Rotating electric machine control device and program

Abstract

A winding excitation type rotating electric machine (40) includes a stator (50) including a stator winding (52), and a rotor (60) including a plurality of magnetic poles arranged in a circumferential direction and including an excitation winding (70) provided on each of the magnetic poles. A control device (30) is provided with: a control unit for controlling a stator current flowing through a stator winding and an excitation current flowing through an excitation winding; and an acquisition unit that acquires a rotation parameter indicating the rotation state of the rotor. The control unit controls the magnitude of the excitation current and the phase of the stator current on the basis of the rotation parameter, and increases the excitation current when in a high-speed rotation state in which the rotation speed of the rotor is higher than a predetermined rotation speed than when not in the high-speed rotation state. And the phase of the stator current is controlled to be a weak excitation phase for weakening the excitation magnetic flux of the excitation winding.

Description

[0001] Cross-references of related applications

[0002] This application is based on Japanese application No. 2022-143326 filed on September 8, 2022 and Japanese application No. 2023-100662 filed on June 20, 2023, and the contents thereof are cited herein. Technical Field

[0003] The invention in this specification relates to a control device and a program for a rotating electrical machine. Background Art

[0004] Conventionally, there is known a winding-excitation type rotating electric machine including a stator including a stator winding and a rotor including an excitation winding, as described in Patent Document 1. In this rotating electric machine, a current flowing through the stator winding and an excitation current flowing through the excitation winding are operated in order to control the torque of the rotating electric machine to a command torque.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2018-102111

[0008] However, in an internal magnet type rotating electrical machine (IPM motor), it is known to perform field weakening control in a high speed rotation range in order to increase the reluctance torque by reducing the interlinkage flux to the stator winding (reducing the back electromotive force).

[0009] On the other hand, in the above-mentioned winding excitation type rotating electric machine, it is also considered to perform weak excitation. In this case, it is desirable to construct an appropriate structure based on making the excitation amount by the excitation winding variable. Summary of the invention

[0010] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a control device and a program for a rotating electrical machine which can reduce the required voltage of the rotating electrical machine and increase the output.

[0011] A control device for a rotating electric machine in the present invention is applied to a system including a winding-excitation type rotating electric machine, the winding-excitation type rotating electric machine including a stator including a stator winding and a rotor including a plurality of magnetic poles arranged in a circumferential direction and including an excitation winding provided for each magnetic pole, the control device for the rotating electric machine including:

[0012] a control unit that controls a stator current flowing through the stator winding and an excitation current flowing through the excitation winding; and

[0013] an acquisition unit, the acquisition unit acquiring a rotation parameter indicating a rotation state of the rotor,

[0014] The control unit controls the magnitude of the excitation current and the phase of the stator current based on the rotation parameter. When the rotor is in a high-speed rotation state where the rotation speed is higher than a specified rotation speed, the control unit increases the excitation current compared to a case where the rotor is not in the high-speed rotation state, and controls the phase of the stator current to a weak excitation phase that weakens the excitation flux of the excitation winding.

[0015] In the above structure, when the rotor is in a specified high-speed rotation state, the control of increasing the excitation current and setting the phase of the stator current to a weak excitation phase that weakens the excitation flux of the excitation winding is performed compared to the case where the rotor is not in a high-speed rotation state. In this case, by increasing the excitation current, the inductance of the magnetic pole center (d-axis) of the rotor can be reduced, and the excitation flux can be increased. In addition, by controlling the stator current with a weak excitation phase, the interlinked flux that interlinks with the stator winding can be reduced. Thereby, the drive voltage applied to the stator winding can be reduced, and the output torque of the rotating motor can be increased. As a result, the required voltage of the rotating motor can be reduced and the output can be increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above-mentioned object and other objects, features and advantages of the present invention will become more apparent through the following detailed description with reference to the accompanying drawings. In the accompanying drawings:

[0017] Figure 1 It is the overall structure diagram of the control system of the rotating motor.

[0018] Figure 2 A diagram showing an inverter and its peripheral structure.

[0019] Figure 3 It is a cross-sectional view of the rotor and stator.

[0020] Figure 4 This is a diagram showing a circuit included in the rotor.

[0021] Figure 5 It is the functional block diagram of torque control.

[0022] Figure 6 This is a diagram showing the transition of fundamental wave current and harmonic current.

[0023] Figure 7 This is a diagram showing the magnetic flux generated between the stator and the rotor in a state of weak field excitation.

[0024] Figure 8 This is a diagram showing the relationship between the phases of the field current and the stator current in a case where field weakening is performed with respect to the output torque.

[0025] Fig. 9 This is a diagram showing the relationship between the excitation current and the required voltage.

[0026] Fig.10 This is a diagram showing the relationship between current phase and torque.

[0027] Fig.11 It is a timing chart showing the transition of the U-phase current, U-phase voltage, output torque, and excitation current.

[0028] Fig.12 It is a timing chart showing the transition of the U-phase current, U-phase voltage, output torque, and excitation current.

[0029] Fig.13 This is a timing chart showing the transition of the fundamental wave current and harmonic current of one phase and the transition of the harmonic superimposed current.

[0030] Fig.14 This is a diagram for explaining the energization control for each operating state of the rotating electrical machine.

[0031] Fig.15 : is a flowchart showing the energization control process.

[0032] Fig.16 This is a flowchart showing a processing procedure for increasing the field magnetic flux in a high-speed rotation and high-load state.

[0033] Fig.17 It is a diagram showing the relationship between the rotor rotation speed and the excitation current, and the relationship between the rotor rotation speed and the stator current phase. DETAILED DESCRIPTION

[0034] Hereinafter, an embodiment of a control device according to the present invention will be described with reference to the accompanying drawings. The control device constitutes a control system for a rotating electric machine, and the control system is mounted on a vehicle. The rotating electric machine is a driving power source for the vehicle.

[0035] like Figure 1 As shown, the control system 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 synchronous machine of a winding excitation type. For example, the rotating electric machine 40, the inverter 20, and the control device 30 are provided to form a mechatronic drive device, or the rotating electric machine 40, the inverter 20, and the control device 30 are respectively composed of individual components.

[0036] 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 the present embodiment is an inner rotor type rotating electric machine in which the rotor 60 is arranged radially inward of the stator 50.

[0037] 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 a U-phase winding 52U, a V-phase winding 52V, and a W-phase winding 52W that are arranged to be offset by 120 degrees in electrical angle.

[0038] The rotor 60 includes a rotor core 61 and an excitation winding 70. The excitation winding 70 is formed, for example, by compression molding. As a result, the occupancy rate is improved, and the installability of the excitation winding 70 is improved. In addition, the excitation winding 70 can be formed, for example, by aluminum wire. The specific gravity of the aluminum wire is small, and the centrifugal force when the rotor 60 rotates can be reduced. Aluminum wire has lower strength and hardness than copper wire, and is preferably used in the case of compression molding. In addition, the excitation winding 70 is not limited to aluminum wire, and may be, for example, copper wire or CNT (carbon nanotube) etc. In addition, the excitation winding may not be compression molded.

