Rotating electric machine device

Abstract

A rotating electric machine device is provided, which uses a rotating electric machine in which a deflection is provided in a rotor permanent magnet at each position in an axial direction so that a magnetic pole position is offset in a circumferential direction, thereby enabling current control to effectively reduce a torque ripple component. In the rotating electric machine device, a current vector of a current command value calculated on a rotating coordinate system of dq axes at an earliest phase is set as an earliest phase current vector (Iadv), a current vector of a current command value calculated on a rotating coordinate system of dq axes at an intermediate phase is set as an intermediate phase current vector (Iave), and a controlled current vector (Ic) is caused to approach from the intermediate phase current vector (Iave) to the earliest phase current vector (Iadv) as a winding current increases.

Description

TECHNICAL FIELD

[0001] The present application relates to a rotating electric machine device. BACKGROUND

[0002] As a variable-speed motor, a DC motor that generates torque to rotate by accepting supply of a DC voltage has been widespread. However, the DC motor has a problem in maintainability due to wear of a brush in principle, and with the spread of an inverter that can generate an AC voltage of variable amplitude and variable frequency, an AC motor has gradually become widespread as a variable-speed motor. As the AC motor, an induction motor has first become widespread, and in particular, a squirrel cage induction motor in which a rotor is formed of a core and a short-circuit ring (secondary conductor) in a cage shape has become more widespread. In addition, in recent years, a permanent magnet synchronous motor using a permanent magnet has also gradually become widespread.

[0003] The induction motor and the permanent magnet synchronous motor that have become widespread as the AC motor are mostly controlled using a technique called "vector control". In the vector control, a current is controlled on a rotating coordinate system of dq axes that rotate in synchronization with a rotor of the AC motor. Therefore, in the vector control, by controlling a q-axis component of a current vector, that is, a q-axis current, torque of the AC motor is controlled, and responsiveness of torque equivalent to that of the DC motor is achieved.

[0004] A rotor of the AC motor is sometimes provided with skew. The purpose of implementing the skew is to reduce a ripple component of torque generated by the AC motor (the ripple component of torque also includes cogging torque in the permanent magnet synchronous motor). First, in the squirrel cage induction motor, skew that continuously shifts a position in a circumferential direction of a short-circuit ring (secondary conductor) of the rotor is provided at each position in an axial direction. On the other hand, in the permanent magnet synchronous motor, as shown in Patent Literature 1, skew that shifts a position of a magnetic pole in a circumferential direction is provided at each position in an axial direction or continuously in a permanent magnet of the rotor. Figure 2 and Figure 5

[0005] Second, vector control of the AC motor provided with the skew is discussed. In the squirrel cage induction motor, the vector control is not dependent on whether the skew is provided or not. This is because the induction motor generates a magnetic flux of the rotor by passing a current through a stator coil in principle, and thus "a direction of the magnetic flux of the rotor can be obtained by passing a current in a direction desired by a control device".

[0006] PRIOR ART DOCUMENTS

[0007] PATENT LITERATURE

[0008] Patent Literature 1: Japanese Patent Application Laid-Open No. 2000-308286 SUMMARY ​

[0009] Technical problem to be solved by the invention

[0010] However, in the permanent magnet synchronous motor, the magnetic flux of the rotor is determined by the magnetic poles of the rotor. Therefore, the direction of the magnetic flux of the rotor cannot be freely changed by the control device. Here, when the permanent magnets of the rotor of the permanent magnet synchronous motor are not provided with a deflection, the circumferential position of the magnetic poles is the same at each position in the axial direction, and therefore the direction of the magnetic pole position is determined on the d-axis, and vector control is performed.

[0011] However, when the permanent magnets of the rotor of the permanent magnet synchronous motor are provided with a deflection, the circumferential position of the magnetic poles changes at each position in the axial direction. Therefore, when current control is performed in the rotating coordinate system of the dq-axis, how to set the magnetic pole position corresponding to the d-axis becomes a problem. In particular, the deflection is provided in order to reduce the ripple component of the torque, but in order to effectively reduce the ripple component of the torque, it is not clear how to set the magnetic pole position corresponding to the d-axis for vector control.

[0012] Therefore, the present application provides a rotating electric machine device that uses a rotating electric machine in which a deflection that shifts the magnetic pole position in the circumferential direction is provided at each position in the axial direction in the permanent magnets of the rotor, and thereby current control can be performed to effectively reduce the ripple component of the torque.

[0013] Technical means for solving the technical problem

[0014] The rotating electric machine device according to the present application includes:

[0015] a rotating electric machine having a rotor provided with permanent magnets and a stator provided with a multiphase winding;

[0016] an inverter having a plurality of switching elements for converting direct current supplied from a direct current power supply and alternating current supplied to the multiphase winding;

[0017] a current detection section that detects a current flowing through the multiphase winding;

[0018] a rotation detection section that detects a rotation angle of the rotor;

[0019] a current control section that sets a control magnetic pole position based on a detected value of the rotation angle, calculates a control current command value, and calculates a voltage command value based on a detected value of the current, the control current command value, and the control magnetic pole position; and

[0020] a switching control section that performs on-off control of the plurality of switching elements based on the voltage command value,

[0021] the permanent magnets are arranged so as to offset the positions of the magnetic poles in the axial direction at each position in the axial direction,

[0022] the current control portion performs control so that the controlled current vector approaches the current vector at the middle phase as the winding current increases.

[0023] the current vector of the current command value calculated in the dq-axis rotating coordinate system at the middle phase is set as the current vector at the middle phase, the dq-axis rotating coordinate system at the middle phase being constituted by a d-axis determined in the direction of the magnetic pole position at the middle phase among the magnetic pole positions at each position in the axial direction in which the magnetic pole position at the most advanced phase and the magnetic pole position at the most delayed phase are in the rotational direction, and a q-axis determined in the direction in which the phase is advanced by 90° in the electrical angle with respect to the d-axis,

[0024] the current vector of the current command value calculated in the dq-axis rotating coordinate system at the middle phase is set as the current vector at the middle phase, the dq-axis rotating coordinate system at the middle phase being constituted by a d-axis determined in the direction of the magnetic pole position at the middle phase among the magnetic pole positions at each position in the axial direction in which the magnetic pole position at the most advanced phase and the magnetic pole position at the most delayed phase are in the rotational direction, and a q-axis determined in the direction in which the phase is advanced by 90° in the electrical angle with respect to the d-axis,

[0025] the controlled current vector approaches the current vector at the middle phase as the winding current increases.

[0026] Inventive Effects

[0027] If the d-axis current of the winding current increases in the positive direction in the dq-axis rotating coordinate system at the most advanced phase, the stator portion opposite to the magnetic pole position at the most advanced phase generates magnetic saturation, and although the cross-link magnetic flux of the d-axis increases, the slope decreases. If such magnetic saturation occurs, the torque ripple component increases. Therefore, when the winding current is large, in order to suppress the d-axis current at the most advanced phase from increasing in the positive direction, it is necessary to make the controlled current vector approach the current vector at the most advanced phase. On the other hand, when the winding current is small, since the influence of magnetic saturation is small, if the controlled current vector approaches the current vector at the middle phase, the torque ripple component generated by the magnetic pole at the most advanced phase and the torque ripple component generated by the magnetic pole at the most delayed phase can be canceled out, and thus it is possible to reduce the torque ripple component.

[0028] According to the rotary electric machine device according to the present application, as the winding current increases, the controlled current vector approaches the current vector of the most advanced phase from the current vector of the neutral phase, and thus, when the winding current is small, the torque ripple component generated by the magnetic pole of the most advanced phase and the torque ripple component generated by the magnetic pole of the most delayed phase can be canceled out, thereby reducing the torque ripple component. Even if the winding current increases, the d-axis current of the most advanced phase can be suppressed from increasing to the point of generating magnetic saturation, and thus, the torque ripple component can be reduced. Therefore, the phase of the current vector with respect to the circumferentially offset magnetic pole position can be appropriately changed according to the increase and decrease of the winding current, and the torque ripple component can be effectively reduced. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a schematic configuration diagram of the rotary electric machine device according to Embodiment 1.

[0030] Figure 2 is a perspective view of the rotor according to Embodiment 1.

[0031] Figure 3 is a cross-sectional view of the rotor according to Embodiment 1.

[0032] Figure 4 is a cross-sectional view of the rotor and the stator according to Embodiment 1.

[0033] Figure 5 is a hardware configuration diagram of the control device according to Embodiment 1.

[0034] Figure 6 is a diagram illustrating a coordinate system according to Embodiment 1.

[0035] Figure 7 is a characteristic diagram of the torque ripple according to Embodiment 1.

[0036] Figure 8 is a diagram illustrating a positive direction increase of the d2-axis current according to Embodiment 1.

[0037] Figure 9 is a diagram illustrating magnetic saturation caused by an increase of the d2-axis current according to Embodiment 1.

[0038] Figure 10 is a diagram illustrating control of the current vector when Id = 0 control according to Embodiment 1.

[0039] Figure 11 is a diagram illustrating setting of a correction amount of the magnetic pole position corresponding to the current according to Embodiment 1.

[0040] Figure 12 is a timing chart of the switching control according to Embodiment 1.

[0041] Figure 13 FIG. 6 is a diagram illustrating control of a current vector involved in Embodiment 2.

[0042] Figure 14 FIG. 7 is a diagram illustrating setting of a d-axis current reduction amount corresponding to a current involved in Embodiment 2.

[0043] Figure 15 FIG. 8 is a diagram illustrating control of a current vector in the vicinity of an upper limit current value involved in Embodiment 2.

[0044] Figure 16 FIG. 9 is a diagram illustrating a coordinate system at the time of rotation in one direction involved in Embodiment 3.

[0045] Figure 17 FIG. 10 is a diagram illustrating a coordinate system at the time of rotation in the other direction involved in Embodiment 3.

[0046] Figure 18 FIG. 11 is a diagram illustrating a coordinate system at the time of rotation in the other direction involved in Embodiment 3, in another example.

[0047] Figure 19 FIG. 12 is a diagram illustrating an electric power steering apparatus involved in Embodiment 3.

[0048] Figure 20 FIG. 13 is a perspective view of a rotor involved in Embodiment 4.

[0049] Figure 21 FIG. 14 is a diagram illustrating setting of a current command value based on maximum torque current control involved in Embodiment 4.

[0050] Figure 22 FIG. 15 is a diagram illustrating control of a current vector at the time of maximum torque current control involved in Embodiment 4.

[0051] Figure 23 FIG. 16 is a diagram illustrating an execution region of field weakening control involved in Embodiment 5.

[0052] Figure 24 FIG. 17 is a diagram illustrating setting of a correction amount of a magnetic pole position corresponding to a current involved in another embodiment.

[0053] Figure 25 FIG. 18 is a perspective view of a rotor involved in another embodiment.

[0054] Figure 26 FIG. 19 is a perspective view of a rotor involved in another embodiment.

