Control device, control program, and control method

Abstract

A control device (30) comprises: a current command value calculation unit (80) that calculates a current command value (Id*, Iq*); a high-frequency current command unit (81) that adds a high-frequency current command value to the current command value; a feedback calculation unit (83) that calculates an operation amount (Vd1*, Vq*) for performing feedback control so as to reduce the current deviation between the current command value to which the high-frequency current command value has been added and a current (Idr, Iqr) flowing through an armature winding; a high-frequency controller (84) having a large gain with respect to a high-frequency current component of the current deviation; a differential controller (85) that performs differential control to mitigate a response delay; and a switch control unit (87). The high-frequency controller and the differential controller are used to calculate an adjustment value for mitigating the response delay while increasing the high-frequency current component, and the switch control unit performs switching control of an inverter on the basis of an operation amount (Vd2*, Vq*) obtained by adding or subtracting the adjustment value.

Description

Control device, control program, and control method CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Japanese Application No. 2024-145403 filed on August 27, 2024, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a control device, a control program, and a control method for a rotating electric machine.

[0003] Conventionally, a magnetic pole position sensorless control system for an interior permanent magnet motor is known, which utilizes phase information of harmonic instantaneous reactive power generated by high-frequency current injection. Such a control system uses a PI regulator in the current control system, resulting in low loop gain for the harmonic current to be injected, which can lead to distortion of the harmonic current due to effects such as spatial harmonics. Therefore, a resonant regulator has been proposed to selectively increase the loop gain for the harmonic current to be injected into the motor. This configuration can suppress distortion of the injected harmonic current due to effects such as spatial harmonics. Such a technology is described, for example, in Non-Patent Document 1.

[0004] Toshihiko Noguchi and Kazunori Motono, "High Performance Sensorless IPM Motor Control System Using Harmonic Current Injection Method," Transactions of the Institute of Electrical Engineers of Japan, Vol. 126, No. 3, pp. 360-367, 2006

[0005] However, even if the harmonic current to be injected is selected and its gain is increased using a resonant regulator, there is a problem in that, depending on the frequency of the harmonic current, a delay in the motor to be controlled may occur, making it impossible to generate harmonic currents of appropriate amplitude in the motor.

[0006] A primary object of the present disclosure is to provide a control device, a control program, and a control method that can appropriately generate a high-frequency current.

[0007] a feedback calculation unit that calculates a control variable for feedback control so as to reduce a current deviation between the current command value to which the high frequency current command value has been added by the high frequency current command unit and the current flowing through the armature winding; a high frequency controller that has a large gain for a component of the high frequency current in the current deviation; a differential controller that performs differential control to reduce a response delay due to the rotating electric machine that is the control target; and a switch control unit that performs switching control of the inverter; wherein the high frequency controller and the differential controller calculate an adjustment value to reduce the response delay while increasing the component of the high frequency current, and the switch control unit performs switching control of the inverter based on the operation variable to which the adjustment value has been added or subtracted.

[0008] According to the above configuration, the differential controller reduces the response delay due to the rotating electric machine, thereby preventing a phase delay in the high-frequency current to be output, which would otherwise cause a loss of system stability, and allowing a high-frequency current of appropriate amplitude to be output.

[0009] A control program for solving the above problem is a control program executed by a control device of a rotating electric machine that is applied to a control system including a rotating electric machine having a multi-phase armature winding and an inverter connecting the armature winding and a DC power supply, and the control device includes: a current command value calculation step of calculating a current command value; a high frequency current command step of adding a high frequency current command value to the current command value for injecting a high frequency current into the armature winding; and a feedback calculation step of calculating a manipulated variable for feedback control so as to reduce a current deviation between the current command value to which the high frequency current command value has been added in the high frequency current command step and the current flowing in the armature winding. a high-frequency control step for calculating an adjustment value with a large gain for the high-frequency current component of the current deviation; a differential control step for performing differential control to reduce response delay due to the rotating electric machine to be controlled; and a switch control step for performing switching control of the inverter based on the operation amount to which the adjustment value has been added or subtracted, wherein the high-frequency control step and the differential control step calculate an adjustment value to reduce response delay while increasing the high-frequency current component, and in the switch control step, switching control of the inverter is performed based on the operation amount to which the adjustment value has been added or subtracted.A control method for solving the above problem is a control method implemented by a control device of a rotating electric machine that is applied to a control system including a rotating electric machine having a multi-phase armature winding and an inverter connecting the armature winding and a DC power source, the control method including: a current command value calculation step of calculating a current command value; a high frequency current command step of adding a high frequency current command value to the current command value for injecting a high frequency current into the armature winding; a feedback calculation step of calculating a manipulated variable for feedback control so as to reduce a current deviation between the current command value to which the high frequency current command value has been added in the high frequency current command step and the current flowing in the armature winding; The method includes a high-frequency control step of calculating an adjustment value with a large gain for the high-frequency current component of the current deviation, a differential control step of performing differential control to mitigate response delays due to the rotating electric machine to be controlled, and a switch control step of performing switching control of the inverter based on the operation amount to which the adjustment value has been added or subtracted, and the high-frequency control step and the differential control step calculate an adjustment value to mitigate response delays while increasing the high-frequency current component, and in the switch control step, switching control of the inverter is performed based on the operation amount to which the adjustment value has been added or subtracted.

[0010] According to the above configuration, the differential controller reduces the response delay due to the rotating electric machine, thereby preventing a phase delay in the high-frequency current to be output, which would otherwise cause a loss of system stability, and allowing a high-frequency current of appropriate amplitude to be output.

