阅读说明：本技术 逆变器装置 (Inverter device ) 是由 中田雄飞 立花亮 向山浩司 于 2020-02-05 设计创作，主要内容包括：本发明提供逆变器装置,在马达的再生动作中,能够实现在切换使在马达中产生的再生电流再次返回到马达的第1状态和将再生电流提供给电力供给部的第2状态时的冗余化。逆变器装置具有：马达；电力供给部,其向马达提供使马达进行动作的电流；逆变器部,其在马达的再生动作中,切换第1状态和第2状态,在该第1状态下,使在马达中产生的再生电流再次返回到马达,在该第2状态下,将再生电流提供给电力供给部；第1检测部,其检测作用于逆变器部的电的第1条件；第2检测部,其检测作用于电力供给部的电的第2条件；以及判断部,其根据第1检测部或第2检测部的检测结果而进行切换第1状态和第2状态的第1判断。(The invention provides an inverter device, which can realize redundancy when switching between a 1 st state of returning regenerative current generated in a motor to the motor again and a 2 nd state of supplying the regenerative current to a power supply unit during regenerative operation of the motor. The inverter device comprises: a motor; a power supply unit that supplies a current for operating the motor to the motor; an inverter unit that switches between a 1 st state and a 2 nd state during a regenerative operation of the motor, returns a regenerative current generated in the motor to the motor again in the 1 st state, and supplies the regenerative current to the power supply unit in the 2 nd state; a 1 st detection unit that detects a 1 st condition of electricity acting on the inverter unit; a 2 nd detection unit that detects a 2 nd condition of electricity acting on the power supply unit; and a determination unit that performs a 1 st determination of switching between the 1 st state and the 2 nd state based on a detection result of the 1 st detection unit or the 2 nd detection unit.)

1. An inverter device is characterized in that a DC-DC converter,

the inverter device includes:

a motor;

a power supply unit that supplies a current for operating the motor to the motor;

an inverter unit that switches between a 1 st state in which a regenerative current generated in the motor is returned to the motor again and a 2 nd state in which the regenerative current is supplied to the power supply unit, during a regenerative operation of the motor;

a 1 st detection unit that detects a 1 st condition of electricity acting on the inverter unit;

a 2 nd detection unit that detects a 2 nd condition of electricity acting on the power supply unit; and

and a determination unit that performs a 1 st determination for switching between the 1 st state and the 2 nd state based on a detection result of the 1 st detection unit or the 2 nd detection unit.

2. The inverter device according to claim 1,

the determination unit performs the 1 st determination for switching to the 1 st state when the 1 st condition exceeds a threshold, and performs the 1 st determination for switching to the 2 nd state when the 1 st condition is lower than the threshold.

3. The inverter device according to claim 2,

the determination unit performs the 1 st determination for switching to the 1 st state when the 2 nd condition exceeds a threshold, and performs the 1 st determination for switching to the 2 nd state when the 2 nd condition is lower than the threshold.

4. The inverter device according to claim 3,

the judging unit makes a 2 nd judgment of whether the 1 st detecting unit has a failure or not and the 2 nd detecting unit has a failure or not, and makes the 1 st judgment based on a result of the 2 nd judgment.

5. The inverter device according to claim 4,

the judging unit performs the 1 st judgment based on the detection result of the 1 st detecting unit when the 1 st detecting unit has no fault as a result of the 2 nd judgment, and performs the 1 st judgment based on the detection result of the 2 nd detecting unit when the 2 nd detecting unit has no fault as a result of the 2 nd judgment.

6. The inverter device according to claim 5,

the determination unit performs the 1 st determination based on the detection result of the 2 nd detection unit when it is determined that the 1 st detection unit has a failure by the 2 nd determination and it is determined that the 2 nd detection unit has no failure, and performs the 1 st determination based on the detection result of the 1 st detection unit when it is determined that the 2 nd detection unit has a failure by the 2 nd determination and it is determined that the 1 st detection unit has no failure.

7. The inverter device according to claim 6,

the determination unit stops the control when the 1 st detection unit is determined to have a failure by the 2 nd determination and the 2 nd detection unit is determined to have a failure.

8. The inverter device according to any one of claims 2 to 7,

the determination unit determines the presence or absence of a failure in the 1 st detection unit based on a change with time in the 1 st condition, and determines the presence or absence of a failure in the 2 nd detection unit based on a change with time in the 2 nd condition.

