JP2023048833A - State estimation method for motor unit and state estimation device - Google Patents

Abstract

To provide a state estimation method for a motor unit capable of improving detection accuracy of a rotation angle of a rotor.SOLUTION: A first magnetic pole position indicating a magnetic pole position of a rotor is detected based on a voltage value detected by a voltage detection section 302, and a second magnetic pole position indicating a magnetic pole position of the rotor is detected based on a signal detected by a resolver 30. A time difference in detection timing of the first magnetic pole position and the second magnetic pole position is calculated, a phase difference between rotation angles of the first magnetic pole position and the second magnetic pole position is calculated based on the calculated time difference, and a temperature of a permanent magnet is estimated based on the calculated phase difference.SELECTED DRAWING: Figure 1

Description

The present invention relates to a state estimation method and a state estimation device for a motor unit.

In a rotating electric machine (motor), the amount of magnetic flux of a permanent magnet changes due to a change in the temperature of the permanent magnet, so it is necessary to perform control in consideration of this change.

Patent Literature 1 discloses a motor control method for estimating a magnetic flux amount corresponding to a permanent magnet temperature based on an induced voltage calculated from a motor terminal voltage, a motor current, and a motor constant.

JP-A-7-212915

In such a conventional technique, it is necessary to obtain the motor constant and the induced voltage at the reference temperature in advance by experiments, etc., so there is a problem that the estimation accuracy decreases due to errors due to individual differences in the motor and changes in the rotation speed. .

SUMMARY OF THE INVENTION It is an object of the present invention to provide a motor unit state estimating method capable of estimating the permanent magnet temperature of a rotor with high accuracy.

According to one aspect of the present invention, a motor includes a stator having windings and a rotor having permanent magnets, a resolver that detects the rotation speed of the rotor, and a voltage detection unit that detects the voltage of the windings of the stator. is applied to a state estimation method in a state estimation device for a motor unit having A first magnetic pole position indicating the magnetic pole position of the rotor is detected based on the voltage value detected by the voltage detection unit, and a second magnetic pole position indicating the magnetic pole position of the rotor is detected based on the signal detected by the resolver. . A time difference between detection timings of the first magnetic pole position and the second magnetic pole position is calculated, and a phase difference in rotation angle between the first magnetic pole position and the second magnetic pole position is calculated based on the calculated time difference. , the temperature of the permanent magnet is estimated based on the calculated phase difference.

According to the present invention, the phase difference is calculated from the time difference between the detection timings of the first magnetic pole position, which is the actual magnetic pole position in the motor, and the second magnetic pole position, whose rotation angle changes according to the temperature of the permanent magnet. and the temperature of the permanent magnet is estimated based on this phase difference. As a result, the permanent magnet temperature can be estimated with high accuracy without being affected by errors due to individual differences in motors and changes in rotational speed.

FIG. 1 is a functional block diagram of a motor unit control device according to an embodiment of the invention. FIG. 2 is an explanatory diagram of the calculation of the deviation. FIG. 3 is an explanatory diagram of an example of a magnet temperature map. FIG. 4 is an explanatory diagram of an example of a torque correction map. FIG. 5 is a control block diagram of a modification.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a functional block diagram of a motor unit control device 10 according to an embodiment of the invention.

The motor unit control device 10 of the present embodiment calculates the electric power to be supplied to the motor 1 based on the command torque Te ^* of the motor 1 commanded by the controller (not shown), and supplies the electric power to the motor 1 so that the motor drive 1. The motor unit control device 10 functions as a motor unit state estimating device that executes processing for estimating a state value (for example, permanent magnet temperature) indicating the operating state of the motor unit.

A motor 1 is mounted on, for example, an electric vehicle and functions as an electric motor that drives wheels. The motor 1 also functions as a generator that generates (regenerates) power by receiving the driving force from the rotation of the wheels. Note that the motor 1 may be used as a driving device for devices other than automobiles, such as various electric devices or industrial machines.

