阅读说明：本技术 电动机控制装置 (Motor control device ) 是由 近藤翔太 家泽雅宏 于 2019-04-26 设计创作，主要内容包括：本发明的目的是获得一种即使在电动机特性变化时也能防止效率降低的电动机控制装置。该电动机控制装置用于控制具有第一定子绕组、第二定子绕组、以及对电流指令的响应比第一定子绕组和第二定子绕组要慢的励磁绕组的电动机,包括：参数获取部(61),其周期性地获取表示电动机的状态的电动机状态数据(62),并获取与电动机状态数据(62)相对应的电动机参数(63)；以及电流指令运算部(60),其基于针对电动机的转矩指令和电动机参数(63)来运算针对各绕组的电流指令,电流指令运算部(60)具有响应延迟再现部,其将励磁绕组电流的响应延迟再现到励磁绕组电流指令中,电流指令运算部(60)使用再现了响应延迟的励磁绕组电流指令运算第一定子绕组电流指令和第二定子绕组电流指令。(The purpose of the present invention is to obtain a motor control device capable of preventing efficiency from being reduced even when motor characteristics change. The motor control device for controlling a motor having a first stator winding, a second stator winding, and a field winding that responds slower to a current command than the first stator winding and the second stator winding, includes: a parameter acquisition unit (61) that periodically acquires motor state data (62) indicating the state of the motor, and acquires motor parameters (63) corresponding to the motor state data (62); and a current command calculation unit (60) that calculates a current command for each winding based on a torque command for the motor and a motor parameter (63), wherein the current command calculation unit (60) has a response delay reproduction unit that reproduces a response delay of the field winding current to the field winding current command, and the current command calculation unit (60) calculates a first stator winding current command and a second stator winding current command using the field winding current command reproduced with the response delay.)

1. A motor control apparatus for controlling a motor having a first winding and a second winding that responds to a current command slower than the first winding, comprising:

a parameter acquisition unit that periodically acquires motor state data indicating a state of the motor, and acquires a motor parameter corresponding to the motor state data; and

a current command calculation unit that calculates current commands for the first winding and the second winding based on a torque command for the motor and the motor parameter,

the current command calculation unit includes:

a first arithmetic unit that calculates a first current command for the first winding;

a second arithmetic unit that calculates a second current command for the second winding; and

a response delay reproduction unit that reproduces a response delay to the second current command in the second winding to the second current command,

the first calculation unit calculates the first current command using a second current command in which the response delay is reproduced.

2. The motor control device according to claim 1,

the response delay reproduction unit reproduces at least one of a response delay due to impedance of the second winding, a response delay due to a current control response of the second winding, a response delay due to a sensor delay of a sensor that detects a current flowing through the second winding, and a response delay due to an operation cycle of the current command operation unit.

3. The motor control device according to claim 1,

the first current command is calculated using a current value of a current flowing through the second winding in place of the second current command in which the response delay is reproduced by the response delay reproduction unit.

4. The motor control device according to any one of claims 1 to 3,

the motor state data includes a temperature of the motor.

5. The motor control device according to any one of claims 1 to 4,

the motor state data includes either or both of a current value of a current flowing through the first winding and a current value of a current flowing through the second winding.

6. The motor control device according to any one of claims 1 to 5,

an estimated value based on a predetermined model is used as the motor state data.

7. The motor control device according to any one of claims 1 to 6,

the first and second arithmetic units calculate a first current command and a second current command that minimize or maximize a predetermined evaluation function under a predetermined constraint condition.

8. The motor control device of claim 7,

the evaluation function represents at least one of a loss generated in the motor, an output torque of the motor, and a torque response of the motor.

9. The motor control device according to any one of claims 1 to 8,

the motor includes a stator having stator windings of three phases and a rotor having field windings, the first winding being the stator windings of the three phases, and the second winding being the field windings.

10. The motor control device according to claim 9,

the three-phase stator winding groups are respectively a plurality of windings.

Technical Field

The present invention relates to a motor control device.

Background

It is pointed out that in a motor having a field winding and a stator winding, deterioration of torque response may be caused due to a response delay of a current flowing through the field winding. Therefore, it is proposed to calculate a current correction value for compensating for a torque that cannot be obtained due to a response delay of an excitation current, and to correct a torque current command value using the current correction value (for example, refer to patent document 1).

Documents of the prior art

Non-patent document

Patent document 1: japanese patent No. 6115392

Disclosure of Invention

Technical problem to be solved by the invention

However, the technique described in patent document 1 requires a current command map or the like created by measurement in advance. In addition, for the salient pole type synchronous motor, an optimum current ratio needs to be determined. In this case, there is a problem that when the motor characteristics change due to a temperature change or the like, the current command map becomes out of practical condition, or the optimum current ratio fluctuates, and thus the efficiency may be lowered.

The present application discloses a technique for solving the above-described problem, and an object thereof is to obtain a motor control device capable of preventing a decrease in efficiency even when a motor characteristic changes.

Means for solving the problems

The motor control device disclosed in the present application controls a motor having a first winding and a second winding that responds to a current command slower than the first winding, and includes: a parameter acquisition unit that periodically acquires motor state data indicating a state of the motor, and acquires a motor parameter corresponding to the motor state data; and a current command calculation unit that calculates current commands for the first winding and the second winding based on a torque command for the motor and a motor parameter, the current command calculation unit including: a first arithmetic unit that calculates a first current command for the first winding; a second arithmetic unit that calculates a second current command for the second winding; and a response delay reproduction unit that reproduces a response delay to the second current command in the second winding to the second current command, wherein the first calculation unit calculates the first current command using the second current command reproduced with the response delay.

Effects of the invention

According to the motor control device disclosed in the present application, a decrease in efficiency can be prevented even when the motor characteristics change.

Drawings

Fig. 1 is a diagram showing a hardware configuration of a motor control device according to embodiment 1.

Fig. 2 is a block diagram showing a motor control device according to embodiment 1.

Fig. 3 is a block diagram showing an excitation winding current control unit according to embodiment 1.

Fig. 4 is a block diagram showing a first stator winding current control unit according to embodiment 1.

Fig. 5 is a block diagram showing a second stator winding current control unit according to embodiment 1.

Fig. 6 is a block diagram showing a drive current command generating unit according to embodiment 1.

