocity command value ω ^* reaches the threshold value ω2, the control mode switching timing is not limited to this case. . Alternatively, this switching process may be performed using the estimated angular velocity ω1 instead of the angular velocity command value ω ^* .

[Characteristics of position sensorless first mode, position sensorless second mode]
The case where the control mode transits to the position sensorless first mode after the synchronous magnetic flux mode has been described with reference to FIGS. 9 and 10, but may transit to the position sensorless second mode after the synchronous magnetic flux mode. In the position sensorless second mode, the permanent magnet motor 6 can be driven at an arbitrary operating point by setting the magnetic flux command value Φ ^* . For example, the permanent magnet motor 6 can be driven at the minimum power point. Further, in the position sensorless second mode, since the speed control and the magnetic flux control are performed on the permanent magnet motor 6, the values of the winding inductance and the induced voltage constant are unnecessary for calculating the applied voltage. . Therefore, changes in the values of the winding inductance and the induced voltage constant and the influence of higher harmonics can be suppressed, and the permanent magnet motor 6 can be driven stably.

On the other hand, the position sensorless second mode is easily affected by variations in the permanent magnet motor and the inverter, and is particularly susceptible to these variations in the low speed rotation range where the motor voltage is low and is easily affected by voltage error. Specifically, the value of the d-axis voltage command value Vd ^* , the d-axis current detection value Idc, and the resistance value R of the primary winding of the permanent magnet motor 6 used in the equation (3) for calculating the d-axis estimated magnetic flux Φd1. For, there is a difference between the value in the calculation formula and the actual value. The estimated d-axis magnetic flux Φd1 is affected by this deviation.

Possible causes of the deviation of the d-axis voltage command value Vd ^* are dead time and variations in the bus voltage detection circuit. Further, variation in the current detection circuit can be considered as a factor of the deviation of the d-axis current detection value Idc. Due to variations in these values, the output voltage of the inverter also varies. Further, the operating point of the permanent magnet motor 6 also varies due to the variation of at least one of the winding inductance and the induced voltage constant of the motor. Due to the influence of variations in the permanent magnet motor and the inverter, the permanent magnet motor 6 becomes unstable and may stop.

  In order to avoid the unstable operation in the low speed rotation range in the position sensorless second mode, in the first embodiment, the position sensorless first mode is applied before the position sensorless second mode. The variation that the position sensorless first mode receives is only the variation of the current detection circuit that causes the deviation of the d-axis current detection value Idc. Therefore, in the position sensorless first mode, it is difficult to be influenced by the variation of the permanent magnet motor and the inverter, and the unstable operation due to the variation of the permanent magnet motor and the inverter in the low speed rotation range can be suppressed. That is, in the position sensorless first mode, stable driving can be realized in the low speed rotation range.

  The motor control device 1 according to the first embodiment detects a power conversion circuit 5 that applies a voltage to the permanent magnet motor 6 corresponding to a voltage command value, and a current supplied from the power conversion circuit 5 to the permanent magnet motor 6. Current detecting means and a control unit 2. The control unit 2 estimates the magnetic flux generated in the current controllers 42 and 43 for calculating the voltage command value corresponding to the current command value and the permanent magnet motor 6. Flux estimator 10 that outputs an estimated magnetic flux that is a value and an estimated angular velocity that is a value that estimates the angular velocity of the permanent magnet motor 6, and a magnetic flux controller 15 that adjusts the current command value so that the estimated magnetic flux becomes the magnetic flux command value. And a speed controller 14 that adjusts the current command value so that the estimated angular velocity becomes the angular velocity command value. The control unit 2 determines whether or not the speed controller 14 is applied to the adjustment of the current command value. The combination of the application and non-application of the magnetic flux controller 15 is switched, the synchronous current mode is switched to the synchronous magnetic flux mode, and then the mode in which the speed controller 14 and the magnetic flux controller 15 are applied is switched.

  According to the first embodiment, after the synchronous magnetic flux mode, transition to the position sensorless second mode in which the current command value is adjusted by the speed control and the magnetic flux control allows the winding inductance to be calculated for the applied voltage. Also, the value of the induced voltage constant becomes unnecessary. As a result, changes in the values of the winding inductance and the induced voltage constant and the influence of higher harmonics can be suppressed, and the permanent magnet motor 6 can be driven stably.

