WO2019181322A1 - Motor control device and motor control method - Google Patents

Abstract

[Problem] To provide a motor control device and a motor control method with which it is possible to stably control weak magnetic flux even when a sudden change occurs in power supply voltage or speed. [Solution] In this motor control device 100 and motor control method, when a motor voltage value Va exceeds a desired voltage value Va_(ref), a supplemental d-axis current value ΔId that corresponds to a voltage difference ΔV is outputted and a d-axis current command value Id^* is made to increase in the negative direction to reduce the motor voltage value Va. Additionally, in this motor control device 100 and motor control method, further to the above configuration, a q-axis current command value correction unit 468 reduces the absolute value of a q-axis current command value Iq^**. This makes it possible to further reduce the motor voltage value Va. Moreover, this makes it possible to quickly eliminate a state in which the motor voltage value Va exceeds the desired voltage value Va_(ref), and to control weak magnetic flux in a continuous and stable manner even with respect to a sudden reduction in a power supply voltage Vdc and/or a sudden change in electric angular velocity ω.

Description

Motor control device and motor control method

The present invention relates to a motor control device and a motor control method capable of stably performing flux-weakening control in PM motor control.

Electric motors are used as a power source for many home appliances and mechanical equipment. Among these, a PM (Permanent Magnet) motor (permanent magnet motor) that provides a permanent magnet on the rotor side, an armature winding on the stator side, and rotates the rotor by controlling the magnetic field of the armature winding. ) Is low loss and high efficiency because there is no field loss, and is often used in large-scale machinery due to the recent trend of energy saving. As a control method of this PM motor, in the operation region of medium / low speed rotation, operation control is performed by sine wave control (PWM control) using a sine wave pattern with high motor efficiency, and the operation region of high speed rotation / high torque. Then, it is common to perform operation control by rectangular wave control using a rectangular wave pattern with a high output voltage and high output.

However, since the permanent magnet has a constant magnetic flux, the counter electromotive force increases as the rotational speed increases. When the permanent magnet reaches a certain rotational speed, the counter electromotive force becomes equal to the applied voltage of the motor and no more current can flow. For this reason, in the high-speed rotation region of the sine wave control in which this phenomenon occurs, current is passed through the armature winding to generate a magnetic flux in the direction opposite to that of the permanent magnet, and the weakening magnetic flux control is performed to reduce the counter electromotive force. Is common. As an example of such a weak flux control, the following [Patent Document 1] discloses a technique for performing a torque control by calculating a torque of a motor by calculation and performing a weak flux control by manipulating a voltage phase at this time. Yes.

Japanese Patent Laid-Open No. 11-299297

In the invention described in [Patent Document 1], a low-pass filter is used to generate a correction value for reducing the deviation between the torque command value and the torque estimation value. Thereby, a rapid change in the correction value can be suppressed. However, when a low-pass filter is used, there may be a delay in response, and further improvement is desired.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a motor control device and a motor control method capable of stably weakening magnetic flux control even when a sudden change occurs in a power supply voltage or a rotation speed. .

(1) In a motor control device including at least a sine wave control unit 40 for controlling the PM motor 10 with a sine wave PWM,
The sine wave control unit 40 includes:
A torque calculator 404 for calculating a torque value T of the PM motor 10;
A current command value setting unit 402 for setting a current command value Ia ^* based on an external torque command value T ^* and the torque value T;
A current command value generation unit 406 that generates a d-axis current command value Id ^** and a q-axis current command value Iq ^** based on the current command value Ia ^* ;
A voltage command value generation unit 416 that generates a d-axis voltage command value Vd and a q-axis voltage command value Vq based on the d-axis current command value Id ^** and the q-axis current command value Iq ^** .
The current command value generation unit 406
A sin unit 464A that generates a d-axis current command value Id ^* that is a source of the d-axis current command value Id ^** ;
A cos unit 464B that generates a q-axis current command value Iq ^* that is a source of the q-axis current command value Iq ^** ;
A phase angle setting unit 462 that sets a current phase angle θi _(base) that outputs a maximum torque at the current command value Ia ^* and outputs the current phase angle to the sin unit 464A and the cos unit 464B;
A voltage difference calculation unit that calculates a voltage difference ΔV based on a motor voltage value Va of the PM motor 10 and a target voltage value Va _(ref) that is the maximum voltage value at which the PM motor 10 can stably operate. 408,
An additional d-axis current value generation unit 466 that calculates an additional d-axis current command value ΔId that increases the d-axis current command value Id ^* in the negative direction based on the voltage difference ΔV;
By providing a motor control device 100, comprising: a q-axis current command value correction unit 468 that decreases the absolute value of the q-axis current command value Iq ^* based on the voltage difference ΔV. To solve.
(2) By adding the predetermined offset value a to the voltage difference ΔV and outputting the sum to the q-axis current command value correction unit 468, the motor control device 100 according to (1) above is provided. To solve.
(3) The q-axis current command value correction unit 468a sets the additional current phase angle Δθi based on the voltage difference ΔV, and the cos unit 464B adds the current phase angle θi _(base) and the additional current phase angle Δθi. The above problem is solved by providing the motor control device 100 according to (1) or (2), wherein the q-axis current command value Iq ^* is generated based on the corrected phase angle θi.
(4) The q-axis current command value correction unit 468a sets the additional current phase angle Δθi based on the voltage difference ΔV, and the sin unit 464A and the cos unit 464B determine the current phase angle θi _(base) and the additional current phase angle. The motor control device 100 according to (1) or (2) above, wherein the d-axis current command value Id ^* and the q-axis current command value Iq ^* are generated based on the corrected phase angle θi added to Δθi. By providing the above, the above-described problems are solved.
(5) The voltage difference calculation unit 408c includes a target voltage value calculation unit 484 that calculates the target voltage value Va _(ref), and a motor voltage value calculation unit 482b that calculates the motor voltage value Va,
The voltage difference ΔV is calculated based on the target voltage value Va _(ref) calculated by the target voltage value calculation unit 484 and the motor voltage value Va calculated by the motor voltage value calculation unit 482b (1) ) To (4) to provide the motor control device 100 according to any one of the above-described problems.
(6) The voltage difference calculation unit 408a determines the voltage difference based on the preset target voltage value Va _(ref) and the d-axis voltage command value Vd and q-axis voltage command value Vq generated by the voltage command value generation unit 416. The above problem is solved by providing the motor control device 100 according to any one of (1) to (4), wherein ΔV is calculated.
(7) The sine wave control unit 40 further includes a polar coordinate conversion unit 418 that generates the motor voltage value Va based on the d-axis voltage command value Vd and the q-axis voltage command value Vq,
The voltage difference calculation unit 408b calculates the voltage difference ΔV based on the preset target voltage value Va _(ref) and the motor voltage value Va generated by the polar coordinate conversion unit 418 (1) ) To (4) to provide the motor control device 100 according to any one of the above-described problems.
(8) A d-axis low-pass filter 490A to which the d-axis current command value Id ^** and the q-axis current command value Iq ^** from the current command value generation unit 406 are input respectively, and a q-axis low-pass filter 490B. ,
The d-axis low pass filter 490A and the q-axis low pass filter 490B, as well as rapidly transmitted when the absolute value of the q-axis current command value ^{Iq **} is decreased, the absolute value of the q-axis current command value ^{Iq **} is increased When the absolute value of the d-axis current command value Id ^** increases, it is transmitted quickly, and when the absolute value of the d-axis current command value Id ^** decreases. By providing the motor control device 100 according to any one of the above (1) to (7), the decrease rate is delayed from the increase rate of the q-axis current command value Iq ^** , whereby the above problem is solved. Resolve.
(9) the q-axis current command value correcting portion 468b is set based additional q-axis current command value ΔIq to reduce the absolute value of q-axis current command value Iq ^* to the voltage difference [Delta] V, q-axis current command value Iq ^* By adding the motor control device 100 according to the above (1) or (2), the above-mentioned problem is solved.
(10) A d-axis low-pass filter 490A to which the d-axis current command value Id ^** and the q-axis current command value Iq ^** from the current command value generation unit 406 are input respectively, and a q-axis low-pass filter 490B. ,
The d-axis low pass filter 490A and the q-axis low pass filter 490B, as well as rapidly transmitted when the absolute value of the q-axis current command value ^{Iq **} is decreased, the absolute value of the q-axis current command value ^{Iq **} is increased When the absolute value of the d-axis current command value Id ^** increases, it is transmitted quickly, and when the absolute value of the d-axis current command value Id ^** decreases. The above problem is solved by providing the motor control device 100 according to the above (9), characterized in that the decreasing speed is delayed from the increasing speed of the q-axis current command value Iq ^** .
(11) A motor control method for a motor control device including at least a sine wave control unit 40 for controlling the PM motor 10 with a sine wave PWM,
The sine wave control unit 40 includes:
A torque calculating step for calculating a torque value T of the PM motor 10;
A current command value setting step for setting a current command value Ia ^* based on an external torque command value T ^* and the torque value T;
A dq current command value generation step for generating a d-axis current command value Id ^** and a q-axis current command value Iq ^** based on the current command value Ia ^* ;
A voltage command value generation step for generating a d-axis voltage command value Vd and a q-axis voltage command value Vq based on the d-axis current command value Id ^** and the q-axis current command value Iq ^** ,
The dq current command value generation step includes:
A d-axis current command value generation step for generating a d-axis current command value Id ^* that is a source of the d-axis current command value Id ^** ;
A q-axis current command value generating step for generating a q-axis current command value Iq ^* that is a source of the q-axis current command value Iq ^** ;
A phase angle setting step for setting a current phase angle θi _(base) that is used in the d-axis current command value generation step and the q-axis current command value generation step and outputs a maximum torque at the current command value Ia ^* ; ,
Voltage difference calculation step of calculating a voltage difference ΔV based on the motor voltage value Va of the PM motor 10 and the target voltage value Va _(ref) which is the maximum voltage value at which the PM motor 10 can stably operate. When,
An additional d-axis current value generation step of calculating an additional d-axis current command value ΔId that increases the d-axis current command value Id ^* in the negative direction based on the voltage difference ΔV;
A q-axis current command value correcting step for reducing an absolute value of the q-axis current command value Iq ^* based on the voltage difference ΔV. To do.
(12) The above-mentioned problem is solved by providing the motor control method according to (11) above, wherein a q-axis current command value correction step is performed by adding a predetermined offset value a to the voltage difference ΔV. .
(13) The q-axis current command value correction step sets the additional current phase angle Δθi based on the voltage difference ΔV, and the q-axis current command value generation step includes the current phase angle θi _(base) and the additional current phase angle Δθi. The motor control method described in (11) or (12) above is generated by generating the q-axis current command value Iq ^* based on the corrected phase angle θi obtained by combining To do.
(14) The q-axis current command value correction step sets the additional current phase angle Δθi based on the voltage difference ΔV, and the d-axis current command value generation step and the q-axis current command value generation step include the current phase angle θi _{(base). )} And the additional current phase angle Δθi are added together to generate the d-axis current command value Id ^* and the q-axis current command value Iq ^* (11) or (12) The above-mentioned problem is solved by providing the motor control method described in 1.
(15) The voltage difference calculation step includes a target voltage value calculation step for calculating the target voltage value Va _(ref), and a motor voltage value calculation step for calculating the motor voltage value Va,
The voltage difference ΔV is calculated based on the target voltage value Va _(ref) calculated in the target voltage value calculating step and the motor voltage value Va calculated in the motor voltage value calculating step. The problem is solved by providing the motor control method according to any one of (14).
(16) The voltage difference calculation step calculates the voltage difference ΔV based on the preset target voltage value Va _(ref) , the d-axis voltage command value Vd generated in the voltage command value generation step, and the q-axis voltage command value Vq. The problem is solved by providing the motor control method according to any one of (11) to (14), wherein the motor control method is calculated.
(17) The sine wave control unit 40 further includes a polar coordinate conversion unit 418 that generates the motor voltage value Va based on the d-axis voltage command value Vd and the q-axis voltage command value Vq,
The voltage difference calculating step calculates the voltage difference ΔV based on the preset target voltage value Va _(ref) and the motor voltage value Va generated by the polar coordinate converter 418 (11) The problem is solved by providing the motor control method according to any one of (14) to (14).
(18) The d-axis low-pass filter 490A and the q-axis low-pass filter 490B to which the d-axis current command value Id ^** and the q-axis current command value Iq ^** generated in the dq current command value generation step are respectively input Have
The d-axis low pass filter 490A and the q-axis low pass filter 490B, as well as rapidly transmitted when the absolute value of the q-axis current command value ^{Iq **} is decreased, the absolute value of the q-axis current command value ^{Iq **} is increased When the absolute value of the d-axis current command value Id ^** increases, it is transmitted quickly, and when the absolute value of the d-axis current command value Id ^** decreases. The motor control method according to any one of the above (11) to (17), wherein the decrease speed is delayed from the increase speed of the q-axis current command value Iq ^** , thereby solving the above problem. To do.
(19) the q-axis current command value correcting step, and set based on additional q-axis current command value ΔIq reduce the q-axis current command value Iq ^* of the absolute value of the voltage difference [Delta] V, the q-axis current command value Iq ^* By adding the motor control method according to the above (11) or (12), the above-mentioned problem is solved.
(20) A d-axis low-pass filter 490A and a q-axis low-pass filter 490B to which the d-axis current command value Id ^** and the q-axis current command value Iq ^** generated in the dq current command value generation step are respectively input Have
The d-axis low pass filter 490A and the q-axis low pass filter 490B, as well as rapidly transmitted when the absolute value of the q-axis current command value ^{Iq **} is decreased, the absolute value of the q-axis current command value ^{Iq **} is increased When the absolute value of the d-axis current command value Id ^** increases, it is transmitted quickly, and when the absolute value of the d-axis current command value Id ^** decreases. The problem is solved by providing the motor control method according to the above (19), characterized in that the decreasing speed is delayed from the increasing speed of the q-axis current command value Iq ^** .