9. The inverter device according to any one of claims 1 to 8,

the 1 st detecting unit detects, as the 1 st condition, a voltage applied from the power supplying unit to the inverter unit, a current flowing in the inverter unit, or power generated in the inverter unit,

the 2 nd detection unit detects, as the 2 nd condition, a voltage applied to the power supply unit, a current flowing in the power supply unit, or power generated in the power supply unit.

10. The inverter device according to claim 9,

the 1 st detecting section has a 1 st converting section for converting the magnitude of the 1 st condition,

the 2 nd detecting unit has a 2 nd converting unit that converts the magnitude of the 2 nd condition.

Technical Field

The present invention relates to an inverter device.

Background

Vehicles that can travel by being driven by a motor, such as hybrid vehicles and electric vehicles, are known (see patent document 1, for example). The vehicle described in patent document 1 includes a motor, a battery, and an inverter that converts a direct current supplied from the battery into an alternating current and supplies the alternating current to the motor. The vehicle described in patent document 1 detects the rotation speed of the motor using a rotation sensor including a resolver or the like, and selects two controls to execute based on the detection result. One of the two controls is a shutdown control (SD control), and the other control is an active short-circuit control (ASC control). The shutdown control is control for turning off all the switching elements of the inverter. The active short-circuit control is a control for turning on one of the upper switching elements of all the plurality of phases or the lower switching elements of all the plurality of phases and turning off the other.

Patent document 1: japanese patent No. 6296169

However, in the vehicle described in patent document 1, a threshold value is set for the rotation speed of the motor detected by the rotation sensor, and control is selected based on the magnitude relationship between the threshold value and the actual rotation speed.

Disclosure of Invention

The present invention aims to provide an inverter device as follows: in the regenerative operation of the motor, redundancy can be achieved when switching between the 1 st state in which the regenerative current generated by the motor is returned to the motor again and the 2 nd state in which the regenerative current is supplied to the power supply unit.

An exemplary invention of the present application is an inverter device, including: a motor; a power supply unit that supplies a current for operating the motor to the motor; an inverter unit that switches between a 1 st state in which a regenerative current generated in the motor is returned to the motor again and a 2 nd state in which the regenerative current is supplied to the power supply unit, during a regenerative operation of the motor; a 1 st detection unit that detects a 1 st condition of electricity acting on the inverter unit; a 2 nd detection unit that detects a 2 nd condition of electricity acting on the power supply unit; and a determination unit that performs a 1 st determination of switching between the 1 st state and the 2 nd state based on a detection result of the 1 st detection unit or the 2 nd detection unit.

According to the present invention, redundancy can be achieved when switching between the 1 st state in which the regenerative current generated in the motor is returned to the motor again and the 2 nd state in which the regenerative current is supplied to the power supply unit during the regenerative operation of the motor.

Drawings

Fig. 1 is a block diagram showing a main part of an inverter apparatus of the present invention.

Fig. 2 is a circuit diagram (state 1) showing a main part of the inverter device of the present invention.

Fig. 3 is a circuit diagram (2 nd state) showing a main part of the inverter device of the present invention.

Fig. 4 is a graph showing an example of a temporal change in the voltage detected by the determination unit when the 1 st detection unit (or the 2 nd detection unit) is in the normal state.

Fig. 5 is a graph showing an example of a temporal change in the voltage detected by the determination unit when the 1 st detection unit (or the 2 nd detection unit) is in the failure state.

Fig. 6 is a flowchart showing a control routine of the inverter device of the present invention.

Description of the reference symbols

1: an inverter device; 2: a motor; 3: a power supply unit; 31: secondary batteries (batteries); 4: an inverter section; 41: a switching element; 41A, 41C, 41E: an upper side switching element; 41B, 41D, 41F: a lower side switching element; 5: a 1 st detection unit; 51: a 1 st converting part; 6: a 2 nd detection unit; 61: a 2 nd conversion section; 7: a judgment section; 14: a switch; 15: a capacitor; 16: a battery management system; g1, G2, G3: a graph; s101 to S112: a step of; α: and (4) a threshold value.

Detailed Description

Hereinafter, an inverter device according to the present invention will be described in detail based on preferred embodiments shown in the drawings.

