JP2015211514A - Motor drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To determine a motor lock at the start of motor drive and protect an inverter.SOLUTION: A motor drive device is configured of: an inverter 6 having a plurality of switching elements; temperature sensors 305U, 306V, 307W provided on one of an upper arm 203 side and a lower arm 204 side; and a controller 209. The controller 209 includes: a temperature information detection unit for detecting a temperature of the switching element using the temperature sensor; a motor position information detection unit for detecting position information of a motor 4; a motor stop position adjustment unit for adjusting a stop position of the motor 4 to a predetermined motor stop reference position so that a current supply is started from the switching element on which the temperature sensor is mounted at the start of driving of the motor 4; and a motor lock state determination unit for determining that the motor 4 is in a lock state when a temperature of the switching element exceeds a threshold after the start of motor drive and causing the motor 4 to stop.

Description

  The present invention relates to a motor drive device, and more particularly to a motor drive device for determining a motor lock state at the start of motor drive and protecting an inverter.

In recent years, hybrid vehicles and electric vehicles have attracted attention as vehicles that take into consideration energy saving and the environment. A hybrid vehicle uses a motor as a power source in addition to a conventional engine, and an electric vehicle uses a motor as a power source.
In both hybrid vehicles and electric vehicles, DC power stored in the battery is converted into AC power by an inverter circuit and supplied to a motor to drive the vehicle.
The inverter circuit is composed of IGBT (Insulated Gate Bipolar Transistor) or FET (Field Effect Transistor) switching elements, and converts the DC power into AC power by ON / OFF control of the switching elements.
At this time, when the switching element is turned on and a current flows, the temperature of the switching element rises. For example, when the motor is in a locked state and a current is continuously supplied to the same switching element, the switching element temperature further rises, exceeds the limit, and the switching element may be destroyed. Therefore, it has been proposed to provide a temperature sensor for measuring the switching element temperature, limit the current flowing through the switching element so that the switching element temperature does not exceed the limit, and protect the switching element from being destroyed.

  In order to reliably protect the switching elements according to the above method, it is desirable to provide temperature sensors for all the switching elements and measure the temperatures of all the switching elements. However, providing temperature sensors for all the switching elements increases the cost of the inverter circuit. Therefore, cost reduction is achieved by reducing the number of temperature sensors.

  As an example, in Patent Document 1, a motor control device is provided with a plurality of switching elements, an inverter circuit that converts DC power into AC power and supplies power to the motor, and a temperature sensor that detects the temperature of the switching elements And. The temperature sensor is provided for all the switching elements on the upper arm side among the plurality of switching elements. On the other hand, the temperature of the switching element on the lower arm side where the temperature detection sensor is not provided is estimated using the measured temperature of the switching element on the upper arm side.

JP 2011-182528 A

  In the above-mentioned Patent Document 1, since the temperature sensor is provided only in the switching element on the upper arm side, the number of temperature sensors can be reduced and the cost can be suppressed. However, for the switching element on the lower arm side, the temperature is estimated from the measured temperature of the switching element on the upper arm side. The estimated temperature is less accurate than the actual temperature actually measured by the temperature sensor. For this reason, when a current is limited by setting a threshold for the estimated temperature, the switching element may be destroyed if the threshold is set to a high value close to the limit temperature. In addition, if the threshold is set to a low value away from the limit temperature, the temperature of the switching element immediately exceeds the threshold, and it is easy to enter current limit, so the motor may not be able to generate the required driving force was there. In patent document 1, since the countermeasure when the motor is in a locked state is not particularly considered, when the motor is in a locked state, the motor cannot be driven satisfactorily while protecting the inverter. was there.

  This invention was made to solve such problems, and it is possible to reliably protect the inverter by reliably determining whether or not the motor is in a locked state at the start of motor driving. It aims at obtaining a low-cost motor drive device.

  The present invention relates to an inverter in which switching elements are provided on the upper arm side and the lower arm side corresponding to a plurality of phases of the motor, respectively, and the switching element on either the upper arm side or the lower arm side. A temperature sensor provided for each phase; a temperature information detector that detects temperature information of the switching element using a sensor signal from the temperature sensor; and a motor position information detector that detects position information of the motor; A drive unit that alternately energizes the switching element on the upper arm side and the switching element on the lower arm side for each phase, and energization from the switching element on the side where the temperature sensor is provided at the start of driving of the motor So that the motor stop position is adjusted to a preset motor stop reference position when the motor is stopped. And when the temperature information of the switching element detected by the temperature information detection unit exceeds a preset threshold after the motor driving start and the motor driving start, it is determined that the motor is in a locked state, It is a motor drive device provided with the motor lock state determination part which stops the said motor.

  According to the present invention, a temperature sensor is provided for each phase of the switching element on either the upper arm side or the lower arm side, and energization starts from the switching element on the side where the temperature sensor is provided at the start of driving the motor. As described above, when the motor is stopped, the motor stop position is adjusted to a preset motor stop reference position, and the temperature of the switching element detected by the temperature sensor exceeds a preset threshold value after the motor driving is started. In this case, since the motor is determined to be locked and the motor is stopped, it is possible to reliably determine whether or not the motor is locked at the start of motor driving. And the inverter can be reliably protected.

1 is a schematic configuration diagram of a vehicle according to an embodiment of the present invention. 1 is a typical schematic configuration diagram of a motor drive device according to an embodiment of the present invention. 1 is a schematic configuration diagram of a motor drive device that starts driving when a U-phase current is 0 (A) according to Embodiment 1 of the present invention; It is a time chart showing the current waveform which flows into each phase of the motor drive unit concerning Embodiment 1 of this invention, and the rotation angle of a motor. It is a schematic block diagram of the motor drive device by which the U-phase current which starts Embodiment 2 of this invention is started to drive with the maximum current. It is a time chart showing the current waveform which flows into each phase of the motor drive unit concerning Embodiment 2 of this invention, and the rotation angle of a motor. It is a schematic block diagram of the motor drive device by which each phase current based on Embodiment 3 of this invention is started to drive with the maximum current. It is a time chart showing the current waveform which flows into each phase of the motor drive unit concerning Embodiment 3 of this invention, and the rotation angle of a motor. It is a flowchart of the process at the time of the motor stop before the motor drive start of the motor drive device which concerns on embodiment of this invention. It is a flowchart of the motor drive start pre-processing at the time of the motor drive start which concerns on embodiment of this invention. It is a flowchart of the motor drive mode processing of the motor drive device according to the embodiment of the present invention. It is the block diagram which showed the structure of the control part of the motor drive device which concerns on embodiment of this invention.

  Hereinafter, preferred embodiments of a motor drive device according to the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts will be described with the same reference numerals.