[0055] Figure 27 FIG. 20 is an expanded view of a rotor involved in another embodiment.

[0056] Figure 28is an exploded view of a rotor according to another embodiment. DETAILED DESCRIPTION

[0057] 1. Embodiment 1

[0058] A rotating electric machine device according to Embodiment 1 will be described with reference to the drawings. Figure 1 is a schematic configuration diagram of a rotating electric machine device according to the present embodiment. The rotating electric machine device includes a rotating electric machine 1, an inverter 4, and a control device 6.

[0059] 1-1. Rotating electric machine 1

[0060] The rotating electric machine 1 is a permanent magnet synchronous motor having a rotor 11 provided with permanent magnets 111 and a stator 21 provided with multiphase windings. As the multiphase windings, three-phase windings Cu, Cv, and Cw of U phase, V phase, and W phase are provided. The three-phase windings can be star-connected or delta-connected.

[0061] The rotor 11 is provided with a rotation detector 2 for detecting a rotation angle of the rotor 11. The rotation detector 2 uses a resolver, an encoder, an MR sensor, or the like. An output signal of the rotation detector 2 is input to the control device 6.

[0062] As shown in Figure 2 , the permanent magnets 111 are provided on a surface of the rotor 11, and the surface magnet type synchronous motor is provided. The rotor 11 is provided with a cylindrical rotor core 110, and the permanent magnets 111 are adhered to an outer peripheral surface of the rotor core 110.

[0063] <Deflection>

[0064] In the permanent magnets 111, a deflection that shifts a magnetic pole position in a circumferential direction is provided at each position in an axial direction X. In the present embodiment, as shown in Figure 2 and Figure 3 , the permanent magnets 111 are provided with a deflection that shifts a magnetic pole position in a circumferential direction in two stages in the axial direction X. A first deflection section 112a is provided on one side X1 of the rotor 11 in the axial direction, and a second deflection section 112b is provided on the other side X2 of the rotor 11 in the axial direction. Figure 2 is a perspective view of the rotor 11, Figure 3 is a cross-sectional view of the first deflection section 112a on the left side, Figure 3 is a cross-sectional view of the second deflection section 112b on the right side. Eight magnetic poles 111 (four N poles and four S poles) are arranged at equal intervals in a circumferential direction on the outer peripheral portions of the first and second deflection sections 112a and 112b, respectively. The N poles and the S poles are alternately arranged in the circumferential direction.

[0065] The magnetic pole 111 (e.g., N pole) of the second deflection segment 112b and the magnetic pole 111 (e.g., N pole) of the first deflection segment 112a are offset in the circumferential direction. In this example, the magnetic pole 111 of the second deflection segment 112b is offset by 30 degrees electrically and 7.5 degrees mechanically relative to the magnetic pole 111 of the first deflection segment 112a in the rotation direction R. Therefore, in this embodiment, the circumferential offset angle of the magnetic pole position, i.e., the deflection angle θe, is 30 degrees electrically and 7.5 degrees mechanically. The electrical angle is the angle obtained by multiplying the mechanical angle by the number of pole pairs (4 in this example). The number of pole pairs is half the number of magnetic poles.

[0066] Figure 4 This is a cross-sectional view of the rotor 11 and the stator 21. The stator, which has three-phase windings 211 wound around it, has 12 slots 212. Therefore, the rotary electric machine 1 is a surface magnet type permanent magnet synchronous motor with 8 poles and 12 slots.

[0067] 1-2. Inverter 4

[0068] Inverter 4 is a power converter used to convert DC power supplied from DC power supply 3 into AC power supplied to the three-phase windings, and it has multiple switching elements. Inverter 4 has three sets of series circuits (legs) corresponding to each of the three phases. Each series circuit consists of a positive-side switching element SP connected to the positive terminal of DC power supply 3 and a negative-side switching element SN connected to the negative terminal of DC power supply 3, connected in series. Then, the connection point of the two switching elements in the series circuit of each phase is connected to the winding of the corresponding phase.

[0069] Specifically, in the series circuit of phase U, the positive-side switching element SCu of phase U is connected in series with the negative-side switching element SNu of phase U, and the connection point of the two switching elements is connected to the winding Cu of phase U. In the series circuit of phase V, the positive-side switching element SPv of phase V is connected in series with the negative-side switching element SNv of phase V, and the connection point of the two switching elements is connected to the winding Cv of phase V. In the series circuit of phase W, the positive-side switching element SPw of phase W and the negative-side switching element SNw of phase W are connected in series, and the connection point of the two switching elements is connected to the winding Cw of phase W.

[0070] The switching elements utilize IGBTs (Insulated Gate Bipolar Transistors), MOSFETs (Metal Oxide Semiconductor Field Effect Transistors), and bipolar transistors with diodes connected in reverse parallel. The gate terminals of each switching element are connected to the control device 6 via gate drive circuitry. Each switching element is turned on or off by a switching signal GPU-GNw output from the control device 6.

[0071] The DC power supply 3 outputs a DC voltage Vdc to the inverter 4. The DC power supply 3 can be any device that outputs a power supply voltage Vdc, such as a battery, DC-DC converter, diode rectifier, or PWM rectifier. The DC power supply 3 is equipped with a voltage sensor for detecting the power supply voltage Vdc, and the output signal of the voltage sensor can be input to the control device 6. The control device 6 can use the detected power supply voltage Vdc for control.

[0072] The current detector 5 is a circuit used to detect the current flowing through the three-phase windings. In this embodiment, the current detector 5 is installed in the series circuit of two switching elements in each of the three phases. The current detector 5 has shunt resistors 5u, 5v, and 5w connected in series to the negative side of the negative-side switching element of each phase. The shunt resistor 5u of phase U is connected in series to the negative side of the negative-side switching element SNu of phase U, the shunt resistor 5v of phase V is connected in series to the negative side of the negative-side switching element SNv of phase V, and the shunt resistor 5w of phase W is connected in series to the negative side of the negative-side switching element SNw of phase W. The potential difference between the two ends of the shunt resistors 5u, 5v, and 5w of each phase is input to the control device 6. Alternatively, the current detector 5 can be installed on the wires connecting the series circuit of the two switching elements of each phase and the windings of each phase. Furthermore, the current detector 5 can be configured to detect the current of any two phases. In this case, since the sum of the currents in the three-phase windings is zero, the control device 6 can calculate the current of the remaining phase based on the current detection values ​​of two phases. For example, current detector 5 detects the currents Iur and Ivr of phase U and phase V, and control device 6 can calculate the current Iwr of phase W by Iwr = -Iur - Ivr.

[0073] 1-3. Control Device 6

[0074] Control device 6 controls rotating motor 1 via inverter 4. For example... Figure 1 As shown, the control device 6 includes a rotation detection unit 31, a current detection unit 32, a current control unit 33, a switch control unit 34, etc. Each function of the control device 6 is implemented by the processing circuitry it possesses. Specifically, the control device 6 is as follows...Figure 5 As shown, the processing circuit includes the following components: an arithmetic processing unit 90 (computer) such as a CPU (Central Processing Unit), a storage device 91 for exchanging data with the arithmetic processing unit 90, an input circuit 92 for inputting external signals to the arithmetic processing unit 90, and an output circuit 93 for outputting signals from the arithmetic processing unit 90 to the outside.

[0075] The arithmetic processing unit 90 can be equipped with ASICs (Application Specific Integrated Circuits), ICs (Integrated Circuits), DSPs (Digital Signal Processors), FPGAs (Field Programmable Gate Arrays), various logic circuits, and various signal processing circuits. Furthermore, multiple arithmetic processing units of the same or different types can be used to share the execution of each process. The storage device 91 can be configured as RAM (Random Access Memory) capable of reading data from and writing data to the arithmetic processing unit 90, or ROM (Read Only Memory) capable of reading data from the arithmetic processing unit 90. The input circuit 92 is connected to various sensors and switches, such as the rotation detector 2 and the current detector 5, and includes an A / D converter that inputs the output signals of these sensors and switches to the arithmetic processing unit 90. The output circuit 93 is connected to electrical loads such as a gate drive circuit that drives the switching elements to turn on and off, and has a drive circuit that outputs control signals from the arithmetic processing unit 90 to these electrical loads.

[0076] The control device 6 has Figure 1 The various functions of the control units 31 to 34 are achieved by the arithmetic processing unit 90 executing the software (program) stored in the storage device 91 such as ROM, and cooperating with other hardware of the control device 6 such as the storage device 91, the input circuit 92, and the output circuit 93. Furthermore, the setting data used by each control unit 31 to 34 is stored as part of the software (program) in the storage device 91 such as ROM. The functions of the control device 6 will be described in detail below.

[0077] The rotation detection unit 31 detects the rotation angle and rotational angular velocity of the rotor. In this embodiment, the rotation detection unit 31 detects the rotation angle θ and rotational angular velocity ω of the rotor based on the output signal of the rotation detector 2.

[0078] The current detection unit 32 detects the currents Iur, Ivr, and Iwr flowing through the three-phase windings based on the output signal of the current detector 5. In the present embodiment, the current detection unit 32 divides the potential difference between both ends of the shunt resistor of each phase by the resistance value of the shunt resistor, thereby detecting the currents Iur, Ivr, and Iwr of each phase winding.

[0079] In the present embodiment, the current control unit 33 includes a magnetic pole position setting unit 331, a current command value calculation unit 332, and a voltage command value calculation unit 333. The magnetic pole position setting unit 331 sets the control magnetic pole position θc based on the rotation angle θ detected by the rotation detection unit 31. The current command value calculation unit 332 calculates the control current command value. The voltage command value calculation unit 333 calculates the voltage command value based on the current detection value, the control current command value, and the control magnetic pole position θc.

[0080] <Current control in the dq-axis rotating coordinate system>

[0081] The current control unit 33 controls the current in the dq-axis rotating coordinate system. The dq-axis rotating coordinate system is composed of a d-axis determined in the direction of the magnetic pole position (the position of the N pole), and a q-axis determined in the direction that is 90° ahead of the d-axis in terms of electrical angle.

[0082] As described using Figure 3 As shown, with respect to the magnetic pole position of the first deflection segment 112a, the magnetic pole position of the second deflection segment 112b is phase-advanced by the deflection angle θe (30 degrees in this example) in terms of electrical angle in the rotation direction R. Therefore, the problem is how to set the magnetic pole position of the dq-axis rotating coordinate system.

[0083] For example, as Figure 6 shown, the dq-axis rotating coordinate system with the most advanced phase set based on the magnetic pole position θ2 of the second deflection segment 112b, which is the most advanced in the rotation direction R, is composed of a d-axis (hereinafter referred to as the d2-axis) set in the direction of the magnetic pole position θ2 of the second deflection segment 112b and a q-axis (hereinafter referred to as the q2-axis) set in the direction that is 90° ahead of the d2-axis in terms of electrical angle.

