Abnormality detection device of voltage detection circuit

Abstract

To suppress addition of a new circuit and detect occurrence of abnormality related to a voltage detection circuit in an abnormality detection device of the voltage detection circuit.SOLUTION: An abnormality detection device (70) detects abnormality of a first voltage detection circuit (30) for detecting a voltage before boosting that is a voltage of an input point (Pi) of a booster circuit (20) and a second voltage detection circuit (40) for detecting a voltage after boosting that is a voltage of an output point (Po) of the booster circuit. The booster circuit has a forward diode (26) for connecting the input point and the output point, and boosts the voltage inputted to the input point and outputs it from the output point. The abnormality detection device determines occurrence of abnormality regarding the first voltage detection circuit or abnormality regarding the second voltage detection circuit when the booster circuit does not execute boosting and a degree of difference between the voltage before boosting detected by the first voltage detection circuit and the voltage after boosting detected by the second voltage detection circuit is larger than a predetermined degree.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an abnormality detection device that detects an abnormality in a voltage detection circuit. [Background technology]

[0002] For example, there is a voltage detection device that divides a voltage to be detected by a resistive voltage dividing means, and detects the voltage divided by the resistive voltage dividing means by isolating it with an insulating amplifier (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-117929 Summary of the Invention [Problem to be solved by the invention]

[0004] In some cases, a pre-boost voltage (before the voltage is boosted by the boost circuit) and a post-boost voltage (after the voltage is boosted by the boost circuit) are detected. In this case, a first voltage detection circuit for detecting the pre-boost voltage and a second voltage detection circuit for detecting the post-boost voltage are provided. If an abnormality occurs in the first voltage detection circuit or the second voltage detection circuit, the accuracy of control using the detection results may be reduced.

[0005] However, if a first abnormality detection circuit that detects abnormalities in the first voltage detection circuit and a second abnormality detection circuit that detects abnormalities in the second voltage detection circuit are provided, the addition of the circuits will increase the size of the board and lead to increased costs.

[0006] The present invention has been made to solve the above-mentioned problems, and its main object is to detect the occurrence of an abnormality related to a voltage detection circuit in an abnormality detection device for a voltage detection circuit while suppressing the addition of new circuits. [Means for solving the problem]

[0007] The first solution to the above problem is: An abnormality detection device (70) for detecting an abnormality in a first voltage detection circuit (30) for detecting a pre-boost voltage, which is a voltage at an input point (Pi) of a boost circuit (20), and a second voltage detection circuit (40) for detecting a post-boost voltage, which is a voltage at an output point (Po) of the boost circuit, the boost circuit has a forward diode (26) connecting the input point and the output point, boosts the voltage input to the input point and outputs it from the output point; The abnormality detection device determines that an abnormality has occurred in the first voltage detection circuit or the second voltage detection circuit when the boost circuit is not performing the boost and the difference between the pre-boost voltage detected by the first voltage detection circuit and the post-boost voltage detected by the second voltage detection circuit is greater than a predetermined degree.

[0008] According to the above configuration, the voltage detection circuit abnormality detection device detects abnormalities in the first voltage detection circuit that detects the pre-boost voltage and the second voltage detection circuit that detects the post-boost voltage.

[0009] Here, the boost circuit has a forward diode connecting the input point and the output point, and boosts the voltage input to the input point and outputs it from the output point. Therefore, when the boost circuit is performing boosting, the boosted voltage is output from the output point, and the diode prevents current from flowing back from the output point to the input point. On the other hand, when the boost circuit is not performing boosting, current flows from the input point to the output point via the diode, and the inventors of the present application have noticed that the difference between the voltage at the input point and the voltage at the output point is about the conduction voltage of the diode.