When the motor voltage value Va exceeds the target voltage value Va _(ref) , the motor control device and motor control method according to the present invention outputs an additional d-axis current value ΔId corresponding to the voltage difference ΔV to output the d-axis current. The command value Id ^* is increased in the negative direction, and the motor voltage value Va is decreased. As a result, the PM motor 10 can be operated at a motor voltage value Va that can be stably controlled and has a maximum torque. In addition to the above-described configuration, the motor control device and the motor control method according to the present invention include a q-axis current command value correction unit that decreases the absolute value of the q-axis current command value Iq ^** . Thereby, the motor voltage value Va can be further reduced. As a result, a margin for controlling the motor current can be further ensured, and stable flux-weakening control can be performed continuously against a sudden drop in the power supply voltage Vdc and fluctuations in the electrical angular velocity ω.

1 is an overall block diagram of a motor control device according to the present invention. It is a block diagram of the characteristic part of the motor control apparatus which concerns on this invention. It is a figure which shows the other example of the voltage difference calculation part of the motor control apparatus which concerns on this invention. It is a figure which shows the other example of the voltage difference calculation part of the motor control apparatus which concerns on this invention. It is a figure which shows the other example of the electric current command value production | generation part of the motor control apparatus which concerns on this invention. It is a figure which shows the other example of the electric current command value production | generation part of the motor control apparatus which concerns on this invention.

Embodiments of a motor control device 100 and a motor control method according to the present invention will be described with reference to the drawings. Here, FIG. 1 is an overall block diagram of a motor control apparatus 100 according to the present invention. A motor control device 100 according to the present invention controls the operation of a PM motor (permanent magnet motor) 10 and includes at least a sine wave control unit 40 that controls the PM motor 10 with sine wave PWM. The motor control device 100 to which the present invention is applied includes an inverter 20 that causes the three-phase AC drive currents Iu, Iv, and Iw to flow down to the PM motor 10 as other basic configurations, and the drive currents Iu, Iv, ( Drive current detectors 12u, 12v for acquiring the value of Iw), angle detector 14 for acquiring the electrical angle θ of the PM motor 10, and drive currents Iu, Iv, (Iw) acquired by the drive current detectors 12u, 12v. ) To a d-axis feedback current value Id and a q-axis feedback current value Iq, and a rectangular shape based on a torque command value T ^* instructed from the outside (such as a high-order control unit of the system). The well-known rectangular wave control unit 50 that generates the d-axis voltage command value Vd and the q-axis voltage command value Vq in the wave control mode, and the sine wave control unit 40 and the rectangular wave control unit 5 control the PM motor 10. The d-axis voltage command value Vd and the q-axis voltage command value Vq output from the switching unit 24 and the sine wave control unit 40 or the rectangular wave control unit 50 are converted into the U-phase, V-phase, and W-phase three-phase voltage commands. Dq / 3-phase converter 32 that converts the values Vu, Vv, and Vw, and three-phase voltage command values Vu, Vv, and Vw and a triangular wave having a predetermined period to compare the drive signals Su, Sv, And a drive signal generation unit 36 that generates Sw. The dq / 3-phase conversion unit 32 and the drive signal generation unit 36 constitute a control signal generation unit 30.