[0039] The 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 .

[0040] like Figure 2 As shown, the inverter 20 includes a series connection body of a U-phase upper arm switch SUP, a V-phase upper arm switch SVp, a W-phase upper arm switch SWp and a U-phase lower arm switch SUn, a V-phase lower arm switch SVn, and a W-phase lower arm switch SWn. The first ends of the U-phase winding 52U, the V-phase winding 52V, and the W-phase winding 52W are connected to the connection point between the U-phase upper arm switch SUP, the V-phase upper arm switch SVp, and the W-phase upper arm switch SWp and the U-phase lower arm switch SUn, the V-phase lower arm switch SVn, and the W-phase lower arm switch SWn. The second ends of the U-phase winding 52U, the V-phase winding 52V, and the W-phase winding 52W are connected by a neutral point. That is, in the present embodiment, the U-phase winding 52U, the V-phase winding 52V, and the W-phase winding 52W are star-connected. In addition, in the present embodiment, each switch SUP to SWn is an IGBT. A freewheeling diode is connected in anti-parallel to each switch SUP to SWn.

[0041] The collectors of the U-phase upper arm switch SUp, the V-phase upper arm switch SVp, and the W-phase upper arm switch SWp are connected to the positive terminal of the DC power supply 10. The emitters of the U-phase lower arm switch SUn, the V-phase lower arm switch SVn, and the W-phase lower arm switch SWn are connected to the negative terminal of the DC power supply 10. In addition, a filter capacitor 11 is connected in parallel to the DC power supply 10.

[0042] Next, use Figure 3 , the stator 50 and the rotor 60 are described.

[0043] The stator 50 and the rotor 60 are both arranged coaxially with the rotating shaft 32. In the following description, the direction in which the rotating shaft 32 extends is referred to as the axial direction, the direction radially extending from the center of the rotating shaft 32 is referred to as the radial direction, and the direction circumferentially extending around the rotating shaft 32 is referred to as the circumferential direction.

[0044] The stator core 51 is formed by stacking steel plates made of a soft magnetic body, and has an annular back yoke 51a and a plurality of teeth 51b protruding radially inward from the back yoke 51a. A plurality of slots 54 arranged in the circumferential direction are formed between adjacent teeth 51b. The stator winding 52 is formed by accommodating the phase windings of each phase in a predetermined order in each of the slots 54. For example, a segment coil structure using a plurality of conductor segments may be adopted in the stator 50. However, the structure of the stator winding 52 is arbitrary.

[0045] The rotor core 61 is made of a soft magnetic material, for example, laminated steel plates. The rotor core 61 has a cylindrical portion 61a and a plurality of main pole portions 62 protruding radially outward from the cylindrical portion 61a. In the present embodiment, eight main pole portions 62 are provided at equal intervals in the circumferential direction.

[0046] The excitation winding 70 includes a first winding portion 71a and a second winding portion 71b. In each main pole portion 62, the first winding portion 71a is wound on the radially outer side, and the second winding portion 71b is wound on the radially inner side compared to the first winding portion 71a. In each main pole portion 62, the winding directions of the first winding portion 71a and the second winding portion 71b are the same as each other. In addition, the winding direction of each winding portion 71a, 71b wound on one of the circumferentially adjacent main pole portions 62 is opposite to the winding direction of each winding portion 71a, 71b wound on the other side. Therefore, the magnetization directions of the main pole portions 62 adjacent to each other in the circumferential direction are opposite to each other. In the rotor 60, a plurality of magnetic poles (excitation poles) arranged in the circumferential direction are formed by each main pole portion 62 in the rotor core 61 and the excitation winding 70 wound on each of the main pole portions 62.

[0047] Figure 4 The diagram shows a circuit on the rotor 60 side having winding portions 71a and 71b wound around the main pole portion 62. The first winding portion 71a and the second winding portion 71b are connected in series, and a diode 80 serving as a rectifying element is connected between both ends of the series connection body formed by these winding portions 71a and 71b. That is, the cathode of the diode 80 is connected to the first end of the first winding portion 71a, and the second end of the first winding portion 71a is connected to the first end of the second winding portion 71b. The anode of the diode 80 is connected to the second end of the second winding portion 71b. A capacitor 90 is connected in parallel to the second winding portion 71b. In addition, a capacitor 90 may be connected in parallel to the first winding portion 71a instead of the second winding portion 71b. Figure 4, L1 represents the inductance of the first winding portion 71 a , L2 represents the inductance of the second winding portion 71 b , and C represents the electrostatic capacitance of the capacitor 90 .

[0048] In this embodiment, a series resonant circuit is formed by the first winding portion 71a, the capacitor 90, and the diode 80, and a parallel resonant circuit is formed by the second winding portion 71b and the capacitor 90. The first resonant frequency, which is the resonant frequency of the series resonant circuit, is set to f1, and the second resonant frequency, which is the resonant frequency of the parallel resonant circuit, is set to f2. The resonant frequencies f1 and f2 are expressed by the following equations (eq1) and (eq2).

[0049] [Mathematical formula 1]

[0050]

[0051] [Mathematical formula 2]

[0052]

[0053] return Figure 2 As described above, the control system includes a current sensor 21, an angle sensor 22, a voltage sensor 23, and an acceleration sensor 24. The current sensor 21 detects the current of at least two phases of each phase current flowing in the rotating electric machine 40. The angle sensor 22 detects the rotation angle (electrical angle) of the rotor 60. The voltage sensor 23 includes a sensor for detecting the voltage of the DC power supply 10 and a sensor for detecting the back electromotive force of each phase winding 52U~52W. The acceleration sensor 24 detects the operation amount of the acceleration operating member (specifically, the accelerator pedal) operated by the driver of the vehicle. The detection values ​​of each sensor 21~24 are input to the control device 30.

[0054] The control device 30 generates a drive signal for turning on and off each switch SUP to SWn constituting the inverter 20. Specifically, the control device 30 generates a drive signal for turning on and off each arm switch 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-phase winding 52U, the V-phase winding 52V, and the W-phase winding 52W, and supplies the generated drive signal to the gate of each arm switch SUP to SWn.

[0055] The control device 30 turns on and off each switch SUP to SWn in such a manner that a composite current of a fundamental wave current and a harmonic current flows through each phase winding 52U, 52V, 52W. The fundamental wave current is a current that mainly generates torque in the rotating electric machine 40. The harmonic current is a current that mainly excites the field winding 70. The phase currents flowing through each phase winding 52U, 52V, 52W are offset by an electrical angle of 120°.

