JPH06261404A - Inverter for electric automobile - Google Patents

Abstract

PURPOSE:To prevent trouble due to abnormality in power circuit or motor by diagnosing them prior to driving of motor. CONSTITUTION:Prior to starting a motor 7, a controller circuit 4 generates an abnormality diagnosis command signal for producing an abnormality diagnosis power supply voltage from a DC voltage generating circuit 3. The power supply voltage is fed to a power circuit 5 and power converting switching elements 15u-15w constituting the power circuit 15 are turned ON/OFF selectively. A current detecting circuit 6 detects I/O current level of the power circuit 5 and then the power circuit 5 and the motor 7 are subjected to abnormality diagnosis based on the detection results.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inverter device for an electric vehicle used for an electric vehicle, and more particularly to an inverter device for an electric vehicle having a function of diagnosing a failure of a power circuit portion of an inverter circuit or a motor. .

[0002]

2. Description of the Related Art As an electric vehicle inverter device used for an electric vehicle, a device shown in FIG. 4 is conventionally known.

The inverter device for an electric vehicle shown in this figure comprises a power supply circuit 101, a DC voltage generating circuit 102, a controller circuit 103, and a power circuit 104. The controller circuit 103 causes the DC voltage generating circuit 102 to operate. , The power circuit 104 and the power circuit 10
The power supply voltage from No. 1 is switched to generate an alternating current, and this is supplied to the motor 115 to be driven to rotate it.

The power supply circuit 101 has a large-capacity battery 116 that serves as a power supply for an electric vehicle, and supplies the power supply voltage obtained by the battery 116 to the DC voltage generation circuit 102.

The DC voltage generating circuit 102 connects the common terminal 105c to either the first terminal 105a or the second terminal 105b based on the control signal output from the controller circuit 103, and a switch 105 of the switch 105. A current value limiting resistor 106 connected to the first terminal 105a, and a voltage stabilizing capacitor 10 charged by the voltage supplied through the resistor 106 or the voltage output from the second terminal 105b of the switch 105.
7 and the common terminal 105c of the switch 105 and the first terminal 105a are designated by the control signal output from the controller circuit 103.
The terminal 105a is connected to limit the current value of the power supply voltage output from the power supply circuit 101 by the resistor 106, and the capacitor 107 is charged by the power supply voltage to increase the capacitor voltage, and then output from the controller circuit 103. The second terminal 105 according to the control signal
When b is designated, the common terminal 105c of the switch 105 and the second terminal 105b are connected, and the voltage output from the second terminal 105b is stabilized by the capacitor 107 and supplied to the power circuit 104.

The power circuit 104 includes two power conversion switching elements (for example, FETs) connected in series.
108u, 109u and reverse voltage bypass diodes 110u, 111u connected in parallel to the respective power conversion switching elements 108u, 109u, and turned on / off based on a control signal output from the controller circuit 103. U-phase power unit 112u
And two switching elements 108v, 109v for power conversion connected in series, and diodes 110v, 111v for reverse voltage bypass connected in parallel to the switching elements 108v, 109v for power conversion, respectively, and a controller circuit. V-phase power unit 112v that turns on / off based on a control signal output from 103
And two switching elements 108w and 109w for power conversion connected in series, and diodes 110w and 111w for reverse voltage bypass connected in parallel to the switching elements 108w and 109w for power conversion, respectively. W-phase power unit 112w that turns on / off based on a control signal output from 103
It has and.

Based on the control signal output from the controller circuit 103, the power circuit 104 has an upper arm or a lower arm of the U-phase power unit 112u, an upper arm or a lower arm of the V-phase power unit 112v,
The upper arm or the lower arm of the W-phase power unit 112w is selectively turned on / off to generate AC currents of a plurality of phases, which are supplied to the motor 115 to be driven and rotated.

The controller circuit 103 also generates various control signals based on the key position of the electric vehicle, supplies them to the DC voltage generation circuit 102 and the power circuit 104, and outputs the power supply voltage output from the power supply circuit 101. In addition to generating a stabilized DC voltage based on the above, the DC voltage is switched by the power circuit 104 to generate a plurality of phases of AC current, and the motor 115 is driven.

In this case, when the driver operates the starting key (not shown) from the OFF position to the ACC position in order to start the electric vehicle, the controller circuit 103 causes the DC voltage generating circuit to operate. The switch 105 of 102 controls the common terminal 105c and the first
The terminal 105a is connected.

