Control device for an alternating current rotating electric machine

Abstract

The object of the present invention is to obtain a control device for an alternating current rotary electric machine, which enables the operation of the alternating current rotary electric machine to continue more stably when a magnetic pole position sensor fails. When it is determined that the magnetic pole position sensor (3) has failed and sensorless vector control is performed, the target value (Mo) of the modulation factor is made smaller than when it is determined that the magnetic pole position sensor (3) is normal and vector control is performed. The current command value (Ido) of the d-axis and the current command value (Iqo) of the q-axis are calculated on the basis of the target value (Mo) of the modulation factor.

Description

Technical Field

[0001] This disclosure relates to a control device for an alternating rotating electric motor. Background Technology

[0002] In existing control mode switching devices, the discriminator determines whether a sensor is faulty based on a current command signal, a current detection signal, and a speed signal. The switcher then switches the motor control mode from vector control to V / F control or sensorless vector control based on the sensor fault signal from the discriminator (see, for example, Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 10-14300 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] Overmodulation control is known as a method to improve the voltage utilization of power converters driving AC rotating motors. However, in the control mode switching device of Patent Document 1, the modulation rate is not considered. Therefore, if overmodulation control is applied in sensorless vector control, the estimation performance of the rotor rotation angle deteriorates due to the influence of harmonics superimposed on the voltage and current. Consequently, it is difficult to stably continue the operation of the motor in the event of sensor failure.

[0008] This disclosure was made to solve the above-mentioned problems, and its purpose is to provide a control device for an AC rotating motor that enables the AC rotating motor to continue operating more stably when the magnetic pole position sensor fails.

[0009] Technical means for solving technical problems

[0010] The control device for the AC rotating electric motor disclosed herein includes: a magnetic pole position detection unit that detects the magnetic pole position of the rotor based on the output signal of a magnetic pole position sensor that outputs an electrical signal corresponding to the rotation angle of the rotor; a magnetic pole position estimation unit that estimates the magnetic pole position of the rotor without relying on the output signal of the magnetic pole position sensor; a fault state determination unit that determines the fault state of the magnetic pole position sensor based on the output signal of the magnetic pole position sensor; and a rotation information switching unit that, based on the output signal of the fault state determination unit, outputs the magnetic pole position detected by the magnetic pole position detection unit when the magnetic pole position sensor is normal, and outputs the magnetic pole position detected by the magnetic pole position detection unit when the magnetic pole position sensor is faulty. The inverter comprises: a magnetic pole position estimated by a presupposition unit; a modulation rate switching unit that outputs a target value of modulation rate and switches the output target value based on the determination result obtained by the fault state determination unit; a current command value calculation unit that calculates a current command value based on the target value; a voltage command value calculation unit that calculates a voltage command value based on the current command value and the magnetic pole position output from the rotation information switching unit; and a switch control unit that turns multiple switching elements provided in the inverter on and off based on the voltage command value. When the fault state determination unit determines that the magnetic pole position sensor is faulty, the modulation rate switching unit reduces the target value compared to when the fault state determination unit determines that the magnetic pole position sensor is normal.

[0011] Invention Effects

[0012] According to the control device for the AC rotating motor disclosed herein, the operation of the AC rotating motor can continue more stably when the magnetic pole position sensor fails. Attached Figure Description

[0013] Figure 1 This is a circuit diagram showing an outline of the AC rotary motor and its control device according to Embodiment 1.

[0014] Figure 2 It is shown Figure 1 A block diagram of the control device.

[0015] Figure 3 It is shown Figure 2 A diagram illustrating the voltage limit processing in the voltage command calculation unit.

[0016] Figure 4 It is shown Figure 2 A diagram illustrating the calculation method of the d-axis current command value and the q-axis current command value performed by the current command calculation unit.

[0017] Figure 5This is a timing diagram showing the control actions of the control device when the output signal of the magnetic pole position sensor changes from normal to abnormal.

[0018] Figure 6 This is a timing diagram showing the control actions of the control device when the output signal of the magnetic pole position sensor changes from abnormal to normal.

[0019] Figure 7 It is shown Figure 2 The flowchart shows the operation of the fault status determination unit, the rotation information switching unit, and the modulation rate switching unit.

[0020] Figure 8 This is a structural diagram showing an example of a processing circuit that implements the functions of the control device in Embodiment 1. Detailed Implementation

[0021] The embodiments will now be described with reference to the accompanying drawings.

[0022] Implementation method 1.

[0023] Figure 1 This is a circuit diagram showing an outline of the AC rotary motor and its control device according to Embodiment 1. The AC rotary motor 1 has a stator, a rotor 2, and a magnetic pole position sensor 3.

[0024] The stator has multi-phase windings. In Embodiment 1, the stator has a U-phase winding Cu, a V-phase winding Cv, and a W-phase winding Cw. The U-phase winding Cu, V-phase winding Cv, and W-phase winding Cw are connected in a star or delta configuration. The rotor 2 rotates relative to the stator. Furthermore, the rotor 2 has multiple permanent magnets (not shown). The AC rotary motor 1 of Embodiment 1 is a permanent magnet type synchronous rotary motor.

[0025] The magnetic pole position sensor 3 outputs an electrical signal corresponding to the rotation angle of the rotor 2. The magnetic pole position sensor 3 can be, for example, a Hall element, an encoder, or a resolver.

[0026] As a DC power supply 10, a rechargeable and dischargeable energy storage device is used, such as a lithium-ion battery, a nickel-metal hydride battery, or an electric double-layer capacitor. Additionally, the DC power supply 10 may be equipped with a DC-DC converter. A DC-DC converter is a DC power converter that boosts or bucks the DC power supply.

[0027] The DC power supply 10 is connected to a positive wire 11 and a negative wire 12. A filter capacitor 13 is connected between the positive wire 11 and the negative wire 12.

[0028] An inverter 20, serving as a power converter, is provided between the U-phase winding Cu, the V-phase winding Cv, and the W-phase winding Cw and the DC power supply 10. A power supply voltage sensor 14 is connected between the positive wire 11 and the negative wire 12. The power supply voltage sensor 14 detects the power supply voltage supplied from the DC power supply 10 to the inverter 20.

[0029] The inverter 20 has multiple switching elements and multiple diodes 24. The multiple switching elements include a first positive switching element 21H, a first negative switching element 21L, a second positive switching element 22H, a second negative switching element 22L, a third positive switching element 23H, and a third negative switching element 23L.