[0056] The control device 30 is mainly composed of a microcomputer (equivalent to a computer), and the microcomputer has a CPU. The functions provided by the microcomputer can be provided by software stored in a physical memory device and a computer that executes the software, only software, only hardware, or a combination of these. For example, in the case of providing by an electronic circuit as hardware, it can be provided by a digital circuit or an analog circuit including a plurality of logic circuits. For example, the microcomputer executes a program stored in a non-transitory tangible storage medium (non-transitory tangible storage medium) as a storage unit provided by the microcomputer. The program includes, for example, the following Fig.15 The program for performing the processing shown in the above-mentioned examples is executed. The method corresponding to the program is executed by executing the program. The storage unit is, for example, a nonvolatile memory. In addition, the program stored in the storage unit can be updated via a communication network such as OTA (Over The Air) or the Internet.

[0057] use Figure 5 , the torque control of the rotating electrical machine 40 performed by the control device 30 will be described.

[0058] The two-phase converter 100 converts the U, V, and W phase currents in the three-phase fixed coordinate system into d-axis current Idr and q-axis current Iqr in the two-phase rotating coordinate system (dq coordinate system) based on the detection value of the current sensor 21 and the electrical angle θe detected by the angle sensor 22 .

[0059] The command current calculation unit 101 calculates the d-axis command current Id* and the q-axis command current Iq* based on the command torque Trq*. The d-axis command current Id* and the q-axis command current Iq* are values ​​reflecting the fundamental wave current and the harmonic current for exciting the field winding 70. In detail, the command current calculation unit 101 calculates the d-axis command current Id* and the q-axis command current Iq* based on the command torque Trq* and the mapping information that associates the command torque Trq* with the d-axis command current Id* and the q-axis command current Iq*. Here, the larger the acceleration operation amount detected by the acceleration sensor 24, the larger the command torque Trq* is set. When the rotation speed Nm of the rotor 60 increases and enters the weak excitation region, the command current calculation unit 101 sets the d-axis command current Id* in a manner that performs weak excitation control. The current control unit 102 increases the d-axis command current Id* in the negative direction in the weak excitation region. In addition, the rotation speed Nm of the rotor 60 may be calculated based on the detection value of the angle sensor 22 .

[0060] The current control unit 102 calculates the d-axis current deviation ΔId by subtracting the d-axis current Idr from the d-axis command current Id*. The current control unit 102 calculates the q-axis current deviation ΔIq by subtracting the q-axis current Iqr from the q-axis command current Iq*.

[0061] The current control unit 102 calculates the d-axis command voltage Vd* as the operation amount for feedback-controlling the d-axis current Idr to the d-axis command current Id* based on the d-axis current deviation ΔId. The current control unit 102 calculates the q-axis command voltage Vq* as the operation amount for feedback-controlling the q-axis current Iqr to the q-axis command current Iq* based on the q-axis current deviation ΔIq.

[0062] The three-phase conversion unit 103 converts the d-axis command voltage Vd and the q-axis command voltage Vq in the two-phase rotating coordinate system into the U-phase voltage command value VU*, the V-phase voltage command value VV*, and the W-phase voltage command value VW* in the three-phase fixed coordinate system based on the d-axis command voltage Vd*, the q-axis command voltage Vq*, and the electrical angle θe. The U-phase voltage command value VU*, the V-phase voltage command value VV*, and the W-phase voltage command value VW* become waveforms whose phases are shifted by 120 degrees in electrical angle, respectively.

[0063] The frequencies of the harmonic components contained in the U-phase voltage command value VU*, the V-phase voltage command value VV*, and the W-phase voltage command value VW* are set to frequencies near the first resonance frequency f1 or near the second resonance frequency f2. This can increase the excitation and reduce the amplitude of the harmonic current, and can reduce the torque pulsation of the high-speed rotary motor 40.

[0064] like Figure 6 As shown in Figure 1, the envelope of the high-order harmonic current has a period of 1 / 2 of the fundamental wave current. Figure 6 The envelope is shown by a dashed line in (b). Figure 6 The values ​​on the vertical axis indicate Figure 6 The relative relationship between the magnitudes of the waveforms shown in (a) and (b) of FIG. 1 . The time when the envelope reaches its peak is offset from the time when the fundamental wave current reaches its peak. Specifically, the time when the envelope reaches its peak is set to the time when the fundamental wave current reaches its variation center (0).

[0065] Furthermore, the time when the envelope of the harmonic current reaches its peak value may be, for example, the time when the fundamental wave current reaches its peak value.

[0066] return Figure 5As described above, the signal generation unit 104 generates drive signals for upper arm switches of U, V, and W phases and lower arm switches of U, V, and W phases by three-phase modulation based on the U-phase voltage command value VU*, the V-phase voltage command value VV*, the W-phase voltage command value VW*, and the voltage Vdc of the DC power supply 10 detected by the voltage sensor 23. The generated drive signals are input to the gates of the switches. Thus, the switching operation of the inverter 20 is performed.

[0067] In the present embodiment, in the winding excitation type rotating electric machine 40, when the rotor rotation speed is in a high-speed rotation state higher than a predetermined rotation speed, the excitation current flowing in the excitation winding 70 is made higher than when it is not in a high-speed rotation state, and the phase of the stator current flowing in the stator winding 52 is set to a weak excitation phase that weakens the excitation flux of the excitation winding 70. Here, the high-speed rotation state of the rotating electric machine 40 is a state including a rotation state in a rotation speed domain in which the drive voltage of the stator winding 52 reaches a saturation region, that is, a weak excitation region. The determination threshold for determining the high-speed rotation state may be, for example, a rotation speed of 1 / 2 or 1 / 3 of the maximum rotation speed of the rotating electric machine 40. In addition, the weak excitation phase is an angle formed by a current vector determined by the d-axis current Id and the q-axis current Iq and the q-axis in the dq coordinate system (specifically, the counterclockwise direction from the q-axis is set to a positive angle), and may be, for example, 45° or more. In this case, in the power running state, the weak excitation phase ranges from 45° to 90°. In the regenerative state, the weak field phase has a range of 90 to 135 degrees. The weak field phase may also be set in other ranges, for example, the weak field phase has a lower limit of 40 degrees and an upper limit of 85 degrees in the power running state.

[0068] Figure 7 : is a diagram showing the magnetic flux generated between the stator 50 and the rotor 60 in the state of weak excitation. Figure 7 For example, U-phase current flows in the U-phase winding (U+, U-), and as the current is energized, magnetic fluxes φ1 and φ2 in opposite directions are generated between the stator 50 and the rotor 60. In addition, the high-order harmonic current contained in the U-phase current induces an excitation current in the excitation winding 70, and the excitation magnetic flux is generated by the excitation current. Figure 7 In the rotor 60, one main pole portion 62 (the left side in the figure) is an N pole, and the other main pole portion 62 (the right side in the figure) is an S pole, and the rotor 60 rotates in the counterclockwise direction.