FIG. 1 is a schematic configuration diagram of a vehicle equipped with a motor drive device according to Embodiments 1 to 3 of the present invention. In FIG. 1, a hybrid vehicle including the engine 1 and the motor 4 is described as an example, but this embodiment can also be applied to an electric vehicle. In FIG. 1, a generator 2 is driven by an engine 1, whereby the generator 2 generates power, and the generated power is charged to a battery 7 via an inverter 6.
Then, the motor 4 is driven by supplying the electric power generated by the generator 2 or the electric power stored in the battery 7 to the motor 4. The motor 4 drives the tire 5 to drive the vehicle. In addition, when the electric power stored in the battery 7 is supplied to the motor 4, the DC power stored in the battery 7 is converted into AC power by the inverter 6 and supplied to the motor 4.

Further, when the vehicle is decelerated, the motor 4 is rotated by the tire 5, and the motor 4 performs regenerative power generation, and the generated electric power is charged into the battery 7 via the inverter 6.
The inverter 6 also converts the DC power stored in the battery 7 into AC power, drives the generator 2, and starts the engine 1.

  Further, the vehicle can be driven by transmitting the driving force of the engine 1 to the tire 5 through the motor 4 by coupling the clutch 3.

In Embodiments 1 to 3 to be described later, the series hybrid vehicle as described above will be described as an example, but a parallel hybrid vehicle may be used.
Further, as described above, the generator 2 and the motor 4 may be a motor / generator having both driving and power generation.
Further, although the vehicle has one battery and one inverter, the vehicle is provided with a plurality of batteries having different voltages, and voltage conversion is performed between the generator and the inverter and between the battery and the inverter. It may have a DC / DC converter or the like.

  FIG. 2 is a typical schematic configuration diagram of the motor drive device according to the embodiment of the present invention. As shown in FIG. 2, the motor driving device includes a motor 4, a battery 7, and an inverter 6. The inverter 6 converts the DC power stored in the battery 7 into AC power and controls the driving of the motor 4.

Inverter 6 includes U-phase switching circuit 205, V-phase switching circuit 206, and W-phase switching circuit 207.
The U-phase switching circuit 205 includes an upper arm side switching element 205H provided on the upper arm 203 side (high voltage side) and a lower arm side switching element 205L provided on the lower arm 204 side (low voltage side). Is done. The upper arm side switching element 205H and the lower arm side switching element 205L are connected in series with each other. In addition, one free-wheeling diode is connected in antiparallel to each of the upper arm side switching element 205H and the lower arm side switching element 205L.
The V-phase switching circuit 206 includes an upper arm side switching element 206H provided on the upper arm 203 side and a lower arm side switching element 206L provided on the lower arm 204 side. The upper arm side switching element 206H and the lower arm side switching element 206L are connected in series with each other. Further, each of the upper arm side switching element 206H and the lower arm side switching element 206L is connected in reverse parallel with one free-wheeling diode.
The W-phase switching circuit 207 includes an upper arm side switching element 207H provided on the upper arm 203 side and a lower arm side switching element 207L provided on the lower arm 204 side. The upper arm side switching element 207H and the lower arm side switching element 207L are connected in series with each other. In addition, one free-wheeling diode is connected in antiparallel to each of the upper arm side switching element 207H and the lower arm side switching element 207L.
As each of the switching elements 205H to 207H and 205L to 207L of the switching circuits 205 to 207, for example, an IGBT (Insulated Gate Bipolar Transistor) and an FET (Field Effect Transistor) can be used.

  Further, in the inverter 6, temperature sensors 205U, 206V, and 207W for measuring the temperatures of the switching elements 205H to 207H of the switching circuits 205 to 207 (hereinafter referred to as switching element temperatures) are provided on the upper arm 203 side. ing. Hereinafter, the switching elements 205H to 207H provided with the temperature sensors 205U, 206V, and 207W are referred to as “switching elements provided with the temperature sensor”.

  Control unit 209 is provided for U-phase switching circuit 205, V-phase switching circuit 206, and W-phase switching circuit 207. The control unit 209 controls driving of the switching elements 205H to 207H and 205L to 207L. Further, the control unit 209 acquires the switching element temperature (temperature information) of the switching element provided with the temperature sensor based on the sensor signals from the temperature sensors 205U, 206V, and 207W. The control unit 209 compares the switching element temperature with a threshold value, and when the switching element temperature exceeds the threshold value, stops the motor 4 or limits the current flowing through the switching elements 205H to 207H and 205L to 207L. Thus, the switching elements 205H to 207H and 205L to 207L are protected from being destroyed by heat.

  In FIG. 2, the control unit 209 is disposed inside the inverter 6, but may be disposed outside the inverter 6.

The configuration of the control unit 209 is shown in FIG.
As shown in FIG. 12, the control unit 209 includes a temperature information detection unit 2091, a motor position information detection unit 2092, a drive unit 2093, a motor stop position adjustment unit 2094, a motor lock state determination unit 2095, and a storage unit. 2096.
The temperature information detection unit 2091 detects temperature information of the switching elements 205H to 207H using sensor signals from the temperature sensors 205U, 206V, and 207W.
The motor position information detection unit 2092 detects the position information of the motor 4 using, for example, a resolver.
The drive unit 2093 alternately energizes the switching element on the upper arm side and the switching element on the lower arm side for each of the U, V, and W phases. For example, as shown in FIG. 4, the current flowing in the U phase, the V phase, and the W phase is a sine wave that is shifted by 120 degrees in electrical angle. In the example of FIG. 4, in each phase, the switching element on the upper arm side is energized in a region where the current value is larger than 0 (A), and in the region where the current value is smaller than 0 (A), The switching element is energized. When the current value is 0 (A), no current flows through any of the switching elements on the upper arm side and the lower arm side.
The motor stop position adjusting unit 2094 adjusts the stop position of the motor 4 when the motor 4 stops so that the motor 4 stops at a preset motor stop reference position. Thus, when the motor 4 starts to be driven next, energization is started from the switching elements 205H, 206H, and 207H provided with the temperature sensors 205U, 206V, and 207W.
The motor lock state determination unit 2095 stops the motor 4 when the temperature information of the switching elements 205H, 206H, and 207H detected by the temperature information detection unit 2091 exceeds a preset threshold after driving of the motor 4 is started. If the motor 4 is stopped, it is determined that the motor 4 is in the locked state, and the motor 4 is stopped. On the other hand, when the motor 4 is not stopped, the current flowing through the switching element is limited in order to prevent the switching element from being destroyed by heat. Examples of the temperature information include, for example, the temperature rise ΔTMx from the start of driving the motor 4 to the present, or the current detected temperature TMx of the switching element.
The storage unit 2096 stores various data used by the control unit 209.