Fig. 7 is a block diagram showing a current command calculation unit according to embodiment 1.

Fig. 8A is a diagram showing a control result of a conventional motor control device.

Fig. 8B is a diagram showing a control result of the motor control device in embodiment 1.

Fig. 9 is a diagram showing a hardware configuration of a motor control device according to embodiment 2.

Fig. 10 is a block diagram showing a motor control device according to embodiment 2.

Detailed Description

Embodiment 1.

Hereinafter, embodiment 1 will be described with reference to fig. 1 to 8B. Fig. 1 is a diagram showing a hardware configuration of a motor control device according to embodiment 1, and shows an entire system including a motor to be controlled. The motor control device 1000 is for controlling the driving of the motor 1, and is connected to each winding of the motor 1 via a first stator winding power conversion device 7, a second stator winding power conversion device 8, and a field winding power conversion device 9, which will be described later. The motor control device 1000 is connected to a position detector 2 and a temperature detector 3 provided in the motor 1. The motor control device 1000 is connected to current detectors 4, 5, and 6, and the current detectors 4, 5, and 6 are connected in series between the first stator winding power conversion device 7, the second stator winding power conversion device 8, and the field winding power conversion device 9, respectively, and the motor 1.

The motor 1 is a double three-phase winding motor including a rotor having permanent magnets and field windings wound around the permanent magnets, and a stator having 2 sets of three-phase stator windings. Hereinafter, the 2 sets of three-phase windings that the stator of the motor 1 has are referred to as "first stator winding" and "second stator winding", respectively. The first stator winding and the second stator winding correspond to a "first winding", and the field winding corresponds to a "second winding". In addition, the illustration of each part of the motor is omitted.

The position detector 2 is provided on the rotation shaft of the motor 1, and detects the angle θ of the rotor. The position detector 2 transmits the detected angle θ to the motor control device 1000. Instead of the position detector 2, a position estimator for estimating the angle θ of the rotor may be provided, and the estimated value of the angle θ may be transmitted to the motor control device 1000.

The temperature detector 3 detects at least one of the temperature ts1 of the first stator winding, the temperature ts2 of the second stator winding 2, the temperature tf of the field winding, and the temperature tM of the permanent magnet. The temperature detector 3 transmits the detected temperatures ts1, ts2, tf, tM to the motor control device 1000. Instead of the temperature detector 3, a temperature estimator may be provided, and the estimated values of ts1, ts2, tf, and tM may be transmitted to the motor controller 1000.

The current detector 4 detects three-phase currents flowing through the first stator winding, and sends the respective current values as first stator winding currents iu1, iv1, iw1 to the motor control device 1000. The current detector 5 detects three-phase currents flowing through the second stator windings, and sends the respective current values as second stator winding currents iu2, iv2, iw2 to the motor control device 1000. The current detector 6 detects a current flowing through the field winding, and transmits a current value thereof to the motor control device 1000 as a field winding current if. Instead of the current detectors 4, 5, and 6, a current estimator may be provided to transmit estimated values of iu1, iv1, iw1, iu2, iv2, iw2, and if to the motor control device 1000.

The first stator winding power conversion device 7 receives the three-phase voltage commands vu1, vv1, vw1 for the first stator winding from the motor control device 1000, and generates voltages corresponding to the respective voltage commands. Further, the first stator winding power conversion device 7 detects a dc link voltage for power conversion relating to the first stator winding, and transmits the voltage value as a dc link voltage VDC1 to the motor control device 1000.

The second stator winding power conversion device 8 receives the three-phase voltage commands vu2, vv2, vw2 for the second stator winding from the motor control device 1000, and generates voltages corresponding to the respective voltage commands. Further, the second stator winding power conversion device 8 detects a dc link voltage for power conversion relating to the second stator winding, and sends the voltage value as a dc link voltage VDC2 to the motor control device 1000.

The field winding power conversion device 9 receives a field winding voltage command vf, which is a voltage command for a field winding, from the motor control device 1000, and generates a voltage corresponding to the field winding voltage command vf. Further, the field winding power conversion device 9 detects a dc link voltage for power conversion relating to the field winding, and transmits the voltage value as a dc link voltage VDC3 to the motor control device 1000.

The motor control device 1000 includes a processor 10 and a storage device 11. The storage device 11 includes a volatile storage device (not shown) such as a random access memory and an auxiliary storage device (not shown) such as a flash memory. Instead of the volatile memory device, an auxiliary memory device such as a hard disk may be provided as the auxiliary memory device. The auxiliary storage device of the storage device 11 stores therein a program executed by the processor 10.

The processor 10 is, for example, a CPU (central processing unit) and executes a program read from the storage device 11 to realize various functional units shown in fig. 2. When the processor 10 reads the program from the storage device 11, the program stored in the auxiliary storage device is read by the volatile storage device. The processor 10 executes the program to generate a current instruction, data, and the like. The processor 10 may output the data to a volatile storage device of the storage device 11, or may store the data in an auxiliary storage device via the volatile storage device.

The processor 10 sends the generated current command to the first stator-winding power conversion device 7, the second stator-winding power conversion device 8, and the field-winding power conversion device 9 through an interface (not shown) with the outside. The processor 10 receives the angle theta from the position detector 2. The processor 10 also receives the temperatures ts1, ts2, tf, tM from the temperature detector 3. Further, the processor 10 receives the first stator winding currents iu1, iv1, iw1 from the current detector 4, the second stator winding currents iu2, iv2, iw2 from the current detector 5, and the field winding current if from the current detector 6. Further, the processor 10 receives dc link voltages VDC1, VDC2, VDC3 from the first stator winding power conversion device 7, the second stator winding power conversion device 8, and the field winding power conversion device 9, respectively. Further, the processor 10 receives a torque command T input from a higher-level control device or a user, a current limit idq1lim as an upper limit value of the current in the first stator winding, a current limit idq2lim as an upper limit value of the current in the second stator winding, and a current limit ifim as an upper limit value of the current in the field winding.