The inverter 20 constituting the motor control device 100 performs a switching operation by Hi-Low drive signals Su, Sv, Sw output from the drive signal generation unit 36, and generates DC power from a known DC power supply unit 18 such as a battery. It is converted into a three-phase AC voltage based on the drive signals Su, Sv, Sw and output. As a result, the three-phase drive currents Iu, Iv, and Iw flow down through the armature winding of the PM motor 10 with a phase shifted by 1/3 period (2 / 3π (rad)).

The PM motor 10 is provided with a permanent magnet on the rotor side as described above, and a three-phase armature winding on the stator side, and the drive current Iu, By causing Iv and Iw to flow down respectively, the magnetic poles and magnetic flux of each armature winding are continuously changed to rotate the rotor. The PM motor 10 is preferably an IPM (Interior Permanent Magnet) motor in which a permanent magnet is embedded in a rotor.

The PM motor 10 is preferably provided with a known cooling mechanism 101. Here, the cooling mechanism 101 is provided around the PM motor 10, for example, a water jacket 102 that cools the PM motor 10 by flowing down the cooling water, and a pump unit 104 that circulates the cooling water flowing down to the water jacket 102. And a heat exchanging means 106 such as a radiator for cooling the cooling water by a predetermined heat exchange, and a known temperature obtaining means 108 for obtaining the water temperature of the cooling water. The cooling water of the cooling mechanism 101 is preferably used for cooling the PM motor 10 and cooling the power elements (switching elements) in the inverter 20. Moreover, the temperature acquisition means 108 acquires the temperature (estimated temperature) of the permanent magnet of the PM motor 10 indirectly by the coolant temperature Temp, and preferably acquires the water temperature after cooling the inverter 20. . According to this configuration, the temperature acquisition unit 108 can be installed in the vicinity of the inverter 20, and the signal wiring of the temperature acquisition unit 108 can be shortened. As a result, the signal wiring can be easily routed and the reliability against disconnection can be improved. Further, by acquiring the estimated temperature of the permanent magnet from the coolant temperature Temp after cooling the inverter 20, the influence of the temperature change of the armature winding of the PM motor 10 whose temperature increases or decreases in the short term can be reduced. . Further, the water temperature Temp acquired by the temperature acquisition means 108 is input to the induced voltage constant correction unit 110, and the induced voltage constant correction unit 110 indirectly acquires the estimated temperature of the permanent magnet of the PM motor 10 from the input water temperature Temp. The induced voltage constant φa of the PM motor 10 is corrected by the estimated temperature of the permanent magnet and output. At this time, the induced voltage constant correcting unit 110 preferably outputs induced voltage constants φa _(T) and φa _(Va) having different estimated temperatures for torque calculation and voltage calculation.

Also, the drive current detection units 12u and 12v can use known current sensors that can acquire the drive currents Iu, Iv, and Iw that flow down by the switching operation of the inverter 20 in a non-contact manner. In this example, two drive currents Iu and Iv out of the drive currents Iu, Iv and Iw are acquired and converted into d-axis and q-axis feedback current values Id and Iq.

Further, as the angle detection unit 14, a known angle sensor capable of acquiring the rotor angle can be used. In particular, it is particularly preferable to acquire the electrical angle θ of the PM motor 10 using a resolver rotation angle sensor. The electrical angle θ and the drive currents Iu and Iv are preferably acquired at both the apex and trough timings of the triangular wave and used in each part of the motor control device 100 every half cycle of the triangular wave. The electrical angle θ acquired by the angle detection unit 14 is also output to the angular velocity calculation unit 16, and the angular velocity calculation unit 16 calculates the electrical angular velocity ω (rad / s) from the input electrical angle θ, and the motor control device 100. Output to each part of.

In addition, the three-phase / dq conversion unit 22 is configured such that the drive currents Iu, Iv, (Iw) acquired by the drive current detection units 12u, 12v based on the electrical angle θ (rad) of the PM motor 10 acquired by the angle detection unit 14. The three-phase two-phase conversion and the rotational coordinate conversion are performed on the value of the drive current Iu, Iv, (Iw) to the d-axis current value (magnetic flux current value) Id and the q-axis current value (torque current value) Iq. Convert. These are output to the switching unit 24 as a d-axis feedback current value Id and a q-axis feedback current value Iq.

The switching unit 24 is a switching circuit that switches the generation method of the d-axis voltage command value Vd and the q-axis voltage command value Vq in accordance with the operation status (torque, rotation speed) of the PM motor 10. When operating at a low speed, the PM motor 10 is operated in the sine wave control mode by the sine wave control unit 40. When the PM motor 10 operates at a predetermined high rotation speed and high torque, the control of the PM motor 10 is switched to the rectangular wave control unit 50 and is operated in the rectangular wave control mode.

Further, the rectangular wave control unit 50 calculates the torque T of the PM motor 10 from the d-axis feedback current value Id and the q-axis feedback current value Iq, and uses this torque T and a torque command value T ^* instructed from the outside. Based on this, the d-axis voltage command value Vd and the q-axis voltage command value Vq are generated by a well-known method and output to the control signal generation unit 30 via the switching unit 24. At this time, the voltage command value | Va | in the rectangular wave control mode and carrier setting information Sc described later may be output to the control signal generation unit 30.

Next, the sine wave control unit 40 includes a current command value setting unit 402, a torque calculation unit 404, a current command value generation unit 406, a voltage difference calculation unit 408, and a voltage command value generation unit 416 as basic configurations. Have as. The sine wave control unit 40 includes a polar coordinate conversion unit 418 and a synchronization control unit 419.

The voltage command value generation unit 416 constituting the sine wave control unit 40 includes a d-axis current command value Id ^** and a q-axis current command value Iq ^** input from the current command value generation unit 406 and a three-phase / dq conversion unit 22. Based on the d-axis feedback current value Id and the q-axis feedback current value Iq input from, the well-known arithmetic processing is performed to generate the d-axis voltage command value Vd and the q-axis voltage command value Vq, which are controlled via the switching unit 24. It outputs to the signal generation part 30 (voltage command value generation step).

Further, the polar coordinate conversion unit 418 generates d-axis and q-axis voltage command values Vd and Vq generated by the voltage command value generation unit 416 (the values generated by the output values of the well-known current integration control and the non-interference control and the values based on the current proportional control). Polar coordinate conversion is performed on the pre-added one to obtain the voltage phase θv and the voltage command value | Va |. Then, the polar coordinate conversion unit 418 outputs the voltage phase θv to the synchronization control unit 419. When the control signal generation unit 30 includes the linear correction unit 38, the voltage command value | Va | is output to the linear correction unit 38, and the d-axis and q-axis voltage command values Vd and Vq and the voltage command value | Va are output. You may make it correct | amend nonlinearity with | and the fundamental wave component of an inverter output voltage.

Further, the synchronization control unit 419 generates triangular wave carrier setting information Sc from the voltage phase θv, the electrical angular velocity ω, and the electrical angle θ obtained by the polar coordinate conversion unit 418, and outputs them to the triangular wave generation unit 34 of the drive signal generation unit 36. To do. The carrier setting information Sc is used to maintain the frequency of the triangular wave generated by the triangular wave generating unit 34 in an appropriate state.

The dq / 3-phase converter 32 constituting the control signal generator 30 includes the d-axis and q-axis voltage command values Vd and Vq, the electrical angle θ from the angle detector 14, and the angular velocity calculator 16. An electrical angular velocity ω is input, and based on the electrical angle θ and the electrical angular velocity ω, a predicted electrical angle θ ′ at a new timing at which the inverter 20 performs a switching operation is calculated, and a d-axis is calculated based on the predicted electrical angle θ ′. , Q-axis voltage command values Vd, Vq are converted into three-phase voltage command values Vu, Vv, Vw and output to the drive signal generator 36.

Further, the drive signal generation unit 36 has a triangular wave generation unit 34. The above-described carrier setting information Sc is input to the triangular wave generation unit 34, and a triangular wave having a period based on the carrier setting information Sc is generated. . Then, the drive signal generator 36 compares the triangular wave with the three-phase voltage command values Vu, Vv, and Vw, respectively. As a result, Hi-Low drive signals Su, Sv, Sw are generated.

The inverter 20 is turned on and off by the drive signals Su, Sv, Sw output from the drive signal generator 36, and the DC power from the DC power supply unit 18 is based on the drive signals Su, Sv, Sw. Convert to AC voltage and output. As a result, AC drive currents Iu, Iv, and Iw having phases shifted by 1/3 period (2 / 3π (rad)) flow down to the armature winding of the PM motor 10, respectively. As a result, the PM motor 10 rotates with a torque corresponding to the torque command value T ^* .