  Hereinafter, specific embodiments of the present invention will be described. In the following, differences from FIG. 2 will be mainly described, and description of the same configuration and operation as in FIG. 2 will be omitted. The configuration and operation of the control unit 209 are basically the same as those in FIG. 12, but in the following first to third embodiments, the reference numerals of the temperature sensors are different from those in FIG. 2. It shall be read as the sensor code.

Embodiment 1 FIG.
FIG. 3 is a diagram showing the configuration of the motor drive device according to Embodiment 1 of the present invention. FIG. 4 is a timing chart showing values of currents flowing in the U phase, the V phase, and the W phase in the present embodiment. In the present embodiment, an embodiment in which the U-phase current is 0 (A) and driving of the motor 4 is started will be described. Details will be described below.

  The difference between FIG. 3 and FIG. 2 is the installation position of the temperature sensor. In FIG. 2, all of the temperature sensors 205U, 206V, and 207W are disposed on the upper arm 203 side. On the other hand, in FIG. 3, a temperature sensor 306V is provided on the upper arm 203 side, and temperature sensors 305U and 307W are provided on the lower arm 204 side. Thus, in the present embodiment, the temperature sensor of one phase is arranged on the arm side different from the temperature sensors of the other phases. That is, in this embodiment, as shown in FIG. 3, temperature sensor 306V is provided for V-phase upper arm side switching element 206H, and temperature sensor 305U is provided for U-phase lower arm side switching element 205L. A temperature sensor 307W is provided for the W-phase lower arm switching element 207L. The control unit 209 detects temperature information of the switching elements 205L, 206H, and 207L based on sensor signals from the temperature sensors 305U, 306V, and 307W, and the temperature information is a threshold value (a second threshold value and a second threshold value described later). 3), the motor 4 is stopped or the current flowing through the switching elements 205H to 207H and 205L to 207L is limited. This can prevent the switching elements 205H to 207H and 205L to 207L from being destroyed by heat.

4A to 4C are time charts showing the relationship between the current waveform flowing in each phase and the motor rotation angle (motor position) of each phase. 4A to 4C, the vertical axis represents the current value, and the horizontal axis represents the rotation angle of the motor.
The time chart in FIG. 4A shows the current flowing through the U-phase switching elements 205H and 205L.
The time chart in FIG. 4B shows the current flowing through the V-phase switching elements 206H and 206L. The current shown in FIG. 4B is delayed by 120 degrees in electrical angle from the current shown in FIG.
The time chart in FIG. 4C shows the current flowing through the W-phase switching elements 207H and 207L. The current shown in FIG. 4C is delayed by 120 degrees in electrical angle from the current shown in FIG.
That is, the currents flowing in the U phase, the V phase, and the W phase are sine waves that are shifted by 120 degrees in electrical angle, as shown in FIGS.

  In the time chart of each phase shown in FIGS. 4A to 4C, in the region where the current value is plus (+), a current flows through the switching elements 205H to 207H on the upper arm 203 side, and the current value is minus ( In the region −), a current flows through the switching elements 205L to 207L on the lower arm 204 side. In this way, ON / OFF of the switching elements 205H to 207H and 205L to 207L is controlled, and the motor 4 is driven by controlling the inverter 6.

4A to 4C, a straight line indicated by a dotted line indicates a desired motor stop reference position set in advance. When the motor 4 is stopped, the position of the motor 4 is adjusted by the motor stop position adjusting unit 2094 of the control unit 209 and stopped at the motor stop reference position. Therefore, the motor position when the motor 4 starts to drive next is the motor stop reference position.
4A to 4C, the circles indicated by dotted lines indicate the values of current flowing through the switching elements of the respective phases at the motor stop reference position. That is, when the motor 4 stopped at the motor stop reference position starts driving next, a current having a current value indicated by the circle flows through the switching element of each phase.
In the example of FIG. 4, the motor 4 starts to be driven at the motor position where the current value flowing through the U-phase switching elements 205H and 205L is 0 (A). That is, in this embodiment, the motor position at which the U-phase current is 0 (A) is set as the motor stop reference position.

4A to 4C, shaded areas in the time charts of the respective phases indicate ranges of current values that can be measured by the temperature sensors 305U, 306V, and 307W disposed in the respective phases.
As shown in FIG. 4A, in the U phase, after the motor driving is started, current flows in a region on the minus side from 0 (A) indicated by a dotted circle, so that the switching element of the switching element 205L on the lower arm 204 side The temperature should be measured. Therefore, as shown in FIG. 3, a U-phase temperature sensor 305U is arranged on the lower arm 204 side.
Similarly, as shown in FIG. 4B, in the V phase, since a current flows in a positive region after the start of motor driving, as shown in FIG. 306V is arranged.
Similarly, as shown in FIG. 4 (c), in the W phase, current flows in the minus side region after the start of motor driving. Therefore, as shown in FIG. 307W is arranged.

In the present embodiment shown in FIGS. 3 and 4, assuming that the motor is locked at the start of motor driving, the current value of the U phase at that time is 0 (A), so U phase switching elements 205H and 205L Temperature does not rise. On the other hand, in the V phase, a current having the same value as the current value indicated by the dotted circle is continuously supplied to the upper arm side. Similarly, in the W phase, a current having the same current value as that indicated by the dotted circle is continuously energized on the lower arm side. Therefore, the switching element temperatures of V-phase switching element 206H and W-phase switching element 207L increase, and the switching element temperatures of V-phase switching element 206L and W-phase switching element 207H do not increase.
At this time, unlike the prior art, in the present embodiment, as shown in FIG. 4, the motor stop reference position is set and the motor drive is started at that position, and the current flowing region at the start of the motor drive is The temperature sensor is arranged on the arm side that is different for each phase depending on the plus side or minus side, so the switching element temperature can be grasped reliably and accurately, and the motor is switched by stopping the motor or limiting the drive current before the threshold is exceeded. The element can be protected.
In the present embodiment, control is performed using only the temperature of the switching element on the side where the temperature sensor is provided, so that accuracy can be improved. Further, in the present embodiment, it is not necessary to estimate the temperature of the switching element on the side where the temperature sensor is not provided, and a complicated setting operation for the threshold is not required.

  In the example of FIG. 4, since the current flowing through the U-phase switching elements 205H and 205L when the motor is locked at the start of motor driving is 0 (A), the temperature of these switching elements does not increase. The temperature sensor 305U is not necessarily provided. However, it can be assumed that the motor 4 is in a locked state after the motor 4 has rotated a little, for example, after the motor 4 has rotated by an electrical angle of 30 degrees. In this case, a negative current flows in the U phase in the motor locked state, and the temperature of the U phase switching element 205L on the lower arm 204 side rises. Therefore, the U phase temperature sensor 305U is disposed on the lower arm 204 side. Better to do. Therefore, in FIG. 3, the U-phase temperature sensor 305U is arranged on the lower arm 204 side.

