In-vehicle power conversion device

Abstract

To determine a connection state of a connector and a state of an inspection circuit that inspects the connection state.SOLUTION: An on-vehicle power conversion device 30 includes an inverter circuit 44, a conversion device-side connector 110, a microcomputer 90, and an inspection circuit 50. The conversion device-side connector 110 includes a first inspection terminal 113 and a second inspection terminal 114. The microcomputer 90 includes an output terminal 92 that outputs a square wave, a first detection terminal 93, and a second detection terminal 94. The microcomputer 90 determines a connection state of a connector and a state of the inspection circuit 50 that inspects the connection state, based on detection results from the first detection terminal 93 and the second detection terminal 94.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to an in-vehicle power conversion device. [Background technology]

[0002] The vehicle-mounted electric compressor disclosed in Patent Document 1 includes a motor, an inverter device, a compressor-side connector, an inspection circuit, and a microcomputer. An external connector is connected to the compressor-side connector. A high-voltage power supply is connected to the inverter device by electrically connecting the external connector to the compressor-side connector. The inverter device converts DC power supplied from the high-voltage power supply into AC power and outputs it to the motor. The inspection circuit is a circuit for inspecting the connection state of the connector. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-170907 Summary of the Invention [Problem to be solved by the invention]

[0004] There are cases where it is necessary to determine the connection state of a connector and the state of an inspection circuit that inspects the connection state. [Means for solving the problem]

[0005] The in-vehicle power conversion device that solves the above problem includes a power conversion device having a switching element, a drive circuit that drives the switching element, and a microcomputer that controls the drive circuit, and converts power from a power source and supplies it to a load, a housing that houses the power conversion device, and a conversion-device-side connector that is electrically connected to the power conversion device and to which an external connector is connected, the microcomputer has an output terminal that outputs a rectangular wave, and first and second detection terminals that are capable of detecting the output rectangular wave, the conversion-device-side connector has a pair of inspection terminals that can be connected to inspection conductors provided on the external connector, and an inspection circuit is provided between the output terminal and the first detection terminal, and inspects a connection state between the conversion-device-side connector and the external connector together with the pair of inspection terminals and the inspection conductors, and the microcomputer detects the pair of An in-vehicle power conversion device in which inspection terminals are electrically connected and which determines that the conversion device side connector and the external connector are connected when the rectangular wave output from the output terminal is detected by the first detection terminal, wherein the inspection circuit has a rectifying element capable of transmitting the rectangular wave in only one direction from the output terminal to one of the inspection terminals, and a branch circuit branching off from a branch point between an anode of the rectifying element and the output terminal and extending from the branch point to the second detection terminal, and the microcontroller determines the following abnormalities based on detection results from the first detection terminal and the second detection terminal, and outputs an abnormality signal indicating which of the following abnormalities is present: a connection abnormality between the conversion device side connector and the external connector, a ground short-circuit abnormality in which the inspection circuit is short-circuited to ground, or a power supply short-circuit abnormality in which the inspection circuit is short-circuited to a power supply that applies voltage to the power conversion device.

[0006] When the converter-side connector and the external connector are connected, a pair of inspection terminals are electrically connected by the inspection conductor. In this case, a rectangular wave is detected at the first detection terminal, so the microcontroller can determine that the converter-side connector and the external connector are connected. Furthermore, the detection results of the first detection terminal and the second detection terminal differ depending on a connection abnormality, a ground short-circuit abnormality, and a power supply short-circuit abnormality. The microcontroller can determine an abnormality depending on the detection results of the first detection terminal and the second detection terminal. Therefore, the microcontroller can determine the connection state of the connector and the state of the inspection circuit that inspects the connection state.

[0007] In the above-mentioned in-vehicle power conversion device, the microcomputer may determine that a connection abnormality has occurred when the first detection terminal detects only a low level signal and the second detection terminal detects the square wave, determine that a ground short-circuit abnormality has occurred when the first detection terminal detects only a low level signal and the second detection terminal detects only a low level signal, and determine that a power supply short-circuit abnormality has occurred when the first detection terminal detects only a high level signal and the second detection terminal detects the square wave.

[0008] In the above-mentioned in-vehicle power conversion device, the microcomputer may determine that a connection abnormality has occurred when the first detection terminal detects only a high level signal and the second detection terminal detects the square wave, determine that a ground short-circuit abnormality has occurred when the first detection terminal detects only a high level signal and the second detection terminal detects only a low level signal, and determine that a power supply short-circuit abnormality has occurred when the first detection terminal detects only a low level signal and the second detection terminal detects the square wave. Effect of the Invention