Fig. 2 is a block diagram showing a motor control device according to embodiment 1. The motor control device 1000 includes: a drive current command generating unit 24 for generating current commands for controlling currents flowing through the windings of the motor 1, and driving the motor 1; a first stator winding current control unit 22 for converting first stator winding current commands id1, iq1 for controlling the current flowing through the stator windings into first stator winding voltage commands vu1, vv1, vw1 as three-phase voltage commands; a second stator winding current control unit 23 for converting second stator winding current commands id2, iq2 for controlling the current flowing through the second stator winding into second stator winding voltage commands vu2, vv2, vw2 as three-phase voltage commands; and a field winding current control unit 21 for converting a field winding current command if for controlling the current flowing through the field winding into a field winding voltage command vf. The motor control device 1000 includes a differentiator 20, and the differentiator 20 receives the angle θ of the rotor of the motor 1 from the position detector 2 of the motor 1 and calculates the angular velocity ω of the rotor.

The differentiator 20 calculates the angular velocity ω by performing a differentiation operation with respect to time on the angle θ. The differentiator 20 outputs the calculated angular velocity ω to the driving current command generating unit 24.

The field winding current control unit 21 receives a field winding current command if from the drive current command generation unit 24 and a field winding current if from the current detector 6, and calculates a field winding voltage command vf such that the field winding current if follows the field winding current command if. The field winding current control unit 21 transmits the calculated field winding voltage command vf to the field winding power conversion device 9. The field winding current control unit 21 transmits the field winding current if received from the current detector 6 to the driving current command generation unit 24.

The first stator-winding current controller 22 receives the first stator-winding current commands id1 and iq1 from the driving current command generator 24, receives the first stator-winding currents iu1, iv1 and iw1 from the current detector 4, and calculates the first stator-winding voltage commands vu1, vv1 and vw1 so that the first stator-winding currents iu1, iv1 and iw1 follow the first stator-winding current commands id1 and iq 1. Here, the first stator winding current commands id1, iq1 generated by the drive current command generating unit 24 are current commands expressed in an orthogonal two-phase coordinate system, while the first stator winding voltage commands vu1, vv1, vw1 are voltage commands in a three-phase ac coordinate system, and therefore the first stator winding current control unit 22 performs coordinate conversion from the orthogonal two-phase coordinate system to the three-phase ac coordinate system using the angle θ. The first stator winding current controller 22 transmits the calculated first stator winding voltage commands vu1, vv1, vw1 to the first stator winding power converter 7. The first stator-winding current controller 22 coordinates-converts the first stator-winding currents iu1, iv1, iw1 received from the current detector 4 into an orthogonal two-phase coordinate system using the angle θ, and sends the obtained results to the driving current command generator 24 as the first stator-winding d-axis current id1 and the first stator-winding q-axis current iq 1.

The second stator winding current control unit 23 receives the second stator winding current commands id2 and iq2 from the driving current command generation unit 24, receives the second stator winding currents iu2, iv2 and iw2 from the current detector 5, and calculates the second stator winding voltage commands vu2, vv2 and vw2 so that the second stator winding currents iu2, iv2 and iw2 follow the second stator winding current commands id2 and iq 2. Similarly to the first stator winding current control unit 22, the second stator winding current control unit 23 performs coordinate conversion from the orthogonal two-phase coordinate system to the three-phase ac coordinate system using the angle θ. The second stator winding current controller 23 transmits the calculated second stator winding voltage commands vu2, vv2, vw2 to the second stator winding power converter 8. The second stator winding current controller 23 coordinates-converts the second stator winding currents iu2, iv2, iw2 received from the current detector 5 into an orthogonal two-phase coordinate system by the angle θ, and sends the obtained results to the driving current command generator 24 as the second stator winding d-axis current id2 and the second stator winding q-axis current iq 2.

The drive current command generation unit 24 drives the motor 1 to realize the torque indicated by the torque command T, and calculates the first stator winding current commands id1, iq1, the second stator winding current commands id2, iq2, and the single-phase field winding current command if in the orthogonal two-phase coordinate system. The drive current command generation unit 24 calculates each of the above current commands based on the torque command T, the current value and the upper limit value of the current flowing through each winding, the voltage value of the dc link voltage for power conversion, the temperature of each part of the motor 1, and the angular velocity ω of the rotor of the motor 1. Here, "current values of currents flowing through the respective windings" are the first stator winding d-axis current id1, the first stator winding q-axis current iq1, the second stator winding d-axis current id2, the second stator winding q-axis current iq2, and the field winding current if, and "limit values" are the current limit idq1lim, the current limit idq2lim, and the current limit ifim. The "voltage values of the dc link voltages" are dc link voltages VDC1, VDC2, VDC 3. The "temperatures of the respective portions of the motor 1" are the temperature ts1 of the first stator winding, the temperature ts2 of the second stator winding 2, the temperature tf of the field winding, and the temperature tM of the permanent magnet. The first stator winding current commands id1, iq1, and the second stator winding current commands id2, iq2 correspond to "first current commands", and the field winding current command if corresponds to "second current commands".

Next, a more detailed configuration of the field winding current control unit 21 will be described with reference to fig. 3. As shown in fig. 3, the field winding current control unit 21 includes an adder-subtractor 30 and a PI control unit 31. First, the field winding current control unit 21 obtains a difference between a field winding current command if input from the driving current command generation unit 24 and a field winding current if received from the current detector 6 by the adder-subtractor 30, and obtains a field winding current deviation (if — if). Next, the field winding current control unit 21 performs PI (Proportional-Integral) control in the PI control unit 31 based on the field winding current deviation, and generates a field winding voltage command vf. The calculation in the PI control is, for example, as shown in the following expression (1). In the formula (1), Kpf and Kif are proportional gain and integral gain in the control of the exciting winding current. Note that s is a differential operator of laplace transform, and the same applies to the following equations.

vf＊＝(Kpf+Kif/s)×(if＊－if)

···(1)

Although illustration is omitted, the decoupling process may be performed after the field winding voltage command vf is generated.

Next, a more detailed configuration of the first stator-winding current control unit 22 will be described with reference to fig. 4. As shown in fig. 4, the first stator-winding current control unit 22 includes an adder-subtractor 40, a PI control unit 41, a two-phase three-phase coordinate converter 42, and a three-phase two-phase coordinate converter 43. First, the first stator-winding current controller 22 coordinate-converts the three-phase first stator-winding currents iu1, iv, iw received from the current detector 4 into the first stator-winding d-axis current id1 and the first stator-winding q-axis current iq1 by the angle θ via the three-phase two-phase coordinate converter 43. For the coordinate conversion by the three-phase two-phase coordinate converter 43, a known coordinate conversion method can be used.