  In the first embodiment, the motor position at which the U-phase current value is 0 (A) is the motor stop reference position. However, the present invention is not limited to this, and the V-phase or W-phase current value is 0 (A). It is good also considering the motor position used as a motor stop reference position.

As described above, the inverter 6 provided with the switching elements 205H to 207H and 205L to 207L on the upper arm 203 side and the lower arm 204 side in correspondence with the plurality of phases (U, V, W) of the motor 4, Temperature sensors 305U, 306V, 307W provided for each phase (U, V, W) with respect to any one of the switching elements 205L, 206H, 207L on the upper arm 203 side and the lower arm 204 side, and temperature sensors 305U, A temperature information detector 2091 that detects temperature information of the switching elements 205L, 206H, and 207L using sensor signals from 306V and 307W, a motor position information detector 2092 that detects position information of the motor 4, and a phase (U, V, W) for each switching element 205H to 207H on the upper arm 203 side and on the lower arm 204 side. A motor 2093 that alternately energizes the switching elements 205L to 207L and a motor so that energization can be started from the switching elements 205L, 206H, and 207L on the side where the temperature sensors 305U, 306V, and 307W are provided when the motor 4 starts to be driven. The motor stop position adjustment unit 2094 that adjusts the position of the motor 4 to a preset motor stop reference position when the motor 4 stops, and the temperature information of the switching element detected by the temperature information detection unit 2091 after the start of motor driving are preset. The motor drive device includes a motor lock state determination unit 2095 that determines that the motor 4 is in a locked state and stops the motor 4 when the threshold value is exceeded.
According to the present embodiment, with the above configuration, the temperature sensor is provided in only one of the upper arm 203 or the lower arm 204 for each phase (U, V, W), thereby reducing the motor driving device. Cost reduction and size reduction can be achieved.
Furthermore, only one of the upper arm 203 and the lower arm 204 is provided for each phase (U, V, W) so that energization can be started from the switching element on the side where the temperature sensor is provided when the motor is started. Since the motor drive is started after the position is adjusted in advance when the motor is stopped before the motor drive is started, the temperature can be measured with a temperature sensor without estimating the switching element temperature. The inverter can be protected by determining the motor lock state.

Further, in the present embodiment, the motor stop reference position is the position of the motor 4 where the current flowing through the switching element of any one phase is 0 (A).
In this embodiment, when the current of any one phase (U phase) becomes 0 (A) at the start of motor driving, other phases (V phase, W phase) other than that phase (U phase) The temperature sensors 306V and 307W are arranged on different arms so that the temperature of the switching elements 206H and 207L can be measured, and the motor is positioned at the motor stop reference position where the current of the phase (U phase) becomes 0 (A). After the stop position of 4 is adjusted, the temperature of the motor 4 is increased by starting the driving of the motor 4, that is, the switching element temperature of the other phase (V phase, W phase) other than the phase (U phase). Since the determination of the motor lock state at the start of motor driving can be performed only by this, the determination process can be simplified and the accuracy can be improved. Further, by determining the motor stop reference position, that is, the motor drive start position, it is possible to save labor and improve accuracy in setting a threshold value for performing current limiting.

Further, in the present embodiment, when the motor position information detection unit 2092 detects that the current position of the motor 4 is deviated from the motor stop reference position before the motor 4 starts driving or immediately after the motor 4 starts driving. In addition, the motor stop position adjusting unit 2094 readjusts the position of the motor 4 to the motor stop reference position.
Accordingly, even when the motor 4 is stopped when the motor 4 is started or immediately after the motor driving is started and the position of the motor 4 is deviated from the motor stop reference position, the driving of the motor 4 is started after readjustment. Therefore, it is possible to accurately and accurately determine the motor lock state at the start of driving of the motor 4.

Embodiment 2. FIG.
FIG. 5 is a diagram showing a configuration of a vehicle motor drive device according to Embodiment 2 of the present invention. FIG. 6 is a timing chart showing current values flowing in the U phase, the V phase, and the W phase in the present embodiment. In the present embodiment, an embodiment will be described in which driving of the U-phase upper arm side switching element 205H is started at the maximum current. Details will be described below.

  The difference between FIG. 5 and FIG. 2 is the installation position of the temperature sensor. In FIG. 2, all of the temperature sensors 205U, 206V, and 207W are disposed on the upper arm 203 side. On the other hand, in FIG. 5, a temperature sensor 505U is provided on the upper arm 203 side, and temperature sensors 506V and 507W are provided on the lower arm 204 side. Thus, in the present embodiment, the temperature sensor of one phase is arranged on the arm side different from the temperature sensors of the other phases. That is, in the present embodiment, as shown in FIG. 5, temperature sensor 505U is provided for U-phase upper arm side switching element 205H, and temperature sensor 506V is provided for V-phase lower arm side switching element 206L. A temperature sensor 507W is provided for the W-phase lower arm switching element 207L. The control unit 209 detects the switching element temperatures of the switching elements 205H, 206L, and 207L based on the sensor signals from the temperature sensors 505U, 506V, and 507W, and the switching element temperature is equal to or higher than a threshold (a third threshold described later). In such a case, the motor 4 is stopped or the current flowing through the switching elements 205H to 207H and 205L to 207L is limited. This can prevent the switching elements 205H to 207H and 205L to 207L from being destroyed by heat.

6A to 6C are time charts showing the relationship between the current waveform flowing in each phase and the motor rotation angle (motor position) of each phase. 6A to 6C, the vertical axis represents the current value, and the horizontal axis represents the rotation angle of the motor.
The time chart of FIG. 6A shows the current flowing through the U-phase switching elements 205H and 205L.
The time chart in FIG. 6B shows the current flowing through the V-phase switching elements 206H and 206L. The current shown in FIG. 4B is delayed by 120 degrees in electrical angle from the current shown in FIG.
The time chart in FIG. 6C shows the current flowing through the W-phase switching elements 207H and 207L. The current shown in FIG. 6C is delayed by 120 degrees in electrical angle from the current shown in FIG.
That is, the currents flowing in the U phase, the V phase, and the W phase are sine waves that are shifted by 120 degrees in electrical angle, as shown in FIGS.

  In the time chart of each phase shown in FIGS. 6A to 6C, in the region where the current value is plus (+), the current flows through the switching element on the upper arm side, and the region where the current value is minus (−). Then, a current flows through the switching element on the lower arm side. Thus, the motor 4 is driven by controlling the inverter 6.