Fig. 1 is a block diagram showing a main part of an inverter apparatus of the present invention. Fig. 2 is a circuit diagram (state 1) showing a main part of the inverter device of the present invention. Fig. 3 is a circuit diagram (2 nd state) showing a main part of the inverter device of the present invention. Fig. 4 is a graph showing an example of a temporal change in the voltage detected by the determination unit when the 1 st detection unit (or the 2 nd detection unit) is in the normal state. Fig. 5 is a graph showing an example of a temporal change in the voltage detected by the determination unit when the 1 st detection unit (or the 2 nd detection unit) is in the failure state. Fig. 6 is a flowchart showing a control routine of the inverter device of the present invention.

The inverter device 1 shown in fig. 1 is mounted on a vehicle such as a Hybrid Electric Vehicle (HEV), a plug-in hybrid electric vehicle (PHV), or an Electric Vehicle (EV), for example, and used as a power source thereof.

The inverter device 1 includes: a motor 2; a power supply unit 3 that supplies a current (electric power) for operating the motor 2 to the motor 2; an inverter unit 4 that converts the direct current supplied from the power supply unit 3 into an alternating current; a 1 st detection unit 5 that detects a 1 st condition (for example, a voltage value) of electricity acting on the inverter unit 4; a 2 nd detection unit 6 that detects a 2 nd condition (for example, a voltage value) of electricity acting on the power supply unit 3; and a determination unit 7 for performing a predetermined determination based on the detection result of the 1 st detection unit 5 or the 2 nd detection unit 6. In the present embodiment, the 2 nd detection unit 6 is mounted in the battery management system 16 that controls the secondary battery (battery) 31 of the power supply unit 3.

Each of the units included in the inverter device 1 is electrically connected to each other via CAN (Controller area network) communication as an in-vehicle network.

The power supply unit 3 has a secondary battery 31 and can supply current to the motor 2 via the inverter unit 4. Thereby, the motor 2 operates. In the inverter unit 4, the dc current supplied from the power supply unit 3 is converted into an ac current. The motor 2 is a DC motor (three-phase motor) having three phases, i.e., a U-phase, a V-phase, and a W-phase, and is supplied with an ac current converted by the inverter unit 4. As shown in fig. 1, the power supply unit 3 is connected to CAN communication via the 2 nd detection unit 6.

As described above, the inverter device 1 is mounted on, for example, a hybrid vehicle and used. In such a use state, the motor 2 may perform regeneration. As a case where the motor 2 performs regeneration, for example, there are cases where: the vehicle in the neutral state is pulled, forcibly rotating the motor 2; the vehicle includes an engine other than the motor 2, and the motor 2 is forcibly rotated by the engine.

During the regenerative operation of the motor 2, for example, the secondary battery 31 and the switching element 41 described later are switched to the 1 st state shown in fig. 2 and the 2 nd state shown in fig. 3 for the purpose of protecting them.

The 1 st state is a state in which the regenerative current generated in the motor 2 is returned to the motor 2 again during the regenerative operation of the motor 2. The control to be set to the 1 st state is generally referred to as "active short circuit control (ASC control)".

The 2 nd state is a state in which the regenerative current generated in the motor 2 is supplied to the power supply unit 3 in the regenerative operation of the motor 2. The control to be set to the 2 nd state is generally referred to as "shutdown control (SD control)".

The switching between the 1 st state and the 2 nd state is performed by the inverter unit 4. As shown in fig. 2 and 3, the inverter unit 4 includes a plurality of (6 in the present embodiment) switching elements 41. In the present embodiment, three sets of two switching elements 41 connected in series are provided in parallel between the potential of the power supply unit 3 and the ground potential. Hereinafter, these switching elements 41 are referred to as "upper switching element 41A", "lower switching element 41B", "upper switching element 41C", "lower switching element 41D", "upper switching element 41E", and "lower switching element 41F" in order from the switching element 41 on the motor 2 side. The upper switching element 41A, the upper switching element 41C, and the upper switching element 41E are disposed (connected) to the + side of the power supply unit 3 (battery 31), and the lower switching element 41B, the lower switching element 41D, and the lower switching element 41F are disposed (connected) to the-side of the power supply unit 3 (battery 31).

The PWM signal is supplied as a pulse wave to each switching element 41. The PWM signal supplied to each switching element 41 has a predetermined duty ratio. As the switching element 41, for example, an Insulated Gate Bipolar Transistor (IGBT) or a Field Effect Transistor (FET) can be used.

The inverter unit 4 is electrically connected to the power supply unit 3 via a switch 14 and a capacitor 15. The switch 14 can be switched between a state in which power can be supplied from the power supply unit 3 to the motor 2 and a state in which the power supply is stopped. The capacitor 15 is provided in parallel with the two switching elements 41 connected in series as described above.