[0011] The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which Fig. 1 is an overall configuration diagram of a control system for a rotating electric machine, Fig. 2 is a diagram showing an inverter and its peripheral configuration, Fig. 3 is a control block diagram showing the functions of a control device, Fig. 4 is a control block diagram showing control related to the d axis of a comparative example, Fig. 5 is a diagram showing closed-loop characteristics of the comparative example, Fig. 6 is a Bode plot showing open-loop characteristics of the comparative example, Fig. 7 is a control block diagram showing control related to the d axis of this embodiment, Fig. 8 is a diagram showing closed-loop characteristics of this embodiment, Fig. 9 is a Bode plot showing open-loop characteristics of this embodiment, and Fig. 10 is a control block diagram showing control related to the d axis of a second embodiment. 11 is a diagram showing open loop characteristics of the second embodiment, FIG. 12 is a control block diagram showing control related to the d axis of the third embodiment, FIG. 13 is a diagram showing the relationship between a current command value and an output current, FIG. 14 is a diagram showing the relationship between a current command value and an output current, FIG. 15 is a diagram showing the relationship between a current command value and an output current, FIG. 16 is a diagram showing the relationship between a current command value and an output current, FIG. 17 is a control block diagram showing control related to the d axis of a modified example, FIG. 18 is a control block diagram showing control related to the d axis of a modified example, FIG. 19 is a control block diagram showing current control of a modified example, and FIG. 20 is a diagram showing open loop characteristics of a modified example.

[0012] Several embodiments will be described with reference to the drawings. In several embodiments, functionally and / or structurally corresponding and / or associated parts may be designated by the same reference numerals or reference numerals that differ in the hundredth or more digit. For corresponding and / or associated parts, reference may be made to the descriptions of other embodiments.

[0013] First Embodiment A first embodiment of a control device for a rotating electric machine according to the present disclosure will now be described with reference to the drawings. A rotating electric machine 40 constitutes a control system 100 for the rotating electric machine 40, and the control system 100 is mounted on a vehicle. The rotating electric machine 40 is a power source for driving the vehicle.

[0014] 1, the control system 100 includes a DC power supply 10, an inverter 20, a control device 30, and a rotating electric machine 40. The rotating electric machine 40 is a self-excited field winding type synchronous machine (synchronous induction excitation motor). For example, the rotating electric machine 40, the inverter 20, and the control device 30 may be included to form an electromechanical integrated drive device, or the rotating electric machine 40, the inverter 20, and the control device 30 may each be formed by a separate component.

[0015] The rotating electric machine 40 includes a housing 41, and a stator 50 and a rotor 60 housed in the housing 41. The rotating electric machine 40 of this embodiment is an inner rotor type rotating electric machine in which the rotor 60 is disposed radially inside the stator 50.

[0016] The stator 50 includes a stator core 51 and a stator winding 52. The stator winding 52 is made of, for example, copper wire, and includes U-, V-, and W-phase windings 52U, 52V, and 52W that are arranged with an electrical angle offset of 120° from one another.

[0017] The rotor 60 includes a rotor core 61 and a field winding 70. The field winding 70 is made of, for example, aluminum wire, copper wire, or CNT (carbon nanotube). A rotating shaft 32 is inserted through the center hole of the rotor core 61. The rotating shaft 32 is rotatably supported by the housing 41 via a bearing 42.

[0018] 2, the rotor 60 is configured with a field winding 70 and a rectifier circuit in which a diode 71 is connected in series to the field winding 70. Note that the circuit configuration of the rotor 60 is an example, and other circuit configurations may also be used.

[0019] As shown in FIG. 2 , the inverter 20 includes a series connection of U-, V-, and W-phase upper-arm switches SUp, SVp, and SWp and U-, V-, and W-phase lower-arm switches SUn, SVn, and SWn. First ends of U-, V-, and W-phase windings 52U, 52V, and 52W are connected to the connection points between the U-, V-, and W-phase upper-arm switches SUp, SVp, and SWp and the U-, V-, and W-phase lower-arm switches SUn, SVn, and SWn. Second ends of the U-, V-, and W-phase windings 52U, 52V, and 52W are connected to the neutral point. That is, in this embodiment, the U-, V-, and W-phase windings 52U, 52V, and 52W are star-connected. Note that, in this embodiment, each of the switches SUp to SWn is an IGBT. A freewheel diode is connected in antiparallel to each of the switches SUp to SWn. Each of the switches SUp to SWn may be, for example, an N-channel MOSFET.

[0020] The collectors, which are high-potential terminals of the U-, V-, and W-phase upper-arm switches SUp, SVp, and SWp, are connected to the positive terminal of a DC power supply 10. The emitters, which are low-potential terminals of the U-, V-, and W-phase lower-arm switches SUn, SVn, and SWn, are connected to the negative terminal of the DC power supply 10. A smoothing capacitor 11 is connected in parallel to the DC power supply 10.

[0021] The control system 100 includes a current sensor 21, an angle sensor 22, a voltage sensor 23, and a temperature sensor 24. The current sensor 21 detects at least two phases of the currents flowing through the rotating electric machine 40. The angle sensor 22 detects the rotation angle (electrical angle) of the rotor 60 and is, for example, a resolver. In this embodiment, the voltage sensor 23 detects the voltage of the DC power supply 10. The temperature sensor 24 detects the temperature of the rotating electric machine or the like and is, for example, a thermistor. The detected values ​​of the sensors 21 to 24 are input to the control device 30.