Then, the first stator winding current control unit 22 obtains a difference between the first stator winding current command id1 input from the driving current command generating unit 24 and the first stator winding d-axis current id1, and a difference between the first stator winding current command iq1 input from the driving current command generating unit 24 and the first stator winding q-axis current iq1, by the adder-subtractor 40, thereby obtaining a first stator winding d-axis current deviation (═ iq 1-id 1) and a first stator winding q-axis current deviation (═ iq 1-iq 1). Next, the first stator winding current control unit 22 performs PI control by the PI control unit 41 based on the first stator winding d-axis current deviation and the first stator winding q-axis current deviation, and generates a first stator winding d-axis voltage command vd1 and a first stator winding q-axis voltage command vq 1. The calculation in the PI control is, for example, as shown in the following equations (2) and (3). In the equations (2) and (3), Kpd1 and Kid1, and Kpq1 and Kiq1 are proportional gain and integral gain in current control of the first stator winding, respectively.

vd1＊＝(Kpd1+Kid1/s)×(id1＊－id1)

···(2)

vq1＊＝(Kpq1+Kiq1/s)×(iq1＊－iq1)

···(3)

Although not shown in the drawings, after the first stator winding d-axis voltage command vd1 and the first stator winding q-axis voltage command vq1 are generated, the decoupling process may be performed to eliminate the disturbance component accompanying the speed electromotive force generated based on the angular speed ω of the rotor of the motor 1.

Next, the first stator winding current control unit 22 converts the d-axis voltage command vd1 and the q-axis voltage command vq1 of the first stator winding into three-phase first stator winding voltage commands vu1, vv1, and vw1 by the two-phase three-phase coordinate converter 42 at the angle θ. For the coordinate conversion by the two-phase three-coordinate converter 42, a known coordinate conversion method can be used.

Next, a more detailed configuration of the second stator winding current control unit 23 will be described with reference to fig. 5. As shown in fig. 5, the second stator winding current control section 23 includes an adder-subtractor 50, a PI control section 51, a two-phase three-phase coordinate converter 52, and a three-phase two-phase coordinate converter 53. First, the second stator winding current control section 23 coordinate-converts the three-phase second stator winding currents iu2, iv2, iw2 received from the current detector 5 into the second stator winding d-axis current id2 and the second stator winding q-axis current iq2 by the angle θ in the three-phase two-phase coordinate converter 53. For the coordinate conversion by the three-phase two-phase coordinate converter 5, a known coordinate conversion method can be used.

Then, the second stator winding current control unit 23 obtains a second stator winding d-axis current deviation (id 2-id 2) and a second stator winding q-axis current deviation (iq 2-iq 2) by obtaining a difference between the second stator winding current command id2 input from the driving current command generating unit 24 and the second stator winding d-axis current id2 and a difference between the second stator winding current command iq2 input from the driving current command generating unit 24 and the second stator winding q-axis current iq2 by the adder-subtractor 50. Next, the second stator winding current control unit 22 performs PI control by the PI control unit 51 based on the second stator winding d-axis current deviation and the second stator winding q-axis current deviation to generate a second stator winding d-axis voltage command vd2 and a second stator winding q-axis voltage command vq 2. The calculation in the PI control is, for example, as shown in the following equations (4) and (5). In the equations (4) and (5), Kpd2 and Kid2 and Kpq2 and Kiq2 are proportional gain and integral gain in current control of the 2 nd stator winding, respectively.

vd2＊＝(Kpd2+Kid2/s)×(id2＊－id2)

···(4)

vq2＊＝(Kpq2+Kiq2/s)×(iq2＊－iq2)

···(5)

Although not shown in the drawings, after the second stator winding d-axis voltage command vd2 and the second stator winding q-axis voltage command vq2 are generated, the decoupling process may be performed to eliminate the disturbance component accompanying the speed electromotive force generated based on the angular speed ω of the rotor of the motor 1.

Next, the second stator winding current control unit 23 converts the second stator winding d-axis voltage command vd2 and the second stator winding q-axis voltage command vq2 into three-phase second stator winding voltage commands vu2, vv2, vw2 in accordance with the angle θ by the two-phase three-phase coordinate converter 52. For the coordinate conversion by the two-phase three-coordinate converter 52, a known coordinate conversion method can be used.

Next, a more detailed configuration of the driving current command generating unit 24 will be described with reference to fig. 6. As shown in fig. 6, the driving current command generating unit 24 includes a current command calculating unit 60 and a parameter acquiring unit 61. The parameter acquiring unit 61 receives data (hereinafter referred to as "motor state data 62") such as the first stator winding d-axis current id1 and the first stator winding q-axis current iq1 output from the first stator winding current control unit 22, the second stator winding d-axis current id2 and the second stator winding q-axis current iq2 output from the second stator winding current control unit 23, the field winding current if output from the field winding current control unit 21, and the temperatures of the respective parts of the motor 1, i.e., the first stator winding temperature ts1, the second stator winding temperature ts2, the field winding temperature tf, and the permanent magnet temperature tM, which are transmitted from the temperature detector 3, and acquires the motor parameters 63 based on the received motor state data 62. Here, the "motor parameter" is a parameter indicating motor characteristics of the motor 1, and includes a resistance value of a resistance of each winding, an inductance value of each winding, a mutual inductance value between windings, and a magnetic flux value of a magnetic flux of the permanent magnet interlinked with each stator winding. Here, the "resistance value of the resistance of each winding" refers to the first stator winding resistance R1, the second stator winding resistance R2, and the field winding resistance Rf. The "inductance value of each winding" refers to the first stator winding d-axis inductance Ld1, the second stator winding d-axis inductance Ld2, the first stator winding q-axis inductance Lq1, the second stator winding q-axis inductance Lq2, and the field winding inductance Lf. The "mutual inductance value between windings" refers to the d-axis mutual inductance Md of the first stator winding and the second stator winding, the q-axis mutual inductance Mq of the first stator winding and the second stator winding, the mutual inductance Mf1 of the first stator winding and the excitation winding, and the mutual inductance Mf2 of the second stator winding and the excitation winding. The "magnetic flux value of the permanent magnet flux interlinked with each stator winding" is the magnetic flux KE1 of the permanent magnet flux interlinked with the first stator winding and the magnetic flux KE2 of the permanent magnet flux interlinked with the second stator winding. The parameter acquiring unit 61 outputs the acquired motor parameter 63 to the current command calculating unit 60.