[0009] According to the present invention, it is possible to determine the connection state of the connector and the state of the inspection circuit that inspects the connection state. [Brief description of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view showing a vehicle-mounted electric compressor with a part cut away; [Diagram 2] FIG. [Diagram 3] FIG. 2 is a diagram showing a first surface of the circuit board. [Figure 4] FIG. 4 is a diagram showing a second surface of the circuit board. [Diagram 5] 1 is a circuit diagram showing an in-vehicle power conversion device; [Figure 6] FIG. 2 is a circuit diagram showing an inverter circuit. [Figure 7] 5A and 5B are diagrams illustrating the relationship between the connection state of the connector, the state of the inspection circuit, and the state of each detection terminal. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] An embodiment of an on-vehicle power conversion device will be described below. <Vehicle> As shown in Fig. 1, a vehicle 10 includes a vehicle air conditioner 11, a high-voltage power supply 12, and an external connector 120. The vehicle air conditioner 11 includes an external refrigerant circuit 13 and an in-vehicle electric compressor 20. The external refrigerant circuit 13 supplies refrigerant to the in-vehicle electric compressor 20. The external refrigerant circuit 13 includes an evaporator, a condenser, an expansion valve, and the like. The external refrigerant circuit 13 cools and heats the interior of the vehicle 10 by exchanging heat between the outside and the refrigerant.

[0012] <Automotive electric compressor> The vehicle-mounted electric compressor 20 includes a housing 21, a compression section 27 that compresses a refrigerant, a motor 28, and an vehicle-mounted power conversion device 30.

[0013] The housing 21 includes a first housing 22 and a second housing 24. The first housing 22 includes an intake port 23. The intake port 23 is connected to the external refrigerant circuit 13. The second housing 24 is fixed to the first housing 22. The second housing 24 includes an exhaust port 25. The exhaust port 25 is connected to the external refrigerant circuit 13.

[0014] The compression section 27 compresses the refrigerant sucked into the housing 21 from the suction port 23. The compressed refrigerant is discharged from the discharge port 25. The compression section 27 may be of any type, such as a scroll type, a piston type, or a vane type. The motor 28 drives the compression section 27. The motor 28 is a three-phase motor. The compression section 27 and the motor 28 are housed in the first housing 22. When the compression section 27 is driven by the motor 28, the refrigerant sucked from the suction port 23 is compressed and discharged from the discharge port 25. The compression section 27 does not have to be housed in the housing 21.

[0015] <Automotive power conversion device> 1 and 2, the in-vehicle power conversion device 30 includes a housing 26, a circuit board 31, a high-voltage circuit 41, an inspection circuit 50, two insulating elements 65 and 66, and a conversion device-side connector 110. The inspection circuit 50 includes a low-voltage circuit 51, a photocoupler 61, and an isolator 71.

[0016] The housing 26 is fixed to the first housing 22. The housing 26 is attached to the first housing 22 to define an accommodation space A1. The circuit board 31 is accommodated in the accommodation space A1. The circuit board 31 is plate-shaped. The circuit board 31 includes a first surface 32 and a second surface 33. The first surface 32 and the second surface 33 are surfaces that are opposite to each other in the thickness direction of the circuit board 31. The circuit board 31 includes slits 34, 35. In this embodiment, two slits 34, 35 are provided. The slits 34, 35 are, for example, oval. The slits 34, 35 may be shaped like a rectangle or the like. The two slits 34, 35 are arranged side by side in the longitudinal direction of the two slits 34, 35. Hereinafter, the longitudinal direction of the slits 34, 35 may be referred to as a first direction, and the direction perpendicular to the first direction and the thickness direction of the circuit board 31 may be referred to as a second direction. For convenience, one of the two slits 34 and 35 will be referred to as a first slit 34 , and the other of the two slits 34 and 35 that is different from the first slit 34 will be referred to as a second slit 35 .

[0017] The high voltage circuit 41 is formed on the circuit board 31. The high voltage circuit 41 includes a first high voltage circuit portion 42 and a second high voltage circuit portion 43. The first high voltage circuit portion 42 is provided on the first surface 32. The second high voltage circuit portion 43 is provided on the second surface 33.

[0018] The low-voltage circuit 51 is formed on the circuit board 31. The low-voltage circuit 51 includes a first low-voltage circuit portion 52 and a second low-voltage circuit portion 53. The first low-voltage circuit portion 52 is provided on the first surface 32. The second low-voltage circuit portion 53 is provided on the second surface 33.

[0019] Different voltages are applied to the high voltage circuit 41 and the low voltage circuit 51. For example, the high voltage circuit 41 operates with a voltage of 400V to 800V applied from the high voltage power supply 12, and the low voltage circuit 51 operates with a voltage of 12V or 24V applied from a low voltage power supply (not shown). The ground of the high voltage circuit 41 and the ground of the low voltage circuit 51 are insulated from each other.

[0020] As shown in Figs. 3 and 4, the high voltage circuit 41 and the low voltage circuit 51 are arranged side by side with a gap between them. The first high voltage circuit section 42 and the first low voltage circuit section 52 are arranged side by side with a gap between them on the first surface 32. The second high voltage circuit section 43 and the second low voltage circuit section 53 are arranged side by side with a gap between them on the second surface 33. The high voltage circuit 41 and the low voltage circuit 51 are arranged with slits 34, 35 sandwiched therebetween. The slits 34, 35 are provided between the high voltage circuit 41 and the low voltage circuit 51. The high voltage circuit 41 and the low voltage circuit 51 are arranged side by side in a second direction. The first direction is a direction intersecting the direction in which the high voltage circuit 41 and the low voltage circuit 51 are arranged side by side.