[0069] exist Figure 7 In this case, the phase of the stator current is shifted to the advance angle side, thereby becoming a weak excitation phase. In this case, the interlinkage flux interlinked with the stator winding 52 is reduced, and the excitation flux generated by the energization of the excitation current suppresses the reduction of the main flux torque. In the high-speed rotation state of the rotating electric machine 40, Figure 7 Hereinafter, the control of the stator current and the field current in the high-speed rotation state of the rotary electric machine 40 will be described in detail.

[0070] Figure 8 It shows the phase relationship between the field current and the stator current when weak excitation is performed with respect to the output torque in the high-speed rotation state of the rotary electric machine 40. In addition, the stator current is set to be constant here.

[0071] according to Figure 8 It can be seen that when the excitation current is low, the degree of weak excitation of the stator current is small on the basis of ensuring the torque, but as the excitation current increases, the degree of weak excitation of the stator current increases on the basis of ensuring the torque. In addition, it can be seen that by increasing the excitation current, the degree of weak excitation of the stator current increases (increasing the current phase in the figure), thereby increasing the output torque.

[0072] Next, the problem of performing field weakening in a high-speed rotation state will be described.

[0073] In the case of increasing the excitation current of the field winding 70, when the excitation current is increased and the excitation flux is set to an increased state, the excitation current gradually increases after the current increase command. In this case, before the excitation current is sufficiently increased (that is, before the excitation flux based on the excitation of the field winding 70 is increased), if the phase of the stator current is made a weak excitation phase, an increase in the drive voltage (necessary voltage) required for energizing the stator winding 52 will occur before the increase in the excitation current. For example, when the excitation current is increased from a state where the excitation current is 0, initially, the excitation current is maintained at 0 and the stator current is energized in a weak excitation phase. In this case, the rotating electrical machine 40 temporarily becomes a reluctance motor state, the inductance on the d-axis becomes higher, the magnetic flux becomes easier to flow, and there is a concern that the necessary voltage becomes higher.

[0074] use Fig. 9 Explain the relationship between the excitation current and the necessary voltage. Fig. 9 In the figure, a1 to a4 represent the relationship between the current phase and the voltage when the excitation current is different. As an example of the excitation current, a1 is 0A, a2 is 10A, a3 is 20A, and a4 is 30A. a1 to a4 are set to a constant effective value of the stator current (250Arms). In addition, the excitation current of a11 is set to 30A, and the effective value of the stator current of a11 is set to 150Arms.

[0075] exist Fig. 9In the figure, it can be seen that when weak excitation is performed (for example, when the current phase is above 45°), the lower the excitation current, the higher the required voltage in the rotating motor 40 becomes, and this tendency becomes more significant when the degree of weak excitation is greater. On the other hand, it can be seen that when the excitation current is high, the required voltage becomes lower by setting it to a weak excitation phase, and this tendency becomes more significant when the excitation current is larger. That is, when the excitation current becomes higher, the d-axis inductance in the rotor 60 becomes smaller, and the magnetic flux caused by the stator current becomes difficult to flow in the excitation pole. In this case, the required voltage can be reduced by setting it to a weak excitation phase. In addition, in the comparison under the same excitation current in the weak excitation state, it can be seen that when the stator current is high, the required voltage is lower than when the stator current is low.

[0076] in addition, Fig.10 Indicates the relationship between current phase and torque. Fig.10 In the figure, b1 to b4 represent the relationship between the current phase and the torque when the excitation current is different. As an example of the excitation current, b1 is 0A, b2 is 10A, b3 is 20A, and b4 is 30A. The effective value of the stator current is constant. Fig.10 It can be seen that in a weak excitation state (eg, phase -60°), the higher the excitation current, the higher the torque.

[0077] Therefore, in the present embodiment, when the excitation current is increased, the excitation current is increased in accordance with the instruction to increase the excitation current until the excitation flux is increased, and the phase of the stator current is not shifted and the state is maintained not in a weak excitation phase. Then, after the excitation current increases and the excitation flux is increased, the phase of the stator current is set to a weak excitation phase, and the stator current is increased. For example, the state in which the excitation current reaches the instruction value (target value) in accordance with the instruction to increase the excitation current is the state in which the excitation flux is increased. However, the state in which the excitation current rises to a specified value less than the instruction value after the instruction to increase the excitation current can also be the state in which the excitation flux is increased.

[0078] In addition, in the present embodiment, the field winding 70 is subjected to excitation based on the harmonic current (harmonic excitation). In the initial state of the harmonic excitation, it can be considered that the induction of the excitation current based on the harmonic current is insufficient and the excitation flux does not become the desired state. In this case, if the excitation flux does not become the desired state, as described above, there is a concern that the necessary voltage exceeds the power supply voltage as the stator current is set to the weak excitation phase.

[0079] Fig.11This is a timing diagram showing the transition of the stator current (U-phase current) of one phase, the transition of the drive voltage (U-phase voltage) of one phase, the transition of the output torque, and the transition of the excitation current in a state where the phase of the stator current (fundamental wave current) is set to the weak excitation phase and the specified higher harmonic current is superimposed. In addition, the rotor rotation speed is 9000rpm, the effective value of the stator current is 260Arms, and the stator current phase is -60°.

[0080] exist Fig.11 In the embodiment, from the initial state just after the high-order harmonic excitation starts, the phase of the stator current becomes a weak excitation phase. In addition, as the U-phase current as the high-order harmonic superimposed current is energized, the excitation current gradually increases. In this case, at the beginning of the high-order harmonic excitation, the drive voltage exceeds the power supply voltage and gradually decreases as the excitation current increases. In addition, the torque gradually increases as the excitation current increases. However, at the beginning of the high-order harmonic excitation, in the state of low excitation current, the output torque becomes a negative torque.

[0081] In contrast, Fig.12 In the example, the amplitude and phase of the stator current are made different in the initial state just after the high-order harmonic excitation and in the subsequent excitation completion state. In addition, the rotor rotation speed is 9000rpm, the effective value of the stator current is 150Arms and the stator current phase is -30° in the initial state, and the effective value of the stator current is 260Arms and the stator current phase is -60° in the excitation completion state.

[0082] exist Fig.12 In the initial state, since the excitation current is in the middle of increasing and sufficient excitation flux is not generated, the phase of the stator current (U-phase current) is not set to the weak excitation phase (the period from t1 to t2 in the figure). Then, at time t2, the phase of the stator current is transferred to the weak excitation phase, and at time t3, the amplitude of the stator current is amplified. In this case, after the instruction to increase the excitation current, the excitation current is waited for to increase, and the stator current is transferred to the weak excitation phase and the amplitude of the stator current is increased. As a result, in Fig.12 In the whole period including the initial state, the U-phase voltage is suppressed from exceeding the power supply voltage. In addition, the output torque gradually increases with the increase of the excitation current from the initial state. In addition, the moment when the phase of the stator current is shifted to the weak excitation phase and the moment when the amplitude of the stator current is increased may be the same or the same.