Next, the configuration of the current command value setting unit 402, the torque calculation unit 404, the current command value generation unit 406 (406a to 406c), and the voltage difference calculation unit 408 (408a to 408c) constituting the sine wave control unit 40 is shown in FIG. Description will be made with reference to a partially enlarged view shown in FIG. 2 to 6 are partially enlarged views of the block A in FIG.

First, the d-axis and q-axis current command values Id ^** and Iq ^** generated by the current command value generation unit 406 are input to the torque calculation unit 404. Then, the torque calculation unit 404 vector-synthesizes the input d-axis and q-axis current command values Id ^** and Iq ^** , and the absolute value of the current command absolute value | Ia ^** | and the phase angle thereof. The current command phase angle θi ′ is calculated. Then, by referring to a preset inductance map 442, a value of (Ld−Lq) corresponding to the calculated current command absolute value Ia ^** and the current command phase angle θi ′ is acquired. Note that (Ld−Lq) is the difference between the d-axis inductance Ld and the q-axis inductance Lq of the PM motor 10. Further, the torque calculation unit 404 refers to a preset torque correction map 444 and acquires a torque correction value _AT corresponding to the calculated current command absolute value Ia ^** and the current command phase angle θi ′. Further, the induced voltage constant φa _(T) from the induced voltage constant correction unit 110 is input to the torque calculation unit 404. The torque calculation unit 404, these d-axis, q-axis current command value ^Id **, ^{Iq **,} the induced voltage constant _{φa (T), Ld-Lq} , the torque of the PM motor 10 and a torque correction value _{A T} T Is calculated based on the following equation (A), for example.
T = P (A _T φa _(T) Iq ^** + (Ld−Lq) Id ^** Iq ^** ) [N · m] · (A)
P is the number of pole pairs of the permanent magnet of the PM motor. Then, the torque calculation unit 404 outputs the calculated torque T to the current command value setting unit 402 (torque calculation step).

The torque calculation unit 404 calculates the torque T based on the d-axis and q-axis current command values Id ^** and Iq ^** generated by the current command value generation unit 406. Therefore, the additional d-axis current value generation unit 466 Even when the q-axis current command value correction unit 468 increases or decreases the d-axis and q-axis current command values Id ^* and Iq ^* , the torque of the PM motor 10 can be matched with the torque command value T ^* .

The current command value setting unit 402 includes a torque limiter unit 420, a current command value calculation unit 424, a current limiter unit 422, a torque limit map 420a, and a current limit map 422a. The torque command value T ^* from the outside is First, an input is made to the torque limiter unit 420. The torque limit map 420a and the current limit map 422a are supplied with the power supply voltage Vdc of the DC power supply 18 and the electrical angular velocity ω of the PM motor 10, and the torque limit map 420a is operated at the input power supply voltage Vdc and electrical angular velocity ω. An upper limit torque limit value that can be stably controlled is selected from a preset data map, and is output to the torque limiter unit 420. When the input torque command value T ^* exceeds the torque limit value, the torque limiter unit 420 limits the torque command value T ^* to this torque limit value. The torque command value T ^* is subtracted from the torque T input from the torque calculation unit 404, and the difference ΔT is input to the current command value calculation unit 424.

The current limit map 422a selects an upper limit current limit value that can be stably controlled during operation at the input power supply voltage Vdc and electrical angular velocity ω from a preset data map, and the current command value calculation unit 424 and current Output to the limiter unit 422.

Then, the current command value calculation unit 424 performs well-known integral control, proportional control, etc. on the input difference ΔT to generate a current command value Ia ^* . In this case, the integration control is limited by the above-described current limit value. The calculated current command value Ia ^* is output to the current limiter unit 422. When the input current command value Ia ^* exceeds the current limit value, the current command value Ia ^* is limited to this current limit value. It outputs to the production | generation part 406 (current command value setting step).

Next, configurations of the current command value generation unit 406 and the voltage difference calculation unit 408, which are characteristic configurations of the present invention, will be described. First, the voltage difference calculation unit 408a according to the first embodiment will be described with reference to FIG. The voltage difference calculation unit 408a of the first embodiment shown in FIG. 2 has a target voltage value setting unit 480. The target voltage value setting unit 480 has a target voltage value Va _(ref) acquired in advance by actual measurement or the like. Is set for each voltage utilization rate K. The target voltage value Va _(ref) is the maximum voltage value that can be stably operated when the PM motor 10 is operated at the voltage utilization factor K.

Further, the voltage difference calculation unit 408a has a motor voltage value calculation unit 482a of the first form, and the motor voltage value calculation unit 482a of the first form has a d generated by the voltage command value generation unit 416. The shaft voltage command value Vd and the q-axis voltage command value Vq are input. Then, the motor voltage value calculation unit 482a calculates the motor voltage value Va based on the following formula.
Va = (Vd ² + Vq ² ) ^1/2
Further, the target voltage value setting unit 480 selects a target voltage value Va _(ref) corresponding to the voltage utilization rate K. The voltage utilization rate K may be set by selecting a voltage utilization rate K corresponding to the power supply voltage Vdc of the DC power supply unit 18 from the voltage utilization rate data map 484b described later.

The voltage difference calculation unit 408a according to the first embodiment subtracts the target voltage value Va _(ref) selected by the target voltage value setting unit 480 from the motor voltage value Va calculated by the motor voltage value calculation unit 482a. A difference ΔV is generated and output to the current command value generation unit 406.

The voltage difference calculation unit 408 directly acquires the voltage command value | Va | calculated by the polar coordinate conversion unit 418 or the like as shown in the voltage difference calculation unit 408b of the second embodiment in FIG. The voltage difference ΔV may be generated.

Further, the voltage difference calculation unit may obtain the target voltage value Va _(ref) and the motor voltage value Va by calculation as shown in the voltage difference calculation unit 408c of the third embodiment in FIG. Here, the voltage difference calculation unit 408c of the third embodiment includes a target voltage value calculation unit 484 that calculates the target voltage value Va _(ref) and a motor voltage value calculation unit of the second embodiment that calculates the motor voltage value Va. 482b. The target voltage value calculation unit 484 receives the power supply voltage Vdc and the d-axis and q-axis current command values Id ^** and Iq ^** . Then, the current command absolute value Ia ^** is calculated based on the following formula.
Ia ^** = (Id ^{** 2} + Iq ^{** 2} ) ^1/2
Then, the voltage drop value V _(drop) corresponding to the calculated current command absolute value Ia ^** is acquired from the voltage drop data map 484a. The voltage drop value V _(drop) is a value of the voltage drop related to the switching element of the inverter 20 that changes according to the flowing current, and the voltage drop data map 484a is created based on the characteristic data sheet of the switching element.

Further, the target voltage value calculation unit 484 acquires the voltage usage rate K corresponding to the input power supply voltage Vdc from the voltage usage rate data map 484b, and calculates the target voltage value Va _(ref) based on the following equation (target _). Voltage value calculation step).
Va _(ref) = K · (Vdc−V _(drop) )

The motor voltage value calculation unit 482b of the second embodiment includes a calculation unit 489 that calculates the motor voltage value Va, an inductance map 488 in which the d-axis inductance Ld and the q-axis inductance Lq are recorded, and a q-axis inductance correction coefficient. Q-axis inductance correction coefficient map 486 in which is recorded. In the q-axis inductance correction coefficient map 486, the coolant temperature Temp acquired by the temperature acquisition unit 108, the voltage command value | Va | calculated by the polar coordinate converter 418, and the winding temperature of the PM motor 10 are displayed. Tc is input, and the water temperature Temp, the voltage command value | Va |, the winding temperature Tc, and the q-axis inductance correction coefficient C _Lq corresponding to the coil temperature Tc are selected from a preset data map and output to the calculation unit 489. The winding temperature Tc can be obtained by providing a temperature sensor such as a thermistor in the armature winding of the PM motor 10, for example.

Further, the d-axis and q-axis current command values Id ^** and Iq ^** are input to the calculation unit 489, and the calculation unit 489 is based on the input d-axis and q-axis current command values Id ^** and Iq ^** . The current command absolute value Ia ^** and the current command phase angle θi ′ are calculated. Then, referring to the inductance map 488, the calculated current command absolute value Ia ^** , the values of the d-axis inductance Ld and the q-axis inductance Lq corresponding to the current command phase angle θi ′ are acquired. At this time, the calculation unit 489 refers to the voltage correction map, obtains a voltage correction value corresponding to the current command absolute value Ia ^** and the current command phase angle θi ′, and corrects the motor voltage value Va. Also good.