It is considered that the parameter acquisition section 61 may acquire the motor parameters 63 corresponding to the motor state data 62, and is constituted by, for example, a look-up table (hereinafter referred to as "LUT") for storing respective data of the motor parameters 63 corresponding to the motor state data 62. Further, it may be constituted by an arithmetic section that calculates a function defining the input motor state data 62 as an input and each data of the motor parameters 63 as an output. The motor state data 62 is not limited to the actual measurement values, and may be estimated values based on a predetermined model. When the estimated value is used for the motor state data 62, the influence of harmonic interference and the like that may be included in the actual measurement value such as the actual current can be eliminated.

The current command calculation unit 60 calculates the first stator winding current commands id1, iq1, the second stator winding current commands id2, iq2, and the field winding current command if at a predetermined calculation cycle, based on the torque command T, the current limits idq1lim, idq2lim, iflim of the first stator winding, the second stator winding, and the field winding, the angular velocity ω of the rotor, the dc link voltages VDC1, VDC2, VDC3, and the motor parameter 63 output from the parameter acquisition unit 61.

The parameter acquisition unit 61 periodically receives the motor state data 62, updates the motor parameter 63, and outputs the updated motor parameter to the current command calculation unit 60. The update cycle of the motor parameter 63 in the parameter acquisition unit 61 is shorter than or equal to the calculation cycle of the current command calculation unit 60. Thus, each current command calculated by the current command calculation unit 60 reflects the change of the motor parameter 63 in real time.

Next, a more detailed configuration of the current command operation unit 60 will be described with reference to fig. 7. As shown in fig. 7, the current command calculation unit 60 includes a torque time constant filter 70, a second calculation unit that is an excitation current command generator 71, a response delay reproduction unit that is an excitation current time constant filter 72, and a first calculation unit that is a stator current command generator 73. The torque time constant filter 70 receives the torque command T, adjusts the received torque command T according to a predetermined reference, and outputs the adjusted torque command T to the field current command generator 71 and the stator current command generator 73. The torque time constant filter 70 is constituted by a filter, a state estimator, a LUT, or the like.

When there is a sharp fluctuation in the torque command T and the fluctuation amount or fluctuation rate thereof exceeds a predetermined threshold value, the torque time constant filter 70 filters the fluctuation amount or fluctuation rate of the torque command T and performs adjustment or the like for removing the fluctuation exceeding the threshold value.

The field current command generator 71 calculates a current command for each winding based on the torque command T adjusted by the torque time constant filter 70 and the motor parameter 63. The excitation current command generator 71 uses the lagrangian indeterminate constant method for calculating the current command for each winding that achieves the maximum efficiency. The field current command generator 71 determines the field winding current command if so that the evaluation function represented by the following expression (7) is minimized under the constraint condition represented by the following expression (6).

[ mathematical formula 1]

[ mathematical formula 2]

Equation (6) is an equation representing the relationship between the torque and the current flowing through each winding of a double three-phase winding motor having a permanent magnet and a field winding, and corresponds to a "predetermined constraint condition". The evaluation function Pw shown in equation (7) represents copper loss caused by the current flowing through each winding of the motor 1. That is, minimizing the evaluation function Pw of equation (7) means minimizing copper loss, which is one of the losses generated in the motor 1. In equations (6) and (7), T represents the torque of the motor 1, Pn represents the pole pair number, T1 represents the torque of the first stator winding, and T2 represents the torque of the second stator winding. In addition, in consideration of magnetic saturation and inter-axis interference of magnetic flux, terms representing these influences may be added to equation (6). The evaluation function Pw may be a function representing the iron loss or the switching loss, or may be a function representing the total loss including losses such as the copper loss, the iron loss, and the switching loss. The evaluation function may be set not only to a loss but also to an output torque, a torque response, and the like. When the evaluation function is set as the output torque, the output torque may be maximized or minimized under the constraint condition. When the evaluation function is set as a torque response, the torque response may be maximized or minimized under the constraint condition.

When lagrangian functions L (id1, iq1, id2, iq2, if, λ) are constructed based on the above equations (6) and (7), equation (8) is obtained. Where λ is the lagrange coefficient.

[ mathematical formula 3]

When the simultaneous equations are created by making zero the respective derivatives obtained by partial differentiation of the lagrangian function L shown in expression (8) by the respective variables and solving the simultaneous equations, id1, iq1, id2, iq2, if, and λ which minimize the evaluation function of expression (7) can be obtained under the constraint condition of expression (6). In order to calculate each current command for minimizing the evaluation function Pw under the torque command T, the current commands are replaced with T, id1, id1, id2, id2, iq1, iq1, iq2, iq2, and if, if in equation (8), and the simultaneous equations are solved. That is, the simultaneous equations represented by the formula (13) may be solved from the following formula (9).

[ mathematical formula 4]

[ math figure 5]

[ mathematical formula 6]

[ math figure 7]

[ mathematical formula 8]

By solving the simultaneous equations shown in equations (9) to (13), the first stator winding current commands id1, iq1, the second stator winding current commands id2, q2, and the field winding current command if, which minimize the evaluation function Pw under the condition that each current command realizes the torque command T, can be obtained.

When several parameters related to the first stator winding and the second stator winding are equal, R1 ═ R2 ═ 2R, Ld1 ═ Ld2 ═ 2Ld, Mf1 ═ Mf2 ═ Mf, KE1 ═ KE2 ═ KE, Md, and Mq may be set to be twice the above-described defined values, each current command is generated such that first stator winding current commands id1 ·, iq1 · and second stator winding current commands id2 ·, iq2 ·areequal. Namely, id1 ═ id2 ═ id, and iq1 ═ iq2 ═ iq ═ 2 ═ iq. In this case, equations (14) to (16) below are derived by modifying equations (9) to (13).

[ mathematical formula 9]

[ mathematical formula 10]

[ mathematical formula 11]

As described above, when the parameters related to the first stator winding and the second stator winding are equal to each other, the current command id (═ id1 ═ id2 ═ 2), iq (═ iq1 ═ iq2 ═ 2), if, which minimizes the evaluation function Pw under the condition of realizing the torque command T, can be obtained by solving the simultaneous equations expressed by expressions (14) to (16).