[0030] The collector terminals of the first positive switching element 21H, the second positive switching element 22H, and the third positive switching element 23H are each connected to the positive wire 11. The emitter terminals of the first negative switching element 21L, the second negative switching element 22L, and the third negative switching element 23L are each connected to the negative wire 12.

[0031] The first positive switching element 21H and the first negative switching element 21L are connected in series. The emitter terminal of the first positive switching element 21H is connected to the collector terminal of the first negative switching element 21L.

[0032] The second positive switching element 22H and the second negative switching element 22L are connected in series. The emitter terminal of the second positive switching element 22H is connected to the collector terminal of the second negative switching element 22L.

[0033] The third positive switching element 23H and the third negative switching element 23L are connected in series. The emitter terminal of the third positive switching element 23H is connected to the collector terminal of the third negative switching element 23L.

[0034] The connection point of the first positive switching element 21H and the first negative switching element 21L is connected to the U-phase winding Cu. The connection point of the second positive switching element 22H and the second negative switching element 22L is connected to the V-phase winding Cv. The connection point of the third positive switching element 23H and the third negative switching element 23L is connected to the W-phase winding Cw.

[0035] IGBTs (Insulated Gate Bipolar Transistors) were used as the switching elements. Each diode 24 was connected in reverse parallel with its corresponding switching element.

[0036] Alternatively, MOSFETs (Metal Oxide Semiconductor Field Effect Transistors) with the function of diodes connected in reverse parallel can be used as switching elements.

[0037] The gate terminals of each switching element are connected to the control device 30. Thus, each switching element is turned on and off by a control signal output from the control device 30.

[0038] Multiple current sensors 15 are provided between the inverter 20 and the AC rotating motor 1. Each current sensor 15 outputs an electrical signal corresponding to the current flowing through the corresponding winding in the U-phase winding Cu, V-phase winding Cv, and W-phase winding Cw.

[0039] in addition, Figure 1 In this configuration, each current sensor 15 is mounted on the wire connecting the corresponding winding to the inverter 20. However, each current sensor 15 may also be mounted on a corresponding series circuit within the inverter 20.

[0040] The output signals of the magnetic pole position sensor 3, the power supply voltage sensor 14, and the multiple current sensors 15 are respectively input to the control device 30.

[0041] Figure 2 It is shown Figure 1 A block diagram of the control device 30. The control device 30 controls the AC rotating motor 1 via the inverter 20. In addition, as functional blocks, the control device 30 includes a voltage detection unit 31, a current detection unit 32, a current command calculation unit 33, a voltage command calculation unit 34, a switching element control unit 35, a rotation detection unit 36, a fault status determination unit 37, and a modulation rate switching unit 38.

[0042] The voltage detection unit 31 detects the power supply voltage VDC supplied from the DC power supply 10 to the inverter 20 based on the output signal of the power supply voltage sensor 14.

[0043] The current detection unit 32 detects the current flowing through the U-phase winding Cu (Iur), the current flowing through the V-phase winding Cv (Ivr), and the current flowing through the W-phase winding Cw (Iwr) based on the output signals of multiple current sensors 15. Additionally, Figure 2 For simplicity, only one current sensor 15 is shown in the image.

[0044] Alternatively, two current sensors 15 can be used to detect the current flowing through two of the three windings: the U-phase winding Cu, the V-phase winding Cv, and the W-phase winding Cw. The current flowing through the remaining winding is calculated based on the detection values ​​obtained from the two current sensors 15.

[0045] For example, two current sensors 15 can be used to detect the current detection value Ivr and the current detection value Iwr. The current detection value Iur of the U-phase winding Cu is calculated by Iur = -Ivr - Iwr.

[0046] In addition, the current detection unit 32 converts the three-phase current detection values ​​Iur, Ivr, and Iwr into the d-axis current detection value Idr and the q-axis current detection value Iqr on a rotating coordinate system composed of the d-axis and q-axis.

[0047] The d-axis of the rotating coordinate system is positioned in the direction of the detected magnetic pole position θ. The q-axis of the rotating coordinate system is positioned in the direction of advancing an electrical angle of 90° from the d-axis. The rotating coordinate system rotates synchronously with the rotation of the magnetic pole position of rotor 2.

[0048] Specifically, the current detection unit 32 performs three-phase to two-phase conversion and rotational coordinate conversion on the three-phase current detection values ​​Iur, Ivr, and Iwr based on the magnetic pole position θ, thereby converting them into the d-axis current detection value Idr and the q-axis current detection value Iqr.

[0049] The current command calculation unit 33 calculates multiple current command values ​​using the calculation method described later. In this embodiment, the current command value calculation unit 33 calculates the current command value Ido of the d-axis and the current command value Iqo of the q-axis as multiple current command values.

[0050] The voltage command calculation unit 34 calculates multiple voltage command values ​​based on the d-axis current detection value Idr and the q-axis current detection value Iqr obtained by the current detection unit 32, and the d-axis current command value Ido and the q-axis current command value Iqo calculated by the current command value calculation unit 33. In this embodiment, the voltage command value calculation unit 34 calculates the voltage command value Vuo of phase U, the voltage command value Vvo of phase V, and the voltage command value Vwo of phase W as multiple voltage command values.

[0051] Furthermore, the voltage command value calculation unit 34 performs current feedback control, such as PI (Proportional-Integral) control. In current feedback control, the d-axis voltage command value Vdo and the q-axis voltage command value Vqo change so that the d-axis current detection value Idr is close to the d-axis current command value Ido, and the q-axis current command value Iqr is close to the q-axis current command value Iqo.

[0052] Alternatively, feedforward control can be implemented to prevent interference between the d-axis current and the q-axis current.

[0053] Furthermore, the voltage command calculation unit 34 can perform only feedforward control. In this case, multiple current sensors 15 and current detection units 32 are not required.

[0054] In addition, the voltage command value calculation unit 34, such as Figure 3 As shown, the d-axis voltage command value Vdo and the q-axis voltage command value Vqo are limited based on the maximum value Mmax of the modulation rate, and the limited d-axis voltage command value VdoL and the limited q-axis voltage command value VqoL are output.

[0055] If the magnitudes of the vectors containing the d-axis voltage command value Vdo and the q-axis voltage command value Vqo in the dq coordinate system exceed the voltage limit value Vmax, the magnitude of the vectors is limited to Vmax. In this case, only the magnitude of the vector changes, while the direction of the vector remains unchanged. The voltage limit value Vmax is calculated using the following formula.