As a result, the capacitor 107 is charged with a time constant determined by the resistance value of the resistor 106 connected to the first terminal 105a and the capacitance of the capacitor 107 connected to this resistor.

At this time, the value of the resistor 106 is determined so that the maximum value of the current value is within the range of the allowable inrush current of the capacitor 107, so that the capacitor 107 is not broken and the shortest time is required. Capacitor 107
Can be charged.

When the charging of the capacitor 107 is completed and the charging voltage becomes substantially equal to the power source voltage of the battery 116, the controller circuit 103 controls the switch 105 to control the common terminal 105c and the second terminal 10.
5b is connected.

Thereafter, when the driver turns the key to the ON position and depresses the accelerator, the controller circuit 1
Each of the power conversion switching elements 108u to 109w of the power circuit 104 is assigned to the upper arm or lower arm of the U-phase power unit 112u, the upper arm or lower arm of the V-phase power unit 112v, or the W-phase power unit 112 according to 03.
Each of the upper arm or the lower arm of w is selectively turned on / off to generate a multi-phase alternating current, and the motor 1
Energization of 15 is started.

[0014]

However, in the above-mentioned conventional inverter device for an electric vehicle, since the power circuit 104 and the motor 115 cannot be diagnosed before the motor 115 is driven, these failures occur. Is generated, it is not possible to generate a plurality of phases of alternating current, the motor 115 cannot be driven, and the power supply voltage of the battery 116 that constitutes the power supply circuit 101 is large. There was a risk of failure.

In view of the above situation, the present invention can diagnose the power circuit and the motor before driving the motor, and thus the failure caused by the abnormality of the power circuit or the abnormality of the motor is caused. It is an object of the present invention to provide an inverter device for an electric vehicle, which can be prevented.

[0016]

In order to achieve the above object, the present invention provides an abnormality diagnosis command signal in an electric vehicle inverter device which is mounted on an electric vehicle which runs using a motor as a prime mover and which drives the motor. Is input, a DC voltage generation circuit that generates a power supply voltage for abnormality diagnosis and supplies the power circuit to the motor, a current detection circuit that detects a current input to and output from the power circuit, and the motor Before starting, an abnormality diagnosis command signal is generated to output an abnormality diagnosis power supply voltage from the DC voltage generation circuit, and each power conversion switching element forming the power circuit is selectively turned on / off. A controller circuit for diagnosing whether or not there is an abnormality in the power circuit and the motor based on the detection result of the current detection circuit. There.

[0017]

In the above structure, before starting the motor,
An abnormality diagnosis command signal is generated by the controller circuit, a power supply voltage for abnormality diagnosis is output from the DC voltage generation circuit, and this is supplied to the power circuit, and at the same time, each power conversion switching element forming the power circuit is selectively operated. While being turned on / off, the presence / absence of abnormality of the power circuit and the motor is diagnosed based on the detection result of the current detection circuit that detects the value of the current input to the power circuit.

[0018]

1 is a circuit diagram showing an embodiment of an inverter device for an electric vehicle according to the present invention.

The inverter device for an electric vehicle shown in this figure includes a power supply circuit 1, a key position recognition circuit 2, a DC voltage generation circuit 3, a controller circuit 4, a power circuit 5, and a current detection circuit 6. Therefore, when the motor 7 is energized based on the operation content of the start key 23, the controller circuit 4 performs a failure diagnosis of the power circuit 5 and the motor 7 before the energization of the motor 7 is started. Only when there is no abnormality by the diagnosis, the DC voltage generation circuit 3
Then, the power circuit 5 is controlled to switch the power supply voltage output from the power supply circuit 1 to generate an alternating current, which is supplied to the motor 7 to be driven and rotated.

The power supply circuit 1 is a large-capacity battery 8 for generating a power supply voltage of about several hundreds of volts which is a power supply for an electric vehicle.
And a battery voltage detection circuit 9 for detecting the power supply voltage value of the battery 8 and generating a power supply voltage value signal. The power supply voltage obtained by the battery 8 is supplied to the DC voltage generation circuit 3 and The battery voltage detection circuit 9 detects the power supply voltage value of the battery 8 to generate a power supply voltage value signal, which is supplied to the controller circuit 4.