[0021] As shown in FIG. 3, the photocoupler 61 is mounted on the first surface 32. The photocoupler 61 is provided between the high voltage circuit 41 and the low voltage circuit 51. The photocoupler 61 is provided between the first high voltage circuit section 42 and the first low voltage circuit section 52. The photocoupler 61 faces the first slit 34. The dimension of the photocoupler 61 in the first direction is shorter than the dimension of the first slit 34 in the first direction. The photocoupler 61 is provided so that the first slit 34 protrudes in the first direction beyond the outer edge of the photocoupler 61 when the circuit board 31 is viewed from the plate thickness direction. In this embodiment, when the circuit board 31 is viewed from the plate thickness direction, the first slit 34 protrudes from the outer edge of the photocoupler 61 on both sides in the first direction. When the circuit board 31 is viewed from the plate thickness direction, the first slit 34 may protrude from the outer edge of the photocoupler 61 to one side in the first direction.

[0022] The isolator 71 is mounted on the first surface 32. The isolator 71 is provided between the high voltage circuit 41 and the low voltage circuit 51. The isolator 71 is provided between the first high voltage circuit section 42 and the first low voltage circuit section 52. The isolator 71 faces the second slit 35. The dimension of the isolator 71 in the first direction is shorter than the dimension of the second slit 35 in the first direction. The isolator 71 is provided such that the second slit 35 protrudes in the first direction beyond the outer edge of the isolator 71 when the circuit board 31 is viewed from the plate thickness direction. In this embodiment, when the circuit board 31 is viewed from the plate thickness direction, the second slit 35 protrudes from the outer edge of the isolator 71 on both sides in the first direction. When the circuit board 31 is viewed from the plate thickness direction, the second slit 35 may protrude from the outer edge of the isolator 71 to one side in the first direction.

[0023] As shown in FIG. 4, the insulating element 65 is mounted on the second surface 33. The insulating element 65 is provided between the high voltage circuit 41 and the low voltage circuit 51. The insulating element 65 is provided between the second high voltage circuit section 43 and the second low voltage circuit section 53. The insulating element 65 faces the first slit 34. The dimension of the insulating element 65 in the first direction is shorter than the dimension of the first slit 34 in the first direction. The insulating element 65 is provided so that the first slit 34 protrudes in the first direction beyond the outer edge of the insulating element 65 when the circuit board 31 is viewed from the plate thickness direction. In this embodiment, when the circuit board 31 is viewed from the plate thickness direction, the first slit 34 protrudes from the outer edge of the insulating element 65 on both sides in the first direction. When the circuit board 31 is viewed from the plate thickness direction, the first slit 34 may protrude from the outer edge of the insulating element 65 to one side in the first direction. It can be said that the photocoupler 61 and the insulating element 65 are provided with the first slit 34 therebetween. The insulating element 65 may be a photocoupler or an isolator.

[0024] The insulating element 66 is mounted on the second surface 33. The insulating element 66 is provided between the high voltage circuit 41 and the low voltage circuit 51. The insulating element 66 is provided between the second high voltage circuit section 43 and the second low voltage circuit section 53. The insulating element 66 faces the second slit 35. The dimension of the insulating element 66 in the first direction is shorter than the dimension of the second slit 35 in the first direction. The insulating element 66 is provided such that the second slit 35 protrudes in the first direction beyond the outer edge of the insulating element 66 when the circuit board 31 is viewed from the plate thickness direction. In this embodiment, when the circuit board 31 is viewed from the plate thickness direction, the second slit 35 protrudes from the outer edge of the insulating element 66 on both sides in the first direction. When the circuit board 31 is viewed from the plate thickness direction, the second slit 35 may protrude from the outer edge of the insulating element 66 to one side in the first direction. It can be said that the isolator 71 and the insulating element 66 are provided with the second slit 35 sandwiched therebetween. The insulating element 66 may be a photocoupler or an isolator.

[0025] 5, the photocoupler 61 includes a photodiode 62 and a phototransistor 63. The cathode of the photodiode 62 is connected to the ground of the low-voltage circuit 51. The phototransistor 63 is, for example, an NPN-type transistor. The collector of the phototransistor 63 is connected to a power supply. The phototransistor 63 is turned on when it receives light emitted by the photodiode 62. The photocoupler 61 is an insulating element that transmits a signal between the low-voltage circuit 51 and the high-voltage circuit 41 while maintaining insulation between the low-voltage circuit 51 and the high-voltage circuit 41.