[0022] The control device 30 is an electronic control unit (EC) primarily composed of a microcomputer 31. The microcomputer 31 includes a central processing unit (CPU). The functions provided by the microcomputer 31 can be provided by software stored in a physical memory device and a computer executing the software, software alone, hardware alone, or a combination thereof. For example, if the microcomputer 31 is provided by a hardware electronic circuit, the functions can be provided by a digital circuit including multiple logic circuits or an analog circuit. For example, the microcomputer 31 executes a program stored in a non-transitory tangible storage medium (NSS) that serves as its own storage unit. The program includes a program for controlling the rotating electric machine 40. A method corresponding to the program is executed by executing a set of instructions that constitute the program. The storage unit is, for example, a non-volatile memory. The program stored in the storage unit can be updated via a communication network such as the Internet, for example, via OTA (Over the Air).

[0023] The control device 30 generates drive signals that turn on and off each of the switches SUp to SWn that constitute the inverter 20 in order to control the control variable of the rotating electric machine 40 to a command value. In this embodiment, the control variable is torque. That is, the control device 30 generates drive signals that turn on and off each of the arm switches SUp to SWn in order to convert the DC power output from the DC power supply 10 into AC power and supply it to the U-, V-, and W-phase windings 52U, 52V, and 52W, and supplies the generated drive signals to the gates of each of the arm switches SUp to SWn. As a result, the upper arm switches and the lower arm switches in each phase are alternately turned on with dead times therebetween.

[0024] The control device 30 turns on and off the switches SUp to SWn so that a composite current of a fundamental current and a high-frequency current (specifically, a harmonic excitation current) having a frequency higher than that of the fundamental current flows through each of the phase windings 52U, 52V, and 52W. The fundamental current is a current that mainly generates torque in the rotating electric machine 40. The high-frequency current is an excitation AC current that mainly excites the field winding 70 and induces a field current in the field winding 70. The phase currents flowing through the phase windings 52U, 52V, and 52W are shifted by 120 electrical degrees.

[0025] The high-frequency current flowing through the stator winding 52 may be a harmonic current whose fluctuating frequency is N times (N is an integer of 2 or more) the frequency of the fundamental current, or may be a current whose fluctuating frequency is different from N times the frequency of the fundamental current.

[0026] Next, the control process of the rotary electric machine 40 executed by the control device 30 will be described with reference to Fig. 3. Fig. 3 is a block diagram of the control process.

[0027] The current command value calculation unit 80 calculates a d-axis current command value Id1* and a q-axis current command value Iq* in a dq coordinate system, which is a two-phase rotating coordinate system, using a torque-dq map or the like based on the command torque Trq* received from a control device that is higher in level than the control device 30. Here, the currents commanded by the d-axis current command value Id1* and the q-axis current command value Iq* are fundamental wave currents.

[0028] The excitation current command value calculation unit 81 calculates a high-frequency current command value Idh* for generating a harmonic excitation current. The d-axis current command value Id1* and the high-frequency current command value Idh* are summed to obtain a d-axis current command value Id2*. The excitation current command value calculation unit 81 in this embodiment corresponds to a high-frequency current command unit. The harmonic excitation current may or may not be an order component relative to the fundamental wave component (i.e., it may be a fundamental wave component).

[0029] The current conversion unit 82 calculates the d-axis current value Idr and the q-axis current value Iqr in the dq-axis coordinate system, which is a rotating coordinate system, based on the current values ​​Iur, Ivr, and Iwr of each phase detected by the current sensor 21 and the electrical angle θr detected by the angle sensor 22.

[0030] The d-axis current feedback control unit 83 (hereinafter simply referred to as the d-axis control unit 83) calculates a d-axis voltage command value Vd1* as a manipulated variable based on the d-axis current command value Id2* and the d-axis current value Idr. Specifically, the d-axis control unit 83 inputs a d-axis current deviation, which is the difference (Id2*-Idr) between the d-axis current command value Id2* and the d-axis current value Idr, and calculates the d-axis voltage command value Vd1* as a manipulated variable for feedback-controlling the d-axis current deviation to zero. The feedback control is, for example, proportional-integral control (PI control).

[0031] A high-frequency controller 84 and a differential controller 85 are provided in parallel to the d-axis control unit 83. The high-frequency controller 84 will now be described. When performing feedback control (here, PI control), even if a harmonic excitation current is superimposed on a fundamental current, the loop gain is low, making it difficult to flow the harmonic excitation current as commanded. Therefore, the high-frequency controller 84 is provided to increase the gain of the harmonic excitation current component. The high-frequency controller 84 is a controller that has a large gain characteristic with respect to the frequency of the harmonic excitation current component. Note that the high-frequency controller 84 is also a feedback control (of the harmonic excitation current), but the control provided in parallel with the high-frequency controller 84 and the differential controller 85 will be referred to as feedback control in this specification.

[0032] This high-frequency controller 84 is represented by a transfer function G(s) shown in equation (eq.1). The high-frequency controller 84 calculates the adjustment value ADJ1 by multiplying the d-axis current deviation (Id2*-Idr) by the transfer function G(s) shown in equation (eq.1). Here, "k" is a control gain, "s" is a differential operator, and "Wc" is the center frequency of the high-frequency controller 84.

[0033] As shown in equation (eq.1), the high-frequency controller 84 extracts a component of the d-axis current deviation that has the same frequency as the center frequency Wc, multiplies the extracted component by a control gain k, and calculates the adjustment value ADJ1. The high-frequency controller 84 has a second-order transfer characteristic (a second-order differential operator) in the denominator of the transfer function G(s). In this embodiment, the center frequency Wc is set to the frequency of the harmonic excitation current. Therefore, the high-frequency controller 84 of this embodiment extracts the harmonic excitation current component of the d-axis current deviation, multiplies the harmonic excitation current component by a control gain k, and calculates the adjustment value ADJ1. In other words, the high-frequency controller 84 functions as a resonant regulator, extracts the harmonic excitation current component from the d-axis current deviation using the resonant regulator function, and multiplies the extracted component by the control gain k.