The key position recognition circuit 2 is a circuit for detecting the key position of the starting key 23, and the starting key 23.
Is switched from the OFF position to the ACC position or the ON position, this is detected to generate a key position recognition signal, which is supplied to the controller circuit 4 and the DC voltage generation circuit 3.

The DC voltage generating circuit 3 is based on the key position recognition signal output from the key position recognition circuit 4 and the control signal output from the controller circuit 4, and the common terminal 10
c is the first terminal 10a, the second terminal 10b, the third terminal 10d
The first switch 10 to be connected to any of the
A resistor (resistance value is R1) 11 for limiting a current value, which is connected to the first terminal 10a of the switch 10;
A resistor for resistance to current value (resistance value is R2, R2 <R1) 12 connected to the second terminal 10b of the resistor 1 and each resistor 1 based on the key position recognition signal output from the key position recognition circuit 2.
A voltage supplied via either 1, 1 or 12
The switch 10 includes a second switch 13 that opens and closes the voltage output from the third terminal 10d, and a voltage stabilizing capacitor 14 that is charged by the voltage supplied via the second switch 13.

In this case, the resistor 11 connected to the first terminal 10a is a resistor selected when the driver switches the starting key 23 from the OFF position to the ACC position,
Switching elements 15u to 1 for power conversion of the power circuit 5
Even when 6w is energized at the same time, the power conversion switching elements 15u to 16w are set to a large value so as not to destroy them, and the resistor 12 connected to the second terminal 10b charges the capacitor 14, It is set to such a small value that the capacitor 14 is not destroyed by the inrush current.

The direct current voltage generating circuit 3 operates when the first terminal 10a is designated by the key position recognition signal output from the key position recognition circuit 2 and the control signal output from the controller circuit 4. The switch 13 is turned off, and the common terminal 10c and the first terminal 10a of the first switch 10 are connected to each other to connect the resistor 11
By limiting the current value of the power supply voltage output from the power supply circuit 1 to the power circuit 5, and by the key position recognition signal output from the key position recognition circuit 2 and the control signal output from the controller circuit 4. Second terminal 10
When b is designated, the second switch 13 is turned on and the common terminal 10 of the first switch 10 is turned on.
The capacitor 14 is charged while the current value of the power supply voltage output from the power supply circuit 1 is limited by the resistor 12 by connecting the c and the second terminal 10b. Then, by the key position recognition signal output from the key position recognition circuit 2 and the control signal output from the controller circuit 4,
When the terminal 10d is designated, the second switch 1
3 is turned on, the common terminal 10c of the first switch 10 is connected to the third terminal 10d, and the voltage output from the third terminal 10d is stabilized by the capacitor 14 and supplied to the power circuit 5. .

The power circuit 5 includes two power conversion switching elements (for example, FETs) 15 connected in series.
u and 16u and reverse voltage bypass diodes 17u and 18u connected in parallel to the power conversion switching elements 15u and 16u, respectively, and turned on / off based on a control signal output from the controller circuit 4. U-phase power unit 19u, two power conversion switching elements 15v and 16v connected in series, and a reverse voltage bypass diode 17 connected in parallel to each of these power conversion switching elements 15v and 16v.
V, 18v, and a V-phase power unit 19v that is turned on / off based on a control signal output from the controller circuit 4, two power conversion switching elements 15w and 16w connected in series, and each of these powers. The conversion switching elements 15w and 16w each include a reverse voltage bypass diode 17w and 18w that are connected in parallel, and include a W-phase power unit 19w that is turned on / off based on a control signal output from the controller circuit 4. ing.

The power circuit 5 selectively performs a diagnostic operation on each of the power conversion switching elements 15u to 16w based on the control signal output from the controller circuit 4, or the upper arm or the lower arm of the U-phase power unit 19u. , The upper arm or lower arm of the V-phase power unit 19v and the upper arm or lower arm of the W-phase power unit 19w are selectively turned on / off to generate AC currents of a plurality of phases, which are supplied to the motor 7 to be driven. And drive this.