[0083] In the initial state and the excitation completion state, the amplitude of the fundamental wave current in the stator current is different. Fig.13 (a) indicates that in the initial state ( Fig.12Under X1), the fundamental wave current and harmonic current of one phase change and the synthetic current (harmonic superimposed current) of these fundamental wave current and harmonic current change. In addition, Fig.13 (b) indicates that in the excitation completion state ( Fig.12 The fundamental wave current and harmonic current of one phase and the synthetic current (harmonic superimposed current) of these fundamental wave currents and harmonic currents are shown in Figure 1. As shown in these figures, in the initial state, the amplitude of the fundamental wave current is set low, while in the excitation completion state, the amplitude of the fundamental wave current is amplified.

[0084] In the present embodiment, the operating range of the rotary electric machine 40 is divided into a low speed rotation range, a high speed rotation low load range, and a high speed rotation high load range, and stator current control and field current control are independently implemented in each of these ranges. Fig.14 (a) shows the state of power-on control in the low-speed rotation area, Fig.14 (b) shows the state of power-on control in the high-speed rotation and low-load region. Fig.14 (c) shows the state of energization control in the high-speed rotation and low-load region.

[0085] exist Fig.14 In the low-speed rotation area shown in (a), the phase of the stator current (fundamental wave current phase) is set to the phase without weak excitation (current phase 0°) or its vicinity, and when a torque increase is required in the low-speed rotation state, the torque increase is performed based on the increase of the stator current and the excitation current. In the low-speed rotation area, since the voltage drop based on the back electromotive force and inductance is small, even if the excitation flux is increased in the state without weak excitation, it can be handled within the power supply voltage. In this case, the setting of the excitation current and the stator current can be determined based on the efficiency.

[0086] exist Fig.14In the high-speed rotation low-load region shown in (b), the phase of the stator current (fundamental wave current phase) is set to a phase without weak excitation (current phase 0°) or its vicinity, similarly to the low-speed rotation region. In this state, if the torque is increased based on the increase of the stator current and the excitation current, there is a concern that the drive voltage will exceed the power supply voltage as the stator current and the excitation current increase. Therefore, the phase of the stator current is not set to a weak excitation phase, and the excitation current is not increased compared to the case where it is not in the high-speed rotation state (that is, it is set to be equal to or less than the low-speed rotation state). On the other hand, the amplitude of the stator current is increased compared to the case where it is not in the high-speed rotation state. Regarding the setting of the amplitude of the stator current, for example, as the relationship between the command value of the stator current (d-axis command current Id*, q-axis command current Iq*) and the command torque, the same command torque is used for comparison, and the relationship that the command value of the stator current becomes larger in the high-speed rotation state than in the low-speed rotation state is determined. In this case, the excitation current is reduced to reduce the interlinkage flux, thereby suppressing the back electromotive force and reducing the drive voltage. Although a small interlinkage flux will cause torque limitation, it is an effective measure in the low load range.

[0087] exist Fig.14 In the high-speed rotation and high-load area shown in (c), the phase of the stator current (the fundamental wave current phase) is set to a weak excitation phase, and the excitation current is increased in this state. That is, the excitation current is increased compared to the case where it is not in a high-speed rotation state, and the phase of the stator current is set to a weak excitation phase. Regarding the setting of the excitation current, for example, it may be that as a relationship between the command value of the excitation current and the command torque, the command value of the excitation current becomes larger in the high-speed rotation state than in the low-speed rotation state by comparison with the same command torque. In this case, the output can be increased by enhancing the excitation flux and thereby reducing the d-axis inductance, so it is an effective means in the high-load area. Alternatively, the amplitude of the stator current may be set to be larger than that in the case where it is not in a high-speed rotation state. In addition, it may be that in the case of weak excitation, the relationship between the current phase and the torque is considered to become Figure 8 As shown, adjustment is performed so that the main flux torque does not decrease excessively.

[0088] Fig.15 2 is a flowchart showing the energization control process in the present embodiment. This process is executed by the control device 30 at a predetermined cycle.

[0089] exist Fig.15In step S11, it is determined whether the rotor 60 is in a prescribed high-speed rotation state. Specifically, it is determined whether the rotor rotation speed is higher than a prescribed rotation speed (for example, 6000 rpm). At this time, it may be that as a rotation parameter representing the rotation state of the rotor 60, a calculated rotor rotation speed (acquisition unit) is acquired based on the detection value of the angle sensor 22, and based on the rotor rotation speed, it is determined whether the rotor 60 is in a high-speed rotation state. When the rotor 60 is not in a high-speed rotation state, the process proceeds to step S12, and when the rotor 60 is in a high-speed rotation state, the process proceeds to step S13. In step S12, the rotating motor 40 is controlled in a low-speed rotation mode. That is, the phase of the stator current is not set to a weak excitation phase, and the stator current and the excitation current are controlled based on the command torque.

[0090] In addition, in step S13, it is determined whether the command torque of the rotary electric machine 40 is greater than a predetermined value in a high-load state (torque determination unit). If it is determined in step S13 that it is not in a high-load state (i.e., in a high-speed rotation and low-load state), the process proceeds to step S14, and if it is determined in step S13 that it is in a high-load state (i.e., in a high-speed rotation and high-load state), the process proceeds to step S15.

[0091] In step S14, the rotating electric machine 40 is controlled in a high-speed rotation and low-load mode. That is, the phase of the stator current is not set to a weak excitation phase, and the excitation current is not increased compared to the case where it is not in a high-speed rotation state (that is, the excitation current is set to be equal to or less than the low-speed rotation state). On the other hand, the amplitude of the stator current is increased compared to the case where it is not in a high-speed rotation state. In step S15, the rotating electric machine 40 is controlled in a high-speed rotation and high-load mode. That is, the excitation current is increased compared to the case where it is not in a high-speed rotation state, and the phase of the stator current is set to a weak excitation phase. In addition, the amplitude of the stator current is increased compared to the case where it is not in a high-speed rotation state.

[0092] Fig.16 This is a flowchart showing the processing sequence for increasing the field flux in a high-speed rotation and high-load state. Fig.15 The process is performed in step S15.

[0093] exist Fig.16 In step S21, it is determined whether the condition is such that the field magnetic flux is increased. In the vehicle running condition, for example, when the acceleration operation is performed from the high-speed rotation state of the rotary electric machine 40, in the condition where the command torque is increased, step S21 is affirmative. In other words, when the rotary electric machine 40 is transferred from the high-speed rotation low-load condition to the high-speed rotation high-load condition, step S21 is affirmative. If step S21 is affirmative, the process proceeds to step S22.