On the other hand, when there is a difference in response speed to the current command between the excitation winding and the first and second stator windings, equations (14) to (16) do not actually hold. Specifically, when the response speed of the field winding current if to the field winding current command if is slower than the response speeds of the first stator winding d-axis current id1, the first stator winding q-axis current iq1, and the second stator winding d-axis current id2, the second stator winding q-axis current iq2 to the first stator winding current commands id1, iq1, and the second stator winding current commands id2, iq2, if is not satisfied, in the transient state, if is, equation (14) to equation (16) does not hold. Therefore, even if the simultaneous equations of equations (14) to (16) are solved without considering the influence of the response delay of the field winding current if, an optimal solution is not obtained, and the current command obtained as the operation result does not minimize the evaluation function Pw. Further, since the constraint condition of expression (6) is not satisfied, the followability to the torque command T is also reduced. Thus, when the difference in response speed between the windings (response delay of the field winding) is not considered, the copper loss increases and the efficiency decreases, and the followability to the torque command T decreases, so that the torque response deteriorates.

A field winding current command if satisfying the following expression (17) obtained by modifying expressions (14) to (16) is calculated in the field current command generator 71 according to embodiment 1.

[ mathematical formula 12]

Equation (17) which is a quartic equation of the field winding current command if can be obtained by a recursive numerical solution such as a newton method or a torque feedback method. The field current command generator 71 outputs the calculated field winding current command if to the field winding current control unit 21 and the field current time constant filter 72.

The field current time constant filter 72 artificially reproduces a response delay of the field winding current if with respect to the field winding current command if so that the field winding current command if at a certain point in time approaches the field winding current if. As the exciting current time constant filter 72, one or more filters of filters G1, G2, G3, and G4 shown in the following expression (18) are used.

[ mathematical formula 13]

In equation (18), G1 reproduces the response delay caused by the impedance of the field winding in a simulation. TLf is the time constant of the field winding with respect to current, depending on the impedance of the field winding. Further, G2 simulates a response delay in reproduction current control response. TCf is a time constant of the field winding current control section 21, and depends on the impedance of the field winding. In addition, G3 simulates reproducing the response delay due to sensor delay. Tsensor is a time constant of the sensor delay and depends on the characteristics of the sensor used by the current detector 6 or the like. In addition, G4 reproduces the response delay due to the operation cycle in an analog manner. Tcc is a time constant of the operation period and depends on the characteristics of the processor 10. The field current time constant filter 72 applies one or more filters among the filters G1, G2, G3, and G4 to the field winding current command if output from the field current command generator 71, and outputs the field winding current command if, which simulates a response delay that reproduces the field winding current if, to the stator current command generator 73. The excitation current time constant filter 72 may be constituted by a filter, a LUT, a function, and a state estimator. Further, the field winding current command if may be the field winding current if received from the current detector 6.

The stator current command generator 73 calculates the first stator winding current commands id1, iq1 and the second stator winding current commands id2, iq2 using the following expressions (19) and (20) based on the torque command T output from the torque time constant filter 70, the field winding current command if output from the field current time constant filter 72, and the motor parameter 63.

[ mathematical formula 14]

[ mathematical formula 15]

The stator current command generator 73 outputs the first stator winding current commands id1, iq1 and the second stator winding current commands id2, iq2 calculated by using equations (19) and (20) to the first stator winding current control unit 22 and the second stator winding current control unit 23, respectively. Since the first stator winding current commands id1, iq1 and the second stator winding current commands id2, iq2 calculated by the stator current command generator 73 are calculated based on the field winding current command if in which the response delay of the field winding current if is reproduced in a simulated manner, the evaluation function Pw is minimized and the constraint condition of expression (6) is satisfied. Therefore, as compared with the case where the response delay of the field winding current if is not taken into consideration, the followability to the torque command T is improved, the transient torque response is improved, and the copper loss is reduced, and the efficiency is improved.

The calculation of each current command in the current command calculation unit 60 is summarized as follows. First, the simultaneous equations obtained by the lagrange indeterminate constant method are transformed to derive an equation of the field winding current command if, and the field winding current command if is obtained by solving the equation.

Next, a response delay of the field winding current if with respect to the field winding current command if is reproduced in a simulated manner, and the field winding current command if, which is reproduced in a simulated manner, is calculated.

Then, the first stator winding current commands id1, iq1 and the second stator winding current commands id2, iq2 are calculated by using the field winding current command if whose response delay is reproduced in analog.

The field winding current if is controlled by a field winding current command if, i.e., a field winding current command if without considering the response delay. The field winding current command if, reproduced with a response delay, is used to calculate the first stator winding current commands id1, iq1 and the second stator winding current commands id2, iq2, but not to control the field winding current if.

When parameters related to the first stator winding and the second stator winding are different, and R1 ≠ R2, Ld1 ≠ Ld2, Mf1 ≠ Mf2, KE1 ≠ KE2, the first stator winding current commands id1 ≠ iq1 and the second stator winding current commands id2 ≠ iq2 are calculated so that id1 ≠ id2, iq1 ≠ iq 2.

In embodiment 1, it is assumed that the response of the excitation winding current is slower than the response of the first stator winding current and the second stator winding current for the plurality of windings, but the present invention is not limited thereto. For example, embodiment 1 can also be applied to a case where the response of the first stator winding is slow. In this case, first stator winding current commands id1, iq1 are first calculated, response delays are reproduced for them, and current commands for the other windings are calculated using first stator winding current commands id1, iq1, which reproduce the response delays. In this case, the first stator winding corresponds to the "second winding", and the other windings correspond to the "first winding".

The constraint conditions of the lagrangian indeterminate constant method are not limited to the constraint conditions shown in equation (6), and current limits shown in equations (21) to (23) and voltage limits shown in equations (24) to (26) may be added.