6A to 6C, a straight line indicated by a dotted line indicates a desired motor stop reference position set in advance. When the motor 4 is stopped, the position of the motor 4 is adjusted by the motor stop position adjusting unit 2094 of the control unit 209 and stopped at the motor stop reference position. Therefore, the motor position when the motor 4 starts to drive next is the motor stop reference position.
6A to 6C, the circles indicated by dotted lines indicate the values of current flowing through the switching elements of the respective phases at the motor stop reference position. That is, when the motor 4 stopped at the motor stop reference position starts driving next, a current having a current value indicated by the circle flows through the switching element of each phase.
In the example of FIG. 6, the motor 4 is started to be driven at the motor position where the current value flowing through the U-phase switching element 205H becomes the maximum current. That is, in the present embodiment, the motor position at which the current flowing through U-phase switching element 205H is the maximum current is set as the motor stop reference position.

6A to 6C, shaded areas in the time charts of the phases indicate ranges of current values that can be measured by the temperature sensors 305U, 306V, and 307W arranged in the phases.
As shown in FIG. 6 (a), in the U phase, after starting motor driving, current flows in a region on the plus side from the maximum current indicated by the dotted circle, so the switching element temperature of the switching element 205H on the upper arm 203 side is Should be measured. Therefore, as shown in FIG. 5, a U-phase temperature sensor 505U is disposed on the upper arm 203 side.
Similarly, as shown in FIG. 6 (b), in the V phase, a current flows in the minus side region after the start of motor driving. Therefore, as shown in FIG. 506V is arranged.
Similarly, as shown in FIG. 6 (c), in the W phase, current flows in the minus side region after the start of motor driving. Therefore, as shown in FIG. 507W is arranged.

In the present embodiment shown in FIGS. 5 and 6, assuming that the motor is locked at the start of motor driving, the current value of the U phase is the maximum current, so the switching element 205H of the U phase has the highest temperature rise. Is likely to exceed the threshold. On the other hand, in the V phase, a current having the same value as the current value indicated by the dotted circle is continuously energized on the lower arm side. Similarly, in the W phase, a current having the same current value as that indicated by the dotted circle is continuously energized on the lower arm side. Therefore, the switching element temperatures of the V-phase switching element 206L and the W-phase switching element 207L increase, and the switching element temperatures of the U-phase switching element 205L, the V-phase switching element 206H, and the W-phase switching element 207H do not increase.
At this time, unlike the prior art, in the present embodiment, as shown in FIG. 6, the motor stop reference position is set and the motor driving is started at that position, and the current flowing region at the start of the motor driving is The temperature sensor is arranged on the arm side that is different for each phase depending on the plus side or minus side, so the switching element temperature can be grasped reliably and accurately, and the motor is switched by stopping the motor or limiting the drive current before the threshold is exceeded. The element can be protected.
In the present embodiment, control is performed using only the temperature of the switching element on the side where the temperature sensor is provided, so that accuracy can be improved. Further, in the present embodiment, it is not necessary to estimate the temperature of the switching element on the side where the temperature sensor is not provided, and a complicated setting operation for the threshold is not required.

  In the example of FIG. 6, the current flowing through the switching elements 206L and 207L of the V-phase and W-phase when the motor is locked at the start of motor driving is the same, and the temperature rises similarly, but the motor 4 slightly rotates. Therefore, when the motor 4 is locked, the V-phase current decreases and the W-phase current increases.

  In the second embodiment, the motor position at which the U-phase current value is the maximum current is set as the motor stop reference position. However, the present invention is not limited to this, and the motor position at which the V-phase or W-phase current value is the maximum current is used. May be used as the motor stop reference position.

  As described above, also in the present embodiment, the same effect as in the first embodiment can be obtained.

In the present embodiment, the motor stop reference position is the position of the motor 4 at which the current flowing through the switching element of any one phase becomes the maximum current.
In the present embodiment, when the current of any one phase (U phase) becomes the maximum current at the start of motor driving, the temperature is set to a different arm so that the temperature of all switching elements through which the current flows can be measured. After arranging the sensors 505U, 506V, and 507W, after adjusting the position of the motor 4 to the motor stop reference position where the current of any one phase (U phase) becomes the maximum current at the start of motor driving, the motor driving By starting, it is possible to determine the motor lock state at the start of motor drive only with the switching element temperature of the phase (U phase) that is most likely to rise at the start of motor drive. It can be improved. Further, by determining the motor stop reference position, that is, the motor drive start position, it is possible to save labor and improve accuracy in setting a threshold value for current limitation.

Embodiment 3 FIG.
FIG. 7 is a diagram showing a configuration of a vehicle motor drive device according to Embodiment 3 of the present invention. FIG. 8 is a timing chart showing current values flowing in the U phase, the V phase, and the W phase in the present embodiment. In the present embodiment, an embodiment in which driving of the switching element of the upper arm of any one phase is started with the maximum current will be described. Details will be described below.

  The installation position of the temperature sensor of FIG. 7 and FIG. 2 is the same. In FIG. 2, the temperature sensors 205U, 206V, and 207W are all disposed on the upper arm 203 side. Similarly, in FIG. 7, the temperature sensors 705U, 706V, and 707W are all disposed on the upper arm 203 side. Is arranged. Thus, in the present embodiment, the U-phase, V-phase, and W-phase temperature sensors are all arranged on the same arm side. That is, in the present embodiment, as shown in FIG. 7, temperature sensor 705U is provided for U-phase upper arm side switching element 205H, and temperature sensor 706V is provided for V-phase upper arm side switching element 206H. The temperature sensor 707W is provided for the W-phase upper arm side switching element 207H. The control unit 209 detects the switching element temperatures of the switching elements 205H, 206H, and 207H based on the sensor signals from the temperature sensors 705U, 706V, and 707W, and the switching element temperature is equal to or higher than a threshold (a third threshold described later). In such a case, the motor 4 is stopped or the current flowing through the switching elements 205H to 207H and 205L to 207L is limited. This can prevent the switching elements 205H to 207H and 205L to 207L from being destroyed by heat.

8A to 8C are time charts showing the relationship between the current waveform flowing in each phase and the motor rotation angle (motor position) of each phase. 8A to 8C, the vertical axis represents the current value, and the horizontal axis represents the rotation angle of the motor.
The time chart of FIG. 8A shows the current flowing through the U-phase switching elements 205H and 205L.
The time chart in FIG. 8B shows the current flowing through the V-phase switching elements 206H and 206L. The current shown in FIG. 8B is delayed by 120 degrees in electrical angle from the current shown in FIG.
The time chart in FIG. 8C shows the current flowing through the W-phase switching elements 207H and 207L. The current shown in FIG. 8C is delayed by 120 degrees in electrical angle from the current shown in FIG.
That is, the currents flowing in the U phase, the V phase, and the W phase are sine waves that are shifted by 120 degrees in electrical angle, as shown in FIGS.