[0034] The transfer function (analog filter) shown in equation (eq.1) is digitized and implemented (embedded in a program). In other words, the analog filter shown in equation (eq.1) is converted into a digital filter. When digitizing the transfer function shown in equation (eq.1), it is converted using, for example, a bilinear transformation. At this time, prewarping may be performed.

[0035] The adjustment value ADJ1 is adjusted by a differential controller 85 (described later) to become a final adjustment value ADJ2. The final adjustment value ADJ2 is then added to the d-axis voltage command value Vd1* to become a final d-axis voltage command value Vd2*, which is input to the drive signal generation unit 87.

[0036] The q-axis current feedback control unit 86 (hereinafter referred to as the q-axis control unit 86) calculates a q-axis voltage command value Vq* as a manipulated variable based on the q-axis current command value Iq* and the q-axis current value Iqr. Specifically, the q-axis control unit 86 inputs a q-axis current deviation, which is the difference (Iq*-Iqr) between the q-axis current command value Iq* and the q-axis current value Iqr, and calculates the q-axis voltage command value Vq* as a manipulated variable for feedback-controlling the q-axis current deviation to zero. The feedback control is, for example, proportional-integral control (PI control).

[0037] Based on the calculated d-axis voltage command value Vd2* and q-axis voltage command value Vq*, the drive signal generator 87 generates drive signals for the switches SUp to SWn of the inverter 20. The drive signals include on and off commands for the switches.

[0038] An example of a method for generating drive signals in the drive signal generator 87 will be described. The drive signal generator 87 calculates U-, V-, and W-phase voltage command values ​​Vu*, Vv*, and Vw* in a three-phase fixed coordinate system based on the calculated d-axis voltage command value Vd2*, q-axis voltage command value Vq*, and electrical angle θr. The U-, V-, and W-phase voltage command values ​​Vu*, Vv*, and Vw* are shifted in phase by 120° in electrical angle. The drive signal generator 87 generates drive signals for each switch SUp to SWn of the inverter 20 based on a magnitude comparison between the U-, V-, and W-phase voltage command values ​​Vu*, Vv*, and Vw* and a carrier signal (e.g., a triangular wave signal). The drive signal generator 87 in this embodiment corresponds to a switch control unit.

[0039] Based on the generated drive signal, the drive circuit 88 controls the charge / discharge current of the gates of the switches SUp to SWn of the inverter 20. As a result, the switching of the switches SUp to SWn of the inverter 20 is controlled in accordance with the drive signal.

[0040] However, it has been found that simply selecting the harmonic excitation current component and increasing its gain using the high frequency controller 84 results in a delayed response due to the characteristics of the rotating electrical machine 40, which is the object of control. This will now be explained in detail with reference to Figs.

[0041] FIG. 4 is a control block diagram showing feedback control of the d-axis current in a comparative example, FIG. 5 is a diagram showing closed-loop characteristics in the comparative example, and FIG. 6 is a Bode plot showing open-loop characteristics in the comparative example. FIG. 7 is a control block diagram showing feedback control of the d-axis current in this embodiment, FIG. 8 is a diagram showing open-loop characteristics in this embodiment, and FIG. 9 is a Bode plot showing open-loop characteristics in this embodiment. As can be seen by comparing FIG. 4 with FIG. 7, the comparative example in FIG. 4 does not have a differential controller 85 compared to FIG. 7, but the other components are the same. Note that FIGS. 4 and 7 only show components necessary for explanation.

[0042] As shown in the comparative example of FIG. 4 , when the high-frequency controller 84 increases the gain for the high-frequency current component of the d-axis current deviation, the closed-loop characteristics shown in FIG. 5 are obtained. As shown in the area surrounded by the dashed line in FIG. 5 , there is a problem in that the gain becomes excessively larger than 0 dB (i.e., overshoot occurs) near the frequency of the harmonic excitation current. Here, by analyzing the open-loop characteristics from the d-axis current deviation (Id2*-Idr) to the output value (d-axis current value Idr) from the rotating electric machine 40, as shown in FIG. 6 , it is found that there is a phase delay near the frequency where the gain (control response) of the high-frequency controller 84 is high, i.e., near the frequency of the harmonic excitation current. Specifically, there is a delay of about 180 degrees. This is thought to be due to the characteristics of the rotating electric machine 40. As a result of the large phase delay, the system stability is reduced, leading to overshoot. For this reason, in the comparative example, when the frequency of the harmonic excitation current shifts slightly or there is a slight error in the control constant due to differences in operating conditions, disturbances, hardware, etc., it is difficult to output a harmonic excitation current with an appropriate amplitude, and it is also difficult to adjust the control constant.

[0043] Therefore, in this embodiment, as shown in Figures 3 and 7, the delay is alleviated by performing differential control on the adjustment value ADJ1 calculated by the high-frequency controller 84 using the differential controller 85.

[0044] More specifically, the transfer function (transfer function from voltage to current) of the rotating electric machine 40 can be expressed as a first-order lag transfer function M(s) using a resistance value "R" (unit: Ω) indicating the motor resistance of the rotating electric machine 40 and an inductance value "L" (unit: H) indicating the inductance of the rotating electric machine 40. Specifically, the transfer function M(s) of the rotating electric machine 40 is as shown in equation (eq.2).

[0045] Therefore, the transfer function D(s) of the differential controller 85 is the inverse transfer function. That is, the transfer function D(s) of the differential controller 85 is as shown in equation (eq. 3).