In addition, the induced voltage constant φa _(Va) corresponding to the estimated temperature of the magnet of the PM motor 10 and the electrical angular velocity ω of the PM motor 10 are input to the computing unit 489 from the induced voltage constant correcting unit 110, and the computing unit 489. Calculates a motor voltage value Va from these numerical values and a preset armature winding resistance Ra of the PM motor 10 based on the following equation (motor voltage value calculating step). The armature winding resistance Ra may be corrected for temperature based on the winding temperature Tc.
Vd ′ = RaId ^** − ω (C _Lq Lq) Iq ^**
Vq ′ = RaIq ^** + ωφa _(Va) + ωLdId ^**
Va = {(Vd ′) ² + (Vq ′) ² } ^1/2

And the voltage difference calculation part 408c of the 3rd form is Va ₍ calculated by the target voltage value calculation part 484) from the motor voltage value Va calculated by this calculating part 489 (2nd motor voltage value calculation part 482b). _The voltage difference ΔV is calculated by subtracting _ref) (the voltage difference calculation step).

Since the voltage difference calculation unit 408c of the third embodiment has a fast response of the voltage difference ΔV, a d-axis low-pass filter 490A and a q-axis low-pass filter 490B are provided on the output side of the current command value generation unit 406 as shown in FIG. It is preferable that the d-axis and q-axis current command values Id ^** and Iq ^** are output to the voltage command value generation unit 416 via the low- pass filters 490A and 490B. At this time, by optimizing the time constant of the q-axis low pass filter 490B, quickly so that does not cause the q-axis current command value Iq ^** is a large delay in the absolute value of the q-axis current command value Iq ^** is reduced When the absolute value of the q-axis current command value Iq ^** increases, the increase speed is preferably delayed within a range in which the response of the torque T required for the system can be satisfied. . Further, by optimizing the time constant of the d-axis low-pass filter 490A, when the absolute value of the d-axis current command value Id ^** increases, the d-axis current command value Id ^** can be quickly generated so as not to cause a large delay. In addition to the transmission, when the absolute value of the d-axis current command value Id ^** decreases, it is preferable to output the decrease rate slower than the increase rate of the q-axis current command value Iq ^** . That is, the time constant when the d-axis current command value Id ^** of the d-axis low-pass filter 490A is increased is τd (up), the time constant when it is decreased is τd (down), and the q-axis current command of the q-axis low-pass filter 490B is When the time constant at the time of increase of the value Iq ^** is τq (up) and the time constant at the time of decrease is τq (down),
τd (up) <τq (up) <τd (down)
τq (down) <τq (up)
It is preferable that The same applies to current command value generation units 406b and 406c described later.

As will be described later, when the absolute value of the d-axis current command value Id ^** increases and the q-axis current command value Iq ^** decreases, the motor voltage value Va exceeds the target voltage value Va _(ref) . The control may become unstable. Therefore, in such a case, changes in the d-axis and q-axis current command values Id ^** and Iq ^** are quickly output to the voltage command value generation unit 416, and measures for reducing the motor voltage value Va are quickly performed. . Thereby, the state where the motor voltage value Va is excessive can be quickly resolved. Conversely, when the absolute value of the d-axis current command value Id ^** decreases and the q-axis current command value Iq ^** increases, the motor voltage value Va is less than the target voltage value Va _(ref). In this case, the PM motor 10 is stably controlled. Therefore, in this case, the d-axis and q-axis current command values Id ^** and Iq ^** are slowly changed so that the motor voltage value Va does not exceed the target voltage value Va _(ref) again. Increase gently.

Next, the configuration of the current command value generation unit 406 (406a to 406c) and the dq current command value generation step will be described. In addition, when the power supply voltage Vdc of the DC power supply unit 18 rapidly decreases during the control by the sine wave control unit 40 or the rotational speed (electrical angular velocity ω) of the PM motor 10 rapidly increases, the motor voltage value Va is There is a possibility that the target voltage value Va _(ref) will be exceeded and voltage shortage will occur and stable control cannot be performed. The current command value generation unit 406 constituting the present invention increases the d-axis current command value Id ^** in the negative direction when the motor voltage value Va exceeds the target voltage value Va _(ref) , thereby reducing the q-axis voltage. The command value Vq is decreased, and the absolute value of the q-axis current command value Iq ^** is decreased to decrease the d-axis voltage command value Vd, thereby reducing the motor voltage value Va and the target voltage value Va _(ref). The purpose is to keep it at a minimum.

First, the current command value generation unit 406 constituting the present invention includes a phase angle setting unit 462 having a current-phase angle map, a sin unit 464A, a cos unit 464B, a current limiter unit 472, and an induced voltage d. An axis current value generation unit 470, an additional d axis current value generation unit 466, a q axis current command value correction unit 468 (468a, 468b), and an offset unit 469 are provided. The voltage difference ΔV input from the voltage difference calculation unit 408 is branched into two, and one is input to the additional d-axis current value generation unit 466. On the other hand, after a predetermined offset value a (fixed value) is subtracted from the offset unit 469, it is input to the q-axis current command value correcting unit 468.

Then, the phase angle setting unit 462 of the current command value generation unit 406 refers to the current-phase angle map based on the current command value Ia ^* input from the current command value setting unit 402, and corresponds to this current command value Ia ^*. Current phase angle θi _(base) to be acquired is acquired (phase angle setting step). Incidentally, the current phase angle .theta.i _(base) is a current phase angle output a maximum torque at a current command value Ia ^*, is set in advance for each current command value Ia ^*. In the current command value generation unit 406a of the first embodiment shown in FIGS. 2 to 4, the current phase angle θi _(base) is input to the sin unit 464A, and the cos unit 464B has the current phase angle θi _(base) . A corrected phase angle θi to which an additional phase angle Δθi described later is added is input.

Also, the input current command value Ia ^* is branched into two and one is input to the sin portion 464A and the other is input to the cos portion 464B. In the current command value generation unit 406a of the first embodiment, the sin unit 464A calculates the d-axis current command value Id ^* based on the following equation (d-axis current command value generation step).
Id ^* = Ia ^* · sin (θi _(base) )
The cos unit 464B calculates the q-axis current command value Iq ^* based on the following formula (q-axis current command value generation step).
Iq ^* = Ia ^* .cos (θi)
The current phase angle θi _(base) and the correction phase angle θi are angles formed with the q axis, and are limited to 0 ° to the upper limit phase angle (about 90 ° to 85 °) by a phase angle limiter described later. Also, the d-axis current command value Id ^* is always a negative value, and the q-axis current command value Iq ^* is controlled to have the same sign as the current command value Ia ^* .

The induced voltage d-axis current value generation unit 470 of the current command value generation unit 406 receives the power supply voltage Vdc of the DC power supply unit 18 and the electrical angular velocity ω of the PM motor 10. The induced voltage d-axis current value generation unit 470 has a data map (not shown) of the induced voltage d-axis current value ΔId ′ for the flux weakening control set for each of the power supply voltage Vdc and the electrical angular velocity ω. The induced voltage d-axis current value generation unit 470 selects the induced voltage d-axis current value ΔId ′ corresponding to the input power supply voltage Vdc and the electrical angular velocity ω from this data map, and selects the d-axis current command value Id ^*. Add to. The induced voltage d-axis current value ΔId ′ takes a negative value. Therefore, by adding the induced voltage d-axis current value ΔId ′, the d-axis current command value Id ^* increases in the negative direction, and its absolute value increases. The induced voltage d-axis current value generation unit 470 sets the induced voltage d-axis current value ΔId ′ by reading the data map as described above. Therefore, the responsiveness is faster than the additional d-axis current value ΔId that requires integral control, and the induced voltage d-axis current value ΔId ′ is output in response to a sudden drop in the power supply voltage Vdc or a change in the electrical angular velocity ω. Can do. Thereby, the excess state of the motor voltage value Va can be reduced to some extent.

Further, the voltage difference ΔV is input from the voltage difference calculation unit 408 to the additional d-axis current value generation unit 466 constituting the current command value generation unit 406. When the voltage difference ΔV is a positive value, that is, when the motor voltage value Va exceeds the target voltage value Va _(ref) , the input voltage difference ΔV is added by performing well-known integral control, proportional control, etc. A d-axis current value ΔId is generated. In this case, the integration control and the generated additional d-axis current value ΔId are limited by a predetermined current limit value described later. Then, the generated additional d-axis current value ΔId is added to the d-axis current command value Id ^* output from the sin unit 464A. The additional d-axis current value ΔId also takes a negative value. Therefore, by adding the additional d-axis current value ΔId, the d-axis current command value Id ^* increases in the negative direction, and its absolute value increases. Further, when the voltage difference ΔV becomes negative while the additional d-axis current value ΔId is being output, the additional d-axis current value generation unit 466 generates the additional d-axis current value ΔId only by integral control. As a result, the additional d-axis current value ΔId reflects the value of the negative voltage difference ΔV, and its absolute value gradually decreases and finally becomes “0”. By not performing proportional control, a sudden fluctuation component is not added to the additional d-axis current value ΔId, and the motor voltage value Va can be prevented from exceeding again due to a sudden decrease in the additional d-axis current value ΔId. . Further, when the negative voltage difference ΔV is input in a state where the additional d-axis current value ΔId is not output, the additional d-axis current value generation unit 466 does not operate and the additional d-axis current value ΔId is not generated (additional d Axis current value generation step).