[0094] In step S22, the start of harmonic excitation is instructed to increase the excitation current. Specifically, the amplitude of the harmonic current contained in the stator current is increased. At this time, the start of harmonic excitation is instructed when the phase of the stator current has not become a weak excitation phase. In the next step S23, it is determined whether a specified time Ta has passed since the start of the instruction to increase the excitation current, and the subsequent step S24 is entered if step S23 is affirmative.

[0095] In step S24, the phase of the stator current is set to the weak field phase. In the next step S25, it is determined whether a predetermined time Tb (>Ta) has passed since the command to increase the field current was issued, and the process proceeds to the next step S26 if the answer to step S25 is yes. In step S26, the amplitude of the fundamental wave current is amplified. Fig.16 In the processing, it is also possible to omit the processing of step S25, and implement weak excitation of the stator current (step S24) and increase the amplitude of the fundamental wave current (step S26) at the moment when a specified time Ta has passed since the instruction to increase the excitation current was started.

[0096] According to the present embodiment described in detail above, the following excellent effects can be obtained.

[0097] The structure is as follows: when the rotor 60 is in a predetermined high-speed rotation state, the control of increasing the excitation current and setting the phase of the stator current to a weak excitation phase that weakens the excitation flux of the excitation winding 70 is performed compared to the case where the rotor 60 is not in a high-speed rotation state. In this case, by increasing the excitation current, the d-axis inductance of the rotor 60 can be reduced, and the excitation flux can be increased. In addition, by controlling the stator current in the weak excitation phase, the interlinked flux interlinked with the stator winding 52 can be reduced. As a result, the drive voltage applied to the stator winding 52 can be reduced, and the output torque of the rotating motor 40 can be increased. As a result, the required voltage of the rotating motor 40 can be reduced and the output can be increased.

[0098] The following structure is adopted: when the rotor 60 is in a predetermined high-speed rotation state, in addition to the control of increasing the excitation current and the control of setting the phase of the stator current to a weak excitation phase, the amplitude of the stator current is also controlled to be increased compared with the case where the rotor 60 is not in a high-speed rotation state. As a result, the following technical effects can be further improved: the drive voltage applied to the stator winding 52 is reduced and the torque of the rotating electric machine 40 is increased.

[0099] When the excitation magnetic flux is increased due to the increase in the excitation current, the excitation current gradually increases after the instruction to increase the current. In this case, if the phase of the stator current is set to a weak excitation phase before the excitation current is sufficiently increased (that is, before the excitation magnetic flux based on the excitation of the excitation winding 70 increases), the drive voltage of the stator winding 52 increases before the increase in the excitation current. In this regard, since the phase of the stator current is set to a weak excitation phase after the excitation magnetic flux is increased due to the instruction to increase the excitation current, when the excitation current increases, the effect of reducing the drive voltage applied to the stator winding 52 and increasing the torque of the rotating electric machine 40 can be well achieved in the period including the period immediately after the increase instruction is issued.

[0100] After the increase of the excitation current is instructed, before the excitation current is sufficiently increased (that is, before the excitation flux based on the excitation of the excitation winding 70 increases), if the phase of the stator current is set to a weak excitation phase or the stator current is increased, the drive voltage of the stator winding 52 is increased before the increase of the excitation current. In this regard, after the excitation flux increases in accordance with the instruction to increase the excitation current, by setting the phase of the stator current to a weak excitation phase and increasing the stator current, the effect of reducing the drive voltage applied to the stator winding 52 and increasing the torque of the rotating electric machine 40 can be well achieved in the period including the period immediately after the instruction to increase the excitation current is issued.

[0101] In the structure in which the excitation current is induced in the excitation winding 70 by the harmonic current included in the stator current, the output of the rotating electric machine 40 can be improved by the combination of the excitation current and the weak excitation of the stator current. In this case, in particular, after the harmonic current is switched to a command value corresponding to the increase in the excitation magnetic flux and the excitation magnetic flux is increased by the induction of the excitation current accompanying the switching, the phase of the stator current is set to the weak excitation phase. Therefore, when the excitation current increases, in the period including the period immediately after the command of the harmonic current is issued, the effect of reducing the drive voltage applied to the stator winding 52 and increasing the torque of the rotating electric machine 40 can be well achieved.

[0102] In the high-speed rotation state, the required level of output torque is different in the high-load state and the low-load state. By controlling the stator current and the field current in consideration of this, appropriate energization control can be achieved according to the operating state of the rotating electric machine 40.

[0103] (Other embodiments)

[0104] The above-mentioned embodiment may be modified as follows.

[0105] Alternatively, when the rotor 60 is in a high-speed rotation state, when the rotor rotation speed is relatively high, the control device 30 increases the excitation current and advances the phase of the stator current compared to when the rotor rotation speed is relatively low. Specifically, when the rotor 60 is in a high-speed rotation state, when the excitation current is increased by the harmonic current included in the phase current of each phase (for example, Fig.16 In step S22), the control device 30 is based on Fig.17 The excitation current is increased by the relationship (a). Fig.17 In (a), in the rotation state where the rotor rotation speed is less than the specified value Nx, the excitation current is determined to be a specified value (lower limit value) regardless of the rotor rotation speed. On the other hand, in the high-speed rotation state where the rotor rotation speed is greater than the specified value Nx, the relationship is determined that the higher the rotor rotation speed, the higher the excitation current.

[0106] Alternatively, when the rotor 60 is in a high-speed rotation state, the phase of the stator current may be set to a weak field phase (for example, Fig.16 In step S24), the control device 30 is based on Fig.17 The relationship (b) makes the phase of the stator current advance. Fig.17 In (b), in the rotation state where the rotor rotation speed is less than a specified value Nx, the phase of the stator current is determined to be a specified value (the most delayed angle value) regardless of the rotor rotation speed. On the other hand, in the high-speed rotation state where the rotor rotation speed is greater than the specified value Nx, the phase of the stator current is advanced as the rotor rotation speed increases.

[0107] In addition, Fig.17 In (a) and (b), when the rotor 60 is rotating at a high speed, the phases of the field current and the stator current in multiple stages may be determined according to the rotor rotation speed.

[0108] Alternatively, the control device 30 uses the correlation between the drive voltage applied to the stator winding 52 and the rotor rotation speed, and determines the rotation state of the rotor 60 based on the drive voltage of the stator winding 52. In a rotating electrical machine, the greater the rotor rotation speed, the greater the drive voltage of the stator winding 52. In this case, the drive voltage of the stator winding 52 corresponds to a "rotation parameter".