[0046] The closed-loop characteristics of the feedback control shown in FIG. 7 are shown in FIG. 8 , and a Bode plot of the open-loop characteristics is shown in FIG. 9 . Analysis of the open-loop characteristics from the d-axis current deviation to the output value (d-axis current value Idr) from the rotating electric machine 40 reveals that, as shown in FIG. 9 , the phase lag near the frequency where the gain (control response) is high due to the high-frequency controller 84, i.e., the phase lag near the frequency of the harmonic excitation current, is alleviated by the differential controller 85. Specifically, as can be seen by comparing FIG. 6 with FIG. 9 , the phase lag of approximately 180 degrees is reduced to approximately 90 degrees. In other words, the differential controller 85 is able to alleviate the response lag of the rotating electric machine 40. As a result, in the closed-loop characteristics shown in FIG. 8 , the gain near the frequency of the harmonic excitation current becomes 0 (dB). Therefore, it can be seen that overshooting can be eliminated, and a harmonic excitation current with an appropriate amplitude can be output.

[0047] The effects of this embodiment will be described.

[0048] The control device 30 includes a high-frequency controller 84 that calculates an adjustment value ADJ1 to increase the gain for the harmonic excitation current component of the d-axis current deviation, and a differential controller 85 that performs differential control on the adjustment value ADJ1 to reduce a response delay due to the rotating electric machine 40 that is the control target. That is, the high-frequency controller 84 and the differential controller 85 calculate an adjustment value ADJ2 to reduce a response delay while increasing the harmonic excitation current (high-frequency current) component. Then, drive signals for the switches SUp to SWn of the inverter 20 are generated based on the d-axis voltage command value Vd2* and the q-axis voltage command value Vq* to which the adjustment value ADJ2 has been added. This prevents a phase delay in the harmonic excitation current to be output, which would otherwise cause a decrease in system stability, and allows a harmonic excitation current of an appropriate amplitude to be output.

[0049] The differential controller 85 has a transfer function that is the inverse function of the transfer function (transfer function from voltage to current) of the rotating electric machine 40. More specifically, as shown in equation (eq. 3), the differential controller 85 is expressed by a transfer function in which the coefficient of a first-order differential operator is the inductance value "L" of the rotating electric machine 40 and the coefficient of a zero-order differential operator is the resistance value "R" of the rotating electric machine 40. As a result, the differential controller 85 can be easily set by calculating the inductance value "L" and the resistance value "R" of the rotating electric machine 40. Note that the frequency of the rotating electric machine 40, determined by the inductance value "L" and the resistance value "R," is smaller than the frequency of the harmonic excitation current. Therefore, even if the inductance value "L" and the resistance value "R" deviate from the actual values, it is possible to reduce a phase delay of approximately 180 degrees to a phase delay of approximately 90 degrees, thereby eliminating overshoot and outputting a harmonic excitation current with an appropriate amplitude.

[0050] The harmonic excitation current is an excitation AC current for causing a field current to flow through the field winding 70. This allows the field winding 70 to generate an appropriate magnetic field.

[0051] Second Embodiment A second embodiment will be described in which the configuration of the control device 30 of the first embodiment is partially modified. Note that the same components as those of the first embodiment are denoted by the same reference numerals, and their description and drawings will be omitted.

[0052] 10, the high-frequency controller 184 of the second embodiment is represented by the transfer function shown in equation (eq.4). This high-frequency controller 184 calculates the adjustment value ADJ1 by multiplying the d-axis current deviation (Id2*-Idr) by the value calculated by equation (eq.4). Here, "k" is the control gain, "s" is a differential operator, "b" indicates the bandwidth, and "Wc" indicates the center frequency of the high-frequency controller 184 of the second embodiment.

[0053] As shown in equation (eq.4), the high-frequency controller 184 of the second embodiment extracts components of a predetermined frequency band from the d-axis current deviation and multiplies the extracted components by a control gain k to calculate an adjustment value ADJ1. The center frequency of the predetermined frequency band corresponds to the center frequency Wc, and the width of the frequency band corresponds to the bandwidth b. In this embodiment, the frequency of the harmonic excitation current is set as the center frequency Wc.

[0054] Therefore, the high frequency controller 184 of this embodiment uses a filter with a center frequency Wc and a bandwidth b to extract the harmonic excitation current component determined by the center frequency Wc and the bandwidth b from the d-axis current deviation, and multiplies the extracted component by a control gain k to calculate the adjustment value ADJ1. The configuration other than the high frequency controller 184 is the same as that of the first embodiment, and therefore a description thereof will be omitted.

[0055] The effects and functions of the second embodiment will be described.

[0056] Fig. 11 shows a Bode diagram of the closed-loop characteristics of the feedback control in the second embodiment. As can be seen from a comparison of the closed-loop characteristics of the first embodiment shown in Fig. 8 with the closed-loop characteristics of the second embodiment shown in Fig. 11, the high-frequency controller 184 sets the frequency of the harmonic excitation current as the center frequency Wc, and in a frequency band of a predetermined bandwidth b, the gain is improved and approaches 0 (dB). As a result, even if the frequency of the harmonic excitation current deviates slightly due to differences in operating conditions, disturbances, hardware, etc., or even if there is a slight error in the control constant, an appropriate output can be obtained.

[0057] In the above embodiment, the inductance value "L" is effective even if it deviates slightly from the actual value. For example, as shown in FIG. 20, the inductance value "L" is effective even if it is 1 / 4 or 4 times the actual value. In FIG. 20, the dashed line indicates the case where the inductance value "L" is 1 / 4 of the actual value, and the dashed-dotted line indicates the case where the inductance value "L" is 4 times the actual value. Furthermore, the solid line indicates the case where the inductance value "L" is the same as the actual value.

[0058] Third Embodiment A third embodiment will be described in which the configuration of the control device 30 of the first embodiment is partially modified. Note that the same components as those of the first embodiment are denoted by the same reference numerals, and their description and drawings will be omitted.