Then, the d-axis current command value Id ^* ′ obtained by adding the additional d-axis current value ΔId and the induced voltage d-axis current value ΔId ′ is output to the current limiter 472, and the d-axis current command value Id ^* ′ is the current. If it is below the current limit value of limiter unit 472, d-axis current command value Id ^* ′ is output to voltage command value generation unit 416 as d-axis current command value Id ^** as it is. If the current limit value is exceeded, it is limited to the current limit value and output to the voltage command value generation unit 416. The limit value of the current limiter 472 may be set individually for each of the d-axis current command value Id ^* ′ and the q-axis current command value Iq ^* described later, or may be set separately for the d-axis and q-axis current command value Id ^* ′. , Iq ^* may be set with the size of the combined vector while maintaining the angle of the combined vector. Moreover, you may carry out by both.

Here, the relationship between the motor voltage value Va and the current command value generation unit 406 follows the configuration of the current command value generation unit 406c of the third embodiment, using the following formulas (1), (2), and (3). explain. First, the motor voltage value Va is obtained by the following equation (1),
Va = (Vd ² + Vq ² ) ^1/2 (1)
The d-axis voltage command value Vd and the q-axis voltage command value Vq are obtained by the following equations (2) and (3) (description of coefficients, correction values, etc. is omitted).
Vd = RaId ^**- ωLqIq ^** (2)
Vq = RaIq ^** + ωφa + ωLdId ^** (3)
When the power supply voltage Vdc decreases or the electrical angular velocity ω increases to enter the field-weakening magnetic flux control region, first, the induced voltage d-axis current value generation unit 470 first induces corresponding to the power supply voltage Vdc and the electrical angular velocity ω. The voltage d-axis current value ΔId ′ is added to the d-axis current command value Id ^* . As a result, the d-axis current command value Id ^** increases in the negative direction, and ωLdId ^{** in the} equation (3) also increases in the negative direction. As a result, the q-axis voltage command value Vq decreases and the motor voltage value Va decreases.

At this time, if the motor voltage value Va exceeds the target voltage value Va _(ref) , the voltage difference ΔV becomes positive and the additional d-axis current value generation unit 466 operates to output the additional d-axis current value ΔId. It is added to the shaft current command value Id ^* . As a result, the d-axis current command value Id ^** further increases in the negative direction, and as a result, the ωLdId ^{** in the} equation (3) further increases in the negative direction and the q-axis voltage command value Vq decreases. Thereby, the motor voltage value Va decreases. When the motor voltage value Va becomes equal to the target voltage value Va _(ref) , the voltage difference ΔV becomes “0” and the operation of the additional d-axis current value generation unit 466 stops. As a result, the PM motor 10 can be operated with a motor voltage value Va (target voltage value Va _(ref) ) that can be stably controlled and has a maximum torque. The term RaId ^{** in} the equation (2) also fluctuates due to the change in the d-axis current command value Id ^** , but since this term does not involve the electrical angular velocity ω, the fluctuation amount is small compared to the other terms. The influence on the motor voltage value Va is small.

Here, for example, when the q-axis current command value Iq ^** and the electrical angular velocity ω are positive, (RaIq ^** + ωφa) in the above equation (3) takes a positive value and (ωLdId ^** ) is negative. Takes a value. When the additional d-axis current value ΔId increases in the negative direction and (RaIq ^** + ωφa) and (ωLdId ^** ) in the above equation (3) are balanced, the d-axis current command value Id ^** The motor voltage value Va cannot be reduced any more. Accordingly, in parallel with the additional d-axis current value generation unit 466, the following q-axis current command value correction units 468a and 468b reduce the q-axis current command value Iq ^** .

As described above, when (RaIq ^** + ωφa) and (ωLdId ^** ) are balanced, the motor voltage value Va cannot be reduced any more. Therefore, the additional d-axis current value ΔId is added by the current limiter in the additional d-axis current value generation unit 466 so that the above (RaIq ^** + ωφa) and (ωLd (Id ^* + ΔId ′ + ΔId)) are balanced. It is preferable to limit the current value ΔId so that it does not flow down. Further, the current limiter in the additional d-axis current value generation unit 466 has an additional d-axis current value such that (Id ^* + ΔId ′ + ΔId) is a current value that outputs the maximum torque for each power supply voltage Vdc and electrical angular velocity ω. The current value of ΔId may be limited.

Next, the q-axis current command value correction unit 468a according to the first embodiment will be described. First, a voltage difference ΔV (hereinafter referred to as a deviation) obtained by subtracting the offset value a by the offset unit 469 is input to the q-axis current command value correction unit 468a of the first embodiment. Here, the additional d-axis current value generation unit 466 and the q-axis current command value correction unit 468 (468a, 468b) operate simultaneously to correct the d-axis current command value Id ^* and the q-axis current command value Iq ^*. If the control is started at the same time, the motor voltage value Va may decrease excessively or move up and down oscillatingly, and the control may become unstable. For this reason, in the motor control device 100 according to the present invention, the value of the voltage difference ΔV that starts the operation by adding the offset value a to the input of the q-axis current command value correction unit 468 is different, and the additional d-axis current value The generation unit 466 and the q-axis current command value correction unit 468 are controlled so as not to start operation simultaneously. Thus, the additional d-axis current value generation unit 466 performs the reduction operation of the motor voltage value Va first, and the q-axis current command value correction unit 468 further increases the motor voltage value Va from the target voltage value Va _(ref). The operation starts when it rises by an offset amount.

When the deviation is a positive value, that is, when the motor voltage value Va exceeds (Va _(ref) + a), the q-axis current command value correction unit 468a of the first embodiment is well-known for the input deviation. An additional phase angle Δθi is generated by performing integral control, proportional control, and the like. In this case, the integration control and the generated additional phase angle Δθi are limited by a predetermined phase angle limiter. The phase angle limit value in the phase angle limiter is preferably a value that varies depending on the current phase angle θi _(base) output from the phase angle setting unit 462 as shown in the following equation.
Phase angle limit value = upper limit phase angle−current phase angle θi _(base)
The correction phase angle θi obtained by adding the additional phase angle Δθi to the current phase angle θi _(base) is always equal to or less than the upper limit phase angle (90 °) by setting the upper limit phase angle to about 90 ° to 85 °. be able to. Further, by setting the upper limit phase angle to be smaller than 90 °, the correction phase angle θi can be set to 90 ° or less even when an error occurs in the electrical angle θ.

Thus, the additional phase angle Δθi generated by the q-axis current command value correction unit 468a of the first embodiment is added to the current phase angle θi _(base) output from the phase angle setting unit 462, and the correction phase angle θi And input to the cos part 464B. Then, the cos unit 464B calculates the q-axis current command value Iq ^* based on the corrected phase angle θi and outputs it to the current limiter unit 472. If less current limiter section 472 in the q-axis current command value Iq ^* is a current limit value, and outputs the voltage command value generating unit 416 a q-axis current command value Iq ^* as the q-axis current command value ^{Iq **} intact. Also, if the q-axis current command value Iq ^* exceeds the current limit value, it is limited to the current limit value and output to the voltage command value generation unit 416.

Here, since the additional phase angle Δθi is positive and the correction phase angle θi is limited to 90 ° or less by the phase angle limiter, the correction phase angle θi is 90 °>θi> θi _(base) . Therefore, Iq ^* = Ia ^* · cos (θi) output from the cos unit 464B is smaller than Iq ^* = Ia ^* · cos (θi _(base) ).
As a result, the q-axis current command value Iq ^* (Iq ^** ) decreases, and the absolute value of the term (ωLqIq ^** ) in the above equation (2) decreases. As a result, the d-axis voltage command value Vd decreases, and the motor voltage value Va can be reduced.

Further, when the deviation becomes negative while the positive additional phase angle Δθi is output as described above, the q-axis current command value correction unit 468a generates the additional phase angle Δθi only by integral control. As a result, the additional phase angle Δθi is gradually reduced to reflect the value of the negative deviation, and finally becomes “0”. By not performing proportional control, a sudden fluctuation component is not added to the additional phase angle Δθi, and it is possible to prevent the motor voltage value Va from exceeding again due to a sudden decrease in deviation. In addition, the q-axis current command value correction unit 468a does not operate in a state where the additional phase angle Δθi is “0”. Therefore, the q-axis current command value correction unit 468a does not operate even if a negative deviation is input in a state where the additional phase angle Δθi is not output. The same applies to the q-axis current command value correction unit 468b of the second embodiment described later.