The motor unit control device 10 has a microcomputer including a CPU, a storage device, etc. The CPU executes a program recorded in the storage device, thereby realizing the function of each part shown in FIG. It should be noted that the motor unit control device 10 may be configured such that part or all of it is realized by an electronic circuit or an ASIC.

The motor unit control device 10 includes an inverter 20, a resolver 30, a PWM signal generator 40, a modulation factor generator 50, a dq-uvw converter 60, a uvw-dq converter 70, a d-axis PI compensator 90, and a q-axis PI compensator. A section 100 , a current command value generation section 110 , a torque correction section 120 , a current sensor 201 and a voltage sensor 202 are provided.

Based on the corrected command torque Te ^* ', the current command value generation unit 110 obtains the dq-axis current component of the rotating coordinate system for vector control from a pre-stored torque map or the like. A current command value generator 110 calculates a d-axis current command value id ^* and a q-axis current command value iq ^* from the dq-axis current components.

As for the d-axis current component, a difference Δid is obtained by subtracting the d-axis current id actually flowing through the motor 1 from the d-axis current command value id ^* in the subtraction unit 109 . The difference Δid is input to the d-axis PI compensator 90 . The d-axis PI compensator 90 calculates a d-axis voltage component vd that acts to reduce the difference Δid.

As for the q-axis current component, subtraction section 111 obtains difference Δiq by subtracting q-axis current iq actually flowing in motor 1 from q-axis current command value iq ^* . The difference Δiq is input to the q-axis PI compensator 100 . The q-axis PI compensator 100 calculates a q-axis voltage component vq that acts to reduce the difference Δiq.

The d-axis voltage component vd and the q-axis voltage component vq calculated in this manner are input to the dq-uvw conversion section 60 . The dq-uvw converter 60 converts two-phase voltage values of the q-axis and d-axis of the rotating coordinate system into three-phase voltage values of u, v, and w of the fixed coordinate system based on the rotation angle. The converted three-phase voltage values are converted into a u-phase modulation factor command value mu ^* , a v-phase modulation factor command value mv ^* , and a w-phase modulation factor command value mw ^* by the modulation factor generator 50, respectively, and are generated by PWM. It is sent to the signal generator 40 .

The PWM signal generator 40 controls the output of the inverter 20 based on the input u-phase modulation rate command value mu ^* , v-phase modulation rate command value mv ^* , and w-phase modulation rate command value mw ^* . The phase modulation signals D ^* u, D ^* v, D ^* w are commanded to the inverter 20 .

The inverter 20 is composed of a plurality of power transistors, and converts the DC power of the battery 2 into three-phase AC power based on this command, and supplies current to each of the U-phase, V-phase, and W-phase of the motor 1. supply.

A current sensor 201 detects actual current values iu and iv supplied to the motor 1 by the inverter 20 . The uvw-dq conversion unit 70 converts the detected current values iu and iv and the current value iw calculated from the difference between the current values iu and iv to the d-axis current id and the q-axis current id of the rotating coordinate system based on the rotation angle. to current iq respectively. The converted current value, that is, the actual current value that actually flows through the motor 1 is used in the subtraction units 109 and 111 to calculate the difference between the d-axis current command value id ^* and the q-axis current command value iq ^* as described above. Used.

The torque correction unit 120 calculates a torque correction value ΔT based on the permanent magnet temperature Th of the rotor. The calculated torque correction value ΔT is input to the subtraction unit 109 ^, and the corrected command torque Te ^*′ , which is the value obtained by subtracting the torque correction value ΔT from the command torque Te* of the motor 1, is obtained. The corrected command torque Te ^* ' is input to the current command value generator 110, and the control described above is performed.

In this way, by performing feedback control based on the difference between the actual current value supplied to the motor 1 and the command current value based on the command torque Te ^* , it is possible to cause the motor 1 to generate the actual torque corresponding to the command torque Te ^* . It becomes possible.