[0056] [Mathematical Expression 1]

[0057]

[0058] The voltage limit value Vmax is obtained by converting the maximum modulation rate Mmax into the magnitude of the voltage vector on the dq coordinate. By using the voltage limit value Vmax to limit the dq axis voltage command value, the actual modulation rate can be limited to below the maximum modulation rate Mmax.

[0059] Furthermore, the voltage command value calculation unit 34 performs fixed coordinate transformation and two-phase / three-phase transformation on the limited d-axis voltage command value VdoL and the limited q-axis voltage command value VqoL based on the magnetic pole position θ. Thus, the voltage command value calculation unit 34 calculates the voltage command value Vuo for phase U, the voltage command value Vvo for phase V, and the voltage command value Vwo for phase W.

[0060] Additionally, a zero-phase component, such as the third harmonic, can be added to the three-phase voltage command value. When a zero-phase component is superimposed, even within the range of overmodulation control, the larger the modulation rate becomes, the larger the magnitude of the higher harmonic components becomes. Therefore, the smaller the modulation rate becomes, the smaller the higher harmonic components become.

[0061] The switching control unit 35 performs switching control based on the three-phase voltage command values ​​Vuo, Vvo, and Vwo from the voltage command value calculation unit 34, and applies voltages to the U-phase winding Cu, the V-phase winding Cv, and the W-phase winding Cw. In the switching control, multiple switching elements of the inverter 20 are turned on and off by PWM (Pulse Width Modulation) control.

[0062] Furthermore, the switch control unit 35 compares the three-phase voltage command values ​​Vuo, Vvo, and Vwo with the carrier wave to generate multiple switch signals. Each switch signal is a signal that turns the corresponding switch element on or off.

[0063] The carrier wave is set as a triangular wave, which oscillates at the carrier frequency with an amplitude of 0 and the power supply voltage VDC / 2. When the three-phase voltage command values ​​Vuo, Vvo, and Vwo exceed the carrier wave, the switch control unit 35 turns on the switch signal. Conversely, when the three-phase voltage command values ​​Vuo, Vvo, and Vwo are lower than the carrier wave, the switch control unit 35 turns off the switch signal.

[0064] The switching signal is directly transmitted to the first positive switching element 21H, the second positive switching element 22H, and the third positive switching element 23H. The signal obtained after reversing the switching signal is directly transmitted to the first negative switching element 21L, the second negative switching element 22L, and the third negative switching element 23L.

[0065] here, Figure 4 It is shown Figure 2 A diagram illustrating the calculation method of the d-axis current command value Ido and the q-axis current command value Iqo performed by the current command value calculation unit 33.

[0066] The current command value calculation unit 33 uses the target value Mo of the modulation rate calculated by the modulation rate switching unit 38 in the calculation of the current command value Ido on the d-axis and the current command value Iqo on the q-axis. The modulation rate is the ratio of the amplitude of the fundamental component of the voltage applied to the U-phase winding Cu, the V-phase winding Cv and the W-phase winding Cw to the power supply voltage VDC / 2.

[0067] The current command value calculation unit 33 calculates the linkage flux command value Ψo based on the target value Mo of the modulation rate. The linkage flux command value Ψo is the command value of the armature linkage flux. The current command value calculation unit 33 calculates the linkage flux command value Ψo by multiplying the power supply voltage VDC by the target value Mo of the modulation rate and dividing by the rotational angular velocity ω.

[0068] In detail, the current command value calculation unit 33, as shown in the figure... Figure 4 The linkage flux command value Ψo is calculated as shown in the following formula.

[0069] [Mathematical Expression 2]

[0070]

[0071] Furthermore, the linkage flux command value Ψo can be corrected through feedback control to reduce the difference between the target modulation rate Mo and the actual modulation rate Mr. The actual modulation rate Mr is calculated, for example, based on the limited d-axis voltage command value VdoL and the limited q-axis voltage command value VqoL.

[0072] The current command value calculation unit 33 calculates the current command value Ido of the d-axis and the current command value Iqo of the q-axis based on the linkage flux command value Ψo and the torque command value To.

[0073] The current command value calculation unit 33 has preset d-axis current setting data and q-axis current setting data. The d-axis current setting data shows the relationship between the linkage flux command value Ψo and the torque command value To and the d-axis current command value Ido. The q-axis current setting data shows the relationship between the linkage flux command value Ψo and the torque command value To and the q-axis current command value Iqo.

[0074] The current command value calculation unit 33 calculates the normal d-axis current command value Ido, which corresponds to the link flux command value Ψo and the torque command value To, by referring to the d-axis current setting data. Similarly, the current command value calculation unit 33 calculates the normal q-axis current command value Iqo, which corresponds to the link flux command value Ψo and the torque command value To, by referring to the q-axis current setting data.

[0075] The d-axis and q-axis current setting data are calculated based on the target modulation rate value Mo. Therefore, the actual modulation rate is approximately consistent with the target modulation rate value Mo. Thus, if the target modulation rate value Mo is reduced, the actual modulation rate is reduced, resulting in a smaller d-axis current command value Ido and a smaller q-axis current command value Iqo.

[0076] In addition, the torque command value To can be calculated within the control device 30 or transmitted from an external device.

[0077] The rotation detection unit 36 ​​detects the rotational speed of the rotor 2 at an electrical angle, i.e., the magnetic pole position θ1, and the electrical angular velocity of the rotor 2, i.e., the rotational angular velocity ω1, based on the output signal of the magnetic pole position sensor 3. Furthermore, the rotation detection unit 36 ​​estimates the magnetic pole position θ2 and the rotational angular velocity ω2 based on the d-axis current detection value Idr and the q-axis current detection value Iqr, as well as the limited d-axis voltage command value VdoL and the limited q-axis voltage command value VqoL.

[0078] The rotation detection unit 36 ​​switches between the output magnetic pole position θ and rotational angular velocity ω when performing vector control and sensorless vector control.

[0079] like Figure 2 As shown, the rotation detection unit 36 ​​includes a magnetic pole position detection unit 36a, a magnetic pole position estimation unit 36b, and a rotation information switching unit 36c, which serve as functional blocks.

[0080] The magnetic pole position detection unit 36a detects the magnetic pole position θ1 and rotational angular velocity ω1 of the rotor 2 at the electrical angle based on the output signal of the magnetic pole position sensor 3, and outputs the detected magnetic pole position θ1 and rotational angular velocity ω1. In this embodiment, the magnetic pole position θ1 is set along the direction of the N pole of the permanent magnet of the rotor 2.

[0081] Alternatively, the value input to the software-constructed PLL (Phase Locked Loop) can be set as θ1, and the value input to the integrator as the controller's output value can be set as ω1.