[0109] Alternatively, the control device 30 may calculate the rotor rotation speed based on the voltage command value of the stator winding 52, and determine the rotation state of the rotor 60 based on the rotor rotation speed. In this case, the rotor rotation speed calculated from the voltage command value of the stator winding 52 corresponds to the "rotation parameter".

[0110] In the above embodiment, Fig.15The structure is as follows: by comparing the rotor rotation speed with a specified rotation speed (for example, 6000 rpm), it is determined whether the rotor 60 is in a high-speed rotation state (step S11). When the rotor 60 is in a high-speed rotation state, the excitation current is increased compared to when it is not in a high-speed rotation state, and the phase of the stator current is controlled to a weak excitation phase, but it can also be changed. Specifically, the determination of the rotor rotation state can be performed not based on the comparison between the rotor rotation speed and the specified rotation speed, but using Fig.17 According to the relationship between (a) and (b), when the rotor 60 is in a high-speed rotation state, the excitation current is increased compared to the case where it is not in a high-speed rotation state, and the phase of the stator current is controlled to a weak excitation phase.

[0111] In the above embodiment, Figure 5 In the command current calculation unit 101, the d and q axis command currents are calculated in a manner that reflects the fundamental wave current and the higher harmonic current, but they can also be changed. For example, the d and q axis command currents are calculated based on the command torque as the values ​​reflecting the fundamental wave current, and the fundamental wave voltage command values ​​of the U, V, and W phases are calculated based on the d and q axis command currents (command current calculation unit 101, current control unit 102, three-phase conversion unit 103). On the other hand, for the higher harmonic current set according to the command torque, the higher harmonic voltage command values ​​of the U, V, and W phases are calculated. In addition, the fundamental wave voltage command values ​​of the U, V, and W phases are added to the higher harmonic voltage command values ​​to calculate the voltage command values ​​of the U, V, and W phases, and the switching control of the inverter 20 is implemented by these voltage command values ​​of each phase.

[0112] The capacitor 90 constituting the resonant circuit may be connected in parallel with the first winding portion 71a instead of the second winding portion 71b. In addition, in the resonant circuit, the anode of the diode 80 may be connected to the first winding portion 71a side of the series connection of the first winding portion 71a and the second winding portion 71b, and the cathode of the diode 80 may be connected to the second winding portion 71b side.

[0113] In the rotor 60 , the second winding portion 71 b may be arranged closer to the stator 50 in the radial direction than the first winding portion 71 a .

[0114] The rotating electric machine is not limited to an inner rotor type rotating electric machine, and may be an outer rotor type rotating electric machine. In this case, the main pole portion protrudes radially inward from the rotor core.

[0115] The rotating electric machine is not limited to a star-connected rotating electric machine, and may be a delta-connected rotating electric machine.

[0116] The stator core may be a stator core not provided with teeth.

[0117] As a structure for making the exciting current flow through the exciting winding, it is not limited to Figure 4 The circuit shown may also be a structure including, for example, brushes electrically connected to the field winding and a power source electrically connected to the brushes. In this case, the control device 30 controls the field current flowing in the field winding by increasing the output voltage of the power source electrically connected to the brushes when the rotor 60 is rotating at a high speed. In addition, when the brushes are used, it is not necessary to flow the harmonic current for inducing the field current in the stator winding.

[0118] The rotating electric machine is not limited to one used as a vehicle-mounted main machine, and may be one used as an ISG (Integrated Starter Generator) serving as a motor and a generator, for example.

[0119] The mobile body equipped with the control system is not limited to a vehicle, and may be, for example, an aircraft or a ship. In addition, the control system is not limited to a system mounted on a mobile body, and may be a stationary system.

[0120] The control unit and its method described in the present invention can be implemented by a special-purpose computer, which is provided by a processor and a memory programmed to perform one or more functions embodied by a computer program. Alternatively, the control unit and its method described in the present invention can also be implemented by a special-purpose computer, which is provided by a processor composed of one or more special-purpose hardware logic circuits. Alternatively, the control unit and its method described in the present invention can be implemented by one or more special-purpose computers, which are composed of a combination of a processor and a memory programmed to perform one or more functions and a processor composed of one or more hardware logic circuits. In addition, the computer program can be stored as an instruction executed by a computer in a non-transient tangible storage medium that can be read by the computer.

[0121] The following describes technical concepts refined from the above-mentioned embodiments.

[0122] [Structure 1]

[0123] A control device (30) for a rotating electrical machine is applied to a system having a winding-excitation type rotating electrical machine (40), the winding-excitation type rotating electrical machine having a stator (50) including a stator winding (52) and a rotor (60) having a plurality of magnetic poles arranged in a circumferential direction and including an excitation winding (70) provided at each magnetic pole, and comprising:

[0124] a control unit that controls a stator current flowing through the stator winding and an excitation current flowing through the excitation winding; and

[0125] an acquisition unit, the acquisition unit acquiring a rotation parameter indicating a rotation state of the rotor,

[0126] The control unit controls the magnitude of the excitation current and the phase of the stator current based on the rotation parameter. When the rotor is in a high-speed rotation state where the rotation speed is higher than a specified rotation speed, the control unit increases the excitation current compared to a case where the rotor is not in the high-speed rotation state, and controls the phase of the stator current to a weak excitation phase that weakens the excitation flux of the excitation winding.

[0127] [Structure 2]

[0128] In the control device for a rotating electrical machine according to configuration 1,

[0129] In the high-speed rotation state, when the rotation speed of the rotor is relatively high, the control unit increases the field current and advances the phase of the stator current compared to when the rotation speed is relatively low.

[0130] [Structure 3]

[0131] In the control device for a rotating electrical machine according to configuration 1 or 2,

[0132] When in the high-speed rotation state, the control unit not only increases the excitation current compared to the case where it is not in the high-speed rotation state and controls the phase of the stator current to the weak excitation phase, but also increases the amplitude of the stator current compared to the case where it is not in the high-speed rotation state.

[0133] [Structure 4]

[0134] In the control device for a rotating electrical machine according to any one of Configurations 1 to 3,

[0135] When the field current is increased in the high-speed rotation state, the control unit sets the phase of the stator current to the field weakening phase after the field flux is increased in accordance with the command to increase the field current.

[0136] [Structure 5]

[0137] In the control device for a rotating electrical machine according to any one of Configurations 1 to 3,

[0138] When the field current is increased in the high-speed rotation state, after the field flux increases in response to the command to increase the field current, the control unit sets the phase of the stator current to the weak field phase and increases the amplitude of the stator current.

[0139] [Structure 6]

[0140] In the control device for a rotating electrical machine according to any one of Configurations 1 to 5,

[0141] The system includes an inverter (20) which is electrically connected to the stator winding.

[0142] The rotor has a rotor core (61) and a main pole portion (62) provided at each of the magnetic poles and protruding radially from the rotor core.