[0084] The dq-axis rotating coordinate system with the most delayed phase set based on the magnetic pole position θ1 of the first deflection segment 112a, which is the most delayed in the rotation direction R, is composed of a d-axis (hereinafter referred to as the d1-axis) set in the direction of the magnetic pole position θ1 of the first deflection segment 112a and a q-axis (hereinafter referred to as the q1-axis) set in the direction that is 90° ahead of the d1-axis in terms of electrical angle.

[0085] Furthermore, the rotating coordinate system of the control dq axis, which is set with reference to the control magnetic pole position θc, is composed of the d axis (hereinafter referred to as the dc axis) set in the direction of the control magnetic pole position θc and the q axis (hereinafter referred to as the qc axis) set in the direction that is 90° ahead of the dc axis in terms of electrical angle.

[0086] The positions θ2, θ1, and θc of each magnetic pole are the rotation angles of the magnetic poles in electrical angles relative to the U-axis (U-phase winding position) of the three-phase stationary coordinate axes (U-axis, V-axis, W-axis) set at the position of the three-phase winding.

[0087] <Changes in the sixth-order torque ripple component caused by the phase of the magnetic pole position θc used for control>

[0088] In this embodiment, the current command value is calculated by controlling Id = 0, as described later. The d-axis current command value Ido is set to zero (Ido = 0), and the q-axis current command value Iqo is set to the value corresponding to the torque command value Tref. Therefore, the current vector is aligned with the qc axis of the rotating coordinate system of the dq axis for control.

[0089] Figure 7 An example is shown showing the characteristic plot of the phase lead α (=θc-θ1) of the control magnetic pole position θc relative to the magnetic pole position θ1 with the most delayed phase and the sixth-order torque ripple component in the electrical angle. Figure 7 The characteristics (isocurrent curves) of four current vectors with different absolute values ​​are shown. When α = 0, the control pole position θc coincides with the pole position θ1 of the latest delayed phase, and the direction of the current vector is aligned with the q1 axis. When α = θe, the control pole position θc coincides with the pole position θ2 of the latest advanced phase, and the direction of the current vector is aligned with the q2 axis. When α = θe / 2, the control pole position θc coincides with the pole position θave of the intermediate phase between the pole positions θ2 of the latest advanced phase and θ1 of the latest delayed phase, and the direction of the current vector is aligned with the direction of the intermediate phase between the q2 and q1 axes.

[0090] When the absolute value of the current vector is small, the 6th-order torque ripple component becomes the smallest phase advance α, which is the deflection angle θe / 2. When α = θe / 2, the control pole position θc becomes the intermediate phase between the pole position θ2 with the earliest advance phase and the pole position θ1 with the latest delay phase. This is because at the intermediate phase, the 6th-order torque ripple component generated by the pole of the second deflection segment 112b cancels out the 6th-order torque ripple component generated by the pole of the first deflection segment 112a.

[0091] On the other hand, as the absolute value of the current vector increases, the phase advance α of the 6th-order torque ripple component gradually approaches the deflection angle θe, becoming the smallest. This is due to the generation of magnetic saturation, as explained below. Figure 8As shown in the following formula, if α = θe / 2 is set, as the absolute value of the current vector |I| increases, the d2 axis component Id2 of the current vector I (also called the d2 axis current Id2) increases in the positive direction, and the d1 axis component Id1 of the current vector I (also called the d1 axis current Id1) increases in the negative direction.

[0092] Id2=|I|×cos(π / 2-θe+α)

[0093] Id1=-|I|×cos(π / 2-α)···(1)

[0094] Figure 9 The characteristics of the d2-axis linkage flux Φd2 relative to the d2-axis current Id2 are shown. The d2-axis linkage flux Φd2 generated when the d2-axis current Id2 = 0 is the flux generated by the magnetic pole of the second deflection segment 112b. If the d2-axis current Id2 is reduced from 0, the d2-axis linkage flux Φd2 decreases proportionally to the d2-axis current Id2 with a slope corresponding to the specified d-axis inductance Ld, since it is the direction of weak flux.

[0095] On the other hand, if the d2-axis current Id2 is increased from 0, although the linkage flux Φd2 of the d2-axis increases, the slope decreases. This is because magnetic saturation occurs in the stator tooth portion opposite the magnetic pole of the second deflection segment 112b, reducing the d-axis inductance Ld. If this magnetic saturation occurs, the 6th-order torque ripple component increases. Even if the absolute value of the current vector |I| increases, if the d2-axis current Id2 can be maintained near 0, the generation of magnetic saturation and the 6th-order torque ripple component can be suppressed. To maintain the d2-axis current Id2 near 0, as the absolute value of the current vector |I| increases, the phase advance α needs to change from the deflection angle θe / 2 to the deflection angle θe.

[0096] Due to this magnetic saturation, the 6th-order torque ripple component becomes the smallest phase advance α, which moves from the deflection angle θe / 2 to the deflection angle θe as the absolute value of the current vector increases. Therefore, as the absolute value of the current vector |I| increases, the phase advance α of the control pole position θc relative to the pole position θ1 with the most delayed phase can be shifted from the deflection angle θe / 2 corresponding to the intermediate phase between the pole position θ1 with the most delayed phase and the pole position θ2 with the most advanced phase to the deflection angle θe corresponding to the pole position θ2 with the most advanced phase.

[0097] Furthermore, since the characteristics of magnetic saturation vary with the design of the stator teeth and windings, in the case of a rotating motor that is difficult to magnetically saturate with the increase of the d-axis current, the sixth-order torque ripple component can be minimized even if the phase advance α does not increase to the deflection angle θe.

[0098] <Phase change of the control current vector corresponding to the current>

[0099] Therefore, the current control unit 33 sets the current vector of the current command value calculated on the rotating coordinate system of the dq axis at the earliest phase as the current vector Iadv of the earliest phase, and sets the current vector of the current command value calculated on the rotating coordinate system of the dq axis at the intermediate phase as the current vector Iave of the intermediate phase, and so on. Figure 10 As shown, as the winding current flowing through the three-phase winding increases, the controlled current vector Ic approaches the current vector Iave of the middle phase from the current vector Iadv of the earliest phase.

[0100] Here, the rotating coordinate system of the dq axis with the earliest phase is formed by the d2 axis, which is defined in the direction of the magnetic pole position θ2 of the second deflection segment 112b with the earliest phase in the rotation direction R, and the q2 axis, which is defined in the direction of the phase leading by an electrical angle of 90° relative to the d2 axis. The rotating coordinate system of the dq axis with the intermediate phase is formed by the d-axis (hereinafter referred to as the dave axis) and the q-axis (hereinafter referred to as the qave axis), wherein the d-axis is defined as the direction of the intermediate phase between the magnetic pole position θ2 of the second deflection segment 112b with the earliest phase in the rotation direction R and the magnetic pole position θ1 of the first deflection segment 112a with the latest phase, and the q-axis is defined as the direction of the phase leading by an electrical angle of 90° relative to the dave axis.

[0101] According to this structure, as the winding current (the absolute value of the current vector) increases, the controlled current vector Ic approaches the current vector Iave from the middle phase towards the current vector Iadv at the earliest phase. Therefore, when the winding current is small, it can cancel out the torque ripple components generated by the earliest phase magnetic pole and the torque ripple components generated by the latest phase magnetic pole, thereby reducing the 6th-order torque ripple component. Even if the winding current increases, it can suppress the d2-axis current Id2 at the earliest phase from increasing to magnetic saturation, thereby reducing the 6th-order torque ripple component. Therefore, the phase of the current vector relative to the circumferentially offset magnetic pole position can be appropriately changed according to the increase or decrease of the winding current, effectively reducing the 6th-order torque ripple component.

[0102] like Figure 10 As shown, the current control unit 33 sets the current vector of the current command value calculated by controlling Id=0 on the rotating coordinate system of the dq axis of the earliest phase as the current vector Iadv of the earliest phase, and sets the current vector of the current command value calculated by controlling Id=0 on the rotating coordinate system of the dq axis of the middle phase as the current vector Iave of the middle phase. As the winding current flowing through the three-phase winding increases, the controlled current vector Ic approaches the current vector Iadv of the earliest phase from the current vector Iave of the middle phase.

[0103] According to this structure, the current vector Iadv of the earliest leading phase becomes the current vector along the q2 axis of the rotating coordinate system of the dq axis of the earliest leading phase, and the current vector Iave of the intermediate phase becomes the current vector along the qave axis of the rotating coordinate system of the dq axis of the intermediate phase. Furthermore, as the winding current increases, the controlled current vector can be made to approach the current vector along the qave axis of the rotating coordinate system of the dq axis of the intermediate phase towards the current vector along the q2 axis of the rotating coordinate system of the dq axis of the earliest leading phase. This can suppress the increase of the d2 axis current Id2, which represents the current in the rotating coordinate system of the dq axis of the earliest leading phase, and suppress the increase of the sixth-order torque ripple component in the electrical angle.

[0104] <Changes in the position of the magnetic poles used for control in relation to current>

[0105] In this embodiment, as the winding current increases, the magnetic pole position setting unit 331 moves the control magnetic pole position θc from the magnetic pole position θave towards the magnetic pole position θ2, which is the pole position with the earliest phase in the rotation direction R. This magnetic pole position θave is the magnetic pole position with an intermediate phase between the magnetic pole position θ2 of the second deflection segment 112b, which is the pole position with the earliest phase in the rotation direction R, and the magnetic pole position θ1 of the first deflection segment 112a, which is the pole position with the latest phase in the rotation direction R. Then, the current command value calculation unit 332 calculates the control current command value on a rotating coordinate system of the control dq axis, which is set with the control magnetic pole position θc as a reference. Then, the voltage command value calculation unit 333 calculates the voltage command value on a rotating coordinate system of the control dq axis, which is set with the control magnetic pole position θc as a reference, based on the current detection value and the control current command value.

[0106] According to this structure, as the winding current increases, the control magnetic pole position θc approaches the magnetic pole position θ2 of the earliest phase from the magnetic pole position of the middle phase. This allows the current vector Ic of the control current command value and the controlled current vector Ic to approach the current vector Iave of the middle phase calculated on the rotating coordinate system of the dq axis of the middle phase from the current vector Iadv of the earliest phase calculated on the rotating coordinate system of the dq axis of the earliest phase.

[0107] <Magnetic pole position setting unit 331>

[0108] As described above, as the winding current increases, the magnetic pole position setting unit 331 moves the control magnetic pole position θc from the magnetic pole position θave, which is the intermediate phase between the magnetic pole position θ2 of the earliest phase and the magnetic pole position θ2 of the latest phase, toward the magnetic pole position θ2 of the earliest phase.