[0026] The isolator 71 includes a low-voltage power supply terminal 72, a first low-voltage signal terminal 73, a second low-voltage signal terminal 74, a third low-voltage signal terminal 75, a low-voltage ground terminal 76, a high-voltage power supply terminal 77, a first high-voltage signal terminal 78, a second high-voltage signal terminal 79, a third high-voltage signal terminal 80, and a high-voltage ground terminal 81. The low-voltage power supply terminal 72 is connected to a power supply. The low-voltage ground terminal 76 is connected to the ground of the low-voltage circuit 51. The high-voltage power supply terminal 77 is connected to a power supply. The high-voltage ground terminal 81 is connected to the ground of the high-voltage circuit 41. The isolator 71 is an insulating element that transmits signals between the low-voltage circuit 51 and the high-voltage circuit 41 while maintaining insulation between the low-voltage circuit 51 and the high-voltage circuit 41. Isolator 71 transmits signals between first low-voltage side signal terminal 73 and first high-voltage side signal terminal 78, between second low-voltage side signal terminal 74 and second high-voltage side signal terminal 79, and between third low-voltage side signal terminal 75 and third high-voltage side signal terminal 80. As isolator 71, a magnetically coupled isolator or a capacitively coupled isolator may be used. A magnetically coupled isolator is an isolator that uses magnetic coupling of a coil. A capacitively coupled isolator is an isolator that uses a capacitor. Isolator 71 in this embodiment is a magnetically coupled isolator.

[0027] High-voltage circuit 41 includes power conversion device 45, first high-voltage side resistor element 101, second high-voltage side resistor element 102, and high-voltage side capacitor 103. Power conversion device 45 includes inverter circuit 44 and microcomputer 90.

[0028] The inverter circuit 44 is a three-phase inverter that converts DC power supplied from the high-voltage power supply 12 as a power supply into AC power and outputs the AC power. The inverter circuit 44 and the motor 28 are electrically connected. The motor 28 is a load.

[0029] As shown in FIG. 6, the inverter circuit 44 includes switching elements Q1, Q2, Q3, Q4, Q5, and Q6, and drive circuits D1, D2, D3, D4, D5, and D6. The switching elements Q1 to Q6 may be, for example, insulated gate bipolar transistors or MOSFETs. Each of the switching elements Q1 to Q6 includes a diode D. The switching element Q1 constituting the U-phase upper arm and the switching element Q2 constituting the U-phase lower arm are connected in series. The switching element Q3 constituting the V-phase upper arm and the switching element Q4 constituting the V-phase lower arm are connected in series. The switching element Q5 constituting the W-phase upper arm and the switching element Q6 constituting the W-phase lower arm are connected in series. The connection points between the upper arm switching elements Q1, Q3, Q5 and the lower arm switching elements Q2, Q4, Q6 are connected to the motor 28 for each phase.

[0030] The drive circuits D1 to D6 are provided for each of the switching elements Q1 to Q6, respectively. The drive circuits D1 to D6 drive the switching elements Q1 to Q6. The microcomputer 90 drives the motor 28 by controlling the inverter circuit 44. The microcomputer 90 outputs control signals for controlling the switching elements Q1 to Q6 to the drive circuits D1 to D6. In this way, the microcomputer 90 controls the drive circuits D1 to D6.

[0031] As shown in FIG. 5, the microcomputer 90 includes a processor 91, an output terminal 92, a first detection terminal 93, a second detection terminal 94, a third detection terminal 95, a communication terminal 96, and an A / D conversion unit 97. The A / D conversion unit 97 is provided for each of the output terminal 92, the first detection terminal 93, the second detection terminal 94, and the third detection terminal 95. The processor 91 can set the potential of the output terminal 92 to a high level or a low level via the A / D conversion unit 97. The processor 91 can determine whether the potentials of the first detection terminal 93, the second detection terminal 94, and the third detection terminal 95 are at a high level or a low level via the A / D conversion unit 97. The first detection terminal 93, the second detection terminal 94, and the third detection terminal 95 can detect the square wave output from the output terminal 92.

[0032] The first high-voltage side resistor element 101 is connected to the emitter of the phototransistor 63. The emitter of the phototransistor 63 is connected to the ground of the high-voltage circuit 41 via the first high-voltage side resistor element 101. The first detection terminal 93 is connected between the emitter of the phototransistor 63 and the first high-voltage side resistor element 101. The first high-voltage side resistor element 101 is a pull-down resistor. The second high-voltage side resistor element 102 connects the high-voltage side power supply terminal 77 and the output terminal 92. The high-voltage side capacitor 103 is provided between the high-voltage side power supply terminal 77 and the high-voltage side ground terminal 81.

[0033] The output terminal 92 is connected to the first high-voltage side signal terminal 78. The second detection terminal 94 is connected to the second high-voltage side signal terminal 79. The third detection terminal 95 is connected to the output terminal 92. The communication terminal 96 is connected to the third high-voltage side signal terminal 80.

[0034] Conversion device side connector 110 includes first connection terminal 111, second connection terminal 112, first inspection terminal 113, and second inspection terminal 114. First connection terminal 111 and second connection terminal 112 are electrically connected to inverter circuit 44. First inspection terminal 113 and second inspection terminal 114 are a pair of inspection terminals. An external connector 120 is connected to conversion device side connector 110.