Next, the configuration of the current command value generation unit 406b using the q-axis current command value correction unit 468b of the second embodiment will be described with reference to FIG. First, the current command value generating portion 406b of the second embodiment is to input current phase angle .theta.i from the phase angle setting section 462 _(base) is to cos unit 464B, as with sin portion 464A current phase angle .theta.i _(base) The q-axis current command value Iq ^* is calculated based on

The q-axis current command value correction unit 468b according to the second embodiment performs well-known integral control, proportional control, limiter limitation, etc., similar to the additional d-axis current value generation unit 466, according to the deviation. An additional q-axis current value ΔIq is generated. Then, the additional q-axis current value ΔIq is subtracted from the q-axis current command value Iq ^* . As a result, the q-axis current command value Iq ^** decreases, and the d-axis voltage command value Vd decreases. Thereby, the motor voltage value Va is reduced (the q-axis current command value correction step).

As described above, in the motor control device 100 according to the present invention, in addition to the reduction of the motor voltage value Va by the additional d-axis current value ΔId, the q-axis current command value correction unit 468 (468a, 468b) has the q-axis current command value Iq. ^{Since *} is reduced, the motor voltage value Va can be further reduced. As a result, the state in which the motor voltage value Va exceeds the target voltage value Va _(ref) can be quickly eliminated, and the motor voltage value Va is continuously stable even against a sudden drop in the power supply voltage Vdc and fluctuations in the electrical angular velocity ω. Magnetic flux weakening control can be performed.

Note that the integral control of the q-axis current command value correction unit 468 is such that the integral gain in the direction in which the integral value increases (when the deviation is a positive value) is set large, and the integral value decreases (the deviation is negative). It is preferable to set the integral gain in the case of a value small. According to this configuration, when the motor voltage value Va exceeds (Va _(ref) + a) and it is assumed that the motor voltage is insufficient, the integrated value (additional phase angle Δθi or additional q-axis current value ΔIq ) Can be increased quickly. As a result, the motor voltage value Va can be quickly reduced, and the shortage of the motor voltage can be eliminated in advance or quickly. Further, in the direction in which the integral value decreases, the integral value (additional phase angle Δθi or additional q-axis current value ΔIq) is gradually decreased with a small integral gain to prevent the motor voltage value Va from rapidly increasing, and the target voltage value Va _{(ref )} Can be prevented again.

Further, in the q-axis current command value correction unit 468, when the deviation value exceeds a predetermined threshold value set in advance, an additional phase angle Δθi ′ or an additional q-axis current value ΔIq set in advance to an integral value in normal integration control. 'May be added to generate an additional phase angle Δθi and an additional q-axis current value ΔIq. According to this configuration, when a large voltage difference ΔV is input such that the motor voltage value Va significantly exceeds (Va _(ref) + a) and exceeds the threshold value, the additional phase angle Δθi ′ that quickly increases the integral value. Since the additional phase angle Δθi and the additional q-axis current value ΔIq obtained by adding the additional q-axis current value ΔIq ′ can be output, the motor voltage value Va can be quickly and urgently reduced.

Further, the current command value generation units 406 and 406a may be the current command value generation unit 406c of the third embodiment shown in FIG. In the current command value generation unit 406c of the third embodiment shown in FIG. 6, the correction phase angle θi is input to both the sin unit 464A and the cos unit 464B. Therefore, the sine unit 464A of the current command value generation unit 406a of the second embodiment calculates the d-axis current command value Id ^* based on the corrected phase angle θi. The d-axis current command value Id ^* based on the correction phase angle θi has a larger absolute value than the d-axis current command value Id ^* based on the current phase angle θi _(base) .

Here, when the q-axis current command value Iq ^** decreases, the torque T shown in the above equation (A) decreases. However, since the current command value generation unit 406b of the third embodiment calculates the d-axis current command value Id ^* based on the corrected phase angle θi, the absolute value of the d-axis current command value Id ^* (Id ^** ) is If the above-mentioned (RaIq ^** + ωφa) and (ωLdId ^** ) do not reach a balanced state, a decrease in torque T due to a decrease in q-axis current command value Iq ^** can be suppressed. The torque calculation unit 404 calculates the torque T based on the decreased q-axis current command value Iq ^** , and the current command value setting unit 402 determines the value of the current command value Ia ^* according to the value of the torque T. Is increased, the operation for compensating for the decrease in the torque T is performed.

As described above, in the motor control device 100 and the motor control method according to the present invention, when the motor voltage value Va exceeds the target voltage value Va _(ref) , the additional d-axis current value ΔId corresponding to the voltage difference ΔV. To increase the d-axis current command value Id ^* in the negative direction and reduce the motor voltage value Va. As a result, the PM motor 10 can be operated with a motor voltage value Va (target voltage value Va _(ref) ) that can be stably controlled and has a maximum torque. In addition to the above configuration, the motor control device 100 and the motor control method according to the present invention include a q-axis current command value correction unit 468 that decreases the absolute value of the q-axis current command value Iq ^** . Thereby, the motor voltage value Va can be further reduced. As a result, the state in which the motor voltage value Va exceeds the target voltage value Va _(ref) can be quickly eliminated, and the motor voltage value Va is continuously stable even against a sudden drop in the power supply voltage Vdc and fluctuations in the electrical angular velocity ω. Magnetic flux weakening control can be performed.

In addition, in the configuration in which the temperature of the permanent magnet of the PM motor 10 is estimated by the temperature acquisition means 108, fluctuations in motor parameters due to the estimated temperature of the magnet can be corrected, so that more accurate operation control with less error is performed. Can do.

The motor control device 100 and the motor control method shown in this example are only examples, and the configuration, operation, configuration of each step, and the like of each unit can be changed and implemented without departing from the gist of the present invention. .

DESCRIPTION OF SYMBOLS 10 PM motor 40 Sine wave control part 418 Polar coordinate conversion part 402 Current command value setting part 404 Torque calculation part 406 Current command value generation part 408, 408a-408c Voltage difference calculation part 416 Voltage command value generation part 462 Phase angle setting part 464A sin Unit 464B cos unit 466 additional d-axis current value generation unit 468, 468a, 468b q-axis current command value correction unit 482b motor voltage value calculation unit 484 target voltage value calculation unit 490A d-axis low-pass filter 490B q-axis low-pass filter 100 motor control device T torque value T ^* torque command value Ia ^* current command value Id ^{*, Id **} d-axis current command value ^{Iq *,} Iq ^** q-axis current command value ΔId additional d-axis current command value ΔI Add q-axis current command value Va motor voltage Va _(ref) the target voltage value ΔV voltage difference Vd d-axis voltage command value Vq q-axis voltage command value .theta.i _(base) current phase angle .theta.i correction phase angle Δθi additional current phase angle a offset value

Claims (20)