[0109] For example, the magnetic pole position setting unit 331 refers to Figure 11The correction amount setting data shown pre-sets the relationship between the winding current |I| and the correction amount Δθ of the magnetic pole position. The correction amount Δθ corresponding to the current winding current |I| is calculated. Then, the magnetic pole position setting unit 331 sets a reference magnetic pole position θ0 based on the rotation angle θ detected by the rotation detection unit 31, as shown in the following formula. Then, the magnetic pole position setting unit 331 calculates the control magnetic pole position θc by adding the correction amount Δθ to the reference magnetic pole position θ0. For example, if the magnetic pole position θave of the intermediate phase is set as the reference magnetic pole position θ0, the correction amount Δθ of the magnetic pole position is set to approach from 0 to the deflection angle θe / 2 as the winding current |I| increases.

[0110] θc=θ0+Δθ···(2)

[0111] θ0=θave

[0112] The magnetic pole position setting unit 331 calculates the absolute value of the current vector based on the control d-axis current command value Ido and the control q-axis current command value Iqo, as shown in the following formula, to obtain the winding current |I|. Furthermore, since Id = 0 is controlled, Ido = 0, therefore the winding current |I| is proportional to the q-axis current command value Iqo. The d-axis current detection value Idr and the q-axis current detection value Iqr can be used instead of the control d-axis current command value Ido and the control q-axis current command value Iqo.

[0113] |I|=√(Ido2+Iqo2)=Iqo···(3)

[0114] <Current Command Value Calculation Unit 332>

[0115] The current command value calculation unit 332 calculates the control d-axis current command value Ido and the control q-axis current command value Iqo in the rotating coordinate system of the control dq axis by controlling Id = 0. For example, the current command value calculation unit 332 sets the control d-axis current command value Ido to 0 and sets the control q-axis current command value Iqo to the value obtained by multiplying the torque command value Tref by the conversion coefficient Kt, as shown in the following formula. The torque command value Tref can be calculated within the control device 6 or transmitted from an external control device.

[0116] Ido=0

[0117] Iqo=Kt×Tref···(4)

[0118] <Voltage Command Value Calculation Unit 333>

[0119] The voltage command value calculation unit 333 calculates the voltage command value based on the current detection value, the control current command value, and the control magnetic pole position θc. In this embodiment, the voltage command value calculation unit 333 calculates the voltage command value based on the current detection value and the control current command value in a rotational coordinate system of the control dq axis set with the control magnetic pole position θc as a reference. Figure 1 As shown, the voltage command value calculation unit 333 includes a current coordinate conversion unit 3331, a dq axis voltage command value calculation unit 3332, and a voltage coordinate conversion unit 3333.

[0120] The current coordinate conversion unit 3331 converts the current detection values ​​Iur, Ivr, and Iwr of the three-phase winding detected by the current detection unit 32 into d-axis current detection values ​​Idr and q-axis current detection values ​​Iqr in a rotating coordinate system with the control magnetic pole position θc as a reference. The d-axis is defined as the direction of the control magnetic pole position θc, and the q-axis is defined as the direction that advances 90° from the d-axis in electrical angle. Specifically, the current coordinate conversion unit 3331 performs three-phase to two-phase conversion and rotating coordinate conversion on the three-phase current detection values ​​Iur, Ivr, and Iwr based on the control magnetic pole position θc, thereby converting them into d-axis current detection values ​​Idr and q-axis current detection values ​​Iqr.

[0121] [Mathematical Expression 1]

[0122] Number 1

[0123]

[0124] The dq-axis voltage command value calculation unit 3332 performs current feedback control. In this current feedback control, the d-axis voltage command value Vdo and the q-axis voltage command value Vqo are changed through PI control or the like, so that the d-axis current detection value Idr approaches the control d-axis current command value Ido, and the q-axis current detection value Iqr approaches the control q-axis current command value Iqo. Additionally, feedforward control can be performed to achieve non-interference between the d-axis and q-axis currents.

[0125] The voltage coordinate transformation unit 3333 performs fixed coordinate transformation and two-phase to three-phase transformation on the d-axis and q-axis voltage command values ​​Vdo and Vqo in the rotating coordinate system of the control dq axis based on the control magnetic pole position θc, so as to convert them into three-phase voltage command values ​​Vuo, Vvo, and Vwo. Various modulations, such as third harmonic injection modulation, can be applied to the three-phase voltage command values.

[0126] [Mathematical Expression 2]

[0127] Number 2

[0128]

[0129] <Switch Control Unit 34>

[0130] The switch control unit 34 performs on / off control of multiple switching elements based on voltage command values. In this embodiment, the switch control unit 34 performs on / off control of the switching elements by comparing each of the three-phase voltage command values ​​Vuo, Vvo, and Vwo with a carrier CA that oscillates with a carrier period Tc. The carrier CA is a triangular wave that oscillates with a center of 0 and an amplitude of half the power supply voltage Vdc / 2 under the carrier period Tc. The power supply voltage Vdc can be detected by a voltage sensor.

[0131] like Figure 12 As shown, for each phase, when the carrier CA is lower than the voltage command value, the switch control unit 34 turns on the switch signal GP (1 in this example) of the positive-side switch element and turns on the positive-side switch element. When the carrier CA is higher than the voltage command value, it turns off the switch signal GP (0 in this example) of the positive-side switch element and turns off the positive-side switch element. On the other hand, for each phase, when the carrier CA is lower than the voltage command value, the switch control unit 34 turns off the switch signal GN (0 in this example) of the negative-side switch element and turns off the negative-side switch element. When the carrier CA is higher than the voltage command value, it turns on the switch signal GN (1 in this example) of the negative-side switch element and turns on the negative-side switch element. In addition, for each phase, a short-circuit prevention period (dead time) for turning off both the positive-side and negative-side switch elements can be set between the conduction period of the positive-side switch element and the conduction period of the negative-side switch element.

[0132] 2. Implementation Method 2

[0133] The rotary electric motor device according to Embodiment 2 will be described. Descriptions of structural parts identical to those in Embodiment 1 are omitted. The basic structures of the rotary electric motor 1, inverter 4, and control device 6 according to this embodiment are the same as in Embodiment 1, but the processing of the control device 6 differs from that in Embodiment 1.

[0134] In this embodiment, to minimize the increase in the sixth-order torque ripple component caused by magnetic saturation, such as... Figure 10 As shown, as the winding current flowing through the three-phase winding increases, the current control unit 33 causes the current vector Ic of the control current command value to approach the current vector Iave of the middle phase to the current vector Iadv of the earliest phase.

[0135] However, in this embodiment, the implementation method differs from that in Embodiment 1. Specifically, the magnetic pole position setting unit 331 detects the magnetic pole position θave of the intermediate phase between the magnetic pole position θ2 of the second deflection segment 112b with the earliest phase in the rotation direction R and the magnetic pole position θ1 of the first deflection segment 112a with the latest phase in the rotation direction R, and uses this as the control magnetic pole position θc. The current command value calculation unit 332 calculates the current command value on a rotating coordinate system of the dq axis of the intermediate phase, set with the intermediate phase magnetic pole position θave as a reference. It then reduces the d-axis component of this current command value by a d-axis current reduction amount ΔId, thereby calculating the control current command value. The current command value calculation unit 332 increases the d-axis current reduction amount ΔId, causing the current vector Ic of the control current command value to approach the current vector Iave of the intermediate phase from the current vector Iave of the earliest phase as the winding current increases. Then, the voltage command value calculation unit 333 calculates the voltage command value based on the current detection value and the control current command value on a rotating coordinate system of the dq axis of the intermediate phase, which is set with the magnetic pole position θave of the intermediate phase as a reference.

[0136] According to this structure, as the winding current increases, by reducing the d-axis component of the current command value calculated in the rotating coordinate system of the dq axis at the intermediate phase, the current vector Ic of the control current command value can be made to approach the current vector Iave at the intermediate phase from the current vector Iadv at the earliest phase. This can suppress the increase in the d2-axis current Id2, which represents the current in the rotating coordinate system of the dq axis at the earliest phase, and suppress the increase in the sixth-order torque ripple component at the electrical angle.

[0137] The current command value calculation unit 332 calculates the d-axis and q-axis current command values ​​Idave and Iqave of the intermediate phase in the rotating coordinate system of the dq-axis of the intermediate phase by controlling Id = 0. For example, the current command value calculation unit 332 sets the d-axis current command value Idave of the intermediate phase to 0 and sets the q-axis current command value Iqave of the intermediate phase to the value obtained by multiplying the torque command value Tref by the conversion coefficient Kt, as shown in the following formula.

[0138] Idave = 0

[0139] Iqave=Kt×Tref···(7)

[0140] Then, the current command value calculation unit 332, as follows Figure 13 As shown in the following formula, the control d-axis current command value Ido is calculated by reducing the d-axis current reduction amount ΔId of the intermediate phase d-axis current command value Idave. Furthermore, the current command value calculation unit 332 directly sets the intermediate phase q-axis current command value Iqave as the control q-axis current command value Iqo.

[0141] Ido = Idave - ΔId

[0142] Iqo=Iqave···(8)

[0143] The current command value calculation unit 332 calculates the d-axis current reduction ΔId corresponding to the current winding current |I| by referring to reduction amount setting data that pre-sets the relationship between the winding current |I| and the d-axis current reduction ΔId. For example... Figure 14 As shown, the reduction amount setting data is set such that as the winding current |I| increases, the d-axis current reduction amount ΔId increases, thereby causing the current vector Ic of the control current command value to approach the current vector Iave of the middle phase to the current vector Iadv of the earliest phase. Furthermore, the d-axis current reduction amount ΔId*, where the current vector Ic of the control current command value coincides with the current vector Iadv of the earliest phase, is shown in the following formula: as the winding current |I| increases, the d-axis current reduction amount ΔId approaches ΔId* from 0.

[0144] ΔId*=tan(θe / 2)×Iqave···(9)

[0145] like Figure 13 As shown in the example, in the rotating coordinate system of the dq axis of the intermediate phase, the current vector Iave of the intermediate phase current command value calculated by controlling Id=0 is consistent with the q axis, i.e., the qave axis, of the rotating coordinate system of the intermediate phase dq axis. By reducing the d-axis current reduction ΔId of the d-axis component of the intermediate phase current command value, the current vector Ic of the control current command value can be made close to the current vector Iadv of the earliest phase, which is consistent with the q2 axis.

[0146] The current command value calculation unit 332 calculates the absolute value of the current vector as the winding current |I| based on the d-axis current command value Idave and the q-axis current command value Iqave of the intermediate phase, as shown in the following formula. Furthermore, by controlling Id = 0, Idave = 0, therefore the winding current |I| is proportional to the q-axis current command value Iqave. The d-axis current detection value Idr and the q-axis current detection value Iqr can be used instead of the intermediate phase d-axis current command value Idave and q-axis current command value Iqave.