[0035] The external connector 120 includes a first external terminal 121, a second external terminal 122, and an inspection conductor 123. The first external terminal 121 and the second external terminal 122 are connected to the high-voltage power supply 12. When the external connector 120 is connected to the conversion device side connector 110, the first external terminal 121 and the first connection terminal 111 are electrically connected. When the external connector 120 is connected to the conversion device side connector 110, the second external terminal 122 and the second connection terminal 112 are electrically connected. This allows DC power to be supplied from the high-voltage power supply 12 to the inverter circuit 44. This drives the motor 28. The first inspection terminal 113 and the second inspection terminal 114 are connectable to the inspection conductor 123. When the external connector 120 is connected to the conversion device side connector 110, the first inspection terminal 113 and the second inspection terminal 114 are electrically connected to the inspection conductor 123. As a result, first terminal for inspection 113 and second terminal for inspection 114 are electrically connected via conductor for inspection 123 .

[0036] The vehicle 10 includes a system main relay 130, a vehicle ECU 131, a power switch 132, a first communication connector 133, and a second communication connector 134. The system main relay 130 is provided between the high voltage power supply 12 and the external connector 120. The vehicle ECU 131 is an ECU (Electronic Control Unit) that controls the system main relay 130. When the power switch 132 is turned on, the vehicle ECU 131 closes the system main relay 130. When the power switch 132 is turned off, the vehicle ECU 131 opens the system main relay 130. The first communication connector 133 is connected to the vehicle ECU 131. The first communication connector 133 is connected to the second communication connector 134.

[0037] The inspection circuit 50 is provided between the conversion device side connector 110 and the microcomputer 90. The inspection circuit 50 is provided between the output terminal 92 and the first detection terminal 93, and inspects the connection state between the conversion device side connector 110 and the external connector 120 together with the pair of inspection terminals 113, 114 and the inspection conductor 123. The inspection circuit 50 is also a part of the power conversion device 45.

[0038] The low-voltage circuit 51 includes a first connecting line 141, a first resistive element 142, a first varistor 143, a second connecting line 144, a second varistor 145, a diode 146, a second resistive element 147, a third resistive element 148, a capacitor 149, a communication unit 150, and a connecting line 152.

[0039] The first connection line 141 connects the first inspection terminal 113 and the photocoupler 61. The first connection line 141 is connected to the anode of the photodiode 62 via a first resistor element 142. The first connection line 141 is grounded via a first varistor 143. The photocoupler 61 is provided between the first inspection terminal 113 and the first detection terminal 93. When a high-level signal is input to the photocoupler 61, the photodiode 62 emits light. This turns on the phototransistor 63, and the signal input to the first detection terminal 93 changes from low level to high level.

[0040] The second connection line 144 connects the second terminal for inspection 114 and the diode 146. The second connection line 144 is connected to the cathode of the diode 146. The second connection line 144 is grounded via a second varistor 145. The diode 146 is connected to the second terminal for inspection 114 by the second connection line 144. The diode 146 allows a current to flow toward the second terminal for inspection 114. The diode 146 is a rectifying element.

[0041] The anode of diode 146 is connected to first low-voltage side signal terminal 73 via second resistor element 147. Connection line 152 branches off from branch point 151 between the anode of diode 146 and output terminal 92, and extends from branch point 151 to second low-voltage side signal terminal 74. Connection line 152 and isolator 71 form a branch circuit.

[0042] When output terminal 92 outputs a rectangular wave, the rectangular wave is input to first high-voltage side signal terminal 78. The rectangular wave output from first low-voltage side signal terminal 73 is transmitted to diode 146. Diode 146 is capable of transmitting the rectangular wave in only one direction from output terminal 92 toward second inspection terminal 114, which is one of the inspection terminals. In addition, the rectangular wave output from first low-voltage side signal terminal 73 is input to second low-voltage side signal terminal 74. As a result, a rectangular wave is output from second high-voltage side signal terminal 79, and thereby a rectangular wave is input to second detection terminal 94.

[0043] Third resistor element 148 connects low-voltage power supply terminal 72 and second low-voltage signal terminal 74. Capacitor 149 is provided between low-voltage power supply terminal 72 and low-voltage ground terminal .

[0044] The communication unit 150 is a transceiver for communication between the vehicle ECU 131 and the microcomputer 90. The communication unit 150 is connected to the second communication connector 134. The communication unit 150 is connected to the third low-voltage side signal terminal 75.

[0045] [Operation of this embodiment] The operation of this embodiment will now be described together with the control performed by the microcomputer 90. When the power switch 132 is turned on while the external connector 120 is attached to the converter-side connector 110, the system main relay 130 is closed, electrically connecting the high-voltage power supply 12 to the inverter circuit 44. The microcomputer 90 determines the connection state of the connector and the state of the inspection circuit 50, which inspects the connection state.

[0046] As shown in FIG. 7, the connection state of the connector can be a connection and a connection abnormality. The state of the inspection circuit 50 can be a power supply short circuit abnormality, a ground short circuit abnormality, and an output abnormality. The connection is a state in which the external connector 120 is attached to the converter-side connector 110, and the external connector 120 and the converter-side connector 110 are electrically connected. More specifically, the first external terminal 121 and the first connection terminal 111 are electrically connected, and the second external terminal 122 and the second connection terminal 112 are electrically connected. The connection abnormality is a state in which the external connector 120 and the converter-side connector 110 are not electrically connected. The power supply short circuit abnormality is a state in which the inspection circuit 50 is short-circuited to the high-voltage power supply 12 or the low-voltage power supply. The ground short circuit abnormality is a state in which the inspection circuit 50 is short-circuited to the ground. The output abnormality is an abnormality in the signal output from the output terminal 92.