When the motor 1 rotates, the resolver 30 is used to detect a rotation angle that serves as a reference for the current vector. A signal detected by the resolver 30 is input to a resolver digital converter (RD converter) 301 . The RD converter 301 outputs the rotation angle of the rotor based on the signal detected by the resolver 30 .

The rotation angle is input to the dq-uvw transforming unit 60 and the uvw-dq transforming unit 70, and mutual transformation between the rotating coordinate system and the fixed coordinate system is performed.

Next, control for estimating the permanent magnet temperature Th of the rotor will be described.

The temperature of the motor 1 rises as it is driven. When the temperature of the motor 1 rises, the permanent magnet temperature of the rotor also rises. Permanent magnets have the property that the magnetic flux density decreases as the temperature rises, so it is necessary to consider the temperature of the permanent magnets when controlling the motor 1 .

On the other hand, the rotor is housed inside the stator, and there is the problem that it is difficult to directly detect the temperature of the permanent magnets embedded in the rotor. On the other hand, the permanent magnet temperature, which is one of the state values indicating the operation of the motor 1, is also estimated from the voltage value and current value of the stator winding and the preset constants unique to the motor. there is However, there is a problem that the accuracy of estimation decreases due to individual differences in motors and errors due to changes in rotation speed.

Therefore, in the present embodiment, the permanent magnet temperature Th is estimated based on the voltage value detected by the voltage detector 302 and the signal detected by the resolver 30, as described below.

In the motor unit control device 10 , the RD converter 301 detects the magnetic pole position (second magnetic pole position) of the motor 1 based on the signal detected by the resolver 30 provided in the motor 1 . The magnetic pole positions detected in this way contain errors due to temperature changes in the permanent magnets of the rotor.

Using this fact, the error between the first magnetic pole position based on the actual voltage value of the windings of the stator and the second magnetic pole position detected based on the signal detected by the resolver 30 is calculated as the phase difference θ. and the permanent magnet temperature Th can be estimated based on this phase difference θ.

As shown in FIG. 1, the motor unit control device 10 includes an RD converter 301, a voltage detector 302, a counter 303, a rotation speed calculator 304, a phase difference calculator 305, and a magnet temperature estimator 306.

The RD converter 301 converts the analog signal output from the resolver 30 into a digital signal indicating the rotation angle of the rotor and outputs the digital signal. Also, the RD converter 301 detects the timing (second magnetic pole position) at which the magnetic pole position of the rotor reaches an electrical angle of 0 based on the analog signal output from the resolver 30 . The RD converter 301 outputs a rising second magnetic pole position signal (see FIG. 2) when the second magnetic pole position is detected.

By detecting the second magnetic pole position based on the signal detected by the resolver 30 in this manner, the RD converter 301 functions as a second magnetic pole position detector.

The voltage detection unit 302 acquires an analog signal indicating the actual voltage of each phase of the stator winding of the motor 1 detected by the voltage sensor 202, and based on the acquired analog signal, the stator winding (U phase , V phase, and W phase) are detected.

The voltage detection unit 302 detects the position (zero cross point) where the voltage value becomes 0 from the detected voltage value of any one phase (for example, U phase). The zero cross point is the timing (first magnetic pole position) at which the magnetic pole position of the rotor becomes zero electrical angle. The voltage detection unit 302 outputs a rising first magnetic pole position signal (zero cross signal) when the first magnetic pole position is detected.

By detecting the first magnetic pole position based on the voltage value detected by the voltage sensor 202 in this manner, the voltage detection section 302 functions as a first magnetic pole position detection section.

The voltage detection unit 302 may acquire the voltage value of the windings of the stator during power running of the motor 1, but the induced voltage generated in the windings when the rotor is rotated by an external force, such as during regeneration. It is desirable to obtain the voltage value. This is because the voltage value of the stator windings is affected by fluctuations in the output voltage of the PWM-controlled inverter 20 during power running of the motor 1 . The zero cross point can be accurately detected by detecting the induced voltage when the rotor is rotated by an external force.