[0010] Therefore, when the boost circuit is not performing the boost operation and the difference between the pre-boost voltage detected by the first voltage detection circuit and the post-boost voltage detected by the second voltage detection circuit is greater than a predetermined value (e.g., equivalent to the conduction voltage of a diode), the abnormality detection device can determine that an abnormality has occurred in the first voltage detection circuit or the second voltage detection circuit. Furthermore, there is no need to newly add a first abnormality detection circuit or the like for detecting an abnormality in the first voltage detection circuit; an abnormality in the voltage detection circuit can be detected using the detected pre-boost voltage and the detected post-boost voltage. Therefore, the abnormality detection device for a voltage detection circuit can detect an abnormality in the voltage detection circuit without adding a new circuit. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a circuit diagram showing the electrical configuration of a hybrid vehicle. [Figure 2] 6 is a graph showing the relationship between the power supply voltage on the high-voltage side of the voltage detection circuit and the output gain error. [Figure 3] FIG. 10 is a circuit diagram showing an abnormality detection device of a comparative example. [Figure 4] 5 is a flowchart showing a procedure for detecting an abnormality in a voltage detection circuit. [Figure 5] 4 is a time chart showing a control mode of a hybrid vehicle under normal conditions; [Figure 6] 4 is a time chart showing a control mode of a hybrid vehicle when an abnormality occurs. [Figure 7] FIG. 10 is a schematic diagram showing a modified example of the microcomputer. [Figure 8] FIG. 10 is a schematic diagram showing another modified example of the microcomputer. DETAILED DESCRIPTION OF THE INVENTION

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an abnormality detection device for detecting an abnormality in a voltage detection circuit of a booster circuit mounted on a hybrid vehicle will be described below with reference to the drawings.

[0013] As shown in FIG. 1, a hybrid vehicle 10 includes an engine 11, an ignition switch (IG-SW) 12, an inverter (INV) 13, a motor 14, a high-voltage battery 15, an auxiliary battery 16, regulators 17 and 18, a boost circuit 20, two sets of voltage-dividing resistors r1 to r6, a first voltage detection circuit 30, a second voltage detection circuit 40, a first power supply voltage generation unit 50, a second power supply voltage generation unit 60, a microcomputer 70, an HV-ECU 75, and the like.

[0014] The engine 11 is one of the power sources of the hybrid vehicle 10, and generates power for running the hybrid vehicle 10 by burning fuel.

[0015] When the user turns the IG-SW12 (corresponding to a start switch), it disconnects the high-voltage battery 15 from the boost circuit 20, and when the user turns it on, it connects the high-voltage battery 15 to the boost circuit 20. The IG-SW12 is also used to start the engine 11.

[0016] The high-voltage battery 15 (corresponding to a battery) outputs a voltage of, for example, 230 to 270 V (corresponding to a predetermined range). The positive electrode of the high-voltage battery 15 is connected to an input point Pi of the boost circuit 20. The negative electrode of the high-voltage battery 15 is connected to ground.

[0017] The boost circuit 20 includes a capacitor 21, a coil 22, switching elements 23 and 25, diodes 24 and 26, and a capacitor 27. The capacitor 21 is connected in parallel to the high-voltage battery 15. The switching element 23 and the switching element 25 are connected in series. The coil 22 is connected between a connection point P1 between the switching element 23 and the switching element 25 and an input point Pi. A diode 24 is connected in parallel to the switching element 23. The anode of the diode 24 is connected to ground, and the cathode of the diode 24 is connected to the connection point P1. A diode 26 is connected in parallel to the switching element 25. The anode of the diode 26 is connected to the connection point P1, and the cathode of the diode 26 is connected to an output point Po of the boost circuit 20. That is, the diode 26 is a forward diode that connects the input point Pi and the output point Po, and allows a current to flow from the input point Pi to the output point Po and regulates a current that flows from the output point Po to the input point Pi. A capacitor 27 is connected between the output point Po and ground. The boost circuit 20 boosts the voltage of the high-voltage battery 15 input to the input point Pi by turning on and off switching elements 23 and 25, and outputs the boosted voltage from the output point Po. The operating state of the boost circuit 20 is controlled by a microcomputer 70.

[0018] Between the input point Pi and the ground, voltage dividing resistors r1 to r6 are connected in series in order from the high voltage side. Between the output point Po and the ground, voltage dividing resistors r1 to r6 are connected in series in order from the high voltage side.

[0019] The inverter 13 is, for example, a three-phase inverter, and converts the direct current supplied from the output point Po of the boost circuit 20 into alternating current, and outputs the alternating current to the motor 14.

[0020] The motor 14 (corresponding to a rotating electric machine) is one of the power sources of the hybrid vehicle 10, and generates power to run the hybrid vehicle 10. The motor 14 is, for example, a three-phase AC motor, and is driven by power supplied from an output point Po via an inverter 13. In other words, the motor 14 is driven by a voltage VH output from the output point Po of the boost circuit 20.

[0021] The auxiliary battery 16 is, for example, a Pb battery, and supplies a voltage of 12V.