As shown in fig. 2, the lower switching element 41B, the lower switching element 41D, and the lower switching element 41F are turned ON (ON), and the upper switching element 41A, the upper switching element 41C, and the upper switching element 41E are turned OFF (OFF), respectively, to set the state to the 1 st state. That is, active short circuit control can be performed. The active short-circuit control can be performed not only in the state shown in fig. 2, but also in a state where the upper switching device 41A, the upper switching device 41C, and the upper switching device 41E are turned on, and in a state where the lower switching device 41B, the lower switching device 41D, and the lower switching device 41F are turned off, for example.

On the other hand, as shown in fig. 3, the upper switching element 41A to the lower switching element 41F are turned off to set the 2 nd state. Namely, the closing control can be performed.

The 1 st detection unit 5 is incorporated in the inverter unit 4, and detects the 1 st condition of the electricity acting on the inverter unit 4. The condition 1 is not particularly limited, and examples thereof include a voltage applied from the power supply unit 3 to the inverter unit 4, a current flowing through the inverter unit 4, and power generated in the inverter unit 4. In the present embodiment, a case where the 1 st detecting unit 5 detects the voltage applied from the power supplying unit 3 to the inverter unit 4 as the 1 st condition will be described as an example. In this case, the 1 st detecting unit 5 is a voltmeter. The voltmeter is generally a measuring instrument having a simple structure, hardly causes a failure or the like, and is excellent in durability when mounted on a vehicle for use.

The 2 nd detecting unit 6 detects the 2 nd condition of the electricity acting on the power supplying unit 3. The condition 2 is not particularly limited, and examples thereof include a voltage applied to the power supply unit 3, a current flowing through the power supply unit 3, and power generated in the power supply unit 3. In the present embodiment, a case where the 2 nd detection unit 6 detects the voltage applied to the power supply unit 3 as the 2 nd condition will be described as an example. In this case, the same electrophysical quantity, that is, voltage can be used in the 1 st condition and the 2 nd condition. This makes it possible to smoothly perform switching control between the 1 st state and the 2 nd state by a simple configuration of a program to be described later. When the 2 nd detecting unit 6 detects a voltage, the 2 nd detecting unit 6 is a voltmeter as in the 1 st detecting unit 5.

As shown in fig. 1, the 1 st detecting unit 5 includes a 1 st converting unit 51 that converts the magnitude of the voltage (1 st condition). The 1 st converting unit 51 is not particularly limited, and for example, an amplifier that amplifies a voltage value (actual measurement value) actually detected may be used. This can expand the measurement range of the 1 st detection unit 5, and accordingly, can expand the range effective for the measurement (detection) of the voltage, thereby suppressing the detection error of the 1 st detection unit 5.

On the other hand, the 2 nd detecting unit 6 also has a 2 nd converting unit 61 that converts the magnitude of the voltage (2 nd condition). The 2 nd conversion unit 6 is not particularly limited, and for example, an amplifier that amplifies a voltage value (actual measurement value) actually detected can be used. This can expand the measurement range of the 2 nd detection unit 6, and accordingly, can expand the range effective for the measurement (detection) of the voltage, thereby suppressing the detection error of the 2 nd detection unit 6.

The determination unit 7 switches between the 1 st state and the 2 nd state based on the detection result of the 1 st detection unit 5 or the 2 nd detection unit 6. This determination is hereinafter referred to as "determination 1". Specifically, the determination unit 7 makes the 1 st determination based on whether the detection value is higher or lower than a threshold value α, which will be described later, with reference to the threshold value α. In the present embodiment, the determination Unit 7 is incorporated in the inverter Unit 4 as shown in fig. 1, and is configured by, for example, a CPU (Central Processing Unit) and various memories.

However, the 1 st and 2 nd detection units 5 and 6 may fail due to, for example, deterioration with time. In this case, the voltage cannot be detected accurately, and it is difficult to accurately perform the 1 st determination.

Therefore, the inverter device 1 is configured to eliminate such a problem. The structure and operation will be described below.

The determination unit 7 can perform the 2 nd determination of whether or not the 1 st detection unit 5 has a failure and the 2 nd detection unit 6 has a failure. The determination unit 7 can perform the 1 st determination based on the result of the 2 nd determination. Since the method of determining the presence or absence of a failure in the 1 st detecting unit 5 is the same as the method of determining the presence or absence of a failure in the 2 nd detecting unit 6, the method of determining the presence or absence of a failure in the 1 st detecting unit 5 will be described as a representative method. This determination method is an example, and is not limited to this.