[0082] When performing sensorless vector control, the magnetic pole position estimation unit 36b uses a known estimation method to estimate the magnetic pole position θ2 and rotational angular velocity ω2, without relying on the output signal of the magnetic pole position sensor 3. For example, in angle estimation using an adaptive observer, the d-axis current detection value Idr and the q-axis current detection value Iqr, as well as the d-axis voltage command value Vdo and the q-axis voltage command value Vqo, are input to the adaptive observer. Then, the magnetic pole position θ2 and rotational angular velocity ω2 are output from the adaptive observer. The estimation method is a known technique, so detailed description is omitted.

[0083] In the estimation based on the adaptive observer, the d-axis current sensing value Idr and the q-axis current sensing value Iqr are used. Therefore, under overmodulation control, as higher harmonic components are generated in the output voltage, the estimated values ​​of the magnetic pole position θ and rotational angular velocity ω are affected by the higher harmonics of the respective d-axis current sensing value Idr and the q-axis current sensing value Iqr. Consequently, the estimated values ​​of the magnetic pole position θ and rotational angular velocity ω become oscillatory, and these estimated values ​​may also diverge.

[0084] When the magnetic pole position sensor 3 is functioning normally, the rotation information switching unit 36c outputs rotation information for vector control based on the output signal of the fault state determination unit 37. Specifically, when the fault state signal FAIL_STAT = 0 (described later), the rotation information switching unit 36c outputs the magnetic pole position θ1 and rotational angular velocity ω1 detected and calculated by the magnetic pole position detection unit 36a as the final magnetic pole position θ and rotational angular velocity ω.

[0085] On the other hand, based on the output signal of the fault state determination unit 37, when the magnetic pole position sensor 3 malfunctions, or when a malfunction of the magnetic pole position sensor 3 is suspected, the rotation information switching unit 36c switches the output rotation information to perform sensorless vector control. Specifically, when the fault state signal FAIL_STAT ≠ 0 (described later), the rotation information switching unit 36c outputs the magnetic pole position θ2 and rotational angular velocity ω2 estimated by the magnetic pole position estimation unit 36b as the final magnetic pole position θ and rotational angular velocity ω.

[0086] The operation of the rotation information switching unit 36c is organized as follows.

[0087] 1) When FAIL_STAT = 0: θ = θ1, ω = ω1 → Vector control

[0088] 2) When FAIL_STAT ≠ 0: θ = θ2, ω = ω2 → Sensorless vector control

[0089] The fault status determination unit 37 acquires the output signal of the magnetic pole position sensor 3. Furthermore, based on the output signal of the magnetic pole position sensor 3, the fault status determination unit 37 determines the fault status of the magnetic pole position sensor 3. Additionally, the fault status determination unit 37 outputs a fault status signal FAIL_STAT as the determination result.

[0090] The fault status signal FAIL_STAT indicates whether the magnetic pole position sensor 3 is normal, faulty, or in an intermediate state. An intermediate state means that it is uncertain whether the magnetic pole position sensor 3 is normal or faulty.

[0091] When the magnetic pole position sensor 3 is determined to be normal, and its output signal is normal, the fault status determination unit 37 is set to FAIL_STAT = 0. When the magnetic pole position sensor 3 is determined to be normal, but its output signal is abnormal, the fault status determination unit 37 is set to FAIL_STAT = 1.

[0092] When the magnetic pole position sensor 3 is determined to be faulty, and its output signal is abnormal, the fault status determination unit 37 is set to FAIL_STAT = 2. When the magnetic pole position sensor 3 is determined to be faulty, but its output signal is normal, the fault status determination unit 37 is set to FAIL_STAT = 3.

[0093] The conditions for the fault status signal FAIL_STAT are organized as follows.

[0094] 1) Normal determination: The judgment result is "normal", and the output signal of magnetic pole position sensor 3 is normal → FAIL_STAT = 0

[0095] 2) During fault diagnosis: If the diagnosis result is "normal" and the output signal of magnetic pole position sensor 3 is abnormal, then FAIL_STAT = 1.

[0096] 3) Fault determination: The judgment result is "fault", and the output signal of magnetic pole position sensor 3 is abnormal → FAIL_STAT = 2

[0097] 4) During normal judgment: The judgment result is "fault" and the output signal of magnetic pole position sensor 3 is normal → FAIL_STAT = 3

[0098] Of the four fault status signals mentioned above, FAIL_STAT=1 and FAIL_STAT=3 represent intermediate states.

[0099] The fault status determination unit 37 has a fault determination counter and a normal determination counter. If the magnetic pole position sensor 3 is determined to be normal, but the output signal of the magnetic pole position sensor 3 is abnormal, the count value of the fault determination counter, i.e., the abnormal count value, increases. If the output signal of the magnetic pole position sensor 3 is not abnormal, the abnormal count value decreases.

[0100] The initial value and lower limit of the abnormal count are 0. If the abnormal count reaches the preset fault determination value, the fault status determination unit 37 determines that the magnetic pole position sensor 3 has malfunctioned.

[0101] If the magnetic pole position sensor 3 is determined to be faulty, but the output signal of the magnetic pole position sensor 3 is normal, the count value of the normal determination counter, i.e. the normal count value, will increase. If the output signal of the magnetic pole position sensor 3 is not normal, the normal count value will decrease.

[0102] The initial value and lower limit of the normal count value are 0. If the normal count value reaches the preset normal determination value, the fault state determination unit 37 determines that the magnetic pole position sensor 3 has become normal. Various known methods can be used to determine whether the output signal of the magnetic pole position sensor 3 is abnormal, so they will not be specifically described here.

[0103] Based on the fault status signal FAIL_STAT, the modulation rate switching unit 38 outputs the target value Mo of the modulation rate and the maximum value Mmax of the modulation rate as follows.

[0104] 1) When FAIL_STAT = 0 or FAIL_STAT = 1: Mo = 1.20, Mmax = 1.27

[0105] 2) When FAIL_STAT = 2 or FAIL_STAT = 3: Mo = 1.05, Mmax = 1.15

[0106] In this embodiment, a zero-phase component, such as a third harmonic component, is added to the three-phase voltage command values ​​Vuo, Vvo, and Vwo. Therefore, in overmodulation control, the modulation rate that generates higher harmonics in the output voltage is 1.15 or higher.