The counter 303 updates the counter value at predetermined intervals (for example, every 0.1 [ms]). Also, the counter 303 acquires the second magnetic pole position signal output by the RD converter 301 and the first magnetic pole position signal output by the voltage detector 302 . The counter 303 calculates an integrated value of counter values counted between the detection timing of the first magnetic pole position signal and the detection timing of the second magnetic pole position signal as the time difference t.

A rotation speed calculator 304 calculates a rotation speed n of the motor 1 based on the rotation angle output from the RD converter 301 .

A phase difference calculation unit 305 calculates the first magnetic pole detected by the detection result of the voltage actually flowing through the windings of the stator from the time difference t calculated by the counter 303 and the rotation speed n calculated by the rotation speed calculation unit 304. A phase difference θ between the rotation angle between the position and the second magnetic pole position detected by the resolver 30 is calculated.

The magnet temperature estimator 306 uses a pre-stored magnet temperature table (see FIG. 3) from the phase difference θ calculated by the phase difference calculator 305 and the rotational speed n of the motor 1 calculated by the rotational speed calculator 304. to estimate the permanent magnet temperature Th.

The motor unit controller 10 corrects the command torque Te ^* using the permanent magnet temperature Th thus calculated, and controls the driving force of the motor 1 based on the corrected corrected command torque Te ^* '. .

Next, the magnet temperature estimation control of the motor unit control device 10 configured in this manner will be described more specifically.

FIG. 2 is an explanatory diagram of error correction control according to the present embodiment.

FIG. 2 is a time chart showing, from the top, the counter value of the counter 303, the phase position signal output by the RD converter 301, and the zero cross signal output by the voltage detection unit 302, with time as the horizontal axis.

The counter 303 updates the counter value at predetermined intervals. The counter 303 starts counting the counter value when detecting the rise of the first magnetic pole position signal input from the voltage detection section 302 . After that, when the rise of the second magnetic pole position signal phase position signal input from the RD converter 301 is detected, counting of the counter value is stopped. The integrated value of the counter values during that time is calculated and set as the time difference t. The calculated time difference t is sent to the phase difference calculator 305 .

In the example shown in FIG. 2, when the first magnetic pole position signal is input to the counter 303 at timing T0, counting of the counter value is started. After that, the second magnetic pole position signal is input from the RD converter 301 to the counter 303 at the timing T1, and the counting of the counter value is finished. Four counts counted during that period are calculated as the time difference t, which is the difference between the detection timings of the first magnetic pole position signal and the second magnetic pole position signal.

In this way, the first magnetic pole position signal output by the resolver 30 and the RD converter 301 is detected with respect to the detection timing of the first magnetic pole position signal, which is the actual reference position of the motor 1 based on the induced voltage actually generated in the windings of the stator. The detection timings of the two magnetic pole position signals are obtained with a time difference t.

It should be noted that the counter 303 sends a signal to that effect to the voltage detection unit 302 when the count-up of the counter value is completed. The voltage detection unit 302 resets the first magnetic pole position signal when receiving this signal.

In this manner, the counter 303 functions as a time difference calculator by calculating the time difference t, which is the difference between the detection timings of the first magnetic pole position signal and the second magnetic pole position signal.

Next, a method of calculating the phase difference θ in the phase difference calculator 305 will be described. When the time difference t is sent from the counter 303, the phase difference calculation unit 305 calculates the first magnetic pole by the following calculation based on the time difference t and the rotation speed n of the motor 1 output from the rotation speed calculation unit 304. A phase difference θ in the rotation angle between the position and the second magnetic pole position is calculated.

First, one period Te [sec] of the electrical angle satisfies the following relation between the rotation speed n [rpm] of the motor 1 and the number of pole pairs p of the motor 1 .

In addition, the phase difference θ [°] has a relationship such as the following Equation 2 between the time difference t [sec] calculated by the counter 303 and one cycle Te of the electrical angle.