  In the time charts of the respective phases shown in FIGS. 8A to 8C, in the region where the current value is plus (+), the current flows through the switching element on the upper arm side, and the region where the current value is minus (−). Then, a current flows through the switching element on the lower arm side. Thus, the motor 4 is driven by controlling the inverter 6.

In FIGS. 8A to 8C, straight lines t1 to t3 indicated by dotted lines indicate preset desired motor stop reference positions. In the present embodiment, the motor stop reference position is set to one of t1 to t3. When the motor 4 is stopped, the position of the motor 4 is adjusted by the motor stop position adjusting unit 2094 of the control unit 209 and stopped at the motor stop reference position. Therefore, the motor position when the motor 4 starts to drive next is the motor stop reference position.
8A to 8C, the circles indicated by dotted lines indicate the values of currents flowing through the U-phase, V-phase, and W-phase switching elements at the motor stop reference positions t1 to t3. That is, for example, when t1 is set as the motor stop reference position and the motor 4 stopped there starts driving next, in the U phase, the current is increased in the region on the plus side from the maximum current at the position of the dotted circle. Flows. Further, for example, when t2 is set as the motor stop reference position, and the motor 4 stopped there starts driving next, in the V phase, the current is increased in the region on the plus side from the maximum current at the position of the dotted circle. Flows. For example, when t3 is set as the motor stop reference position and the motor 4 stopped there starts driving next, in the W phase, a current flows in a region on the plus side from the maximum current at the position of the dotted circle. .
As described above, in the example of FIG. 8, the motor 4 starts driving at the motor position where the current value flowing through the switching elements 205H, 206H, and 207H of any one of the U phase, V phase, and W phase becomes the maximum current. Is done. That is, in the present embodiment, the motor position at which the current value of any one of the U phase, the V phase, and the W phase becomes the maximum current is set as the motor stop reference position.

8A to 8C, the shaded areas of the time charts of the phases indicate the current value ranges that can be measured by the temperature sensors 305U, 306V, and 307W arranged in the phases.
As shown in FIG. 8 (a), for example, when t1 is set as the motor stop reference position, in the U phase, the current flows in the positive region from the maximum current indicated by the dotted circle after starting the motor drive. The switching element temperature of the switching element 205H on the 203 side should be measured. Therefore, as shown in FIG. 7, a U-phase temperature sensor 705U is arranged on the upper arm 203 side.
Similarly, for example, when t2 is set as the motor stop reference position, as shown in FIG. 8B, in the V phase, a current flows in a positive region after the motor driving is started. A V-phase temperature sensor 706V is arranged on the upper arm 203 side.
Similarly, when t3 is set as the motor stop reference position, for example, as shown in FIG. 8C, in the W phase, current flows in a positive region after the start of motor driving. A W-phase temperature sensor 707W is disposed on the upper arm 203 side.

In the present embodiment shown in FIGS. 7 and 8, for example, when t1 is set to the motor stop reference position and the motor 4 is locked at the start of motor driving, the U-phase current value is the maximum current. In addition, the switching element 205H has the largest temperature rise and is likely to exceed the threshold. Both the V phase and the W phase are continuously energized at the same current value on the lower arm side, the temperatures of the V phase switching element 206L and the W phase switching element 207L rise, respectively, and the U phase switching element 205L, the V phase switching element 206H, and W The temperature of the phase switching element 207H does not rise. Similarly, when t2 or t3 is set as the motor stop reference position, similarly, the maximum current flows in one phase, the temperature of the switching element in that phase increases greatly, and the possibility of exceeding the threshold is high.
At this time, unlike the prior art, in this embodiment, as shown in FIG. 8, after determining the phase through which the maximum current flows when starting motor driving, the motor position through which the maximum current flows is determined as the motor stop reference position. And the switching element temperature can be protected by stopping the motor or limiting the drive current before the threshold value is exceeded.
In the present embodiment, control is performed using only the temperature of the switching element on the side where the temperature sensor is provided, so that accuracy can be improved. Further, in the present embodiment, it is not necessary to estimate the temperature of the switching element on the side where the temperature sensor is not provided, and a complicated setting operation for the threshold is not required.

  In the third embodiment, the switching element having the maximum current that flows at the start of motor driving is the upper arm 203 side, but may be the lower arm 204 side.

  As described above, also in the present embodiment, the same effects as in the first and second embodiments can be obtained.

In the present embodiment, the motor stop reference position is the position of the motor 4 at which the current flowing through the switching element of any one phase becomes the maximum current.
In the present embodiment, when the current of any one phase (U phase, V phase, W phase) becomes the maximum current at the start of motor driving, the temperature of all switching elements through which the current flows can be measured. In this way, the temperature sensor 705U, 706V, and 707W are arranged on different arms, and the motor stop reference position at which the current of any one phase (U phase, V phase, W phase) becomes the maximum current at the start of motor driving. After adjusting the position of the motor 4 at (t1, t2, t3), switching the phases (U-phase, V-phase, W-phase) where the temperature is most likely to rise at the start of motor driving by starting motor driving Since the motor lock state at the start of motor driving can be determined only by the element temperature, the determination process can be simplified and the accuracy can be improved. Further, by determining the motor stop reference position, that is, the motor drive start position, it is possible to save labor and improve accuracy in setting a threshold value for current limitation.

Embodiment 4 FIG.
In the present embodiment, the operation of control unit 209 of the vehicle motor drive device according to the first to third embodiments of the present invention will be described with reference to FIGS. 9 to 11.

  FIG. 9 is a flowchart showing a process when the motor is stopped before the motor driving is started. Here, the processing of the motor stop position adjusting unit 2094 will be described. The motor stop position adjustment unit 2094 adjusts the position of the motor 4 when the motor is stopped so that energization can be started from the switching element on the side where the temperature sensor is provided when the motor 4 starts to be driven. In the present embodiment, the processing of FIG. 9 assumes a subroutine called from a task executed at a fixed period.

  First, in step S9001, the motor stop position adjustment unit 2094 determines whether the motor 4 is rotating. If the motor 4 is rotating, the process proceeds to step S9002. On the other hand, if the motor 4 has already stopped, the process is terminated.

  In step S9002, it is determined whether a motor stop instruction has been issued. If a motor stop instruction has been issued, the process proceeds to step S9003. On the other hand, if the motor stop instruction has not been issued, the process is terminated.