1. In a motor control device including at least a sine wave control unit that controls a PM motor with sine wave PWM,
   The sine wave control unit is
   A torque calculator for calculating a torque value T of the PM motor;
   A current command value setting unit for setting a current command value Ia ^* based on an external torque command value T ^* and the torque value T;
   A current command value generation unit that generates a d-axis current command value Id ^** and a q-axis current command value Iq ^** based on the current command value Ia ^* ;
   A voltage command value generator that generates a d-axis voltage command value Vd and a q-axis voltage command value Vq based on the d-axis current command value Id ^** and the q-axis current command value Iq ^** .
   The current command value generator is
   A sin unit that generates a d-axis current command value Id ^* that is a source of the d-axis current command value Id ^** ;
   And cos unit which generates the a q-axis current command value ^{Iq **} original q-axis current command value Iq ^*,
   A phase angle setting unit that sets a current phase angle θi _(base) that outputs a maximum torque at the current command value Ia ^* and outputs the current phase angle to the sin unit and the cos unit;
   A voltage difference calculation unit that calculates a voltage difference ΔV based on a motor voltage value Va of the PM motor and a target voltage value Va _(ref) that is a maximum voltage value at which the PM motor can stably operate;
   An additional d-axis current value generation unit that calculates an additional d-axis current command value ΔId that increases the d-axis current command value Id ^* in the negative direction based on the voltage difference ΔV;
   A motor control device, comprising: a q-axis current command value correction unit that decreases an absolute value of the q-axis current command value Iq ^* based on the voltage difference ΔV.
2. 2. The motor control device according to claim 1, wherein the predetermined offset value is added to the voltage difference [Delta] V and output to the q-axis current command value correction unit.
3. The q-axis current command value correction unit sets the additional current phase angle Δθi based on the voltage difference ΔV, and the cos unit corrects the correction phase angle θi obtained by adding the current phase angle θi _(base) and the additional current phase angle Δθi. The motor control device according to claim 1, wherein a q-axis current command value Iq ^* is generated based on
4. The q-axis current command value correction unit sets the additional current phase angle Δθi based on the voltage difference ΔV, and the sine unit and the cos unit correct the current phase angle θi _(base) and the additional current phase angle Δθi. 3. The motor control device according to claim 1, wherein a d-axis current command value Id ^* and a q-axis current command value Iq ^* are generated based on the phase angle θi.
5. The voltage difference calculation unit includes a target voltage value calculation unit that calculates the target voltage value Va _(ref), and a motor voltage value calculation unit that calculates the motor voltage value Va,
   The voltage difference ΔV is calculated based on the target voltage value Va _(ref) calculated by the target voltage value calculation unit and the motor voltage value Va calculated by the motor voltage value calculation unit. Item 5. The motor control device according to any one of Items 4 to 6.
6. The voltage difference calculation unit calculates the voltage difference ΔV based on the preset target voltage value Va _(ref) , the d-axis voltage command value Vd generated by the voltage command value generation unit, and the q-axis voltage command value Vq. The motor control device according to claim 1, wherein the motor control device is a motor control device.
7. The sine wave control unit further includes a polar coordinate conversion unit that generates a motor voltage value Va based on the d-axis voltage command value Vd and the q-axis voltage command value Vq,
   The voltage difference calculation unit calculates a voltage difference ΔV based on a preset target voltage value Va _(ref) and a motor voltage value Va generated by the polar coordinate conversion unit. Item 5. The motor control device according to any one of Items 4 to 6.
8. A d-axis low-pass filter to which a d-axis current command value Id ^** and a q-axis current command value Iq ^** from the current command value generation unit are respectively input; and a q-axis low-pass filter;
   The d-axis low pass filter and the q-axis low pass filter, with rapidly transmitted when the absolute value of the q-axis current command value Iq ^** is decreased, when the absolute value of the q-axis current command value Iq ^** is increased , The speed of increase is delayed, and when the absolute value of the d-axis current command value Id ^** increases, it is transmitted quickly, and when the absolute value of the d-axis current command value Id ^** decreases, its decrease The motor control device according to any one of claims 1 to 7, wherein the speed is delayed from an increasing speed of the q-axis current command value Iq ^** .
9. the q-axis current command value correcting unit, set on the basis of the additional q-axis current command value ΔIq to reduce the absolute value of q-axis current command value Iq ^* to the voltage difference [Delta] V, is added to the q-axis current command value Iq ^* The motor control device according to claim 1, wherein the motor control device is a motor control device.
10. A d-axis low-pass filter to which a d-axis current command value Id ^** and a q-axis current command value Iq ^** from the current command value generation unit are respectively input; and a q-axis low-pass filter;
    The d-axis low pass filter and the q-axis low pass filter, with rapidly transmitted when the absolute value of the q-axis current command value Iq ^** is decreased, when the absolute value of the q-axis current command value Iq ^** is increased , The speed of increase is delayed, and when the absolute value of the d-axis current command value Id ^** increases, it is transmitted quickly, and when the absolute value of the d-axis current command value Id ^** decreases, its decrease 10. The motor control device according to claim 9, wherein the speed is delayed from the increasing speed of the q-axis current command value Iq ^** .
11. A motor control method of a motor control device including at least a sine wave control unit for controlling a PM motor with a sine wave PWM,
    The sine wave control unit is
    A torque calculating step for calculating a torque value T of the PM motor;
    A current command value setting step for setting a current command value Ia ^* based on an external torque command value T ^* and the torque value T;
    A dq current command value generation step for generating a d-axis current command value Id ^** and a q-axis current command value Iq ^** based on the current command value Ia ^* ;
    A voltage command value generation step for generating a d-axis voltage command value Vd and a q-axis voltage command value Vq based on the d-axis current command value Id ^** and the q-axis current command value Iq ^** ,
    The dq current command value generation step includes:
    A d-axis current command value generation step for generating a d-axis current command value Id ^* that is a source of the d-axis current command value Id ^** ;
    A q-axis current command value generating step for generating a q-axis current command value Iq ^* that is a source of the q-axis current command value Iq ^** ;
    A phase angle setting step for setting a current phase angle θi _(base) that is used in the d-axis current command value generation step and the q-axis current command value generation step and outputs a maximum torque at the current command value Ia ^* ; ,
    A voltage difference calculation step of calculating a voltage difference ΔV based on a motor voltage value Va of the PM motor and a target voltage value Va _(ref) that is a maximum voltage value at which the PM motor can stably operate;
    An additional d-axis current value generation step of calculating an additional d-axis current command value ΔId that increases the d-axis current command value Id ^* in the negative direction based on the voltage difference ΔV;
    And a q-axis current command value correcting step for reducing an absolute value of the q-axis current command value Iq ^* based on the voltage difference ΔV.
12. The motor control method according to claim 11, wherein the q-axis current command value correction step is performed by adding the predetermined offset value to the voltage difference ΔV.
13. The q-axis current command value correction step sets the additional current phase angle Δθi based on the voltage difference ΔV, and the q-axis current command value generation step adds the current phase angle θi _(base) and the additional current phase angle Δθi. The motor control method according to claim 11 or 12, wherein a q-axis current command value Iq ^* is generated based on the corrected phase angle θi.
14. The q-axis current command value correction step sets the additional current phase angle Δθi based on the voltage difference ΔV, and the d-axis current command value generation step and the q-axis current command value generation step include the current phase angle θi _(base) and the aforementioned The motor according to claim 11 or 12, wherein the d-axis current command value Id ^* and the q-axis current command value Iq ^* are generated based on the corrected phase angle θi obtained by adding the additional current phase angle Δθi. Control method.
15. The voltage difference calculation step includes a target voltage value calculation step for calculating the target voltage value Va _(ref), and a motor voltage value calculation step for calculating the motor voltage value Va,
    12. The voltage difference ΔV is calculated based on the target voltage value Va _(ref) calculated in the target voltage value calculation step and the motor voltage value Va calculated in the motor voltage value calculation step. Item 15. The motor control method according to any one of Items 14.
16. The voltage difference calculation step calculates a voltage difference ΔV based on the preset target voltage value Va _(ref) , the d-axis voltage command value Vd generated in the voltage command value generation step, and the q-axis voltage command value Vq. The motor control method according to claim 11, wherein:
17. The sine wave control unit further includes a polar coordinate conversion unit that generates a motor voltage value Va based on the d-axis voltage command value Vd and the q-axis voltage command value Vq,
    12. The voltage difference calculation step calculates a voltage difference ΔV based on a preset target voltage value Va _(ref) and a motor voltage value Va generated by the polar coordinate conversion unit. Item 15. The motor control method according to any one of Items 14.
18. a d-axis low-pass filter to which the d-axis current command value Id ^** and the q-axis current command value Iq ^** generated in the dq current command value generation step are respectively input; and a q-axis low-pass filter;
    The d-axis low pass filter and the q-axis low pass filter, with rapidly transmitted when the absolute value of the q-axis current command value Iq ^** is decreased, when the absolute value of the q-axis current command value Iq ^** is increased , The speed of increase is delayed, and when the absolute value of the d-axis current command value Id ^** increases, it is transmitted quickly, and when the absolute value of the d-axis current command value Id ^** decreases, its decrease 18. The motor control method according to claim 11, wherein the speed is delayed from an increasing speed of the q-axis current command value Iq ^** .
19. the q-axis current command value correcting step, and set based on additional q-axis current command value ΔIq to reduce the absolute value of q-axis current command value Iq ^* to the voltage difference [Delta] V, is added to the q-axis current command value Iq ^* The motor control method according to claim 11 or 12, wherein:
20. a d-axis low-pass filter to which the d-axis current command value Id ^** and the q-axis current command value Iq ^** generated in the dq current command value generation step are respectively input; and a q-axis low-pass filter;
    The d-axis low pass filter and the q-axis low pass filter, with rapidly transmitted when the absolute value of the q-axis current command value Iq ^** is decreased, when the absolute value of the q-axis current command value Iq ^** is increased , The speed of increase is delayed, and when the absolute value of the d-axis current command value Id ^** increases, it is transmitted quickly, and when the absolute value of the d-axis current command value Id ^** decreases, its decrease 20. The motor control method according to claim 19, wherein the speed is delayed from the increasing speed of the q-axis current command value Iq ^** .

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