[0047] The microcomputer 90 judges whether a connection abnormality, a power supply short circuit abnormality, a ground short circuit abnormality, or an output abnormality has occurred. The microcomputer 90 outputs an abnormality signal indicating which abnormality has occurred. The abnormality signal is input to the vehicle ECU 131 via the communication unit 150. When the abnormality signal is input, the vehicle ECU 131 issues an alarm. The alarm is issued, for example, by turning on a lamp or activating a buzzer.

[0048] When the microcomputer 90 determines the connection state of the connector and the state of the inspection circuit 50 that inspects the connection state, it outputs a square wave from the output terminal 92. The square wave is a signal that periodically switches between a high level signal and a low level signal. When the microcomputer 90 outputs a square wave from the output terminal 92, it determines the connection state of the connector and the state of the inspection circuit 50 according to the detection results at the first detection terminal 93, the second detection terminal 94, and the third detection terminal 95. The detection results at the first detection terminal 93, the second detection terminal 94, and the third detection terminal 95 are signals detected at the first detection terminal 93, the second detection terminal 94, and the third detection terminal 95.

[0049] <Connection> When the connector is in a connected state, a square wave is detected at the first detection terminal 93. When the connector is in a connected state, the first inspection terminal 113 and the second inspection terminal 114 are electrically connected via the inspection conductor 123. When the output terminal 92 outputs a square wave, the square wave is input to the photocoupler 61 via the isolator 71, the diode 146, the second inspection terminal 114, the inspection conductor 123, and the first inspection terminal 113. When a high-level signal is input to the photocoupler 61, the photodiode 62 emits light, turning on the phototransistor 63. Then, a high-level signal is input to the first detection terminal 93. When a low-level signal is input to the photocoupler 61, the photodiode 62 does not emit light, so the phototransistor 63 is off. Then, a low-level signal is input to the first detection terminal 93. Therefore, when the connector is in a connected state, a square wave is detected at the first detection terminal 93.

[0050] When the connector is in a connected state, the second detection terminal 94 and the third detection terminal 95 detect the same signal as the output of the output terminal 92. That is, the second detection terminal 94 and the third detection terminal 95 detect a square wave. When the output terminal 92 outputs a square wave, the square wave is input to the second detection terminal 94 via the isolator 71. In detail, the square wave input to the first high-voltage side signal terminal 78 and output from the first low-voltage side signal terminal 73 is input to the second low-voltage side signal terminal 74. Then, the square wave output from the second high-voltage side signal terminal 79 is input to the second detection terminal 94. Since the third detection terminal 95 is connected to the first detection terminal 93, the square wave output from the first detection terminal 93 is input to the third detection terminal 95. When the first detection terminal 93 detects a square wave, the microcomputer 90 determines that the connection is established. When the microcomputer 90 detects a square wave at all of the first detection terminal 93, the second detection terminal 94, and the third detection terminal 95, it may determine that a connection has been established.

[0051] <Connection error> When the connection state of the connector is abnormal, the first detection terminal 93 detects only a low level signal. When the connection state of the connector is abnormal, the first inspection terminal 113 and the second inspection terminal 114 are not electrically connected. Even if the output terminal 92 outputs a square wave, the square wave is not input to the photocoupler 61. Therefore, when the connection state of the connector is abnormal, the first detection terminal 93 detects only a low level signal. Also, when the connection state of the connector is abnormal, the second detection terminal 94 and the third detection terminal 95 detect a signal identical to the output of the output terminal 92. When the first detection terminal 93 detects only a low level signal and the second detection terminal 94 detects a square wave, the microcomputer 90 determines that there is an abnormal connection. When the first detection terminal 93 detects only a low level signal and the second detection terminal 94 and the third detection terminal 95 detect a square wave, the microcomputer 90 may determine that there is an abnormal connection.

[0052] <Power supply short circuit abnormality> When the state of the inspection circuit 50 is a power supply short circuit abnormality, the first detection terminal 93 detects only a high level signal. When a power supply short circuit abnormality occurs, a current flows through the first connection line 141 and the second connection line 144 due to the voltage applied from the high voltage power supply 12 or the low voltage power supply. This current flows through the photodiode 62, turning on the phototransistor 63. As a result, a high level signal is always input to the first detection terminal 93. Even if a power supply short circuit abnormality occurs, the diode 146 prevents current from flowing through the isolator 71. Therefore, when the state of the inspection circuit 50 is a power supply short circuit abnormality, the second detection terminal 94 and the third detection terminal 95 detect a signal identical to the output of the output terminal 92. When the first detection terminal 93 detects only a high level signal and the second detection terminal 94 detects a square wave, the microcomputer 90 determines that a power supply short circuit abnormality has occurred. The microcomputer 90 may determine that a power supply short circuit abnormality has occurred when the first detection terminal 93 detects only a high level signal and the second detection terminal 94 and the third detection terminal 95 detect a rectangular wave.