The current detection circuit 6 includes a high-potential-side current sensor 20 for detecting the current value of the voltage supplied from the DC voltage generation circuit 3 to the power circuit 5, and a current returned from the power circuit 5 to the DC voltage generation circuit 3. Low potential side current sensor 21 for detecting the value
And a gate current sensor 22 that detects a gate current value of each of the power conversion switching elements 15u to 16w that form the power circuit 5, and the high potential side current sensor 20.
Detects the current value of the voltage output from the DC voltage generation circuit 3 to generate a high-potential-side current value detection signal, and the low-potential-side current sensor 21 detects the value of the current returned to the power circuit 5 to lower the current value. A potential side current value detection signal is generated, the gate current sensor 22 detects the gate current value of each power conversion switching element to generate a gate current value detection signal, and the high potential side current value detection signal and the low potential side current value detection signal are generated. The potential side current value detection signal and the gate current value detection signal are supplied to the controller circuit 4.

The controller circuit 4 also outputs various control signals based on the key position recognition signal output from the key position recognition circuit 2 and the power supply voltage value signal output from the battery voltage detection circuit 9 of the power supply circuit 1. And supplies them to the DC voltage generation circuit 3 and the power circuit 5 to generate a DC voltage necessary for failure diagnosis and a stabilized DC voltage based on the power supply voltage output from the power supply circuit 1, and Failure diagnosis of each of the power conversion switching elements 15u to 16w and the motor 7 configuring the circuit 5,
The power conversion switching elements 15u to 16w are switched to generate a plurality of phases of alternating current, which are supplied to the motor 7.

Next, referring to the circuit shown in FIG. 1 and the waveform diagrams shown in FIGS. 2 and 3, the diagnostic operation of the power circuit, the diagnostic operation of the motor, and the drive operation of the motor in this embodiment will be described in order. .

<< Power Circuit Diagnostic Operation >> First, if the starting key 23 is switched from the OFF position to the ACC position, and the key position recognition circuit 2 outputs a key position recognition signal indicating the ACC position in response to this. The controller circuit 4 generates a control signal indicating the diagnostic operation to generate the DC voltage generation circuit 3
The second switch 13 is maintained in the OFF state, and the common terminal 10c of the first switch 10 and the first terminal 10a are connected to generate a DC voltage having a small current value from the power supply voltage output from the power supply circuit 1. Then, this is supplied to the power circuit 5.

Further, in parallel with this operation, the controller circuit 4 sequentially selects one of the power conversion switching elements 15u to 16w constituting the power circuit 5 to sequentially select the power conversion switching elements 15u to 16w.
While applying the gate voltage as shown in (a), the gate current value detection signal output from the gate current sensor 22 of the current detection circuit 6 is taken in and the change is determined.

In this case, if the gate of the selected power conversion switching element is not broken down, as shown in FIG.
When the gate voltage is applied as shown in (a), the electrostatic capacity of the gate is charged and discharged, and the gate voltage rises and the gate voltage falls as shown in FIG. 2 (b). In addition, the gate current flows instantaneously, and at other times, the gate current does not flow. Further, when the gate is destroyed, a gate current having a shape corresponding to the gate voltage flows as shown in FIG. Therefore, when a predetermined time (for example, time t1) has passed since the gate voltage was applied (for example, time t0) and the value of the gate current value detection signal is less than or equal to a preset threshold value, the selected electric power is selected. When it is determined that the gate of the conversion switching element has not been destroyed and the value of the gate current value detection signal is higher than a preset threshold value, the selected gate of the power conversion switching element has been destroyed. Is determined.

Next, when the gate diagnosis of each of the power conversion switching elements 15u to 16w is completed, the controller circuit 4 makes the U-phase power section 19 constituting the power circuit 5.
u or the V-phase power unit 19v or the W-phase power unit 19w, for example, the U-phase power unit 19u is selected, and the switching element 15u for power conversion forming the upper arm of the U-phase power unit 19u and the lower arm are connected. By selecting the power conversion switching element 16u to be configured, as shown in FIG.
While applying the gate voltage as shown in (a) and (b),
The high potential side current value detection signal output from the high potential side current sensor 20 of the current detection circuit 6 and the low potential side current sensor 21.
Low-potential-side current value detection signal output from the power supply circuit 1
Of the power supply voltage value signal output from the battery voltage detection circuit 9 of the above, and the power conversion switching element 15u forming the upper arm of the U-phase power section 19u and the power conversion switching element 16 forming the lower arm.
It is determined whether u and u are normal.