In step S9003, it is determined whether the motor rotation speed is smaller than a preset first threshold value. If the condition is met, the process proceeds to step S9004. On the other hand, if the condition is not satisfied, the process proceeds to step S9101.
Note that the first threshold value is determined from an experience value, an experiment, a simulation, and the like, for the motor rotation speed that can be reliably stopped by a motor stop process in step S9005 described later.

Next, in step S9004, it is determined whether the current motor position is equal to the motor stop reference position. If the condition is met, the process proceeds to step S9005. On the other hand, if the condition is not satisfied, the process proceeds to step S9101.
The determination of whether the current motor position is equal to the motor stop reference position is, for example, whether the electrical angle of the phase to be adjusted of the motor 4 is equal to the value of the electrical angle corresponding to the motor stop reference position, or a plurality of phases This is done by determining whether the combination of current values matches the current value corresponding to the motor stop reference position.

  In step S9005, the motor 4 is stopped at the current motor position. For example, the motor 4 is stopped by short-circuit braking due to a three-phase short circuit of the motor 4. After the motor is stopped, the process proceeds to step S9006.

  In step S9006, the “motor drive transition state” indicating the operation mode of the motor 4 is set to the motor stop mode, and the process ends.

In step S9101, the motor speed reduction process is performed, and the process ends.
The motor rotation speed is decreased by, for example, decreasing the motor torque while performing rotation feedback so that the motor rotation speed decreases with a preset inclination so that there is no shock or uncomfortable feeling before the motor stops.

  FIG. 10 is a flowchart showing processing in the motor stop mode in the vehicle motor drive device according to the first to third embodiments of the present invention. The process of FIG. 10 is a process performed after the motor 4 stops and before the motor 4 starts driving again. When the motor position information detection unit 2092 detects that the current position of the motor 4 is deviated from the motor stop reference position before the motor 4 starts driving, the control unit 209 causes the motor stop position adjustment unit 2094 to Readjust position 4 to the motor stop reference position. In the present embodiment, the processing in FIG. 10 is assumed as a subroutine called from a task executed at a fixed period.

  In step S10001, the control unit 209 determines whether the motor drive transition state is the motor stop mode. If the condition is met, the process proceeds to step S10002. On the other hand, if the condition is not satisfied, the process is terminated.

  In step S10002, the control unit 209 confirms whether the driver has issued a motor drive start instruction. If the condition is met, the process proceeds to step S10003. On the other hand, if the condition is not satisfied, the motor drive start pre-processing in FIG. 10 is terminated.

In step S10003, the control unit 209 detects the switching element temperature by the temperature information detection unit 2091, stores the switching element temperature in the storage unit 2096, and proceeds to step S10004.
The switching element temperature here is the current switching element temperature measured by the temperature sensors 205U, 206V, and 207W of the respective phases of the inverter 6, and is used in the motor lock determination in step S11009 of FIG.

In step S10004, the control unit 209 causes the motor stop position adjustment unit 2094 to perform motor drive position alignment processing before starting motor driving, and proceeds to step S10005.
In step S10004, the control unit 209 confirms whether or not the motor 4 is stopped at the motor stop reference position by the motor position information detection unit 2092 before starting motor driving. Even if the motor 4 is stopped according to the motor stop reference position by the processing of FIG. 9, for example, when the tire 5 is slightly rotated due to a step on the road surface after the motor 4 is stopped, the stop position of the motor 4 is shifted. Can be assumed. Therefore, in step S10004, when the motor 4 is deviated from the motor stop reference position, the control unit 209 uses the motor stop position adjustment unit 2094 to readjust the position of the motor 4 to the motor stop reference position. At the time of the readjustment, the motor 4 is driven within a preset time within a current value range smaller than the motor drive current at which the switching element temperature exceeds the limit and is not destroyed. The reason for limiting the current value and time is because, for example, a case where the motor lock has occurred after the motor 4 has deviated from the motor stop reference position can be considered. Alternatively, when the tire 5 is rotated a little but does not reach the motor drive torque that can overcome the step and stops in a state where the torque is balanced, the rotation of the tire 5 can be returned by reducing the motor drive torque. . In this manner, the motor stop position adjusting unit 2094 readjusts the position of the motor 4 to the motor stop reference position. Note that this preset time is a time that does not feel a sway at the start of motor driving, and is determined from experience values, experiments, simulations, and the like.

  When the current position of the motor 4 is deviated from the motor stop reference position, any or all of the switching element temperatures may not be measured depending on the stop position. However, even when the motor 4 is locked in a state where the deviation from the motor stop reference position has occurred, the switching element is not destroyed during the process of aligning the motor 4 by performing as described above. Even after the elapsed time has elapsed, it is possible to determine that the motor is locked in a state where the deviation from the motor stop reference position has occurred because the switching element temperature does not change. Here, the process when the motor lock is determined is not shown in FIG. 10, but the process of FIG. 10 is terminated in step S10004.

  In step S10005, the motor drive transition state is set to the motor drive mode, and the process ends.

  FIG. 11 is a flowchart showing processing in a motor drive mode at the start of motor drive in the vehicle motor drive device according to the embodiment of the present invention. In the present embodiment, it is assumed that the process of FIG. 11 is a subroutine called from a task that is executed at regular intervals.

  In step S11001, the control unit 209 determines whether the motor drive transition state is the motor drive mode. If the condition is met, the process proceeds to step S11002. On the other hand, if the condition is not satisfied, the process of FIG. 11 is terminated.

  In step S11002, the control unit 209 drives the motor according to the driver's request, and proceeds to step S11003. Further, when motor drive restriction described later is performed, motor drive is performed based on the restricted torque or drive current.

  In step S11003, the control unit 209 detects the current position of the motor 4 by the motor position information detection unit 2092, and determines whether or not the current position is the motor stop reference position. As a result of the determination, if the current position of the motor 4 is not equal to the motor stop reference position adjusted in the motor stop process in step S9005 of FIG. 9 or the motor drive alignment before starting the motor drive in step S10004 of FIG. The process proceeds to step S11004. On the other hand, if the condition is not satisfied, the process proceeds to step S11005.

In step S11004, the control unit 209 uses the motor stop position adjustment unit 2094 to perform motor drive position alignment processing before starting motor drive, and proceeds to step S11005.
The motor drive alignment process here is equivalent to step S10004 in FIG. 10, and the position of the motor 4 is adjusted to the motor stop reference position at which the switching element temperature for determining that the motor is locked can be measured. To do.