[0147] |I|=√(Idave2+Iqave2)···(10)

[0148] <Reduction of d-axis component caused by upper limit current value>

[0149] The torque of a rotating electric motor is the average of the torque produced by the pole in the earliest phase and the torque produced by the pole in the latest phase, and therefore varies proportionally to the q-axis current in the middle phase. That is, the larger the q-axis current in the middle phase, the larger the torque of the rotating electric motor. Figure 15 The current-limiting circle shown has an upper limit on the current that can flow to the winding. As mentioned above, by reducing the d-axis current reduction ΔId of the d-axis current command value in the intermediate phase, the absolute value of the current vector increases. On the other hand, if the absolute value of the current vector reaches the upper limit current value, the q-axis current in the intermediate phase cannot be increased, and the torque cannot be increased by the d-axis current reduction ΔId. In the required performance of rotating electrical machines, increasing the maximum torque is sometimes more important than reducing the 6th-order torque ripple component.

[0150] Therefore, when the winding current |I| exceeds the threshold Ith obtained by setting it to be less than the upper limit current value Imax, the current command value calculation unit 332 causes the current vector Ic of the control current command value to approach the upper limit current value Imax as the winding current |I| approaches the upper limit current value Imax. In this embodiment, as Figure 14 As shown, when the winding current |I| (in this example, the q-axis current command value Iqave of the middle phase) exceeds the threshold Ith, the current command value calculation unit 332 reduces the d-axis current reduction ΔId to zero as the winding current |I| approaches the upper limit current value Imax.

[0151] According to this structure, when the winding current |I| approaches the upper limit current value Imax, the current vector Ic of the control current command value can be made to move from the current vector Iadv of the earliest phase to the current vector Iave of the middle phase, thereby increasing the maximum torque at the cost of reducing the 6th order torque ripple component.

[0152] In addition, compared to increasing the maximum torque, this treatment may not be necessary for rotating motors that require a reduction in the sixth-order torque ripple component.

[0153] 3. Implementation Method 3

[0154] The rotary motor device according to Embodiment 3 will be described. Descriptions of structural parts that are the same as those in Embodiments 1 or 2 are omitted. The basic structure of the rotary motor 1, inverter 4 and control device 6 according to this embodiment is the same as that in Embodiments 1 or 2, but the rotary motor 1 can rotate to one side and the other side, and the processing of the control device 6 is different from that in Embodiments 1 or 2.

[0155] In embodiments 1 and 2, the rotary motor 1 rotates only to one side. However, depending on the application, the rotary motor 1 may rotate to both one and the other side. Therefore, the current control unit 33 sets the magnetic pole position with the earliest phase and the magnetic pole position with the latest phase in the rotation direction according to the rotation direction of one and the other side. The rotation direction that is the same as the rotation direction R in embodiment 1 is set as the rotation direction R1 of one side, and the rotation direction that is opposite to the rotation direction R in embodiment 1 is set as the rotation direction R2 of the other side.

[0156] like Figure 16 As shown in Embodiment 1, when the rotation direction is a one-sided rotation direction R1, the rotation coordinate system of the dq axis with the earliest phase is formed by the d2 axis, which is defined in the direction of the magnetic pole position θ2 of the second deflection segment 112b with the earliest phase in the one-sided rotation direction R1, and the q2 axis, which is defined in the direction of the rotation direction R1 with a phase advance of 90° compared to the d2 axis. The rotation coordinate system of the dq axis with the intermediate phase is formed by the dave axis and the qave axis, wherein the dave axis is defined as the direction of the intermediate phase between the magnetic pole position θ2 of the second deflection segment 112b with the earliest phase in the one-sided rotation direction R1 and the magnetic pole position θ1 of the first deflection segment 112a with the latest phase in the one-sided rotation direction R1, and the qave axis is defined as the direction with a phase advance of 90° compared to the dave axis.

[0157] like Figure 17 As shown, contrary to Embodiment 1, when the rotation direction is the opposite rotation direction R2, the rotation coordinate system of the dq axis with the earliest phase is formed by the d1 axis, which is defined in the direction of the magnetic pole position θ1 of the first deflection segment 112a with the earliest phase in the opposite rotation direction R2, and the q1 axis, which is defined in the direction of the opposite rotation direction R2 with a phase advance of 90° compared to the d1 axis. The rotation coordinate system of the dq axis with the intermediate phase is formed by the dave axis and the qave axis. The dave axis is defined as the direction of the intermediate phase between the magnetic pole position θ1 of the first deflection segment 112a with the earliest phase in the opposite rotation direction R2 and the magnetic pole position θ2 of the second deflection segment 112b with the latest phase in the opposite rotation direction R2. The qave axis is defined as the direction of the opposite rotation direction R2 with a phase advance of 90° compared to the dave axis.

[0158] Furthermore, as described above, using a rotating coordinate system of the dq axis set according to the rotation direction, similar to Embodiment 1 or 2, the current control unit 33 sets the current vector of the current command value calculated on the rotating coordinate system of the dq axis of the earliest phase as the current vector Iadv of the earliest phase, and sets the current vector of the current command value calculated on the rotating coordinate system of the dq axis of the middle phase as the current vector Iave of the middle phase. As the winding current flowing through the three-phase winding increases, the controlled current vector approaches the current vector Iadv of the earliest phase from the current vector Iave of the middle phase.

[0159] <Case where the same method as in Implementation 1 is used>

[0160] The case using the same method as in Embodiment 1 will be described. In the case of a rotation direction R1 on one side, similar to Embodiment 1, as the winding current increases, the magnetic pole position setting unit 331 moves the control magnetic pole position θc from the intermediate phase magnetic pole position θave towards the magnetic pole position θ2 of the second deflection segment 112b, which is the phase furthest ahead in the rotation direction R1 on one side. The current command value calculation unit 332 calculates the control current command value on a rotational coordinate system of the control dq axis set with the control magnetic pole position θc as a reference. Then, the voltage command value calculation unit 333 calculates the voltage command value based on the current detection value and the control current command value on a rotational coordinate system of the control dq axis set with the control magnetic pole position θc as a reference. In this case, the rotational coordinate system of the control dq axis consists of the dc axis defined in the direction of the control magnetic pole position θc and the qc axis defined in the rotation direction R1 on one side, which is 90° ahead of the dc axis phase by an electrical angle.

[0161] When the rotation direction is R2 on the other side, the magnetic pole position setting unit 331, as the winding current increases, moves the control magnetic pole position θc from the intermediate phase magnetic pole position θave towards the magnetic pole position θ1 of the first deflection segment 112a, which is the phase furthest ahead in the rotation direction R2 on the other side. The current command value calculation unit 332 calculates the control current command value on a rotational coordinate system of the control dq axis, which is set with the control magnetic pole position θc as a reference. In this case, as with the rotation direction R1 on one side, the q-axis current command value Iqo is positive. Then, the voltage command value calculation unit 333 calculates the voltage command value on a rotational coordinate system of the control dq axis, which is set with the control magnetic pole position θc as a reference, based on the current detection value and the control current command value. In this case, the rotational coordinate system of the control dq axis is composed of the dc axis, which is defined in the direction of the control magnetic pole position θc, and the qc axis, which is defined in the direction of the rotation direction R2 on the other side, which is an electrical angle 90 degrees ahead of the dc axis phase.

[0162] <Case where the same method as in Implementation Method 2 is used>

[0163] Next, the case using the same method as in Embodiment 2 will be described. In the case of rotation direction R1 on one side, as in Embodiment 1, the magnetic pole position setting unit 331 detects the magnetic pole position θave of the intermediate phase as the control magnetic pole position θc. The current command value calculation unit 332 calculates the current command value on a rotating coordinate system of the dq axis of the intermediate phase, set with the magnetic pole position θave of the intermediate phase as a reference, and reduces the d-axis component of the current command value by a d-axis current reduction amount ΔId, thereby calculating the control current command value. The current command value calculation unit 332 increases the d-axis current reduction amount ΔId, causing the current vector Ic of the control current command value to approach the current vector Iave of the intermediate phase from the current vector Iave of the earliest phase as the winding current increases. Then, the voltage command value calculation unit 333 calculates the voltage command value on a rotating coordinate system of the dq axis of the intermediate phase, set with the magnetic pole position θave of the intermediate phase as a reference, based on the current detection value and the control current command value. In this case, the rotating coordinate system of the dq axis of the intermediate phase is composed of the dave axis, which is determined in the direction of the magnetic pole position θave of the intermediate phase, and the qave axis, which is determined in the rotation direction R1 on one side, which is an electrical angle 90 degrees ahead of the dave axis phase.

[0164] When the rotation direction is R2 on the other side, the magnetic pole position setting unit 331 detects the magnetic pole position θave of the intermediate phase as the control magnetic pole position θc. The current command value calculation unit 332 calculates the current command value on the dq axis rotation coordinate system of the intermediate phase, which is set with the magnetic pole position θave of the intermediate phase as a reference. The d-axis component of the current command value is reduced by the d-axis current reduction amount ΔId to calculate the control current command value. The current command value calculation unit 332 increases the d-axis current reduction amount ΔId so that the current vector Ic of the control current command value approaches the current vector Iave of the intermediate phase from the current vector Iave of the earliest phase as the winding current increases. In this case, similar to the case of the rotation direction R1 on one side, the q-axis current command value Iqo is positive and the d-axis current command value Ido is negative. Then, the voltage command value calculation unit 333 calculates the voltage command value based on the current detection value and the control current command value in a rotating coordinate system of the dq axis of the intermediate phase, which is set with reference to the magnetic pole position θave of the intermediate phase. In this case, the rotating coordinate system of the dq axis of the intermediate phase is composed of the dave axis, which is determined in the direction of the magnetic pole position θave of the intermediate phase, and the qave axis, which is determined in the rotation direction R2 on the other side, in the direction that the phase of the dave axis is advanced by an electrical angle of 90 degrees compared to the phase of the dave axis.

[0165] <Other examples of rotation direction on the other side>

[0166] Or, such as Figure 18 As shown, in the case of rotation direction R2 on the other side, the rotation coordinate system of the dq axis with the earliest phase is set as a rotation coordinate system of the dq axis formed by the d1 axis, which is determined in the direction of the magnetic pole position θ1 of the first deflection segment 112a with the earliest phase on the other side of rotation direction R2, and the q1 axis, which is determined in the direction of rotation direction R1 on one side with the phase advanced by an electrical angle of 90° compared to the d1 axis. Alternatively, the rotation coordinate system of the dq axis with the intermediate phase can be set as a rotation coordinate system of the dq axis formed by the dave axis and the qave axis, wherein the dave axis is determined as the direction of the intermediate phase between the magnetic pole position θ1 of the first deflection segment 112a with the earliest phase on the other side of rotation direction R2 and the magnetic pole position θ2 of the second deflection segment 112b with the latest phase on the other side of rotation direction R2, and the qave axis is determined as the direction of rotation direction R1 on one side with the phase advanced by an electrical angle of 90° compared to the dave axis. In this case, the q-axis current command value Iqo is a negative value after the sign is reversed. In this case, it is essentially equivalent to the structure described above.