[0059] In the third embodiment, a control delay is identified, and if the control delay is less than a predetermined value, the control gain k is set to a positive value and an adjustment value ADJ2 is added to the d-axis voltage command value Vd1*, as in the first embodiment (as shown in FIG. 2). On the other hand, if the control delay is equal to or greater than the predetermined value, the control gain k is set to a negative value and an adjustment value ADJ2 is subtracted from the d-axis voltage command value Vd1*, as shown in FIG.

[0060] The control delay refers to a delay related to the control of the rotating electric machine 40, such as an output delay phase Δθa or a phase delay amount Δθb due to current detection. First, the output delay phase Δθa will be described. The output delay phase Δθa (unit: rad) is calculated by equation (eq. 5). "Ts" is the control period (unit: sec) of the microcomputer 31, and "Wc" is the center frequency (unit: rad / s). Note that the center frequency Wc in this embodiment is the frequency of the harmonic excitation current.

[0061] That is, it is known that there is a delay of one control cycle between the current detection value used in the calculation of the control command value (voltage command value) and the output of the PWM signal (drive signal) (actual voltage application). In other words, there is a delay of one control cycle between the timing of current detection and the timing of the output of the control command value (voltage command value). Here, the output delay phase Δθa can be calculated by converting the unit of the delay of 1.5 control cycles, which takes into account the zero-order hold, using the center frequency Wc.

[0062] Next, the phase delay amount Δθb due to current detection will be described. When the current sensor 21 detects the current in the stator winding 52 of the rotating electrical machine 40, a detection delay may occur. The detection delay time is determined by a hardware or software filter (not shown) provided between the current sensor 21 and the microcomputer 31. In the case of an RC filter, the phase delay amount Δθb due to current detection is as shown in equation (eq. 6). "R" is the resistance value of the RC filter, "C" is the capacitance of the RC filter, and "Wc" is the center frequency (unit: rad / s).

[0063] In this embodiment, the control delay is the sum of the output delay phase Δθa and the phase delay amount Δθb, but it may be only one of the output delay phase Δθa and the phase delay amount Δθb due to current detection. Note that the phase delay amount Δθb due to current detection may be so small that it can be ignored.

[0064] In this embodiment, when the control delay is less than 90 degrees (1 / 4 cycle) as a predetermined value, the sign of the control gain k is stored as positive. On the other hand, when the control delay is equal to or greater than 90 degrees (1 / 4 cycle) and equal to or less than 270 degrees (3 / 4 cycle), the sign of the control gain k is stored as negative.

[0065] The operation and effect of the third embodiment will be described below. When the control delay is less than 90 degrees (1 / 4 cycle), if the adjustment value ADJ2 is added to the d-axis voltage command value Vd1*, the harmonic excitation current is output in the rotating electrical machine 40 following the high-frequency current command value without delay, as shown in FIG.

[0066] If the control delay is less than 90 degrees (1 / 4 cycle), subtracting the adjustment value ADJ2 will cause the current to oscillate as shown in FIG. 14, as it will no longer follow the control delay.

[0067] On the other hand, when the control delay is 90 degrees (1 / 4 cycle) or more and 270 degrees (3 / 4 cycle) or less, if the sign of the control gain k is made negative and the adjustment value ADJ2 is subtracted from the d-axis voltage command value Vd1*, as shown in Figure 16, in the rotating electric machine 40, the harmonic excitation current is output following the high-frequency current command value without delay.

[0068] In addition, when the control delay is equal to or greater than 90 degrees (1 / 4 cycle) and equal to or less than 270 degrees (3 / 4 cycle), if the sign of the control gain k is set to be positive and the adjustment value ADJ2 is added, the current will oscillate as shown in Fig. 15. (Modifications) Modifications in which part of the control device 30 of each of the above embodiments is modified will be described below.

[0069] In the above embodiment, the differential controller 85 performs differential control on the adjustment value ADJ1, but the order of control may be changed. For example, as shown in FIG. 17 , differential control may be performed on the d-axis current deviation before control by the high-frequency controllers 84 and 184 is performed. Also, as shown in FIG. 18 , a high-frequency controller 284 that combines the transfer function of the high-frequency controller 84 and the transfer function of the differential controller 85 may be provided in parallel with the d-axis control unit 83. In other words, as long as the transfer functions are equivalent, the same effect can be achieved even if the order is reversed or the two controllers are combined into one.

[0070] In the above embodiment, the transfer function of the rotating electric machine 40 may be as shown in FIG. 19 . In FIG. 19 , “Ld” is the inductance value on the d-axis, “Lq” is the inductance value on the q-axis, and “ω” is the rotational speed (rad / s) of the rotating electric machine 40. A transfer function 101 is a transfer function from voltage to current on the d-axis, and a transfer function 102 is a transfer function related to the interference term on the d-axis. A transfer function 103 is a transfer function related to the interference term on the q-axis, and a transfer function 104 is a transfer function related to voltage to current on the q-axis. In FIG. 19 , the transfer function of the differential controller 185 is the inverse transfer function of the transfer function 101 from voltage to current on the d-axis. The adjustment value ADJ3 is calculated by multiplying the adjustment value ADJ1 calculated by the high-frequency controller 84 by a transfer function 105 related to the interference term related to the d-axis. 19 is calculated by adding the adjustment value ADJ3 to the q-axis voltage command value Vq* output from the q-axis control unit 86. Although not shown, this q-axis voltage command value Vq2* is input to the drive signal generation unit 87.