When the 1 st detecting unit 5 is not malfunctioning, that is, when the 1 st detecting unit 5 is in a state in which it is able to detect an accurate voltage, it is detected that the voltage value detected by the 1 st detecting unit 5 is increased with time during the regenerative operation as shown in the graph G1 in fig. 4. The "accurate voltage" is preferably determined by, for example, variations in hardware (electromagnetic noise of the switching element 41, etc.).

In contrast, when the 1 st detecting unit 5 is malfunctioning, that is, when the 1 st detecting unit 5 is in a state in which it cannot detect an accurate voltage, the communication state from the 1 st detecting unit 5 becomes unstable (collapses), and therefore, as shown in a graph G2 of fig. 5, the voltage value detected by the 1 st detecting unit 5 is maintained constant near the upper limit value of the detection range and hardly changes with time, or as shown in a graph G3, the voltage value detected by the 1 st detecting unit 5 is maintained constant near the lower limit value of the detection range and hardly changes with time.

The determination unit 7 obtains a graph showing a relationship between the voltage value detected by the 1 st detection unit 5 and time, and can determine whether or not the 1 st detection unit 5 has a failure based on whether the graph is similar to the graph of fig. 4 or similar to the graph of fig. 5. When the graph of fig. 4 is similar, it is determined that the 1 st detecting unit 5 has not failed, and when the graph of fig. 5 is similar, it is determined that the 1 st detecting unit 5 has failed.

As described above, the determination unit 7 determines the presence or absence of a failure in the 1 st detection unit 5 based on the temporal change in the voltage value (1 st condition) detected by the 1 st detection unit 5. Further, similarly to the failure determination, the determination unit 7 may determine the presence or absence of a failure in the 2 nd detection unit 6 based on a change over time in the 2 nd condition detected by the 2 nd detection unit 6. This makes it possible to stably and accurately determine whether or not the 1 st and 2 nd detectors 5 and 6 have failed.

Next, a procedure of switching control between the 1 st state and the 2 nd state based on the 1 st determination and the 2 nd determination will be described with reference to a flowchart shown in fig. 6.

First, it is determined whether or not the motor 2 is in the regenerative operation (step S101), and if it is determined that the motor 2 is in the regenerative operation, it is determined whether or not the 1 st detecting unit 5 has a failure by the above-described determination method (step S102). When it is determined that the 1 st detecting unit 5 has no failure as a result of the determination at step S102, the 1 st detecting unit 5 detects the voltage value (the 1 st condition) applied to the inverter unit 4 (step S103).

Next, it is determined whether or not the voltage value detected by the 1 st detecting unit 5 exceeds the threshold value α (step S104). When it is determined as a result of the determination in step S104 that the voltage value exceeds the threshold value α, the inverter device 1 is set to the 1 st state (step S105). On the other hand, if it is determined as a result of the determination in step S104 that the voltage value does not exceed the threshold value α, the inverter device 1 is set to the 2 nd state (step S106). The threshold α can be arbitrarily set, but when the voltage value is used as the 1 st condition (or the 2 nd condition), the threshold α is determined, for example, by the withstand voltage of each switching element 41. The threshold α is stored in the determination unit 7 and can be changed (rewritten) as appropriate.

When it is determined as a result of the determination in step S102 that the 1 st detecting unit 5 has a failure, the presence or absence of a failure in the 2 nd detecting unit 6 is determined by the above-described determination method (step S107). When it is determined as a result of the determination in step S107 that the 2 nd detecting unit 6 has no failure, the 2 nd detecting unit 6 detects the voltage value (the 2 nd condition) applied to the power supplying unit 3 (step S108).

Next, it is determined whether or not the voltage value detected by the 2 nd detecting unit 6 exceeds the threshold value α (step S109). When it is determined as a result of the determination in step S109 that the voltage value exceeds the threshold value α, the inverter device 1 is set to the 1 st state (step S110). On the other hand, when it is determined that the voltage value does not exceed the threshold value α as a result of the determination in step S109, the inverter device 1 is set to the 2 nd state (step S111).

When it is determined as a result of the determination in step S107 that the 2 nd detecting unit 6 has a failure, the operation of the entire inverter device 1 is stopped (step S112).