[0022] The auxiliary battery 16 is connected to regulators 17 and 18, a first power supply voltage generator 50, and a second power supply voltage generator 60. The regulators 17 and 18 adjust the voltage of 12 V supplied from the auxiliary battery 16 to 5 V and output the adjusted voltage.

[0023] The first power supply voltage generating unit 50 includes a transformer 51, a capacitor 52, a diode 53, a regulator 54, etc. The voltage of 12 V supplied from the auxiliary battery 16 is boosted to 20 V by the transformer 51 and supplied to the regulator 54. The regulator 54 adjusts the supplied voltage of 20 V to 5 V and outputs the voltage. The voltage boosted to 20 V is also supplied to other electrical devices of the hybrid vehicle 10.

[0024] The second power supply voltage generating unit 60 includes a transformer 61, a capacitor 62, a diode 63, a regulator 64, etc. The voltage of 12 V supplied from the auxiliary battery 16 is boosted to 20 V by the transformer 61 and supplied to the regulator 64. The regulator 64 adjusts the supplied voltage of 20 V to 5 V and outputs it. The voltage boosted to 20 V is also supplied to other electrical devices of the hybrid vehicle 10.

[0025] The first voltage detection circuit 30 is an isolation amplifier and includes a buffer circuit 31, a transformer 32, a low-pass filter (LPF) 33, etc. A power supply voltage Vd11 is supplied to the low-voltage side of the first voltage detection circuit 30 from a regulator 17. A power supply voltage Vd21 is supplied to the high-voltage side of the first voltage detection circuit 30 from a regulator 54 (i.e., a first power supply voltage generation unit 50). The input terminal of the buffer circuit 31 is connected between voltage-dividing resistors r5 and R6. That is, the voltage VL at the input point Pi is divided by the voltage-dividing resistors r1 to r5 and the voltage-dividing resistor r6, and the resulting voltage is input to the buffer circuit 31. The first voltage detection circuit 30 then detects the voltage VL at the input point Pi (corresponding to the voltage before boosting) by outputting a detection voltage VLs corresponding to the voltage to be detected input to the buffer circuit 31. For example, the voltage dividing resistors r1 to r6 and the first voltage detection circuit 30 are configured so that the detection voltage VLs changes from 0 to 5V when the voltage VL changes from 0 to 500V.

[0026] The second voltage detection circuit 40 is an isolation amplifier and includes a buffer circuit 41, a transformer 42, a low-pass filter (LPF) 43, etc. A power supply voltage Vd12 is supplied to the low-voltage side of the second voltage detection circuit 40 from a regulator 18. A power supply voltage Vd22 is supplied to the high-voltage side of the second voltage detection circuit 40 from a regulator 64 (i.e., a second power supply voltage generation unit 60). The input terminal of the buffer circuit 41 is connected between voltage-dividing resistors r5 and R6. That is, the voltage VH at the output point Po is divided by the voltage-dividing resistors r1 to r5 and the voltage-dividing resistor r6, and the resulting voltage is input to the buffer circuit 41. The second voltage detection circuit 40 then detects the voltage VH at the output point Po (corresponding to the boosted voltage) by outputting a detection voltage VHs corresponding to the voltage to be detected input to the buffer circuit 41. For example, the voltage dividing resistors r1 to r6 and the second voltage detection circuit 40 are configured so that the detection voltage VHs changes from 0 to 5V when the voltage VH changes from 0 to 500V.

[0027] The first voltage detection circuit 30 and the second voltage detection circuit 40 are of the same type. Therefore, the characteristics of the magnitude of the detection voltage VLs output from the first voltage detection circuit 30 relative to the magnitude of the input detection voltage are substantially the same as the characteristics of the magnitude of the detection voltage VHs output from the second voltage detection circuit 40 relative to the magnitude of the input detection voltage.

[0028] The microcomputer 70 (corresponding to an abnormality detection device) is a microcomputer including, for example, a CPU, a ROM, a RAM, an input / output interface, etc. The microcomputer 70 receives the detected voltage VLs detected by the first voltage detection circuit 30 and controls the boost circuit 20 based on the detected voltage VLs. The microcomputer 70 controls the switching elements 23 and 25 of the boost circuit 20 so that the voltage VH output from the output point Po of the boost circuit 20 becomes 500 V, for example. The microcomputer 70 also receives the detected voltage VHs detected by the second voltage detection circuit 40 and controls the inverter 13 based on the detected voltage VHs. The microcomputer 70 controls the inverter 13 so that the motor 14 generates a command torque input from, for example, the HV-ECU 75.