[0167] Electric power steering system

[0168] This type of rotary motor is used for, for example Figure 19 The electric power steering system is shown as a driving force source. The electric power steering system includes: a steering wheel 63 for the driver to rotate left and right; a shaft 64 connected to the steering wheel 63 and transmitting the steering torque of the steering wheel 63 to the wheels 62; a torque sensor 65 mounted on the shaft 64 and detecting the steering torque of the steering wheel 63; and a drive force transmission mechanism 61, such as a worm gear mechanism, transmitting the driving force of the rotary motor 1 to the shaft 64. The control device 6 is configured to cause the rotary motor 1 to output a torque corresponding to the steering torque of the steering wheel 63 detected by the torque sensor 65. Therefore, the torque command value Tref is set based on the steering torque detected by the torque sensor 65.

[0169] When the driver turns the steering wheel 63 to the right, the rotary motor 1 rotates, for example, along a rotation direction R1 on one side, and the control device 6 outputs a torque in the rotation direction R1 on the other side, corresponding to the steering torque. When the driver turns the steering wheel 63 to the left, the rotary motor 1 rotates, for example, along a rotation direction R2 on the other side, and the control device 6 outputs a torque in the rotation direction R2 on the other side, corresponding to the steering torque.

[0170] 4. Implementation Method 4

[0171] The rotary electric motor device according to Embodiment 4 will be described. Descriptions of structural parts that are the same as those in Embodiments 1 or 2 are omitted. The basic structure of the rotary electric motor 1, inverter 4 and control device 6 according to this embodiment is the same as that in Embodiments 1 or 2, but the permanent magnet is embedded inside the rotor, and the method for calculating the current command value is different from that in Embodiments 1 or 2.

[0172] In this embodiment, such as Figure 20 As shown, the permanent magnet 161 is embedded inside the rotor 11, and the rotor is configured as an embedded magnet type synchronous motor. The rotor 11 is provided with a rotor core 162, and the permanent magnet 161 is embedded inside the rotor core 162.

[0173] Similar to Embodiment 1, the permanent magnet 161 is provided with deflection sections in two stages along the axial direction X, which offset the position of the magnetic poles circumferentially. A first deflection section 162a is provided on one side X1 of the rotor's axial direction, and a second deflection section 162b is provided on the other side X2. Eight magnetic poles 161 (four N poles and four S poles) are arranged circumferentially at equal intervals on the outer periphery of each of the first and second deflection sections 162a and 162b. The N poles and S poles are arranged alternately in the circumferential direction.

[0174] The magnetic pole 161 (e.g., N pole) of the second deflection segment 162b and the magnetic pole 161 (e.g., N pole) of the first deflection segment 162a are offset in the circumferential direction. In this example, the magnetic pole 161 of the second deflection segment 162b is electrically offset by 30 degrees relative to 161 of the first deflection segment 162a in the direction of rotation R, and the deflection angle θe is 30 degrees in electrical angle. The magnetic pole position θ2 of the second deflection segment 162b is electrically advanced by the phase deflection angle θe (30 degrees in this example) relative to the magnetic pole position θ1 of the first deflection segment 162a in the direction of rotation R.

[0175] Therefore, similar to Embodiment 1, the rotational coordinate system of the dq axis, which is set with reference to the magnetic pole position θ2 of the second deflection segment 162b with the earliest phase in the rotation direction R, is composed of the d2 axis set in the direction of the magnetic pole position θ2 of the second deflection segment 162b and the q2 axis set in the direction that is 90° earlier in phase in electrical angle than the d2 axis.

[0176] The rotating coordinate system of the dq axis of the most delayed phase, which is set with reference to the magnetic pole position θ1 of the first deflection segment 162a with the most delayed phase in the rotation direction R, is composed of the d1 axis set in the direction of the magnetic pole position θ1 of the first deflection segment 162a and the q2 axis set in the direction of rotation R with the phase 90° ahead of the d1 axis in electrical angle.

[0177] <Phase Change of Current Vector in Maximum Torque Current Control>

[0178] In this type of embedded magnet synchronous motor, the q-axis inductance Lq is greater than the d-axis inductance Ld. Generally, the current command value is set through maximum torque current control. In maximum torque current control, such as... Figure 21 As shown, for the same current, the current command values ​​Ido and Iqo for the d-axis and q-axis that maximize torque are calculated. As the torque command value Tref increases, along the maximum torque current curve, while the q-axis current command value Iqo increases from 0, the d-axis current command value Ido decreases from 0.

[0179] Even in this type of embedded magnet synchronous motor, if the d2-axis current Id2, representing the current in the rotating coordinate system of the dq-axis at the earliest possible phase, increases in the positive direction compared to the d-axis current command value calculated by maximum torque current control in the rotating coordinate system of the dq-axis at the earliest possible phase, then it is consistent with Embodiment 1. Figure 9 Similarly, magnetic saturation occurs, and the sixth-order torque ripple component in the electrical angle increases. Therefore, even if the absolute value of the current vector |I| increases, if the d2-axis current Id2 can be maintained near the d-axis current command value Ido calculated by the maximum torque current control in the rotating coordinate system of the dq-axis with the earliest phase, the occurrence of magnetic saturation and the sixth-order torque ripple component can be suppressed. Therefore, compared with Embodiment 1... Figure 7 Similarly, in order to maintain the d2-axis current Id2 near the d-axis current command value Ido calculated by the maximum torque current control, it is necessary to make the phase advance of the control magnetic pole position θc relative to the magnetic pole position θ1 of the most delayed phase by α from the deflection angle θe / 2 corresponding to the middle phase θave of the magnetic pole position θ1 of the most delayed phase to the deflection angle θe corresponding to the magnetic pole position θ2 of the most advanced phase.

[0180] Therefore, the current control unit 33 sets the current vector of the current command value calculated by maximum torque current control on the rotating coordinate system of the dq axis at the earliest advance phase as the current vector Iadv of the earliest advance phase, and sets the current vector of the current command value calculated by maximum torque current control on the rotating coordinate system of the dq axis at the intermediate phase as the current vector Iave of the intermediate phase, and so on. Figure 22 As shown, as the winding current flowing through the three-phase windings increases, the controlled current vector Ic approaches the current vector Iave of the middle phase from the current vector Iadv of the earliest phase.

[0181] According to this structure, the d2-axis current Id2, which represents the current in the rotating coordinate system of the dq-axis at the earliest phase, can be maintained near the d-axis current command value calculated by the maximum torque current control in the rotating coordinate system of the dq-axis at the earliest phase. Therefore, it can suppress the occurrence of magnetic saturation and the occurrence of the 6th order torque ripple component.

[0182] <Case where the same method as in Implementation 1 is used>

[0183] As the winding current increases, the magnetic pole position setting unit 331 moves the control magnetic pole position θc from the magnetic pole position θave towards the magnetic pole position θ2, which is the pole position with the earliest phase in the rotational direction. This magnetic pole position θave is the magnetic pole position with an intermediate phase between the magnetic pole position θ2 of the second deflection segment 112b, which is the pole position with the earliest phase in the rotational direction, and the magnetic pole position θ1 of the first deflection segment 112a, which is the pole position with the latest phase in the rotational direction. Then, the current command value calculation unit 332 calculates the control current command value using maximum torque current control on a rotating coordinate system of the control dq axis, which is set with the control magnetic pole position θc as a reference. Then, the voltage command value calculation unit 333 calculates the voltage command value based on the current detection value and the control current command value on a rotating coordinate system of the control dq axis, which is set with the control magnetic pole position θc as a reference.

[0184] Unlike Embodiment 1, the current command value calculation unit 332 calculates the control d-axis and q-axis current command values ​​Ido and Iqo in the rotating coordinate system of the control dq-axis using maximum torque current control. For example, the current command value calculation unit 332 refers to... Figure 21 The current command value setting data shown pre-sets the relationship between the torque command value Tref and the current command values ​​Ido and Iqo for the d-axis and q-axis, respectively. The control current command values ​​Ido and Iqo corresponding to the current torque command value Tref are then calculated. Other points are the same as in Embodiment 1, so descriptions are omitted.

[0185] <Case where the same method as in Implementation Method 2 is used>

[0186] The magnetic pole position setting unit 331 sets the magnetic pole position θave, which is the intermediate phase between the magnetic pole position θ2 of the second deflection segment 112b, which is the earliest phase in the rotational direction, and the magnetic pole position θ1 of the first deflection segment 112a, which is the latest phase in the rotational direction, as the control magnetic pole position θc. The current command value calculation unit 332 calculates the current command value on the dq axis of the intermediate phase, which is set with the magnetic pole position θave of the intermediate phase as a reference, by controlling the maximum torque current. The d-axis component of the current command value is reduced by the d-axis current reduction amount ΔId, thereby calculating the control current command value. The current command value calculation unit 332 increases the d-axis current reduction amount ΔId, so that the current vector Ic of the control current command value approaches the current vector Iave of the intermediate phase from the current vector Iave of the earliest phase as the winding current increases. Then, the voltage command value calculation unit 333 calculates the voltage command value based on the current detection value and the control current command value on a rotating coordinate system of the dq axis of the intermediate phase, which is set with the magnetic pole position θave of the intermediate phase as a reference.

[0187] Unlike Embodiment 2, the current command value calculation unit 332 calculates the d-axis and q-axis current command values ​​Idave and Iqave of the intermediate phase in a rotating coordinate system of the dq-axis of the intermediate phase by means of maximum torque current control. For example, the current command value calculation unit 332 refers to... Figure 21 The current command value setting data shown is a pre-set relationship between the torque command value Tref and the d-axis and q-axis current command values ​​Ido and Iqo. The d-axis and q-axis current command values ​​Idave and Iqave are calculated for the intermediate phase corresponding to the current torque command value Tref.

[0188] Then, as shown in equation (8), the current command value calculation unit 332 calculates the control d-axis current command value Ido by reducing the d-axis current reduction amount ΔId of the d-axis current command value Idave of the intermediate phase. In addition, the current command value calculation unit 332 directly sets the q-axis current command value Iqave of the intermediate phase to the control q-axis current command value Iqo.

[0189] The current command value calculation unit 332 calculates the current command value by referring to and Figure 14Similarly, a reduction setting data that pre-sets the relationship between the winding current |I| and the d-axis current reduction ΔId is set, and the d-axis current reduction ΔId corresponding to the current winding current |I| is calculated. The reduction setting data is set such that as the winding current |I| increases, the d-axis current reduction ΔId increases, so that the current vector Ic of the control current command value approaches the current vector Iave of the intermediate phase from the current vector Iave of the earliest phase. As shown in Equation (10), the current command value calculation unit 332 calculates the absolute value of the current vector as the winding current |I| based on the d-axis current command value Idave of the intermediate phase and the q-axis current command value Iqave.