[ mathematical formula 16]

[ mathematical formula 17]

[ mathematical formula 18]

[ math figure 19]

[ mathematical formula 20]

[ mathematical formula 21]

k₃V_DC3≥|v_f|....(26)

In equations (24) to (26), k1, k2, and k3 represent voltage utilization rates, respectively. Each of vd1, vq1, vd2, vq2 and vf indicates a d-axis voltage of the first stator winding, a q-axis voltage of the first stator winding, a d-axis voltage of the second stator winding, a q-axis voltage of the second stator winding and a voltage of the field winding. The relational expressions vd1, vq1, vd2, vq2, vf are expression (27). When the constraint conditions shown in expressions (21) to (23) are added, each current command can be generated so as to minimize the evaluation function Pw during current limitation. When the constraint conditions shown in equations (24) to (26) are added, each current command can be generated so as to minimize the evaluation function Pw when the voltage is saturated. Furthermore, constraints other than the above-described limitations may be changed or added.

[ mathematical formula 22]

Effects when embodiment 1 is applied will be described based on fig. 8A and 8B. Fig. 8A is a diagram showing a control result of a conventional motor control device, and fig. 8B is a diagram showing a control result of a motor control device according to embodiment 1. Fig. 8A and 8B show, in order from top to bottom, the time change of the actual current and the current command of the q-axis current, the time change of the actual current and the current command of the d-axis current, the time change of the actual current and the current command of the excitation current, the time change of the torque and the torque command, and the value (copper loss/torque) obtained by dividing the copper loss by the torque. In fig. 8A, the actual current and the actual torque, and the copper loss/torque are shown by solid lines, and the current command and the torque command are shown by broken lines. In fig. 8B, the actual current and torque and the copper loss/torque in embodiment 1 are indicated by solid lines, the current command and the torque command are indicated by broken lines, the actual current and torque and the copper loss/torque in the conventional example are indicated by broken lines, and the current command and the torque command are indicated by thin broken lines. In the control result of the conventional example shown in fig. 8A, the q-axis current and the d-axis current quickly follow the current command, but the response of the excitation current and the torque to the current command and the torque command is delayed compared to the q-axis current and the d-axis current. Further, it is known that the copper loss/torque increases instantaneously. The delay in torque response and the increase in transient copper loss are considered to be caused by a deviation (if ≠ if) between the actual field winding current and the field winding current command.

On the other hand, in the control result of embodiment 1 shown in fig. 8B, although a response delay of the field winding current occurs, a response delay of the torque and an increase of the transient copper loss hardly occur. This is presumably because, in the control of the field current, the actual current value deviates from the current command, while, in the calculation of the first stator winding current commands id1, iq1 and the second stator winding current commands id2, iq2, the current command is calculated so as to minimize the evaluation function Pw representing the copper loss by using the field winding current command if in which the response delay is reproduced in a simulation manner, thereby suppressing the increase in the copper loss, and the current commands realizing the torque command T are generated with higher accuracy by satisfying the constraint condition of expression (6) for the first stator winding current commands id1, iq1 and the second stator winding current commands id2, iq 2.

The motor 1 according to embodiment 1 is a double three-phase motor having a rotor with permanent magnets, but is not limited to this, and may be a motor having no permanent magnets in the rotor. Further, the motor is not limited to the double three-phase winding motor, and may be a motor having stator windings of three or more phases, or a motor having one or three or more sets of stator windings.

According to embodiment 1, even if the motor characteristics change, the efficiency can be prevented from being lowered. More specifically, the motor control device includes a parameter acquiring unit that periodically acquires motor state data indicating a state of the motor to be controlled, updates the motor parameter by acquiring a motor parameter corresponding to the motor state data, and calculates a current command for each winding based on the motor parameter acquired by the motor parameter acquiring unit. Thus, even when the motor characteristics are changed, the current command is calculated based on the changed motor parameters, and motor control corresponding to the change in the motor characteristics is performed. The field winding current command is calculated prior to the first stator winding current command and the second stator winding current command, the response delay of the field winding current with respect to the field winding current command is reproduced in an analog manner, and the first stator winding current command and the second stator winding current command are calculated using the field winding current command reproduced with the response delay. Thus, the field winding current command for calculating the first stator winding current command and the second stator winding current command becomes almost equal to the actual field winding current, and the current command for minimizing the evaluation function indicating the copper loss can be calculated more accurately. Thus, the current command is calculated in consideration of the difference in response speed between the windings while coping with the change in the motor characteristics, so that the efficiency can be prevented from being lowered even when the motor characteristics are changed. For the same reason, the constraint condition for reflecting the torque command can be satisfied with high accuracy, and therefore deterioration of the torque response can be prevented.

In addition, in the calculation of the current command for each winding, the field winding current command is first calculated, and then the first stator winding current command and the second stator winding current command are calculated using the command in which the response delay is reproduced in the field winding current command. Therefore, the calculation cost and the required memory in the motor control can be reduced.

Further, since the parameter acquiring unit periodically acquires the motor parameter and updates the motor parameter used for the calculation of the current command, it is not necessary to create a map in advance, and thus the number of steps to be performed in advance can be reduced and the memory for storing the map can be reduced.

Further, since the torque time constant filter for eliminating the fluctuation of the torque command by a predetermined amount or more is provided, the fluctuation amount and the fluctuation ratio of the torque of the motor become allowable values or less, and the vibration of the motor and the noise caused by the motor can be suppressed.

Further, when the estimated value is used for the motor state data for determining the motor parameter, the influence of harmonic interference and the like that may be included in the actually measured value can be eliminated, and therefore, the convergence in the current command calculation can be improved.

Embodiment 2.

Next, embodiment 2 will be described with reference to fig. 9. The same or corresponding portions as those in fig. 1 to 8B are denoted by the same reference numerals, and the description thereof is omitted. Fig. 9 is a diagram showing a hardware configuration of a motor control device according to embodiment 2, and shows an entire system including a motor to be controlled. The motor control device 2000 controls driving of the motor 80 and is connected to each winding of the motor 80 via a stator winding power conversion device 85 and a field winding power conversion device 86, which will be described later. The motor control device 2000 is connected to a position detector 81 and a temperature detector 82 provided on the motor 80. The motor control device 2000 is connected to current detectors 83 and 84, and the current detectors 83 and 84 are connected in series between the stator winding power conversion device 85 and the field winding power conversion device 86, respectively, and the motor 1.