The phase difference calculation unit 305 uses the time difference t calculated by the counter 303 and the rotation speed n of the motor 1 calculated by the rotation speed calculation unit 304 based on these formulas 1 and 2, and based on the following formula 3, A phase difference θ in the rotation angle between the first magnetic pole position and the second magnetic pole position is calculated.

Phase difference calculator 305 outputs the calculated phase difference θ to magnet temperature estimator 306 . The magnet temperature estimator 306 stores in advance a magnet temperature table (FIG. 3) showing the relationship between the phase difference θ, the rotation speed n, and the permanent magnet temperature Th. , the permanent magnet temperature Th is estimated based on the magnet temperature table.

The magnet temperature table shown in FIG. 3 is set so that the permanent magnet temperature Th increases as the phase difference θ increases and as the rotational speed n increases. This magnet temperature table is set in advance based on the structure of the motor 1, particularly the number of poles and configuration of the permanent magnets of the rotor.

Magnet temperature estimator 306 outputs permanent magnet temperature Th thus estimated to torque corrector 120 . Torque correction unit 120 uses a pre-stored torque correction table (see FIG. 4) based on permanent magnet temperature Th input from magnet temperature estimation unit 306 and rotation speed n input from rotation speed calculation unit 304. , to calculate the torque correction value ΔT.

More specifically, the torque correction unit 120 calculates the torque correction value ΔT from a preset reference temperature and the input permanent magnet temperature Th and rotation speed n using a torque correction table. The torque correction table shown in FIG. 4 is set to have a negative value as the permanent magnet temperature Th is higher than the reference temperature and as the rotation speed n is higher, and as the permanent magnet temperature Th is lower than the reference temperature. , and the higher the rotational speed n, the more positive the value.

The torque correction value ΔT thus calculated is sent to the subtraction unit 121, and the subtraction unit 121 subtracts the torque correction value ΔT from the command torque Te ^* to calculate the corrected command torque Te ^* '. For example, when the permanent magnet temperature Th is higher than the reference temperature, the torque correction value ΔT, which is a negative value, is calculated. By subtracting the torque correction value ΔT, which is a negative value, from the command torque Te ^* in the subtraction unit 121, the command torque Te ^* is corrected to increase in accordance with the permanent magnet temperature Th. ^* ' is calculated.

Note that the reference temperature in the present embodiment is a value indicating the temperature during steady operation of the motor 1, and is set to 60[° C.], for example.

With this kind of control, the permanent magnet temperature Th is determined by the detection timing of the first magnetic pole position detected by the detection result of the voltage actually flowing in the windings of the stator and the second magnetic pole position detected by the resolver 30. can be estimated based on the phase difference θ from the detection timing of . By correcting the command torque Te ^* using the permanent magnet temperature Th estimated in this way, it is possible to compensate for changes in the magnetic flux density that vary according to the permanent magnet temperature Th, so that the motor 1 can be controlled with high accuracy. .

Although the voltage detection unit 302 is configured to acquire the voltage value of the induced voltage of each winding of each phase of the stator by the voltage sensor 202, the voltage sensor 202 is not limited to this, and the correlation voltage of each phase is acquired by the voltage sensor 202. It may be configured to detect and detect the induced voltage based on this. With such a configuration, the phase of the zero-cross point is different from the phase of the phase voltage. Therefore, when the phase-to-phase voltage is obtained, the following equation 4 is used instead of the equation 3 in the calculation of the phase difference θ.

In this way, even when the voltage sensor 202 cannot directly detect the induced voltage of each phase of the stator windings, the phase difference θ can also be calculated by detecting the phase-to-phase voltage.