[0053] <Ground short circuit abnormality> When the state of the inspection circuit 50 is a ground short-circuit abnormality, the first detection terminal 93 detects only a low level signal. When a ground short-circuit abnormality occurs, even if the first detection terminal 93 outputs a square wave, no current flows to the photocoupler 61 through the first connection line 141 and the second connection line 144. That is, the first connection line 141 and the second connection line 144 are maintained at a low level. As a result, the first detection terminal 93 detects only a low level signal. When a ground short-circuit abnormality occurs, the first connection line 141 and the second connection line 144 are maintained at a low level, so that even if the output terminal 92 outputs a high level signal, a current flows to the ground through the first connection line 141 and the second connection line 144. Since a high level signal is not input to the second low-voltage side signal terminal 74, the second detection terminal 94 detects only a low level signal. The third detection terminal 95 detects a signal identical to the output of the output terminal 92. The microcomputer 90 determines that a ground short-circuit anomaly has occurred when the first detection terminal 93 and the second detection terminal 94 detect only low-level signals. The microcomputer 90 may also determine that a ground short-circuit anomaly has occurred when the first detection terminal 93 and the second detection terminal 94 detect only low-level signals and the third detection terminal 95 detects a square wave.

[0054] <Output abnormality> When the state of the inspection circuit 50 is an output abnormality, the first detection terminal 93 detects only a high level signal or a low level signal. When the state of the inspection circuit 50 is an output abnormality, it can be said that a square wave is not output from the output terminal 92 even though the microcomputer 90 controls the output terminal 92 to output a square wave. The second detection terminal 94 and the third detection terminal 95 detect a signal different from the output of the output terminal 92, i.e., a signal different from a square wave. The microcomputer 90 determines that there is an output abnormality when the first detection terminal 93 detects only a high level signal or a low level signal and the third detection terminal 95 detects a signal different from a square wave. The microcomputer 90 may determine that there is an output abnormality when the first detection terminal 93 detects only a high level signal or a low level signal and the second detection terminal 94 and the third detection terminal 95 detect a signal different from a square wave.

[0055] [Effects of this embodiment] (1) When a rectangular wave is detected at the first detection terminal 93, the microcomputer 90 can determine that the conversion device side connector 110 and the external connector 120 are connected. The microcomputer 90 can determine an abnormality according to the detection results of the first detection terminal 93 and the second detection terminal 94. Therefore, the microcomputer 90 can determine the connection state of the connectors and the state of the inspection circuit 50 that inspects the connection state.

[0056] (2) The inspection circuit 50 includes an isolator 71. If a photocoupler is used instead of the isolator 71, it is necessary to provide one photocoupler between the output terminal 92 and the diode 146 and one photocoupler between the second detection terminal 94 and the diode 146. By using the isolator 71, the number of parts can be reduced compared to when a photocoupler is used. Furthermore, the isolator 71 has a function of transmitting a signal output from the microcomputer 90 to the communication unit 150. The number of parts can be reduced compared to when a separate member is provided to transmit a signal output from the microcomputer 90 to the communication unit 150.

[0057] (3) The circuit board 31 has slits 34 and 35. By providing the slits 34 and 35, the creepage distance between the high-voltage circuit 41 and the low-voltage circuit 51 can be increased. (4) Circuit board 31 has a first surface 32 and a second surface 33. Photocoupler 61 provided on first surface 32 and insulating element 65 provided on second surface 33 face first slit 34. Isolator 71 provided on first surface 32 and insulating element 66 provided on second surface 33 face second slit 35. By using slits 34 and 35, it is possible to increase both the creepage distance between first high-voltage circuit section 42 and first low-voltage circuit section 52 and the creepage distance between second high-voltage circuit section 43 and second low-voltage circuit section 53.

[0058] [Example of change] The embodiment can be modified as follows: The embodiment and the following modified examples can be combined with each other to the extent that there is no technical contradiction.

[0059] The microcomputer 90 may determine that there is a connection abnormality when the first detection terminal 93 detects only a high level signal and the second detection terminal 94 detects a square wave. In this case, a pull-up resistor is provided instead of the first high-voltage side resistor element 101. The pull-up resistor is connected to the collector of the phototransistor 63. By connecting the connection point between the pull-up resistor and the collector of the phototransistor 63 to the first detection terminal 93, when there is a connection abnormality between the conversion device side connector 110 and the external connector 120, the first detection terminal 93 detects only a high level signal.

[0060] Microcomputer 90 may determine that a ground short-circuit anomaly has occurred when first detection terminal 93 detects only a high-level signal and second detection terminal 94 detects only a low-level signal. In this case, a pull-up resistor is provided instead of first high-voltage side resistor element 101, as described above.

[0061] Microcomputer 90 may determine that a power supply short circuit abnormality has occurred when first detection terminal 93 detects only a low level signal and second detection terminal 94 detects a rectangular wave. In this case, as described above, a pull-up resistor is provided instead of first high-voltage side resistor element 101.