  In the first embodiment, the control unit 2 adjusts the current command value by speed control but not by magnetic flux control after the synchronous magnetic flux mode and before the position sensorless second mode. You may switch to 1 mode. In this case, the permanent magnet motor 6 can be stably driven in the low speed rotation range.

  In the first embodiment, when the control mode changes from the synchronous current mode to the synchronous magnetic flux mode, the magnetic flux controller 15 supplies the q-axis current command value supplied to the current controller 43 so that the estimated magnetic flux becomes the magnetic flux command value. Adjust. In this case, the permanent magnet motor 6 can be controlled with the direction of all magnetic flux generated in the motor as the control axis. As a result, it is possible to smoothly transition from the synchronous magnetic flux mode to the mode in which the speed controller 14 is applied to adjust the current command value.

  In the first embodiment, in the synchronous magnetic flux mode, the magnetic flux estimator 10 calculates the d-axis estimated magnetic flux according to the equation (1), calculates the q-axis estimated magnetic flux according to the equation (2), and calculates the q-axis estimated magnetic flux. Is output to the magnetic flux controller 15 as an estimated magnetic flux. In this case, in the synchronous magnetic flux mode, the estimated magnetic flux calculated by the magnetic flux estimator 10 is reflected in the q-axis current command value.

  In the first embodiment, when the synchronous magnetic flux mode is changed to a mode in which the speed controller 14 is applied to adjust the current command value, the magnetic flux estimator 10 outputs the estimated angular velocity, and the speed controller 14 outputs the estimated angular velocity. The q-axis current command value is adjusted so that the angular velocity command value is obtained. In this case, in the position sensorless first mode and the position sensorless second mode, the q-axis current command value is adjusted so that the angular velocity of the permanent magnet motor 6 follows the angular velocity command value.

  In the first embodiment, in the mode in which the speed controller 14 is applied to adjust the current command value, the magnetic flux estimator 10 multiplies the d-axis current detection value by the resistance value of the primary winding of the permanent magnet motor 6 and Is subtracted from the d-axis voltage command value, and the result of the subtraction is subjected to first-order lag filter processing to calculate the d-axis estimated magnetic flux and output the d-axis estimated magnetic flux as the estimated magnetic flux. In this case, in the position sensorless second mode, the estimated magnetic flux calculated by the magnetic flux estimator 10 is reflected in the d-axis current command value.

  In the first embodiment, in the mode in which the speed controller 14 is applied to the adjustment of the current command value, the magnetic flux estimator 10 multiplies the q-axis current detection value by the resistance value of the primary winding of the permanent magnet motor 6 as a result. Is subtracted from the q-axis voltage command value, and the result of the subtraction is divided by the d-axis estimated magnetic flux to calculate the estimated angular velocity. In this case, the estimated angular velocity calculated by the magnetic flux estimator 10 is reflected in the q-axis current command value.

  In the first embodiment, the d-axis current command value may be input from another device in the mode in which the speed controller 14 is applied to adjust the current command value. In this case, in the position sensorless first mode, the d-axis current command value can be set to an arbitrary value that allows stable driving.

  In the first embodiment, in the mode in which the speed controller 14 is applied to adjust the current command value, the magnetic flux command value is input from another device, and the magnetic flux controller 15 calculates the d-axis estimated magnetic flux and the magnetic flux command value. The d-axis current command value may be adjusted so that the difference becomes zero. In this case, in the position sensorless second mode, the permanent magnet motor 6 can be driven at an arbitrary operating point by setting the magnetic flux command value.

  DESCRIPTION OF SYMBOLS 1 motor control device, 2 control part, 4 dq / 3φ converter, 5 power conversion circuit, 6 permanent magnet motor, 7a, 7b motor current detection means, 8 3φ / dq converter, 9 integrator, 10 magnetic flux estimator, 11b to 11e Subtractor, 14 Speed controller, 14A Proportional calculation unit, 14B Integral calculation unit, 14C Adder, 15 Magnetic flux controller, 15A Proportional calculation unit, 15B Integral calculation unit, 15C Adder, 16a to 16c Mode selector switch , 20 DC voltage source, 21 inverter, 22a to 22c pulse signal, 23 driver circuit, 42, 43 current controller, 42A, 43A proportional calculation unit, 42B, 43B integration calculation unit, 42C, 43C adder.