As described above, in the present embodiment, the motor 1 includes a rotor having a stator and permanent magnets, the resolver 30 that detects the rotation angle of the rotor, the voltage detection unit 302 that detects the voltage of the windings of the stator, is configured as a state estimating device for estimating a state value indicating the operating state of the motor unit. The voltage detection unit 302 detects the first magnetic pole position indicating the magnetic pole position of the rotor based on the voltage value detected by the voltage sensor 202 , and the RD converter 301 detects the rotor's magnetic pole position based on the signal detected by the resolver 30 . A second magnetic pole position indicative of the magnetic pole position is detected. The counter 303 calculates the time difference t between the detection timings of the first magnetic pole position and the second magnetic pole position. From this time difference t, the phase difference calculator 305 calculates the phase difference θ in the rotation angle between the first magnetic pole position and the second magnetic pole position. A magnet temperature estimator 306 estimates the temperature of the permanent magnet based on the calculated phase difference θ.

With such a configuration, the first magnetic pole position based on the actual voltage value of the windings of the stator is detected based on the signal detected by the resolver 30, which includes an error caused by the change in the permanent magnet temperature Th of the rotor. A phase difference θ is calculated from the time difference t from the second magnetic pole position, and the permanent magnet temperature Th is estimated based on this phase difference θ. As a result, the permanent magnet temperature Th of the rotor can be estimated with high accuracy without being affected by individual differences in motors and errors due to changes in rotational speed.

Since the command torque Te ^* of the motor 1 is corrected using the permanent magnet temperature Th estimated in this way, the precision of motor control can be improved.

Further, in the present embodiment, using the calculated phase difference θ and a magnet temperature table showing the relationship between the rotation speed n, the phase difference θ, and the permanent magnet temperature Th stored in advance in the magnet temperature estimating unit 306, Since the permanent magnet temperature Th is estimated, the permanent magnet temperature Th can be estimated based on the phase difference θ.

Further, in the present embodiment, the phase difference θ is calculated based on the calculated time difference t and the rotation speed n detected based on the signal detected by the resolver 30. Phase difference θ can be calculated.

Further, in the present embodiment, based on the voltage value detected by the voltage detection unit 302, the timing at which the voltage value becomes zero is detected as the first magnetic pole position, so the first magnetic pole position can be detected more accurately. be able to.

Further, in this embodiment, when the rotor is rotated by an external force, the first magnetic pole position is detected based on the voltage value of the induced voltage detected by the voltage detection unit 302. By using the induced voltage that depends on the rotation of the rotor rather than the varying inverter 20 output voltage, the first pole position can be detected more accurately.

Next, a modified example of this embodiment will be described. This modification is configured to estimate the magnetic flux change amount ΔΦ, which is the state of the motor unit control device 10 .

FIG. 5 is a functional block diagram of main parts of the motor unit control device 10 of the modified example of the present embodiment. The description of the same configuration as that shown in FIG. 1 is omitted.

In FIG. 5, the motor unit control device 10 is different from the configuration explained in FIG.

The subtraction unit 310 calculates the unit A magnetic flux change amount ΔΦ per time is calculated.

In this manner, the magnetic flux change amount ΔΦ per unit time can also be calculated with high accuracy from the permanent magnet temperature Th calculated based on the phase difference θ. Magnetic flux change amount ΔΦ is used, for example, for correcting command torque Te ^* of motor 1 and for other controls of motor 1 . Accuracy of motor control can also be improved by correcting the command torque of the motor 1 using the magnetic flux change amount ΔΦ estimated in this way.

Although the embodiments of the present invention have been described above, the above embodiments merely show a part of application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments. .

In the above embodiment, the voltage sensor 202 detects the induced voltage generated in each phase winding of the stator when the motor 1 is driven by an external force, but the present invention is not limited to this. For example, when the motor 1 is controlled to be energized at 120 degrees, energized periods of 120 degrees and non-energized periods of 60 degrees alternately occur in each of the U, V, and W phases. Therefore, when any one of the phases (for example, the U phase) is in the non-energization period, the voltage sensor 202 detects the induced voltage of the phase as described above, so that the first magnetic pole is detected even during the power running of the motor 1. Position can be detected accurately.