[0190] When the winding current |I| exceeds a threshold Ith obtained by setting it to be less than the upper limit current value Imax, the current command value calculation unit 332, as the winding current |I| approaches the upper limit current value Imax, causes the current vector Ic of the control current command value to move from the earliest phase current vector Iadv to the middle phase current vector Iave. In this embodiment, with Figure 14 Similarly, when the winding current |I| exceeds the threshold Ith, the current command value calculation unit 332 reduces the d-axis current reduction ΔId to zero as the winding current |I| approaches the upper limit current value Imax.

[0191] 5. Implementation Method 5

[0192] The rotating electric machine device according to Embodiment 5 will be described. Descriptions of structural parts identical to those in Embodiments 1, 2, or 4 are omitted. The basic structure of the rotating electric machine 1, inverter 4, and control device 6 according to this embodiment is the same as that in Embodiments 1, 2, or 4, but it is configured to perform flux weakening control in addition to Id=0 control or maximum torque current control. The calculation method for the current command value is different from that in Embodiments 1, 2, or 4.

[0193] In flux weakening control, compared to the d-axis and q-axis current command values ​​calculated through Id=0 control or maximum torque current control, the d-axis current command value is increased more negatively, thereby weakening the magnetic flux of the permanent magnet. Flux weakening control is performed in the region where the induced voltage of the winding is close to the upper limit of the power supply voltage Vdc. By increasing the d-axis current command value negatively to weaken the magnetic flux of the permanent magnet, the induced voltage of the winding is reduced, thus increasing the torque of the rotating motor.

[0194] Current control unit 33 reference Figure 23 The execution region setting data shown is a pre-set relationship between the rotational angular velocity ω and the torque command value Tref and the execution region of each control. The execution region of the control corresponding to the current rotational angular velocity ω and torque command value Tref is determined.

[0195] When the current control unit 33 determines that it is in the execution region of Id=0 control or the execution region of maximum torque current control, in the same way as in embodiments 1, 2 or 4, the current vector of the current command value calculated by Id=0 control or maximum torque current control is set as the current vector Iadv of the earliest phase on the rotating coordinate system of the dq axis of the earliest phase, and the current vector of the current command value calculated by Id=0 control or maximum torque current control is set as the current vector Iave of the intermediate phase on the rotating coordinate system of the dq axis of the intermediate phase. As the winding current flowing through the three-phase winding increases, the controlled current vector Ic is made to approach the current vector Iadv of the earliest phase from the current vector Iave of the intermediate phase.

[0196] On the other hand, when the current control unit 33 determines that it is the execution area of ​​flux weakening control, in the rotating coordinate system of the dq axis of the earliest phase, the current vector of the current command value calculated by flux weakening control is set as the current vector Iadv of the earliest phase, and in the rotating coordinate system of the dq axis of the middle phase, the current vector of the current command value calculated by flux weakening control is set as the current vector Iave of the middle phase. As the winding current flowing through the three-phase winding increases, the controlled current vector Ic approaches the current vector Iadv of the earliest phase from the current vector Iave of the middle phase.

[0197] <Case where the same method as in Implementation 1 is used>

[0198] The method used in Embodiment 1 will be described. As the winding current increases, the magnetic pole position setting unit 331 moves the control magnetic pole position θc from the intermediate phase magnetic pole position θave towards the magnetic pole position θ2, which is the most advanced in the rotational direction. Then, the current command value calculation unit 332 calculates the control current command value using flux weakening control on a rotating coordinate system of the control dq axis, set with the control magnetic pole position θc as a reference. Then, the voltage command value calculation unit 333 calculates the voltage command value based on the current detection value and the control current command value on a rotating coordinate system of the control dq axis, set with the control magnetic pole position θc as a reference.

[0199] The current command value calculation unit 332 calculates the control d-axis and q-axis current command values ​​Ido and Iqo in the rotating coordinate system of the control dq-axis using flux weakening control. For example, the current command value calculation unit 332 calculates the effective value Vamp of the phase-to-phase voltage applied to the winding and increases or decreases the d-axis current command value Ido so that the effective value Vamp of the phase-to-phase voltage is close to the target effective value Vampo.

[0200] The following example illustrates this: By using weak flux control, the d-axis current command value increases more negatively compared to the d-axis and q-axis current command values ​​calculated using Id=0 control. The current command value calculation unit 332 calculates the effective value Vamp of the phase-to-phase voltage using the following formula based on the d-axis and q-axis voltage command values ​​Vdo and Vqo from the previous calculation cycle. The current command value calculation unit 332 sets the target effective value Vampo based on the power supply voltage Vdc.

[0201] Vamp=√(Vdo2+Vqo2)

[0202] Vampo=Vdc / √(2)···(11)

[0203] Then, the current command value calculation unit 332 calculates the deviation ΔVamp between the effective value Vamp of the phase-to-phase voltage and the target effective value Vampo, as shown in the following formula, and integrates the deviation ΔVamp to calculate the control d-axis current command value Ido. In the integration calculation, the current command value calculation unit 332 limits the control d-axis current command value Ido to a maximum of 0 when Id = 0 control is applied, and calculates control d-axis current command values ​​Ido below 0. Here, Ki is the integral gain. Furthermore, the current command value calculation unit 332 calculates the control q-axis current command value Iqo in the same manner as for Id = 0 control.

[0204]

[0205] By using flux weakening control, when the d-axis current command value increases more negatively compared to the d-axis and q-axis current command values ​​calculated using maximum torque current control, the control q-axis current command value Iqo also changes. Furthermore, in the integral calculation, the upper limit of the control d-axis current command value Ido is limited by the d-axis current command value under maximum torque current control.

[0206] <Case where the same method as in Implementation Method 2 is used>

[0207] The magnetic pole position setting unit 331 sets the magnetic pole position θave of the intermediate phase as the control magnetic pole position θc. The current command value calculation unit 332 calculates the current command value in a rotating coordinate system of the dq axis of the intermediate phase, set with the magnetic pole position θave of the intermediate phase as a reference, by means of flux weakening control. The d-axis component of the current command value is reduced by the d-axis current reduction amount ΔId, thereby calculating the control current command value. As the winding current increases, the current command value calculation unit 332 increases the d-axis current reduction amount ΔId, causing the current vector Ic of the control current command value to approach the current vector Iave of the intermediate phase calculated by flux weakening control towards the current vector Iadv of the earliest phase calculated by flux weakening control. Then, the voltage command value calculation unit 333 calculates the voltage command value in a rotating coordinate system of the dq axis of the intermediate phase, set with the magnetic pole position θave of the intermediate phase as a reference, based on the current detection value and the control current command value.

[0208] The following example illustrates this: by controlling the weak magnetic flux, the d-axis current command value increases more negatively compared to the d-axis and q-axis current command values ​​calculated by controlling Id=0. Similarly to equation (11) above, the current command value calculation unit 332 calculates the effective value Vamp and the target effective value Vampo of the phase-to-phase voltage.

[0209] Then, the current command value calculation unit 332 calculates the deviation ΔVamp between the effective value Vamp of the phase-to-phase voltage and the target effective value Vampo, as shown in the following formula, and integrates the deviation ΔVamp to calculate the d-axis current command value Idave for the intermediate phase. In the integration operation, the current command value calculation unit 332 limits the d-axis current command value Idave for the intermediate phase to 0 at the upper limit when Id = 0 control, and calculates the d-axis current command value Idave for the intermediate phase below 0. In addition, the current command value calculation unit 332 calculates the q-axis current command value Iqave for the intermediate phase in the same way as the Id = 0 control.

[0210]

[0211]

[0212] By using flux weakening control, when the d-axis current command value increases more negatively compared to the d-axis and q-axis current command values ​​calculated using maximum torque current control, the q-axis current command value Iqave in the intermediate phase also changes. Furthermore, during integration, the upper limit of the intermediate phase d-axis current command value Idave is limited by the d-axis current command value under maximum torque current control.

[0213] Then, the current command value calculation unit 332 calculates the control d-axis current command value Ido by subtracting the d-axis current reduction amount ΔId from the d-axis current command value Idave of the intermediate phase, as shown in the following formula. Furthermore, the current command value calculation unit 332 directly sets the control q-axis current command value Iqave of the intermediate phase to Iqo. The d-axis current reduction amount ΔId is set in the same way as in Embodiment 1.

[0214] Ido = Idave - ΔId

[0215] Iqo=Iqave···(14)

[0216] [Other Implementation Methods]

[0217] Finally, other embodiments of this application will be described. Furthermore, the structures of the embodiments described below are not limited to individual application; they can be combined with the structures of other embodiments as long as no contradiction arises.

[0218] (1) In the above embodiment 3, the case of using a rotary motor as a driving force source for an electric power steering device was described as an example. However, a rotary motor can be used for various purposes, such as a power unit for wheels.

[0219] (2) In Embodiment 1 described above, when the winding current |I| exceeds a threshold Ith obtained by setting it to be less than the upper limit current value Imax, the current command value calculation unit 332 causes the current vector Ic of the control current command value to approach the current vector Iave of the middle phase from the current vector Iadv of the earliest phase. When the winding current |I| exceeds the threshold Ith, the current command value calculation unit 332 causes the magnetic pole position θc of the control to approach the magnetic pole position θave of the middle phase as the winding current |I| approaches the upper limit current value Imax. Specifically, as... Figure 24 As shown, when the winding current |I| exceeds the threshold Ith, as the winding current |I| approaches the upper limit current value Imax, the correction amount Δθ of the magnetic pole position approaches 0 from the deflection angle θe / 2.

[0220] The current command value calculation unit 332 calculates the component of the qave axis representing the winding current |I| in the rotating coordinate system of the dq axis in the intermediate phase, as shown in the following formula, and uses it as the winding current |I|.

[0221] |I|=√(Ido2+Iqo2)×sin(Δθ)···(15)

[0222] In addition, compared to increasing the maximum torque, this treatment may not be necessary for rotating motors that require a reduction in the sixth-order torque ripple component.

[0223] (3) In the above embodiments, the following case was described as an example: in a permanent magnet, a deflection that shifts the position of the magnetic pole in the circumferential direction is provided in two stages in the axial direction X. However, in a permanent magnet, a deflection that shifts the position of the magnetic pole in the circumferential direction can be provided in three or more stages or continuously in the axial direction X.

[0224] For example, such as Figure 25 As shown, the deflection of the magnetic pole positions in the circumferential direction can be arranged in four stages along the axial direction X. From one side X1 of the axial direction to the other side X2, a first deflection segment 182a, a second deflection segment 182b, a third deflection segment 182c, and a fourth deflection segment 182d are arranged sequentially, and the magnetic pole positions are respectively offset by an electrical angle of 15 degrees in the rotation direction R. Eight magnetic poles 181 (four N poles and four S poles) are arranged at equal intervals in the circumferential direction on the outer periphery of each deflection segment and embedded inside the rotor 11.