[0143] The field winding has a first winding portion (71a) and a second winding portion (71b) connected in series.

[0144] The first winding portion and the second winding portion are wound around each of the main pole portions,

[0145] A rectifying element (80) is connected between both ends of the series connection body, and a capacitor (90) is connected in parallel to either the first winding portion or the second winding portion.

[0146] The control unit performs a switching operation of the inverter so that a fundamental wave current corresponding to a command torque of the rotating electrical machine flows through the stator winding and a harmonic current having a shorter period than the fundamental wave current and used to induce the field current in the field winding flows through the stator winding.

[0147] When in the high-speed rotation state, the control unit switches the higher-order harmonic current to an instruction value corresponding to an increase in the excitation magnetic flux, and after the excitation magnetic flux is increased due to the induction of the excitation current accompanying the switching, the control unit sets the phase of the stator current to the weak excitation phase.

[0148] [Structure 7]

[0149] In the control device for a rotating electrical machine according to any one of Configurations 1 to 6,

[0150] A torque determination unit is provided, the torque determination unit determining whether the command torque of the rotating electric machine is greater than a predetermined value,

[0151] When it is determined that the motor is in the high-speed rotation state and in the high-load state where the command torque is greater than the specified value, the control unit increases the field current compared to a case where the motor is not in the high-speed rotation state and sets the phase of the stator current to the weak field phase.

[0152] When it is determined that the vehicle is in the high-speed rotation state and in the low-load state where the command torque is less than the specified value, the control unit does not set the phase of the stator current to the weak excitation phase, and does not increase the excitation current compared to the case where the vehicle is not in the high-speed rotation state. On the other hand, the control unit increases the amplitude of the stator current compared to the case where the vehicle is not in the high-speed rotation state.

[0153] The present invention is described based on the embodiments, but it should be understood that the present invention is not limited to the embodiments and structures. The present invention also includes various modifications and variations within the equivalent range. In addition, various combinations and methods, and then other combinations and methods of including them into one element, above or below them are also included in the scope and thought scope of the present invention.

Claims

1. A control device for a rotating electrical machine, the control device (30) for a rotating electrical machine being applied to a system having a winding-excitation type rotating electrical machine (40), the winding-excitation type rotating electrical machine having a stator (50) including a stator winding (52) and a rotor (60) having a plurality of magnetic poles arranged in a circumferential direction and including an excitation winding (70) provided at each magnetic pole, characterized in that: have: a control unit that controls a stator current flowing through the stator winding and an excitation current flowing through the excitation winding; and an acquisition unit, the acquisition unit acquiring a rotation parameter indicating a rotation state of the rotor, The control unit controls the magnitude of the excitation current and the phase of the stator current based on the rotation parameter. When the rotor is in a high-speed rotation state where the rotation speed is higher than a specified rotation speed, the control unit increases the excitation current compared to a case where the rotor is not in the high-speed rotation state, and controls the phase of the stator current to a weak excitation phase that weakens the excitation flux of the excitation winding.

2. The control device for a rotating electrical machine according to claim 1, characterized in that: In the high-speed rotation state, when the rotation speed of the rotor is relatively high, the control unit increases the field current and advances the phase of the stator current compared to when the rotation speed is relatively low.

3. The control device for a rotating electrical machine according to claim 1 or 2, characterized in that: When in the high-speed rotation state, the control unit not only increases the excitation current compared to the case where it is not in the high-speed rotation state and controls the phase of the stator current to the weak excitation phase, but also increases the amplitude of the stator current compared to the case where it is not in the high-speed rotation state.

4. The control device for a rotating electrical machine according to claim 1 or 2, characterized in that: When the field current is increased in the high-speed rotation state, the control unit sets the phase of the stator current to the field weakening phase after the field magnetic flux is in an increased state in accordance with the command to increase the field current.

5. The control device for a rotating electrical machine according to claim 1 or 2, characterized in that: When the field current is increased in the high-speed rotation state, after the field flux increases in response to the command to increase the field current, the control unit sets the phase of the stator current to the weak field phase and increases the amplitude of the stator current.

6. The control device for a rotating electrical machine according to claim 1 or 2, characterized in that: The system includes an inverter (20) which is electrically connected to the stator winding. The rotor has a rotor core (61) and a main pole portion (62) which is provided at each of the magnetic poles and protrudes radially from the rotor core. The field winding has a first winding portion (71a) and a second winding portion (71b) connected in series. The first winding portion and the second winding portion are wound around each of the main pole portions, A rectifying element (80) is connected between both ends of the series connection body, and a capacitor (90) is connected in parallel to either the first winding portion or the second winding portion. The control unit performs a switching operation of the inverter so that a fundamental wave current corresponding to a command torque of the rotating electrical machine flows through the stator winding and a harmonic current having a shorter period than the fundamental wave current and used to induce the field current in the field winding flows through the stator winding. When in the high-speed rotation state, the control unit switches the higher-order harmonic current to an instruction value corresponding to an increase in the excitation magnetic flux, and after the excitation magnetic flux is increased due to the induction of the excitation current accompanying the switching, the control unit sets the phase of the stator current to the weak excitation phase.

7. The control device for a rotating electrical machine according to claim 1 or 2, characterized in that: A torque determination unit is provided, the torque determination unit determining whether the command torque of the rotating electric machine is greater than a predetermined value, When it is determined that the motor is in the high-speed rotation state and in the high-load state where the command torque is greater than the specified value, the control unit increases the field current compared to a case where the motor is not in the high-speed rotation state and sets the phase of the stator current to the weak field phase. When it is determined that the vehicle is in the high-speed rotation state and in the low-load state where the command torque is less than the specified value, the control unit does not set the phase of the stator current to the weak excitation phase, and does not increase the excitation current compared to the case where the vehicle is not in the high-speed rotation state. On the other hand, the control unit increases the amplitude of the stator current compared to the case where the vehicle is not in the high-speed rotation state.

8. A program applied to a system having a winding-excitation type rotating electric machine (40), and executed by a computer, the winding-excitation type rotating electric machine having a stator (50) including a stator winding (52) and a rotor (60) having a plurality of magnetic poles arranged in a circumferential direction and including an exciting winding (70) provided for each magnetic pole, characterized in that: Include: a control process for controlling a stator current flowing in the stator winding and a field current flowing in the field winding; and an acquisition process for acquiring a rotation parameter representing a rotation state of the rotor, The control process controls the magnitude of the excitation current and the phase of the stator current based on the rotation parameters. When the rotor is in a high-speed rotation state where the rotation speed is higher than a specified rotation speed, the excitation current is increased compared to a case where the rotor is not in the high-speed rotation state, and the phase of the stator current is controlled to be a weak excitation phase that weakens the excitation flux of the excitation winding.

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