As described above, when the 1 st detecting unit 5 is determined not to have a failure by the 2 nd determination, the determining unit 7 performs the 1 st determination based on the detection result of the 1 st detecting unit 5 (the execution sequence of step S102, step S103, step S104, step S105, or step S106). In this step, the determination unit 7 performs the 1 st determination of switching to the 1 st state when the 1 st condition exceeds the threshold α (the sequence of step S104 and step S105). The determination unit 7 performs the 1 st determination of switching to the 2 nd state when the 1 st condition is lower than the threshold α, that is, when the 1 st condition does not exceed the threshold α (the sequence of step S104 and step S106).

When the 2 nd detection unit 5 has no failure as determined by the 2 nd determination, the determination unit 7 performs the 1 st determination based on the detection result of the 2 nd detection unit 6 (the execution sequence of step S107, step S108, step S109, step S110, or step S111). In this step, the determination unit 7 performs the 1 st determination of switching to the 1 st state when the 2 nd condition exceeds the threshold α (step S109, step S110). The determination unit 7 performs the 1 st determination of switching to the 2 nd state when the 2 nd condition is lower than the threshold α, that is, when the 2 nd condition does not exceed the threshold α (the execution sequence of step S109 and step S111).

By such control, even when one of the 1 st and 2 nd detectors 5 and 6 has failed, the 1 st determination can be accurately performed using the detection result of the other detector. That is, the 1 st state and the 2 nd state can be switched accurately. Therefore, in the inverter device 1, redundancy can be achieved when switching between the 1 st state and the 2 nd state, and even if the 1 st detection unit 5 or the 2 nd detection unit 6 is broken, the motor 2 can be accurately operated. In addition, the load on the power supply unit 3 and the switching elements 41 can be reduced.

When it is determined by the 2 nd determination that the 1 st detecting unit 5 has a failure and it is determined that the 2 nd detecting unit has no failure, the determining unit 7 performs the 1 st determination based on the detection result of the 2 nd detecting unit 6 (the execution sequence of step S102, step S107, step S108, step S109, step S110, or step S111). In the flowchart shown in fig. 6, the execution order of step S102 and step S107 may be reversed. In this case, when it is determined by the 2 nd determination that the 2 nd detecting unit 5 has a failure and the 1 st detecting unit has no failure, the determining unit 7 performs the 1 st determination based on the detection result of the 1 st detecting unit 5. In this way, the determination unit 7 can accurately perform the 1 st determination regardless of the execution order of the failure determination by the 1 st detection unit 5 and the failure determination by the 2 nd detection unit 6.

When the 1 st detection unit 5 determines that there is a failure by the 2 nd determination and the 2 nd detection unit 6 determines that there is a failure, the determination unit 7 stops the control of the entire inverter device 1 (the execution sequence of step S102, step S107, and step S112). This also protects the entire inverter device 1 when both the 1 st and 2 nd detectors 5 and 6 fail.

As described above, the 1 st detection unit 5 detects the 1 st condition of the electricity acting on the inverter unit 4, and the 2 nd detection unit 6 detects the 2 nd condition of the electricity acting on the power supply unit 3. Further, as the 1 st condition, a voltage applied to the inverter unit 4, a current flowing through the inverter unit 4, or power generated in the inverter unit 4 is used, and as the 2 nd condition, a voltage applied to the power supply unit 3, a current flowing through the power supply unit 3, or power generated in the power supply unit 3 is used. Thus, the same physical quantity (voltage in the present embodiment) can be used in the 1 st condition and the 2 nd condition. Further, for each condition, the magnitude relationship between each condition and the threshold α can be compared using a common threshold α. Then, the 1 st judgment is made based on the magnitude relation.

On the other hand, for example, when the 1 st determination is made based on the rotation speed of the motor 2, the determination is made under the condition of the rotation speed of the motor 2, and redundancy cannot be achieved when the 1 st determination is made, that is, when the state is switched between the 1 st state and the 2 nd state. In addition, when two rotation angle sensors for detecting the rotation angle of the motor 2 are arranged, a space for arranging each rotation angle sensor is necessary, and for example, the inverter device 1 may be large. As described above, the inverter device 1 is preferably downsized because it is used on a vehicle. Further, when a plurality of rotation angle sensors are arranged, there is a problem that it is difficult to align the rotation angle sensors with the rotor of the motor 2 in assembly.

The inverter device of the present invention has been described above with reference to the illustrated embodiments, but the present invention is not limited thereto, and each part constituting the inverter device may be replaced with any structure capable of exhibiting the same function. In addition, any structure may be added.