[0071] In the above embodiment, the high-frequency controllers 84, 184, 284 and the differential controller 85 are employed in the control system 100 that supplies a harmonic excitation current, but they may be employed in other control systems. For example, the high-frequency controllers 84, 184, 284 and the differential controller 85 may be employed in a magnetic pole position sensorless control system for an internal permanent magnet motor, as described in the background art. The high-frequency controllers 84, 184, 284 and the differential controller 85 may also be employed in a control system that supplies a high-frequency current to compensate for torque ripple. The high-frequency controllers 84, 184, 284 and the differential controller 85 may also be employed in a control system that intentionally supplies a high-frequency current to generate torque ripple and thereby cancel out vibrations and noise of the rotating electric machine 40.

[0072] In the above embodiment, the high-frequency current command value Idh* is added to the d-axis current command value Id1*, but the high-frequency current command value Idh* may be added to the q-axis current command value Iq* depending on the type of the rotary electric machine 40. In this case, the high-frequency controllers 84, 184, 284 and the differential controller 85 are provided in parallel with the q-axis control unit 86.

[0073] The high-frequency current command value Idh* may be added to the d-axis current command value Id1*, and the high-frequency current command value Idh* may be added to the q-axis current command value Iq*. In this case, the high-frequency controllers 84, 184, 284 and the differential controller 85 are provided in parallel with the d-axis control unit 83 and the q-axis control unit 86, respectively.

[0074] In the above embodiment, the control device 30 receives the control amount (command torque Trq*, etc.) of the rotating electrical machine 40 from a higher-level control device. However, the control device 30 may calculate the control amount itself. The control amount may also be changed arbitrarily. In other words, the control device 30 may perform rotation speed control instead of torque control.

[0075] The control unit and the method described herein may be implemented by a special-purpose computer configured by configuring a processor and memory programmed to perform one or more functions embodied in a computer program. Alternatively, the control unit and the method described herein may be implemented by a special-purpose computer configured by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the control unit and the method described herein may be implemented by one or more special-purpose computers configured by combining a processor and memory programmed to perform one or more functions with a processor configured with one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by a computer on a computer-readable non-transitory tangible storage medium.

[0076] The technical ideas derived from the above-described embodiment and modifications are described below. [Configuration 1] A control device (30) for a rotating electric machine applied to a control system (100) including a rotating electric machine (40) having armature windings (52U, 52V, 52W) of multiple phases, and an inverter (20) connecting the armature windings and a DC power source (10), comprises: a current command value calculation unit (80) that calculates current command values ​​(Id*, Iq*); a high frequency current command unit (81) that adds a high frequency current command value to the current command value for injecting a high frequency current into the armature winding; feedback calculation units (83, 86) that calculate manipulated variables (Vd1*, Vq*) for feedback control so as to reduce a current deviation between the current command value to which the high frequency current command value has been added by the high frequency current command unit and a current (Idr, Iqr) flowing through the armature winding; and a high frequency controller (84, 184, 284) having a large gain for a component of the high frequency current in the current deviation. A control device comprising: a differential controller (85) that performs differential control to mitigate a response delay due to the rotating electric machine that is a control target; and a switch control unit (87) that controls switching of the inverter, wherein the high-frequency controller and the differential controller calculate an adjustment value to mitigate the response delay while increasing a component of the high-frequency current, and the switch control unit controls switching of the inverter based on the manipulated variables (Vd2*, Vq*) to which the adjustment value is added or subtracted. [Configuration 2] The control device according to Configuration 1, wherein the differential controller has a transfer function that is an inverse function of a transfer function of the rotating electric machine. [Configuration 3] The control device according to Configuration 1 or 2, wherein the differential controller is expressed by a transfer function in which a coefficient of a first-order differential operator is the inductance of the rotating electric machine and a coefficient of a zero-order differential operator is the resistance of the rotating electric machine. [Configuration 4] The control device according to any of Configurations 1 to 3, wherein the rotating electric machine has a field winding (70), and the high-frequency current is an exciting AC current for flowing a field current through the field winding. [Configuration 5] The control device according to any one of configurations 1 to 4, wherein the high frequency controller has a large gain for a frequency band that includes the frequency of the high frequency current and has a predetermined bandwidth.[Configuration 6] The control device according to any one of configurations 1 to 5, wherein the high frequency controller is represented by a transfer function having a first-order differential operator in the numerator and a second-order differential operator in the denominator. [Configuration 7] The control device according to configuration 6, wherein the high frequency controller is represented by a transfer function having a first-order differential operator in the denominator. [Configuration 8] The control device according to any one of configurations 1 to 7, wherein a control delay related to control of the rotating electric machine is a delay of less than 90 degrees with respect to a frequency at which a gain is increased by the high frequency controller, and the adjustment value is added to the manipulated variable. [Configuration 9] The control device according to any one of configurations 1 to 7, wherein a control delay related to control of the rotating electric machine is a delay of 90 degrees or more with respect to a frequency at which a gain is increased by the high frequency controller, and the adjustment value is subtracted from the manipulated variable.[Configuration 10] A control program executed by a control device (30) of a rotating electric machine applied to a control system (100) including a rotating electric machine (40) having armature windings (52U, 52V, 52W) of multiple phases, and an inverter (20) connecting the armature windings and a DC power source (10), the control program including: a current command value calculation step (80) of calculating current command values ​​(Id*, Iq*); a high frequency current command step (81) of adding a high frequency current command value for injecting a high frequency current into the armature winding to the current command value; and feedback calculation steps (83, 86) of calculating manipulated variables (Vd1*, Vq*) for feedback control so as to reduce a current deviation between the current command value to which the high frequency current command value has been added in the high frequency current command step and the current (Idr, Iqr) flowing through the armature winding. A control program that carries out a high frequency control step (84, 184, 284) that calculates an adjustment value with a large gain for the high frequency current component of the current deviation; a differential control step (85) that performs differential control to mitigate response delay due to the rotating electric machine that is the control target; and a switch control step (87) that performs switching control of the inverter based on the operation amounts (Vd2*, Vq*) to which the adjustment value has been added or subtracted, wherein the high frequency control step and the differential control step calculate an adjustment value to mitigate response delay while increasing the high frequency current component, and in the switch control step, performs switching control of the inverter based on the operation amounts (Vd2*, Vq*) to which the adjustment value has been added or subtracted.