[0107] If the magnetic pole position sensor 3 is not confirmed to be faulty, overmodulation control is performed in both vector control and sensorless vector control. On the other hand, if the magnetic pole position sensor 3 is confirmed to be faulty, sensorless vector control is executed, but overmodulation control that would generate high-order harmonics in the output voltage is not performed in this case.

[0108] Furthermore, in this embodiment, the target modulation rate value Mo is set to be smaller than the maximum modulation rate value Mmax. This allows for a margin in the modulation rate, ensuring that the actual modulation rate is controlled near the target value Mo.

[0109] The fault status signal FAIL_STAT=1, representing an intermediate state, may oscillate between it and the fault status signal FAIL_STAT=0, representing a confirmed normal state. Similarly, the fault status signal FAIL_STAT=3, representing an intermediate state, may oscillate between it and the fault status signal FAIL_STAT=2, representing a confirmed fault.

[0110] If the target value Mo and the maximum value Mmax of the modulation rate are simply switched based on whether sensor-based vector control or sensorless vector control is used, the d-axis current command value, the q-axis current command value, and the three-phase voltage command value may also fluctuate, resulting in torque surges. Furthermore, in the worst case, the estimation of the magnetic pole position may diverge.

[0111] Furthermore, the oscillation between vector control and sensorless vector control can also generate torque surges. In contrast, for example, after switching to sensorless vector control, the system is prevented from returning to torque control until a set time has elapsed, thereby preventing oscillation.

[0112] If the oscillation is ignored, the fault status signal FAIL_STAT transitions in the order of 0→1→2→3→0. Therefore, distinguishing between the output of fault status signal FAIL_STAT=0 or 1, and the output of fault status signal FAIL_STAT=2 or 3, means that the target value Mo of the modulation rate and the maximum value Mmax of the modulation rate do not change in the intermediate state.

[0113] Next, the control actions of the control device 30 will be explained. Figure 5 This is a timing diagram showing the control actions of the control device 30 when the output signal of the magnetic pole position sensor 3 changes from normal to abnormal.

[0114] At time t0, the magnetic pole position sensor 3 is determined to be normal, and the fault status signal FAIL_STAT is "0". Therefore, in the rotation detection unit 36, the magnetic pole position θ1 and rotation angular velocity ω1 detected by the magnetic pole position detection unit 36a are selected as the magnetic pole position θ and rotation angular velocity ω, respectively.

[0115] At this point, the maximum modulation rate Mmax becomes larger than the target modulation rate Mo. Furthermore, the maximum modulation rate Mmax is 1.27, and the target modulation rate Mo is 1.20, both of which are overmodulation control values.

[0116] At time t1, if the output signal of the magnetic pole position sensor 3 becomes abnormal, for example due to a broken wire, the fault state signal FAIL_STAT from the fault state determination unit 37 becomes "1". Therefore, in the rotation detection unit 36, the magnetic pole position θ2 and the rotation angular velocity ω2 estimated by the magnetic pole position estimation unit 36b are selected as the magnetic pole position θ and the rotation angular velocity ω, respectively.

[0117] At this time, the maximum value Mmax of the modulation rate and the target value Mo of the modulation rate are not switched. The values ​​of the maximum value Mmax of the modulation rate and the target value Mo of the modulation rate remain the same as at time t0.

[0118] Subsequently, if the abnormal output signal of the magnetic pole position sensor 3 continues, and at time t2, the abnormal count value obtained by the fault determination counter reaches the fault determination value, then the magnetic pole position sensor 3 is determined to be faulty. Then, the fault status signal FAIL_STAT becomes "2".

[0119] Therefore, the modulation rate switching unit 38 makes the maximum modulation rate Mmax and the target modulation rate Mo smaller than the normal output signal of the magnetic pole position sensor 3. At this time, the maximum modulation rate Mmax is 1.15 and the target modulation rate Mo is 1.05, both of which are non-overmodulation control values.

[0120] In this embodiment, the modulation rate switching unit 38 gradually switches the target value Mo of the modulation rate and the maximum value Mmax of the modulation rate.

[0121] then, Figure 6 This is a timing diagram showing the control actions of the control device 30 when the output signal of the magnetic pole position sensor 3 changes from abnormal to normal.

[0122] At time t0, the magnetic pole position sensor 3 is determined to be faulty, and the fault status signal FAIL_STAT is "2". Therefore, in the rotation detection unit 36, the magnetic pole position θ2 and rotational angular velocity ω2 estimated by the magnetic pole position estimation unit 36b are selected as the magnetic pole position θ and rotational angular velocity ω, respectively.

[0123] At this point, the maximum modulation rate Mmax becomes larger than the target modulation rate Mo. Furthermore, the maximum modulation rate Mmax is 1.15, and the target modulation rate Mo is 1.05, both of which are values ​​for non-overmodulation control.

[0124] At time t1, if the output signal of the magnetic pole position sensor 3 becomes normal, for example, due to the elimination of the disconnection, the fault state signal FAIL_STAT from the fault state determination unit 37 becomes "3". Therefore, in the rotation detection unit 36, the magnetic pole position θ2 and rotation angular velocity ω2 estimated by the magnetic pole position estimation unit 36b are selected as the magnetic pole position θ and rotation angular velocity ω, respectively.

[0125] At this time, the maximum value Mmax of the modulation rate and the target value Mo of the modulation rate are not switched. The values ​​of the maximum value Mmax of the modulation rate and the target value Mo of the modulation rate remain the same as at time t0.

[0126] Subsequently, if the output signal of the magnetic pole position sensor 3 continues to be in a normal state, and at time t2, the normal count value obtained by the normal determination counter reaches the normal determination value, then the magnetic pole position sensor 3 is determined to be normal. Then, the fault status signal FAIL_STAT becomes "0". Therefore, in the rotation detection unit 36, the magnetic pole position θ1 and rotation angular velocity ω1 detected by the magnetic pole position detection unit 36a are selected as the magnetic pole position θ and rotation angular velocity ω, respectively.

[0127] Therefore, the modulation rate switching unit 38 makes the maximum value Mmax and the target value Mo of the modulation rate larger than when the output signal of the magnetic pole position sensor 3 is abnormal. At this time, the maximum value Mmax of the modulation rate is 1.27 and the target value Mo of the modulation rate is 1.20, both of which are overmodulation control values.

[0128] Furthermore, in this embodiment, the target value Mo of the modulation rate and the maximum value Mmax of the modulation rate are switched progressively.

[0129] Furthermore, the switching between the target modulation rate value Mo and the maximum modulation rate value Mmax can be performed in a step manner. This step switching is effective in sensorless vector control where the influence of higher harmonics is significant and a rapid reduction in the modulation rate is required.