In this case, a power conversion switching element 15u which constitutes the upper arm of the U-phase power section 19u,
Switching element 1 for power conversion forming a lower arm
If 6u is normal, each of the power conversion switching elements 15u and 16u becomes conductive due to the gate voltage and the resistance value between the drain and the source becomes substantially zero, and each of the power conversion switching elements 15u and 16u. If any of the above is in an abnormal state such as an open state, the resistance value of the abnormal power conversion switching element is large. Therefore, the following equation is satisfied and a large value is obtained as shown in FIG. When the current is current, the power conversion switching elements 15u and 16u that form the U-phase power unit 19u
Is determined to be normal. Also, the following formula is not satisfied,
When the current is small as shown in Fig. 3 (d), U
It is determined that at least one of the power conversion switching elements 15u and 16u configuring the phase power unit 19u is abnormal.

I ₁ = I ₂ = Eb / R ₁ (1) where I ₁ is the value of the high potential side current value detection signal output from the high potential side current sensor 20 I _{2 is the} low potential side current sensor 21 The value of the low-potential-side current value detection signal output from Eb: the value of the power supply voltage value signal output from the battery voltage detection circuit 9 R ₁ : the resistance 11 connected to the first terminal 10a of the first switch 10 Next, the controller circuit 4 applies the gate voltage to one of the power conversion switching elements 15u and 16u forming the U-phase power section 19u, for example, the power conversion switching element 15u, while the other power conversion switching element 15u is applied. The application of the gate voltage to 16u is stopped, and at this time, the value of the high potential side current value detection signal output from the high potential side current sensor 20 or the low potential side current sensor 21 is output. The value of the low-potential-side current detection signal is checked whether it is zero. After that, the switching element 16 for power conversion
While applying the gate voltage to u, the application of the gate voltage to the power conversion switching element 15u is stopped, and at this time, the value of the high potential side current value detection signal output from the high potential side current sensor 20 or the low potential side current It is checked whether the value of the low potential side current value detection signal output from the sensor 21 is zero.

Here, in either state, the value of the high potential side current value detection signal output from the high potential side current sensor 20 or the value of the low potential side current value detection signal output from the low potential side current sensor 21. Is zero, it is determined that these power conversion switching elements 15u and 16u are normal, and in either state, the value of the high potential side current value detection signal output from the high potential side current sensor 20. If the value of the low potential side current value detection signal output from the low potential side current sensor 21 is not zero, these power conversion switching elements 15
It is determined that one of u and 16u is in an abnormal state such as a short circuit.

When the diagnostic process for the U-phase power unit 19u is completed, the controller circuit 4 performs the diagnostic process similar to the above-described diagnostic process on the R-phase power unit 19v and the W-phase power unit 19w. , Power conversion switching elements 15v and 16v that configure the R-phase power unit 19v and power conversion switching elements 15w and 16w that configure the W-phase power unit 19w are diagnosed.

When these diagnostic processes are completed,
Does the controller circuit 4 match the value of the high-potential-side current value detection signal output from the high-potential-side current sensor 20 with the value of the low-potential-side current value detection signal output from the low-potential-side current sensor 21? If they do not match, it is determined that an abnormality such as a current leak has occurred somewhere in the power circuit 5.

<< Motor Diagnosis Operation >> After that, when the above-described diagnosis process of the power circuit 5 is completed, the controller circuit 4
Is each coil 25u, 25v, 25w that constitutes the motor 7.
Among them, when two are selected and a power conversion switching element required to supply a current to these coils, for example, the coil 25u and the coil 25v are selected, the upper arm of the U-phase power unit 19u is configured. Power conversion switching element 15u and the power conversion switching element 16v forming the lower arm of the V-phase power unit 19v are selected, and each of these power conversion switching elements 15u is selected.
While simultaneously applying the gate voltage to u and 16v,
The high potential side current value detection signal output from the high potential side current sensor 20 of the current detection circuit 6 and the power supply voltage value signal output from the battery voltage detection circuit 9 of the power supply circuit 1 are taken in, and based on the following equation: An added value of the winding resistance value of the coil 25u and the winding resistance value of the coil 25v is obtained.

Ru + Rv = (Eb / I ₁ ) −R ₁ (2) where Ru: winding resistance value of the coil 25u Rv: winding resistance value of the coil 25v Eb: power output from the battery voltage detection circuit 9 Value of voltage value signal I ₁ : Value of high potential side current value detection signal output from high potential side current sensor 20.