In step S11005, the control unit 209 increases the switching of the switching element provided with the temperature sensors 305U, 306V, 307W, 505U, 506V, 507W, or 705U, 706V, 707W by the temperature information detection unit 2091. The temperature ΔTMx is obtained, and the process proceeds to step S11006.
A method for obtaining the switching increase temperature ΔTMx will be described. First, the temperature information detection unit 2091 detects the current temperature TMx of the switching element provided with the temperature sensor. Next, the switching element temperature before starting motor driving stored in the storage unit 2096 in step S10003 is read. Next, the switching increase temperature ΔTMx is obtained by subtracting the switching element temperature before starting motor driving from the current switching element temperature TMx.

In step S11006, the control unit 209 determines whether the switching element rising temperature ΔTMx obtained in step S11005 is within a preset range (second threshold). If the condition is met, the process proceeds to step S11007. On the other hand, if the condition is not satisfied, the process proceeds to step S11008. The second threshold includes an upper limit value and a lower limit value of a preset range.
In determining whether the switching element rising temperature ΔTMx is within a preset range, for example, the switching element rising temperature ΔTMx is, although the motor 4 starts driving with a driving current based on the motor stop reference position, When the temperature rise corresponding to the drive current is not observed or when the temperature is lowered, there is a possibility that the motor lock has occurred. Further, when the temperature rise corresponding to the drive current is exceeded, motor lock may have occurred. Therefore, in the above case, the process proceeds to step S11008.
Also, for example, when the motor is driven and the switching temperature has already risen, the motor stop position is set so that the current of the U-phase switching element 205H becomes 0 (A) at the start of the next motor drive as shown in FIG. In the case of adjustment, when motor lock occurs at the start of motor driving, the switching element temperature of the U phase decreases. Therefore, also in this case, the process proceeds to step S11008.
Regarding the temperature rise corresponding to the drive current here, the temperature rise when motor lock occurs at the start of motor drive is determined from experience values, experiments, simulations, etc. based on the motor stop position and drive current at the start of motor drive To do.

In step S11007, the control unit 209 determines whether the switching element temperature TMx obtained in step S11005 is equal to or higher than a preset value TMJDGx (third threshold value). If the condition is satisfied, the process proceeds to step S11008. On the other hand, if the condition is not satisfied, the process of FIG. 11 is terminated.
The preset value TMJDGx here is determined from experience values, experiments, simulations, and the like based on the switching element temperature at which the switching element is destroyed. Unlike the prior art, in this embodiment, since the position of the motor 4 is adjusted in advance to the motor stop reference position that is the motor drive start position, it can be compared with the actual switching element temperature measured by the temperature sensor. It is possible to set a threshold value that has a sufficient margin with respect to the switching element temperature, which is a limit for element destruction, and does not easily make a motor drive restriction due to erroneous determination.

In step S11008, the control unit 209 determines whether the motor 4 is in a stopped state by the motor position information detection unit 2092. If the condition is met, the process proceeds to step S11009. On the other hand, if the condition is not satisfied, the process proceeds to step S11101.
Whether the motor is stopped is determined by the motor position information detection unit 2092 based on, for example, the resolver signal of the motor 4.

Here, step S11008 is executed when the motor lock may be generated from the determination result based on the switching element temperature in step S11006 or step S11007.
Therefore, if the motor 4 is stopped in step S11008, it is determined that the motor 4 is locked, the motor drive is stopped in step S11009, and the processing in FIG.

  On the other hand, if the motor 4 is not stopped in step S11008, the motor is not locked, but it is assumed that the switching element temperature is approaching the limit temperature at which the switching element is destroyed. The current is limited, the motor drive is continued in a state where the switching element is not destroyed, and the process of FIG. 11 is terminated.

  As described above, when the motor lock occurs at the start of motor driving, the temperature sensor can measure the switching element temperature of all the switching elements that are energized at the start of motor driving or the maximum current through which the temperature rise is greatest. In addition, the position of the motor drive start position is adjusted in advance, so that the temperature of the switching element can be measured with a temperature sensor without guessing, and the motor lock state at the start of motor drive can be determined accurately and the inverter is protected. Can be done.

  In the first to fourth embodiments, when the motor stop position before starting the motor drive is adjusted to a position where the current flowing in any phase is 0 (A) or a position where any phase is the maximum current. However, the threshold value may be set to adjust the current to a position other than that and set the current limit based on the switching element temperature when the motor driving is started from that position.

  In the first to fourth embodiments, the control target of the present invention has been described as the motor 4 in FIG. 1, but the generator 2 may be driven when the engine 1 is started.

  1 engine, 2 generator, 3 clutch, 4 motor, 5 tires, 6 inverter, 7 battery, 203 upper arm, 204 lower arm, 205 U phase switching circuit, 206 V phase switching circuit, 207 W phase switching circuit, 205H, 206H, 207H Upper arm side switching element, 205L, 206L, 207L Lower arm side switching element, 205U, 305U, 505U, 705U U phase temperature sensor, 206V, 306V, 506V, 706V V phase temperature sensor, 207W, 307W, 507W, 707 W W-phase temperature sensor, 209 control unit.

Claims (6)

An inverter provided with switching elements on the upper arm side and the lower arm side in correspondence with a plurality of phases of the motor,
A temperature sensor provided for each phase with respect to any one of the switching elements on the upper arm side and the lower arm side;
A temperature information detector that detects temperature information of the switching element using a sensor signal from the temperature sensor;
A motor position information detector for detecting position information of the motor;
A drive unit for alternately energizing the switching element on the upper arm side and the switching element on the lower arm side for each phase;
When stopping the motor, the motor stop position is adjusted to a preset motor stop reference position so that energization is started from the switching element on the side where the temperature sensor is provided when the motor starts driving. A motor stop position adjustment unit;
A motor lock that determines that the motor is in a locked state and stops the motor when the temperature information of the switching element detected by the temperature information detection unit exceeds a preset threshold after the motor driving is started. A motor driving device comprising: a state determination unit. The motor drive device according to claim 1, wherein the motor stop reference position is a position of the motor at which a current flowing through the switching element of any one phase becomes zero. The motor driving device according to claim 1, wherein the motor stop reference position is a position of the motor at which a current flowing through the switching element of any one phase becomes a maximum current. 4. The motor driving device according to claim 2, wherein the temperature sensor provided for each phase includes at least one phase temperature sensor arranged on an arm side different from the temperature sensor of the other phase. 5. . The motor drive device according to claim 3, wherein all the temperature sensors provided for each phase are arranged on the same arm side. The motor stop position adjustment unit when the motor position information detection unit detects that the current position of the motor is deviated from the motor stop reference position before or after the start of driving the motor. The motor drive device according to claim 1, wherein the position of the motor is readjusted to the motor stop reference position.

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