[0062] The photocoupler 61 may be integrated with the isolator 71. That is, the isolator 71 may further have the same function as the photocoupler 61. The circuit board 31 does not have to include the slits 34 and 35.

[0063] A photocoupler may be used instead of the isolator 71. In this case, one photocoupler is provided between the output terminal 92 and the diode 146. One photocoupler is provided between the second detection terminal 94 and the diode 146. One photocoupler is provided between the communication terminal 96 and the communication unit 150.

[0064] The isolator 71 does not have to include the third low-voltage side signal terminal 75 and the third high-voltage side signal terminal 80. In this case, a photocoupler may be provided between the communication terminal 96 and the communication unit 150.

[0065] The on-vehicle power conversion device 30 may be used in a device other than the on-vehicle electric compressor 20 as long as it is used in the vehicle 10. Depending on the device in which the on-vehicle power conversion device 30 is used, the power conversion device may be changed to a main engine inverter that drives a driving motor, or a DC / DC converter that converts a high voltage to a low voltage.

[0066] A switching element may be used as the rectifying element. The two slits 34 and 35 may be connected to each other. That is, the circuit board 31 may have one slit that faces the photocoupler 61, the isolator 71, and the insulating elements 65 and 66.

[0067] The circuit board 31 may include only one of the first slit 34 facing the photocoupler 61 and the second slit 35 facing the isolator 71 . A terminal connected to the first detection terminal 93 may be provided in the microcomputer 90 to determine whether an abnormality has occurred in the first detection terminal 93. A terminal connected to the second detection terminal 94 may be provided in the microcomputer 90 to determine whether an abnormality has occurred in the second detection terminal 94.

[0068] The external connector 120 may be an inspection connector that is connected to a diagnostic tester that diagnoses abnormalities in the in-vehicle electric compressor 20 before the in-vehicle electric compressor 20 is shipped from a factory. The low voltage power supply may be omitted. In this case, the voltage of the high voltage power supply 12 may be reduced and applied to the low voltage circuit 51. [Explanation of symbols]

[0069] D1 to D6...drive circuits, Q1 to Q6...switching elements, 12...high-voltage power supply as power source, 26...housing, 30...vehicle-mounted power conversion device, 45...power conversion device, 50...inspection circuit, 71...isolator which is part of the branch circuit, 90...microcontroller, 92...output terminal, 93...first detection terminal, 94...second detection terminal, 110...conversion device side connector, 113, 114...pair of inspection terminals, 120...external connector, 123...inspection conductor, 146...diode which is a rectifying element, 152...connecting wire which is part of the branch circuit.

Claims

1. a power conversion device including a switching element, a drive circuit for driving the switching element, and a microcomputer for controlling the drive circuit, and configured to convert power from a power source and supply the converted power to a load; A housing that houses the power conversion device; a converter-side connector electrically connected to the power converter and to which an external connector is connected; the microcomputer has an output terminal for outputting a rectangular wave, and a first detection terminal and a second detection terminal for detecting the output rectangular wave; the conversion device side connector has a pair of inspection terminals connectable to an inspection conductor provided on the external connector, an inspection circuit is provided between the output terminal and the first detection terminal, and inspects a connection state between the pair of inspection terminals and the inspection conductor, as well as between the conversion device side connector and the external connector; the microcomputer determines that the conversion-apparatus-side connector and the external connector are connected when the pair of the inspection terminals are electrically connected by the inspection conductor and the rectangular wave output from the output terminal is detected by the first detection terminal, the inspection circuit includes a rectifying element capable of transmitting the rectangular wave in only one direction from the output terminal to one of the inspection terminals; a branch circuit branching from a branch point between the anode of the rectifying element and the output terminal and extending from the branch point to the second detection terminal, The microcomputer is determining whether an abnormality occurs based on detection results from the first detection terminal and the second detection terminal; a connection abnormality between the converter side connector and the external connector; a ground short circuit abnormality in which the inspection circuit is shorted to ground; a power supply short circuit abnormality in which the inspection circuit is short-circuited with a power supply that applies a voltage to the power conversion device; An in-vehicle power conversion device characterized in that any of the abnormalities is output as an abnormality signal.

2. The microcomputer is When the first detection terminal detects only a low level signal and the second detection terminal detects the rectangular wave, the connection is determined to be abnormal. When the first detection terminal detects only a low level signal and the second detection terminal detects only a low level signal, the ground short-circuit anomaly is determined; 2. The vehicle-mounted power conversion device according to claim 1, wherein the power supply short circuit abnormality is determined to occur when the first detection terminal detects only a high level signal and the second detection terminal detects the rectangular wave.

3. The microcomputer is When the first detection terminal detects only a high level signal and the second detection terminal detects the rectangular wave, the connection is determined to be abnormal. When the first detection terminal detects only a high level signal and the second detection terminal detects only a low level signal, the ground short-circuit anomaly is determined; 2. The vehicle-mounted power conversion device according to claim 1, wherein the power supply short circuit abnormality is determined to occur when the first detection terminal detects only a low level signal and the second detection terminal detects the rectangular wave.

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