R ₁ : the first terminal 10a of the first switch 10
After that, the controller circuit 4 causes the coils 25u and 25
It is checked whether the added value of v agrees with the preset resistance value at the normal time, and if they match, it is determined that the coil 25u and the coil 25v are normal, and they do not coincide with each other. If so, it is determined that one of the coil 25u and the coil 25v is abnormal.

Hereinafter, two coils 25u, 25v, 25w constituting the motor 7 of the controller circuit 4 are sequentially selected, and a gate voltage is simultaneously applied to the corresponding power conversion switching elements, so that the motor 7 of the motor 7 is controlled. Make a diagnosis.

<< Driving Operation of Motor >> Then, when the diagnosis of the motor 7 is completed, the controller circuit 4 controls the abnormality when the abnormality of the power circuit 5 or the motor 7 is confirmed by the abnormality diagnosis processing described above. The first switch 10 forming the DC voltage generating circuit 3 by generating a signal is turned off, and the driving of the motor 7 is prohibited.

If no abnormality is found in the power circuit 5 or the motor 7 by the above abnormality diagnosis processing, the controller circuit 4 waits until the start key 23 is turned to the ON position.

When the starting key 23 is turned to the ON position, the controller circuit 4 generates a control signal for controlling the charging of the capacitor 14 to turn on the second switch 13 constituting the DC voltage generating circuit 3. And first
The capacitor 14 is charged while connecting the common terminal 10c of the switch 10 and the second terminal 10b to limit the current value of the power supply voltage output from the power supply circuit 1.

After that, when the charging of the capacitor 14 is completed, the controller circuit 4 generates a control signal for controlling the start of energization of the motor 7 and the common terminal 10c of the first switch 10 constituting the DC voltage generating circuit 3. , The third terminal 10d is connected to the power supply circuit 1 so that the power supply voltage output from the power supply circuit 1 is stabilized by the capacitor 14 and supplied to the power circuit 5, and each power conversion switching element 15u constituting the power circuit 5 is provided. The selective energization of ˜16 w is started, and the rotation of the motor 7 is started.

As described above, in this embodiment, when the motor 7 is energized based on the operation contents of the starting key 23, the controller circuit 4 controls the power circuit 5 and the motor 7 before energizing the motor 7. The failure diagnosis of No. 7 is performed, and only when there is no abnormality due to this failure diagnosis, the DC voltage generation circuit 3 and the power circuit 5 are controlled to switch the voltage obtained by the power supply circuit 1 to generate the AC current. Since this is supplied to the motor 7 to be driven so as to be rotationally driven, it is possible to prevent occurrence of a failure due to an abnormality of the power circuit 5 or an abnormality of the motor 7.

[0048]

As described above, according to the present invention, the electric power circuit and the motor can be diagnosed before the motor is driven, which causes an abnormality in the electric power circuit or an abnormality in the motor. It is possible to prevent a failure from occurring.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of an inverter device for an electric vehicle according to the present invention.

FIG. 2 is a waveform diagram showing an example of an abnormality diagnosing operation of the inverter device for an electric vehicle shown in FIG.

3 is a waveform diagram showing an example of abnormality diagnosis operation of the inverter device for an electric vehicle shown in FIG.

FIG. 4 is a circuit diagram showing an example of a conventionally known inverter device for an electric vehicle.

[Explanation of Codes] 1 power supply circuit 2 key position recognition circuit 3 DC voltage generation circuit 4 controller circuit 5 power circuit 6 current detection circuit 7 motor 15u to 16w power conversion switching element 25u to 25w coil 23 start key

Claims (1)

[Claims] 1. An inverter device for an electric vehicle that is mounted on an electric vehicle that runs using a motor as a prime mover and that drives the motor, generates an abnormality diagnosis power supply voltage when an abnormality diagnosis command signal is input. A DC voltage generation circuit to be supplied to the power circuit of the motor, a current detection circuit to detect a current input to and output from the power circuit, and an abnormality diagnosis command signal to generate the DC voltage before starting the motor. While outputting a power supply voltage for abnormality diagnosis from the generation circuit and selectively turning on / off each of the power conversion switching elements forming the power circuit, the power circuit and the power circuit based on the detection result of the current detection circuit An inverter device for an electric vehicle, comprising: a controller circuit for diagnosing whether or not a motor is abnormal.