Further, in the above-described embodiment, the counter 303 calculates the time difference t, which is the detection timing between the first magnetic pole position signal and the second magnetic pole position signal, but the present invention is not limited to this. The difference in rotation angle between the first magnetic pole position signal and the second magnetic pole position signal may be calculated, and the time difference t may be calculated based on the difference in rotation angle.

1: Motor, 10: Motor Unit Control Device, 30: Resolver, 120: Torque Corrector, 121: Subtractor, 202: Voltage Sensor, 301: RD Converter (Second Magnetic Pole Position Detector), 302: Voltage Detector (First magnetic pole position detector), 303: counter, 304: rotation speed calculator, 305: phase difference calculator, 306: magnet temperature estimator, 310: subtractor, 311, magnetic flux change calculator

Claims (10)

A state estimation method for a motor unit having a motor including a stator having windings and a rotor having permanent magnets, a resolver detecting the rotation speed of the rotor, and a voltage detecting section detecting the voltage of the windings of the stator. and
detecting a first magnetic pole position indicating the magnetic pole position of the rotor based on the voltage value detected by the voltage detection unit;
detecting a second magnetic pole position indicating the magnetic pole position of the rotor based on the signal detected by the resolver;
calculating a time difference in detection timing between the first magnetic pole position and the second magnetic pole position;
calculating a phase difference in rotation angle between the first magnetic pole position and the second magnetic pole position based on the calculated time difference;
estimating the temperature of the permanent magnet based on the calculated phase difference;
Motor unit state estimation method. A motor unit state estimation method according to claim 1,
a rotation speed of the rotor calculated based on the calculated phase difference and the signal detected by the resolver; estimating the temperature of the permanent magnet based on
Motor unit state estimation method. The motor unit state estimation method according to claim 1 or 2,
calculating the phase difference based on the calculated time difference and the rotation speed of the rotor detected based on the signal detected by the resolver;
Motor unit state estimation method. A motor unit state estimation method according to any one of claims 1 to 3,
Based on the voltage value detected by the voltage detection unit, the timing at which the voltage value becomes zero is detected as the first magnetic pole position.
Motor unit state estimation method. A motor unit state estimation method according to any one of claims 1 to 4,
detecting the first magnetic pole position based on the voltage value of the induced voltage detected by the voltage detection unit when the rotor is rotated by an external force;
Motor unit state estimation method. A motor unit state estimation method according to any one of claims 1 to 4,
When any one phase of the stator is not energized, the first magnetic pole position is detected based on the voltage value of the induced voltage in the phase detected by the voltage detection unit;
Motor unit state estimation method. A motor unit state estimation method according to any one of claims 1 to 6,
correcting the command torque of the motor based on the estimated temperature of the permanent magnet;
Motor unit state estimation method. A motor unit state estimation method according to any one of claims 1 to 6,
estimating a magnetic flux change amount of the permanent magnet per unit time based on the calculated temperature of the permanent magnet;
Motor unit state estimation method. A motor unit state estimation method according to claim 8,
correcting the command torque of the motor based on the estimated amount of change in magnetic flux;
Motor unit state estimation method. A state estimating device for a motor unit, comprising: a motor including a rotor having a stator and permanent magnets; a resolver that detects the rotation speed of the rotor; and a voltage detection unit that detects the voltage of windings of the stator,
a first magnetic pole position detection unit that detects a first magnetic pole position indicating the magnetic pole position of the rotor based on the voltage value detected by the voltage detection unit;
a second magnetic pole position detector that detects a second magnetic pole position indicating the magnetic pole position of the rotor based on the signal detected by the resolver;
a time difference calculator for calculating a time difference in detection timing between the first magnetic pole position and the second magnetic pole position;
a phase difference calculation unit that calculates a phase difference in rotation angle between the first magnetic pole position and the second magnetic pole position based on the calculated time difference;
a magnet temperature estimating unit that estimates the temperature of the permanent magnet of the stator based on the calculated phase difference,
Motor unit state estimator.

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