[0130] In both gradual and step switching scenarios, the maximum modulation rate Mmax is greater than the target modulation rate Mo during switching. This ensures a margin in the modulation rate.

[0131] Figure 7 It is shown Figure 2 The flowchart shows the operation of the fault condition determination unit 37, the rotation information switching unit 36c, and the modulation rate switching unit 38. The control device 30 repeatedly executes... Figure 7 The handling of this. Additionally... Figure 7 The processing performed by the fault determination counter and the normal determination counter in the intermediate state is omitted.

[0132] In step S101, the fault status determination unit 37 confirms whether the magnetic pole position sensor 3 is determined to be normal. If the magnetic pole position sensor 3 is determined to be normal, the fault status determination unit 37 determines whether the output signal of the magnetic pole position sensor 3 is normal in step S102.

[0133] If the output signal of the magnetic pole position sensor 3 is normal, the fault status determination unit 37 outputs a fault status signal FAIL_STAT = 0 in step S103. If the output signal of the magnetic pole position sensor 3 is abnormal, the fault status determination unit 37 outputs a fault status signal FAIL_STAT = 1 in step S104.

[0134] In step S101, if the magnetic pole position sensor 3 is determined to be faulty, the fault status determination unit 37 determines in step S105 whether the output signal of the magnetic pole position sensor 3 is normal.

[0135] If the output signal of the magnetic pole position sensor 3 is normal, the fault status determination unit 37 outputs a fault status signal FAIL_STAT = 3 in step S106. If the output signal of the magnetic pole position sensor 3 is normal, the fault status determination unit 37 outputs a fault status signal FAIL_STAT = 2 in step S107.

[0136] In step S103, if the output fault status signal FAIL_STAT = 0, the rotation information switching unit 36c selects vector control in step S108. That is, as the magnetic pole position θ and rotational angular velocity ω, the rotation information switching unit 36c selects the magnetic pole position θ1 and rotational angular velocity ω1 based on the output signal of the magnetic pole position sensor 3. Furthermore, in step S109, the modulation rate switching unit 38 sets the target value Mo of the modulation rate to 1.20 and the maximum value Mmax of the modulation rate to 1.27.

[0137] In step S104, if the output fault status signal FAIL_STAT = 1, then the rotation information switching unit 36c selects sensorless vector control in step S110. That is, as the magnetic pole position θ and rotational angular velocity ω, the rotation information switching unit 36c outputs the magnetic pole position θ2 and rotational angular velocity ω2 estimated by the magnetic pole position detection unit 36b. Furthermore, in step S111, the modulation rate switching unit 38 sets the target value Mo of the modulation rate to 1.20 and the maximum value Mmax of the modulation rate to 1.27.

[0138] In step S106, if the output fault status signal FAIL_STAT = 3, then the rotation information switching unit 36c selects sensorless vector control in step S112. That is, as the magnetic pole position θ and rotational angular velocity ω, the rotation information switching unit 36c outputs the magnetic pole position θ2 and rotational angular velocity ω2 estimated by the magnetic pole position detection unit 36b. Furthermore, in step S113, the modulation rate switching unit 38 sets the target value Mo of the modulation rate to 1.05 and the maximum value Mmax of the modulation rate to 1.15.

[0139] In step S107, if the output fault status signal FAIL_STAT = 2, then the rotation information switching unit 36c selects sensorless vector control in step S114. That is, as the magnetic pole position θ and rotational angular velocity ω, the rotation information switching unit 36c outputs the magnetic pole position θ2 and rotational angular velocity ω2 estimated by the magnetic pole position estimation unit 36b. Furthermore, in step S115, the modulation rate switching unit 38 sets the target value Mo of the modulation rate to 1.05 and the maximum value Mmax of the modulation rate to 1.15.

[0140] In such a control device 30, the current command value Ido for the d-axis and the current command value Iqo for the q-axis are calculated based on the target value Mo of the modulation rate. Furthermore, when the magnetic pole position sensor 3 is determined to be faulty and sensorless vector control is performed, the target value Mo of the modulation rate is smaller compared to when the magnetic pole position sensor 3 is determined to be normal and vector control is performed.

[0141] Therefore, in vector control, voltage utilization can be improved. On the other hand, in sensorless vector control, the high-order harmonic components of the output voltage can be reduced, and the deterioration of estimation performance due to the presence of high-order harmonic components in the current can be prevented. As a result, in the event of a failure of the magnetic pole position sensor 3, the operation of the AC rotary motor 1 can continue to be further stabilized.

[0142] Furthermore, when the magnetic pole position sensor 3 is determined to be normal and vector control is performed, the target value Mo of the modulation rate becomes the value for overmodulation control. Then, when the magnetic pole position sensor 3 is determined to be faulty and sensorless vector control is performed, the target value Mo of the modulation rate becomes the value for non-overmodulation control.

[0143] Therefore, it can prevent the generation of high-order harmonic components in the output voltage, and enable the operation based on sensorless vector control to continue more reliably.

[0144] Furthermore, the three-phase voltage command values ​​Vuo, Vvo, and Vwo are limited based on the maximum value of the modulation rate, Mmax. Additionally, when a fault is detected in the magnetic pole position sensor 3 and sensorless vector control is performed, the maximum value of the modulation rate, Mmax, is smaller compared to when the magnetic pole position sensor 3 is detected as normal and vector control is performed.

[0145] Therefore, by reliably limiting the value of the modulation rate, operation based on sensorless vector control can continue more reliably compared to simply reducing the target value Mo of the modulation rate.

[0146] Furthermore, the maximum modulation rate, Mmax, is made larger than the target modulation rate, Mo. This ensures a margin in the modulation rate, allowing control to ensure the actual current matches the d-axis current command value Ido and the q-axis current command value Iqo. Consequently, the estimated magnetic pole position is stabilized, enabling more reliable operation based on sensorless vector control.

[0147] Furthermore, when the fault status signal FAIL_STAT indicates an intermediate state between normal and fault, sensorless vector control is performed, and the target value Mo of the modulation rate is not switched.

[0148] Therefore, even when the control method might fluctuate, by not changing the target value Mo of the modulation rate, the d-axis current command value Ido and the q-axis current command value Iqo are not affected, and fluctuations in the three-phase voltage command values ​​Vuo, Vvo, and Vwo are also prevented. This ensures the estimated stability of the magnetic pole position, allowing for more reliable continuation of operation based on sensorless vector control.