[0225] The magnetic pole (N pole) of the fourth deflection segment 182d, which has the earliest phase in the direction of rotation R, and the magnetic pole (N pole) of the first deflection segment 182a, which has the latest phase in the direction of rotation R, are offset by a deflection angle θe (60 degrees in this example) in electrical angle.

[0226] In this case, the rotating coordinate system of the dq axis with the earliest phase is set as follows: the d-axis is defined in the direction of the magnetic pole position of the fourth deflection segment 182d with the earliest phase in the rotation direction R, and the q-axis is defined in the direction that is electrically 90° ahead of the phase of this d-axis. The rotating coordinate system of the dq axis with the intermediate phase is set as follows: the d-axis is defined in the direction of the intermediate phase between the magnetic pole position of the fourth deflection segment 182d with the earliest phase in the rotation direction R and the magnetic pole position of the first deflection segment 182a with the latest phase in the rotation direction R, and the q-axis is defined in the direction that is electrically 90° ahead of the phase of this d-axis.

[0227] Or, such as Figure 26 As shown, deflections that shift the magnetic pole positions circumferentially can be continuously arranged along the axial direction X. Eight magnetic poles 191 (four N poles and four S poles) are arranged at equal intervals along the outer periphery of the rotor and attached to the surface of the rotor. From one side X1 of the axial direction to the other side X2, each magnetic pole 191 is continuously shifted in the rotational direction R.

[0228] like Figure 27 As shown in the unfolded diagram, the magnetic pole (N pole) at the end of the axis X1 on the side with the earliest phase in the rotation direction R is offset by a deflection angle θe (60 degrees in this example) from the magnetic pole (N pole) at the end of the axis X2 on the other side with the latest phase in the rotation direction R.

[0229] In this case, the rotational coordinate system of the dq axis for the earliest phase is set as follows: a d-axis defined in the direction of the magnetic pole position at the end of the axis on one side X1 of the axis with the earliest phase in the rotational direction R, and a q-axis defined in the direction that is electrically 90° ahead of the phase of this d-axis. The rotational coordinate system of the dq axis for the intermediate phase is set as follows: a d-axis defined in the direction of the intermediate phase between the magnetic pole position at the end of the axis on one side X1 of the axis with the earliest phase in the rotational direction R and the magnetic pole position at the end of the axis on the other side X2 of the axis with the latest phase, and a q-axis defined in the direction that is electrically 90° ahead of the phase of this d-axis.

[0230] Or, such as Figure 28 As shown in the unfolded diagram, a deflection that continuously shifts the magnetic pole position circumferentially along the X-axis can be approximated as a deflection that shifts the magnetic pole position circumferentially in two stages along the X-axis. The magnetic pole position of the deflection segment 192a on one side X1 of the axis is set to the circumferential center position of half of the magnetic poles on one side X1, and the magnetic pole position of the deflection segment 192b on the other side X2 of the axis is set to the circumferential center position of half of the magnetic poles on the other side X2.

[0231] The rotational coordinate system of the dq axis for the earliest phase is set as follows: a d-axis defined in the direction of the magnetic pole position of the deflection segment 192b on the other side of the axis with the earliest phase in the rotational direction R, and a q-axis defined in the direction that is electrically 90° ahead of the phase of this d-axis. The rotational coordinate system of the dq axis for the intermediate phase is set as follows: a d-axis defined in the direction of the intermediate phase between the magnetic pole position of the deflection segment 192b on the other side of the axis with the earliest phase in the rotational direction R and the magnetic pole position of the deflection segment 192a on the side of the axis with the latest phase in the rotational direction R, and a q-axis defined in the direction that is electrically 90° ahead of the phase of this d-axis.

[0232] While this application describes various exemplary embodiments and examples, the various features, methods, and functions described in one or more embodiments are not limited to the application of a particular embodiment and can be applied to the embodiments individually or in various combinations. Therefore, it can be considered that numerous modifications not illustrated are also included within the scope of the technology disclosed in this application. For example, this includes cases where at least one constituent element is modified, added to, or omitted, and cases where at least one constituent element is extracted and combined with constituent elements of other embodiments.

[0233] Label Explanation

[0234] 1 Rotating motor, 3 DC power supply, 4 Inverter, 6 Control device, 31 Rotation detection unit, 32 Current detection unit, 33 Current control unit, 34 Switch control unit, Iadv Current vector of the earliest phase, Iave Current vector of the middle phase, Ic Current vector of the current command value for control, Ido D-axis current command value for control, Iqo Q-axis current command value for control, Idave D-axis current command value of the middle phase, Iqave Q-axis current command value of the middle phase, Idr D-axis current detection value for control, Iqr Q-axis current detection value for control, Imax Upper limit current value, Ith threshold, R rotation direction, rotation direction on one side of R1, rotation direction on the other side of R2, Vdo D-axis voltage command value for control, Vqo Q-axis voltage command value for control, ΔId D-axis current reduction, θ1 Magnetic pole position of the latest phase, θ2 Magnetic pole position of the earliest phase, θave Magnetic pole position of the middle phase, θc Magnetic pole position for control, θe Deflection angle.

Claims

1. A rotary electric motor device, characterized in that, include: A rotary electric motor having a rotor equipped with permanent magnets and a stator equipped with multiphase windings; An inverter having multiple switching elements for converting DC power supplied from a DC power source to AC power supplied to the multiphase windings; A current detection unit that detects the current flowing through the multiphase winding; A rotation detection unit that detects the rotation angle of the rotor; The current control unit sets the position of the control magnetic pole based on the detected value of the rotation angle, calculates the control current command value, and calculates the voltage command value based on the current detection value, the control current command value, and the control magnetic pole position. as well as A switch control unit, which controls the on / off state of the plurality of switching elements based on the voltage command value. The permanent magnet is provided with deflectors at various positions along the axial direction to offset the magnetic pole positions axially. The current control unit performs the following control: The current vector of the current command value calculated on the rotating coordinate system of the dq axis with the earliest phase is set as the current vector of the earliest phase. This rotating coordinate system of the dq axis with the earliest phase is composed of the d-axis, which is defined in the direction of the magnetic pole position with the earliest phase in the rotational direction, within the magnetic pole positions at various positions along the axial direction, and the q-axis, which is defined in the direction that is 90° ahead of the phase in electrical angle compared to the d-axis. The current vector of the current command value calculated on the rotating coordinate system of the dq axis of the intermediate phase is set as the current vector of the intermediate phase. The rotating coordinate system of the dq axis of the intermediate phase is composed of the d-axis, which is defined in the direction of the intermediate phase between the magnetic pole positions at each position in the axial direction and the magnetic pole positions with the most advanced phase and the most delayed phase in the rotational direction, and the q-axis, which is defined in the direction of the d-axis with a phase advanced by 90° in electrical angle compared to the d-axis. As the winding current flowing through the multiphase winding increases, the controlled current vector moves from the current vector of the intermediate phase to the current vector of the earliest phase.

2. The rotary electric motor device as described in claim 1, characterized in that, As the winding current increases, the current control unit causes the control magnetic pole position to approach the magnetic pole position from the intermediate phase between the magnetic pole position with the most advanced phase in the rotational direction and the magnetic pole position with the most delayed phase in the rotational direction, towards the magnetic pole position with the most advanced phase in the rotational direction. On a rotating coordinate system of the control dq axis set with the control magnetic pole position as a reference, the control current command value is calculated, and the voltage command value is calculated based on the current detection value and the control current command value.

3. The rotary electric motor device as described in claim 1, characterized in that, The current control unit sets the magnetic pole position at the intermediate phase between the magnetic pole position with the most advanced phase in the rotation direction and the magnetic pole position with the most delayed phase in the rotation direction as the control magnetic pole position. The current command value is calculated in a rotating coordinate system of the dq axis of the intermediate phase, which is set with the magnetic pole position of the intermediate phase as a reference. The d-axis component of the current command value is reduced by the d-axis current reduction amount to calculate the control current command value. As the winding current increases, the decrease in the d-axis current increases, so that the current vector of the control current command value approaches the current vector of the intermediate phase from the current vector of the earliest phase. On the rotating coordinate system of the dq axis of the intermediate phase, the voltage command value is calculated based on the detected current value and the control current command value.

4. The rotary electric motor device according to any one of claims 1 to 3, characterized in that, When the winding current exceeds a threshold value that is set to be less than the upper limit current value, the current control unit causes the current vector of the control current command value to approach the upper limit current value from the current vector of the earliest phase to the current vector of the intermediate phase as the winding current approaches the upper limit current value.

5. The rotary electric motor device according to any one of claims 1 to 3, characterized in that, The rotary motor is capable of rotating to one side and the other side. The current control unit sets the magnetic pole position with the earliest phase in the rotation direction and the magnetic pole position with the latest phase in the rotation direction according to the rotation direction of one side and the other side.

6. The rotary electric motor device as described in claim 5, characterized in that, The rotary motor serves as the driving force source for the electric power steering system.

7. The rotary electric motor device according to any one of claims 1 to 3, characterized in that, The permanent magnet is disposed on the surface of the rotor. The current control unit performs the following control: The current vector of the current command value calculated by controlling Id=0 on the rotating coordinate system of the dq axis of the earliest phase is set as the current vector of the earliest phase. The current vector of the current command value calculated by the Id=0 control on the rotating coordinate system of the dq axis of the intermediate phase is set as the current vector of the intermediate phase. As the winding current increases, the controlled current vector approaches the current vector of the earliest phase from the current vector of the intermediate phase.

8. The rotary electric motor device according to any one of claims 1 to 3, characterized in that, The permanent magnet is embedded inside the rotor. The current control unit performs the following control: The current vector of the current command value calculated by maximum torque current control on the rotating coordinate system of the dq axis at the earliest possible phase is set as the current vector of the earliest possible phase. The current vector of the current command value calculated by the maximum torque current control on the rotating coordinate system of the dq axis of the intermediate phase is set as the current vector of the intermediate phase. As the winding current increases, the controlled current vector approaches the current vector of the earliest phase from the current vector of the intermediate phase.

9. The rotary electric motor device according to any one of claims 1 to 3, characterized in that, The current control unit performs the following control in the execution region of the weak magnetic flux control: The current vector of the current command value calculated by the weak flux control on the rotating coordinate system of the dq axis of the earliest phase is set as the current vector of the earliest phase. The current vector of the current command value calculated by the weak flux control on the rotating coordinate system of the dq axis of the intermediate phase is set as the current vector of the intermediate phase. As the winding current increases, the controlled current vector moves from the current vector of the intermediate phase to the current vector of the earliest phase.

10. The rotary electric motor apparatus according to any one of claims 1 to 3, characterized in that, The permanent magnets disposed on the rotor have 8 magnetic poles. The stator with the multiphase winding has 12 slots.

11. The rotary electric motor device according to any one of claims 1 to 3, characterized in that, The permanent magnet is configured in two stages along the axial direction to deflect the magnetic pole position in the circumferential direction.

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