[0029] The HV-ECU 75 (corresponding to a higher-level ECU) determines the distribution of torque generated by the engine 11 and torque generated by the motor 14, and inputs command torques to the engine ECU (not shown) that controls the engine 11 and to the microcomputer 70.

[0030] 2 is a graph showing the relationship between the power supply voltage Vd2 (Vd21, Vd22) on the high-voltage side of the voltage detection circuits 30, 40 and the output gain error. Note that this graph shows the case where the power supply voltage Vd1 (Vd11, VD12) on the low-voltage side of the voltage detection circuits 30, 40 is 5V. The output gain error represents the difference when the output values ​​(VLs, VHs) when a full-scale voltage is input do not match an ideal value (for example, 5V).

[0031] The output gain error increases as the high-voltage side power supply voltage Vd2 increases. Therefore, for example, if the high-voltage side power supply voltage Vd21 is outside the recommended range, and the microcomputer 70 controls the boost circuit 20 based on the detected voltage VLs, the voltage VH output from the output point Po may deviate from the target voltage (e.g., 500 V). Also, for example, if the high-voltage side power supply voltage Vd22 is outside the recommended range, and the microcomputer 70 controls the inverter 13 based on the detected voltage VHs, the torque generated by the motor 14 may deviate from the target torque.

[0032] However, it is difficult to determine from the magnitude of the detection voltage VLs output from the first voltage detection circuit 30 whether the high-side power supply voltage Vd21 supplied to the first voltage detection circuit 30 is outside the recommended range. That is, the detection voltage VLs output from the first voltage detection circuit 30 varies depending on the voltage to be detected input to the first voltage detection circuit 30. For this reason, it is difficult to directly determine from the magnitude of the detection voltage VLs whether the detection voltage VLs is normal, and therefore whether the high-side power supply voltage Vd21 is outside the recommended range. For the same reason, it is also difficult to determine from the magnitude of the detection voltage VHs detected by the second voltage detection circuit 40 whether the high-side power supply voltage Vd22 supplied to the second voltage detection circuit 40 is outside the recommended range.

[0033] In response to this, it is conceivable to add a first abnormality detection circuit 81 that detects abnormalities in the high-voltage side power supply voltage Vd21 and a second abnormality detection circuit 82 that detects abnormalities in the high-voltage side power supply voltage Vd22, as in the abnormality detection device of the comparative example shown in Figure 3.

[0034] For example, the first abnormality detection circuit 81 detects the high-voltage side power supply voltage Vd21 supplied to the first voltage detection circuit 30 and determines whether the detected high-voltage side power supply voltage Vd21 is outside the recommended range. If the detected high-voltage side power supply voltage Vd21 is outside the recommended range, the first abnormality detection circuit 81 inputs an abnormality detection signal to the microcomputer 70 via the transformer 83. With this configuration, the microcomputer 70 can determine whether the high-voltage side power supply voltage Vd21 is outside the recommended range. Furthermore, the second abnormality detection circuit 82 detects the high-voltage side power supply voltage Vd22 supplied to the second voltage detection circuit 40 and determines whether the detected high-voltage side power supply voltage Vd22 is outside the recommended range. If the detected high-voltage side power supply voltage Vd22 is outside the recommended range, the second abnormality detection circuit 82 inputs an abnormality detection signal to the microcomputer 70 via the transformer 84. With this configuration, the microcomputer 70 can determine whether the power supply voltage Vd22 on the high-voltage side is outside the recommended range.

[0035] However, if a first abnormality detection circuit 81 that detects abnormalities related to the first voltage detection circuit 30 and a second abnormality detection circuit 82 that detects abnormalities related to the second voltage detection circuit 40 are provided, the addition of the abnormality detection circuits 81, 82 and the transformers 83, 84 will increase the size of the circuit board and contribute to increased costs.

[0036] Therefore, in this embodiment, instead of adding the abnormality detection circuits 81, 82, etc., an abnormality detection process for the voltage detection circuits 30, 40 is executed as shown in the flowchart of FIG.

[0037] First, it is determined whether or not a predetermined time has elapsed since the IG-SW 12 was turned ON (S10). Specifically, it receives a message from the HV-ECU 75 that the IG-SW 12 has been turned ON, and it is determined whether or not the time from when the IG-SW 12 was turned ON to the present time is within the predetermined time. The predetermined time (corresponding to a first predetermined time) is, for example, one to several seconds. The predetermined time after the IG-SW 12 was turned ON corresponds to a period in which the boost circuit 20 is not performing boosting.