[0149] Furthermore, when the fault status signal represents an intermediate state between normal and fault, if sensorless vector control is performed and the target value Mo of the modulation rate is switched, the maximum value Mmax of the modulation rate is not switched.

[0150] Therefore, even when the control method may fluctuate, maintaining the target value Mo and maximum value Mmax of the modulation rate ensures a more reliable margin for the modulation rate. This prevents the three-phase voltage command values ​​Vuo, Vvo, and Vwo from being excessively restricted, and allows control to ensure that the actual current matches the d-axis current command value Ido and the q-axis current command value Iqo. Consequently, the estimated stability of the magnetic pole position allows for more reliable continuation of operation based on sensorless vector control.

[0151] Furthermore, the switching of the target value Mo of the modulation rate is performed gradually. This prevents abrupt changes in the d-axis current command value Ido and the q-axis current command value Iqo in sensorless vector control, as well as variations in the three-phase voltage command values ​​Vuo, Vvo, and Vwo. Consequently, the estimated stability of the magnetic pole position allows for more reliable continuation of operation based on sensorless vector control.

[0152] Furthermore, the switching of the maximum modulation rate Mmax is performed gradually. This prevents the three-phase voltage command values ​​Vuo, Vvo, and Vwo from being excessively restricted, and allows control to ensure that the actual current matches the d-axis current command value Ido and the q-axis current command value Iqo. Consequently, the estimated pole position is stabilized, enabling more reliable operation based on sensorless vector control.

[0153] Here, the functions of the control device 30 in Embodiment 1 are implemented by the processing circuit. Figure 8 This is a structural diagram showing an example of a processing circuit that implements the functions of the control device 30 in Embodiment 1.

[0154] The control device 30 has an arithmetic processing device 90, multiple storage devices 91, an input circuit 92, and an output circuit 93.

[0155] As an arithmetic processing unit 90, a CPU (Central Processing Unit) is used. Multiple storage devices 91 exchange data with the arithmetic processing unit 90. Input circuit 92 inputs signals from the outside into the arithmetic processing unit 90. Output circuit 93 outputs signals from the arithmetic processing unit 90 to the outside.

[0156] As a computing device 90, it can use ASIC (Application Specific Integrated Circuit), IC (Integrated Circuit), DSP (Digital Signal Processor), FPGA (Field Programmable Gate Array), various logic circuits, and various signal processing circuits.

[0157] Furthermore, multiple processing units 90 of the same or different types can be provided in the control unit 30. In this case, the processing performed by the control unit 30 can be shared by multiple processing units 90.

[0158] As multiple storage devices 91, RAM (Random Access Memory) configured to read and write data from the arithmetic processing unit 90, ROM (Read Only Memory) configured to read data from the arithmetic processing unit 90, and the like can be used. At least one storage device 91 stores software, i.e., programs, for implementing the various functions of the control device 30, as well as multiple setting data.

[0159] Signals from multiple sensors and multiple switches are input to input circuit 92. The multiple sensors include a power supply voltage sensor 14, a magnetic pole position sensor 3, a current sensor 15, etc. Additionally, input circuit 92 has an A / D converter (not shown).

[0160] Output circuit 93 has a drive circuit (not shown). The drive circuit is connected to an electrical load, such as a gate drive circuit. The gate drive circuit is a circuit that drives the switching elements of the inverter 20 to turn on and off. The drive circuit outputs control signals from the arithmetic processing unit 90 to the electrical load.

[0161] Figure 2 The functions of the control device 30 shown are implemented by the execution of programs by the arithmetic processing device 90, and in cooperation with other hardware, namely the storage device 91, the input circuit 92, the output circuit 93, etc.

[0162] Furthermore, the application of the AC rotary motor 1 is not particularly limited.

[0163] For example, the AC rotary motor 1 is preferably used as a driving force source for the vehicle's wheels. In this case, when the magnetic pole position sensor 3 is functioning normally, overmodulation control is performed to improve voltage utilization and reduce losses, thereby improving fuel consumption rate, i.e., electricity consumption rate. Furthermore, when the magnetic pole position sensor 3 fails, operation based on sensorless vector control can reliably continue. Therefore, even after the magnetic pole position sensor 3 fails, power generation can continue, minimizing the impact on the driver. Moreover, when the magnetic pole position sensor 3 is in an intermediate state, sensorless vector control is performed without switching between the target value Mo and the maximum value Mmax of the modulation rate. Therefore, fluctuations in the d-axis current command value Ido and the q-axis current command value Iqo can be suppressed, preventing deterioration of drive performance.

[0164] Furthermore, the AC rotary motor 1 is not limited to a permanent magnet type synchronous rotary motor. As long as the AC rotary motor 1 can perform vector control and sensorless vector control, it can also be, for example, an excitation winding type AC rotary motor or induction motor.

[0165] Furthermore, the number of phases of the multiple windings in the AC rotating motor 1 is not limited to three phases; for example, it can be two-phase or four-phase.

[0166] Furthermore, in the above embodiment, one set of three-phase windings and one set of inverters 20 are used. However, two or more sets of multi-phase windings and two or more sets of inverters can also be used. In this case, the same control is performed on each set of inverters as in the above embodiment.

[0167] Furthermore, in the embodiments described above, the current command value calculation unit 33 uses the linkage flux command value Ψo as an intermediate parameter, changes the linkage flux command value Ψo based on the target modulation rate value Mo, and sets the d-axis current command value Ido and the q-axis current command value Iqo based on the linkage flux command value Ψo. However, the current command value calculation unit 33 may also set the d-axis current command value Ido and the q-axis current command value Iqo without using the linkage flux command value Ψo. For example, the current command value calculation unit 33 may use the undervoltage ratio as an intermediate parameter, change the undervoltage ratio based on the target modulation rate value Mo, and set the d-axis current command value Ido and the q-axis current command value Iqo based on the undervoltage ratio.

[0168] Furthermore, the current command value calculation unit 33 can use various known current vector control methods to set the general d-axis current command value Ido and q-axis current command value Iqo. For example, the current command value calculation unit 33 can use maximum torque current control or field weakening control, and set the d-axis current command value Ido and q-axis current command value Iqo based on the torque command value To, rotational angular velocity ω, power supply voltage VDC, etc.