[0077] Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and equivalent modifications. In addition, various combinations and forms, including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

Claims

1. A control device (30) for a rotating electric machine applied to a control system (100) including a rotating electric machine (40) having a multi-phase armature winding (52U, 52V, 52W) and an inverter (20) connecting the armature winding and a DC power source (10), comprising: a current command value calculation unit (80) that calculates current command values ​​(Id*, Iq*); a high frequency current command unit (81) that adds a high frequency current command value to the current command value for injecting a high frequency current into the armature winding; a feedback calculation unit (83, 86) that calculates manipulated variables (Vd1*, Vq*) for feedback control so as to reduce a current deviation between the current command value to which the high frequency current command value has been added by the high frequency current command unit and the current (Idr, Iqr) flowing through the armature winding; and a high frequency controller (84, 184, 284) having a large gain for the high frequency current component of the current deviation. A control device comprising: a differential controller (85) that performs differential control to mitigate a response delay due to the rotating electric machine that is the control target; and a switch control unit (87) that performs switching control of the inverter, wherein the high frequency controller and the differential controller calculate an adjustment value to mitigate the response delay while increasing the component of the high frequency current, and the switch control unit performs switching control of the inverter based on the operation amount (Vd2*, Vq*) to which the adjustment value has been added or subtracted.

2. The control device according to claim 1, wherein the differential controller has a transfer function that is an inverse function of the transfer function of the rotating electrical machine.

3. The control device according to claim 1, wherein the differential controller is expressed by a transfer function in which the coefficient of a first-order differential operator is the inductance of the rotating electrical machine and the coefficient of a zero-order differential operator is the resistance of the rotating electrical machine.

4. A control device according to any one of claims 1 to 3, wherein the rotating electric machine has a field winding (70), and the high frequency current is an exciting AC current for causing a field current to flow through the field winding.

5. A control device according to any one of claims 1 to 3, wherein the high frequency controller has a large gain for a frequency band having a predetermined bandwidth and including the frequency of the high frequency current.

6. The control device according to any one of claims 1 to 3, wherein the high frequency controller is expressed by a transfer function having a first-order differential operator in the numerator and a second-order differential operator in the denominator.

7. The control device according to claim 6, wherein the high frequency controller is represented by a transfer function having a first-order differential operator in the denominator.

8. A control device according to any one of claims 1 to 3, wherein the control delay relating to the control of the rotating electric machine is a delay of less than 90 degrees relative to the frequency at which the gain is increased by the high frequency controller, and the adjustment value is added to the manipulated variable.

9. A control device according to any one of claims 1 to 3, wherein the control delay relating to the control of the rotating electric machine is a delay of 90 degrees or more relative to the frequency at which the gain is increased by the high frequency controller, and the adjustment value is subtracted from the manipulated variable.

10. A control program executed by a control device (30) for a rotating electric machine applied to a control system (100) including a rotating electric machine (40) having armature windings (52U, 52V, 52W) of multiple phases and an inverter (20) connecting the armature windings and a DC power source (10), the control program including: a current command value calculation step (80) for calculating current command values ​​(Id*, Iq*); a high frequency current command step (81) for adding a high frequency current command value for injecting a high frequency current into the armature winding to the current command value; and feedback calculation steps (83, 86) for calculating manipulated variables (Vd1*, Vq*) for feedback control so as to reduce a current deviation between the current command value to which the high frequency current command value has been added in the high frequency current command step and the current (Idr, Iqr) flowing through the armature winding. A control program that carries out a high frequency control step (84, 184, 284) that calculates an adjustment value with a large gain for the high frequency current component of the current deviation; a differential control step (85) that performs differential control to mitigate response delay due to the rotating electric machine that is the control target; and a switch control step (87) that performs switching control of the inverter based on the operation amounts (Vd2*, Vq*) to which the adjustment value has been added or subtracted, wherein the high frequency control step and the differential control step calculate an adjustment value to mitigate response delay while increasing the high frequency current component, and in the switch control step, performs switching control of the inverter based on the operation amounts (Vd2*, Vq*) to which the adjustment value has been added or subtracted.

11. A control method implemented by a control device (30) for a rotating electric machine applied to a control system (100) including a rotating electric machine (40) having a multi-phase armature winding (52U, 52V, 52W) and an inverter (20) connecting the armature winding and a DC power source (10), the control method comprising: a current command value calculation step (80) for calculating current command values ​​(Id*, Iq*); a high frequency current command step (81) for adding a high frequency current command value to the current command value for injecting a high frequency current into the armature winding; feedback calculation steps (83, 86) for calculating manipulated variables (Vd1*, Vq*) for feedback control so as to reduce a current deviation between the current command value to which the high frequency current command value has been added in the high frequency current command step and the current (Idr, Iqr) flowing through the armature winding; and a high frequency control step (84, 184, 284) for calculating an adjustment value having a large gain for a component of the high frequency current out of the current deviation. A control method comprising: a differential control step (85) of performing differential control to mitigate response delay due to the rotating electric machine to be controlled; and a switch control step (87) of performing switching control of the inverter based on the operation amounts (Vd2*, Vq*) to which the adjustment value has been added or subtracted, wherein an adjustment value for reducing response delay while increasing the component of the high frequency current is calculated by the high frequency control step and the differential control step, and wherein switching control of the inverter is performed based on the operation amounts (Vd2*, Vq*) to which the adjustment value has been added or subtracted in the switch control step.

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