The motor 80 is a three-phase winding motor including a rotor having a permanent magnet and an excitation winding wound around the permanent magnet, and a stator having three-phase stator windings. The permanent magnets of the rotor may be omitted. Hereinafter, the three-phase winding provided in the stator of the motor 1 is referred to as a "stator winding". The stator winding corresponds to a "first winding", and the field winding corresponds to a "second winding". In addition, the illustration of each part of the motor is omitted.

The position detector 81 is provided on the rotation shaft of the motor 80, and detects the angle θ of the rotor. The position detector 81 transmits the detected angle θ to the motor control device 2000. Instead of the position detector 2, a position estimator for estimating the angle θ of the rotor may be provided, and the estimated value of the angle θ may be transmitted to the motor control device 1000.

The temperature detector 82 detects at least one of the temperature ts of the stator winding, the temperature tf of the field winding, and the temperature tM of the permanent magnet. The temperature detector 82 transmits the detected temperatures ts, tf, and tM to the motor control device 2000. Instead of the temperature detector 82, a temperature estimator may be provided, and the estimated values of ts, tf, and tM may be transmitted to the motor control device 2000.

The current detector 83 detects three-phase currents flowing through the stator windings, and transmits the respective current values as stator winding currents iu, iv, iw to the motor control device 2000. The current detector 83 detects a current flowing through the field winding, and sends the current value thereof to the motor control device 2000 as a field winding current if. Instead of the current detectors 83 and 84, a current estimator may be provided, and the estimated values of iu, iv, iw, and if may be transmitted to the motor control device 2000.

The stator winding power conversion device 85 receives three-phase voltage commands vu, vv, and vw for the stator windings from the motor control device 2000, and generates voltages corresponding to the respective voltage commands. Further, the stator winding power conversion device 85 detects a dc link voltage for power conversion relating to the stator winding, and transmits the voltage value as a dc link voltage VDCS to the motor control device 2000.

The field winding power conversion device 86 receives a field winding voltage command vf, which is a voltage command for the field winding, from the motor control device 2000, and generates a voltage corresponding to the field winding voltage command vf. The field winding power conversion device 86 detects a dc link voltage for power conversion with respect to the field winding, and transmits the voltage value as a dc link voltage VDCf to the motor control device 2000.

The processor 87 is, for example, a CPU, and executes a program read from the storage device 88 to realize various functional units shown in fig. 10. When the processor 87 reads the program from the storage device 88, the program stored in the auxiliary storage device is read by the volatile storage device. The processor 87 executes the program to generate a current instruction, data, and the like. The processor 10 may output the data to a volatile storage device of the storage device 11, or may store the data in an auxiliary storage device via the volatile storage device.

The processor 87 sends the generated current command to the stator winding power conversion device 85 and the field winding power conversion device 86 through an interface (not shown) with the outside. The processor 87 receives the angle theta from the position detector 81. The processor 87 receives the temperatures ts, tf, tM from the temperature detector 82. Further, the processor 10 receives the stator winding currents iu, iv, iw from the current detector 83, and the field winding current if from the current detector 84. Further, the processor 10 receives the dc link voltages VDCS, VDCf from the stator winding power conversion device 85 and the field winding power conversion device 86, respectively. Further, the processor 10 receives a torque command T input from a higher-level control device or a user, a current limit idqlim as an upper limit value of a current in the stator winding, and a current limit iflim as an upper limit value of a current in the field winding.

Fig. 10 is a block diagram showing a motor control device according to embodiment 2. The motor control device 2000 includes: a drive current command generating unit 93 that generates current commands for controlling currents flowing through the windings of the motor 80 and drives the motor 1; a stator winding current control unit 92 that converts stator winding current commands id, iq for controlling currents flowing through the stator windings into stator winding voltage commands vu, vv, vw as three-phase voltage commands; and a field winding current control unit 91 that converts a field winding current command if for controlling the current flowing through the field winding into a field winding voltage command vf. The motor control device 2000 includes a differentiator 90, and the differentiator 20 receives the angle θ of the rotor of the motor 80 from the position detector 81 of the motor 80 and calculates the angular velocity ω of the rotor. The stator winding current commands id and iq correspond to "a first current command", and the field winding current command if corresponds to "a second current command".

The driving current command generating unit 93, the stator winding current control unit 92, the field winding current control unit 91, and the differentiator 90 correspond to the driving current command generating unit 24, the first stator winding current control unit 22, the second stator winding current control unit 23, the field winding current control unit 21, and the differentiator 20 in embodiment 1, and have the same configuration except that the "first stator winding" and the "second stator winding" in embodiment 1 are replaced with the "stator winding" in embodiment 2, and therefore detailed description of the configuration is omitted.

Since embodiment 2 is obtained by replacing the double three-phase motor in embodiment 1 with a three-phase motor, if the current command, and the voltage command in embodiment 1 are replaced, the same as embodiment 1 is applied. Specifically, id/2 ═ id1 ═ id2 ═ iq1 ═ iq2 ═ vu/2 ═ vu1 ═ vu2, vv/2 ═ vv1 ═ vv2, vw/2 ═ vw1 ═ vw2, iu/2 ═ iu1 ═ iu2, iv/2 ═ iv1 ═ iv2, iw/2 ═ iw1 ═ iw2 may be substituted.

The rest of the description is omitted since it is the same as embodiment 1.

According to embodiment 2, the same effects as those of embodiment 1 can be obtained.

While various exemplary embodiments and examples are described herein, the various features, aspects, and functions described in one or more embodiments are not limited in their application to a particular embodiment, but may be applied to embodiments alone or in various combinations.

Therefore, countless modifications not shown by way of example can be conceived within the technical scope disclosed in the present application. For example, the present invention includes a case where at least one of the components is modified, added, or omitted, and a case where at least one of the components is extracted and combined with the components of the other embodiments.

Description of the reference symbols

1. 80 motors, 4, 5, 6, 83, 84 current detectors, 24, 93 drive current command generating units, 60 current command calculating units, 61 parameter acquiring units, 62 motor state data, 63 motor parameters, 71 field current command generating units, 72 field current time constant filters, 73 stator current command generating units, 1000, 2000 motor control devices, id1, iq1 first stator winding current command, id2, iq2 second stator winding current command, id, iq stator winding current command, if field winding current command, iu1, iv1, iw1 first stator winding current, iu2, iv2, iw2 second stator winding current, iu, iv, iw stator winding current, if field winding current, T torque command.