[0169] Furthermore, in the above embodiments, the target modulation rate value Mo and the maximum modulation rate value Mmax are set to constant values ​​in both vector control and sensorless vector control. However, the target modulation rate value Mo and the maximum modulation rate value Mmax can vary, for example, based on the possibility of resonance. Moreover, the target modulation rate value Mo and the maximum modulation rate value Mmax can vary based on operating conditions such as the power supply voltage VDC, torque command value To, and rotational angular velocity ω. By varying the target modulation rate value Mo and the maximum modulation rate value Mmax, the occurrence of resonance can be more appropriately suppressed. However, in this case, the maximum modulation rate value Mmax is also set to be larger than the target modulation rate value Mo.

[0170] Furthermore, in the above embodiments, as a more preferred approach, the target value Mo of the modulation rate and the maximum value Mmax of the modulation rate are changed together. However, it is also possible to change only the target value Mo of the modulation rate. In this case, the following effect can also be obtained: the average higher harmonic components can be reduced, and the operation based on sensorless vector control can continue more reliably. Similarly, when only the maximum value Mmax of the modulation rate is changed, the following effect can also be obtained: the upper limit of the generated higher harmonic components can be reduced, and the operation based on sensorless vector control can continue more reliably.

[0171] Furthermore, the various features, aspects, and functions described in the above embodiments 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 this disclosure. For example, at least one structural element can be modified, added to, or omitted.

[0172] Label Explanation

[0173] 1. Alternating Rotary Motor

[0174] 2 rotors

[0175] 3. Magnetic pole position sensor

[0176] 20 Inverters

[0177] 21H First Positive Switching Element

[0178] 21L First Negative Pole Switching Element

[0179] 22H Second Positive Switching Element

[0180] 22L Second Negative Pole Switching Element

[0181] 23H Third Positive Switching Element

[0182] 23L Third Negative Pole Switching Element

[0183] 30 Control device

[0184] 33 Current Command Value Calculation Unit

[0185] 34 Voltage Command Value Calculation Unit

[0186] 35 Switch Control Unit

[0187] 36a Magnetic pole position detection unit

[0188] 36b Magnetic pole position estimation section

[0189] 36c Rotary Information Switching Unit

[0190] 37 Fault Status Determination Department

[0191] 38 Modulation rate switching unit.

Claims

1. A control device for an AC rotating electric motor, characterized in that, include: A magnetic pole position detection unit detects the magnetic pole position of the rotor based on the output signal of a magnetic pole position sensor that outputs an electrical signal corresponding to the rotation angle of the rotor. A magnetic pole position estimation unit estimates the magnetic pole position of the rotor without relying on the output signal of the magnetic pole position sensor; The fault status determination unit determines the fault status of the magnetic pole position sensor based on the output signal of the magnetic pole position sensor. The rotation information switching unit, based on the output signal of the fault state determination unit, outputs the magnetic pole position detected by the magnetic pole position detection unit when the magnetic pole position sensor is normal, and outputs the magnetic pole position estimated by the magnetic pole position estimation unit when the magnetic pole position sensor is faulty. A modulation rate switching unit outputs a target value for the modulation rate and switches the output target value based on the determination result obtained by the fault state determination unit. A current command value calculation unit calculates a current command value based on the target value; A voltage command value calculation unit calculates the voltage command value based on the current command value and the magnetic pole position output from the rotation information switching unit; as well as The switching control unit, based on the voltage command value, turns multiple switching elements installed in the inverter on and off. When the fault state determination unit determines that the magnetic pole position sensor is faulty, the modulation rate switching unit makes the target value smaller compared to when the fault state determination unit determines that the magnetic pole position sensor is normal.

2. The control device for an AC rotating electric motor as described in claim 1, characterized in that, When the fault state determination unit determines that the magnetic pole position sensor is normal, the modulation rate switching unit sets the target value to the overmodulation control value; when the fault state determination unit determines that the magnetic pole position sensor is faulty, the target value is set to the non-overmodulation control value.

3. The control device for an AC rotating electric motor as described in claim 1 or 2, characterized in that, The modulation rate switching unit outputs the maximum value of the modulation rate, and switches the output maximum value based on the determination result obtained by the fault state determination unit. The voltage command value calculation unit limits the voltage command value based on the maximum value. When the fault state determination unit determines that the magnetic pole position sensor is faulty, the modulation rate switching unit reduces the maximum value compared to when the fault state determination unit determines that the magnetic pole position sensor is normal.

4. The control device for an AC rotating electric motor as described in claim 3, characterized in that, The modulation rate switching unit makes the maximum value larger than the target value.

5. The control device for an AC rotating electric motor as described in claim 1 or 2, characterized in that, The fault status determination unit outputs a fault status signal indicating whether the magnetic pole position sensor is normal, faulty, or an intermediate state (uncertain whether it is normal or faulty), as the determination result of the fault status of the magnetic pole position sensor. When the fault status signal indicates the intermediate state, the rotation information switching unit outputs the magnetic pole position estimated by the magnetic pole position estimation unit. When the fault status signal indicates the intermediate state, the modulation rate switching unit does not switch the target value.

6. The control device for an AC rotating electric motor as described in claim 3, characterized in that, The fault status determination unit outputs a fault status signal indicating whether the magnetic pole position sensor is normal, faulty, or an intermediate state (uncertain whether it is normal or faulty), as the determination result of the fault status of the magnetic pole position sensor. When the fault status signal indicates the intermediate state, the rotation information switching unit outputs the magnetic pole position estimated by the magnetic pole position estimation unit. When the fault status signal indicates an intermediate state, the modulation rate switching unit does not switch between the target value and the maximum value.

7. The control device for an AC rotating electric motor as described in claim 4, characterized in that, The fault status determination unit outputs a fault status signal indicating whether the magnetic pole position sensor is normal, faulty, or an intermediate state (uncertain whether it is normal or faulty), as the determination result of the fault status of the magnetic pole position sensor. When the fault status signal indicates the intermediate state, the rotation information switching unit outputs the magnetic pole position estimated by the magnetic pole position estimation unit. When the fault status signal indicates an intermediate state, the modulation rate switching unit does not switch between the target value and the maximum value.

8. The control device for an AC rotating electric motor as described in claim 1 or 2, characterized in that, The modulation rate switching unit gradually switches the target value.

9. The control device for an AC rotating electric motor as described in claim 5, characterized in that, The modulation rate switching unit gradually switches the target value.

10. The control device for an AC rotating electric motor as described in claim 3, characterized in that, The modulation rate switching unit gradually switches the maximum value.

11. The control device for an AC rotating electric motor as described in claim 4, characterized in that, The modulation rate switching unit gradually switches the maximum value.

12. The control device for an AC rotating electric motor as described in claim 6 or 7, characterized in that, The modulation rate switching unit gradually switches the maximum value.

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