Claims (9)

A power conversion circuit that applies a voltage to the motor according to the voltage command value,
A current detection unit that outputs a current detection value that is a value obtained by detecting the current supplied to the motor from the power conversion circuit;
A control unit that adjusts the voltage command value,
The control unit is
A current controller that calculates the voltage command value corresponding to the current command value that is the basis of the voltage applied to the motor;
A magnetic flux estimator that outputs an estimated magnetic flux that is a value that estimates a magnetic flux generated in the motor based on the voltage command value and the detected current value, and an estimated angular velocity that is a value that estimates the angular velocity of the motor,
A magnetic flux controller that adjusts the current command value so that the estimated magnetic flux becomes a magnetic flux command value,
A velocity controller that adjusts the current command value so that the estimated angular velocity becomes an angular velocity command value,
The control unit is
As a controller applied to the adjustment of the current command value, switch the combination of the application of the speed controller and the application of the magnetic flux controller,
After switching from the synchronous current mode in which neither the speed controller nor the magnetic flux controller is applied to the synchronous magnetic flux mode in which the speed controller is not applied but the magnetic flux controller is applied, the speed controller and the magnetic flux control Motor control device that switches to the applicable mode. The control unit is
The motor according to claim 1, wherein the synchronous magnetic flux mode is switched to a mode in which the speed controller is not applied but the speed controller is applied before switching to the mode in which the speed controller and the magnetic flux controller are applied. Control device. The control unit calculates a d-axis current detection value and a q-axis current detection value as the current detection value based on the current supplied to the motor detected by the current detection unit,
The current controller calculates a d-axis voltage command value and a q-axis voltage command value as the voltage command value, corresponding to the d-axis current command value and the q-axis current command value input as the current command value,
When the control unit switches from the synchronous current mode to the synchronous magnetic flux mode,
The magnetic flux controller is
The motor control device according to claim 1, wherein the q-axis current command value supplied to the current controller is adjusted so that the estimated magnetic flux becomes the magnetic flux command value. The magnetic flux estimator is
In the synchronous magnetic flux mode, a value obtained by multiplying the d-axis current detection value by the resistance value of the primary winding of the motor is subtracted from the d-axis voltage command value, and the result of the subtraction is the angular velocity command value and the q-axis The product of the estimated magnetic flux and the q-axis estimated magnetic flux is added, and the result of the addition is subjected to first-order lag filter processing to calculate the d-axis estimated magnetic flux that is the estimated magnetic flux on the d-axis.
A value obtained by multiplying the q-axis current detection value by the resistance value of the primary winding is subtracted from the q-axis voltage command value, and the subtraction result is multiplied by the angular velocity command value and the d-axis estimated magnetic flux. 4. The q-axis estimated magnetic flux is calculated by subtracting the ones and subjecting the result of the subtraction to first-order lag filter processing, and the q-axis estimated magnetic flux is output to the magnetic flux controller as the estimated magnetic flux. Motor control device. The control unit calculates a d-axis current detection value and a q-axis current detection value as the current detection value based on the current supplied to the motor detected by the current detection unit,
The current controller calculates a d-axis voltage command value and a q-axis voltage command value as the voltage command value, corresponding to the d-axis current command value and the q-axis current command value input as the current command value,
When the control unit switches from the synchronous magnetic flux mode to a mode in which the speed controller is applied, the magnetic flux estimator outputs the estimated angular velocity,
The speed controller is
The motor control device according to claim 1, wherein the q-axis current command value is adjusted so that the estimated angular velocity becomes the angular velocity command value. In the mode in which the speed controller is applied,
The magnetic flux estimator is
The d-axis estimated magnetic flux is calculated by subtracting a value obtained by multiplying the detected d-axis current value by the resistance value of the primary winding of the motor from the d-axis voltage command value, and performing a first-order lag filter process on the subtraction result. The motor control device according to claim 5, which calculates and outputs the d-axis estimated magnetic flux as the estimated magnetic flux to the magnetic flux controller. In the mode in which the speed controller is applied,
The magnetic flux estimator is
The estimated angular velocity is calculated by subtracting a value obtained by multiplying the q-axis current detection value by the resistance value of the primary winding from the q-axis voltage command value and dividing the result of the subtraction by the d-axis estimated magnetic flux. The motor control device according to claim 6.   The motor control device according to claim 5, wherein the d-axis current command value is input from another device in a mode in which the speed controller is applied. In a mode in which the speed controller is applied, the magnetic flux command value is input from another device,
The magnetic flux controller is
The motor control device according to claim 5, wherein the d-axis current command value is adjusted so that the estimated magnetic flux becomes the magnetic flux command value.

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