[0038] If it is determined in step S10 that a predetermined time has not elapsed since IG-SW 12 was turned on (YES in step S10), the controller 10 determines whether the difference between detection voltage VHs and detection voltage VLs is equal to or less than a predetermined value (S11). Specifically, the controller 10 determines whether the absolute value of the difference between detection voltage VHs detected by second voltage detection circuit 40 and detection voltage VLs detected by first voltage detection circuit 30 is equal to or less than a predetermined value. The predetermined value is a value, such as 0.01 to 0.1 V, that is greater than the voltage difference between detection voltage VLs and detection voltage VHs and corresponds to the voltage difference between voltage VL and voltage VH caused by the conduction voltage drop of diode 26 when boost circuit 20 is not boosting voltage. That is, when the boost circuit 20 is not performing boosting, it is determined whether the degree of difference between the voltage VL (corresponding to the voltage before boosting) at the input point Pi detected by the first voltage detection circuit 30 and the voltage VH (corresponding to the voltage after boosting) at the output point Po detected by the second voltage detection circuit 40 is greater than a predetermined degree.

[0039] On the other hand, if it is determined in S10 that the predetermined time has not elapsed since the IG-SW 12 was turned ON (S10: NO), it is then determined whether or not the predetermined time has elapsed since the start of non-boost control (S12). Non-boost control is control in which the voltage VH is output from the output point Po without the boost circuit 20 performing voltage boosting, for example, control when the command torque for the motor 14 is smaller than a predetermined torque. The predetermined time (corresponding to a second predetermined time) is the time required from the time the boosting by the boost circuit 20 is stopped until the voltage VH at the output point Po becomes approximately equal to the voltage VL at the input point Pi (i.e., the voltage of the high-voltage battery 15). The time after the predetermined time has elapsed since the start of non-boost control corresponds to a time when the boost circuit 20 is not performing voltage boosting. If it is determined in this determination that the predetermined time has elapsed since the start of non-boost control (S12: YES), the process proceeds to S11. On the other hand, if it is determined that the predetermined time has not elapsed since the start of the non-boost control (S12: NO), normal control is executed. Normal control is a control in which the voltage VH is output from the output point Po in a state in which the boost circuit 20 is boosting or in a state in which the boost circuit 20 is permitted to boost, and is a control in which, for example, the command torque for the motor 14 is greater than a predetermined torque.

[0040] If it is determined in step S11 that the difference between the detected voltage VHs and the detected voltage VLs is equal to or less than a predetermined value (S11: YES), the normal control is executed. On the other hand, if it is determined in step S11 that the difference between the detected voltage VHs and the detected voltage VLs is not equal to or less than the predetermined value (S11: NO), it is determined that an abnormality has occurred in the voltage detection circuits 30, 40 (S13). Specifically, it is determined that an abnormality has occurred in the first voltage detection circuit 30 or the second voltage detection circuit 40. An abnormality in the first voltage detection circuit 30 may be, for example, an abnormality in which the high-voltage-side power supply voltage Vd21 supplied to the first voltage detection circuit 30 is outside the recommended range, an abnormality in which any of the voltage-dividing resistors r1 to r6 connected to the input point Pi is short-circuited, or an abnormality in the function of the first voltage detection circuit 30 itself. Abnormalities related to the second voltage detection circuit 40 include, for example, an abnormality in which the high-voltage side power supply voltage Vd22 supplied to the second voltage detection circuit 40 is outside the recommended range, an abnormality in which any of the voltage-dividing resistors r1 to r6 connected to the output point Po is short-circuited, or an abnormality in the function of the second voltage detection circuit 40 itself.

[0041] Next, the boost drive command to the boost circuit 20 is stopped (S14). Specifically, the ON / OFF operation of the switching elements 23 and 25 for boosting by the boost circuit 20 is stopped, and the switching elements 23 and 25 are kept OFF.

[0042] Thereafter, the microcomputer 70 causes the HV-ECU 75 to execute normal running or evacuation running. Specifically, the microcomputer 70 notifies the HV-ECU 75 that an abnormality related to the first voltage detection circuit 30 or an abnormality related to the second voltage detection circuit 40 has occurred. In response to this notification, the HV-ECU 75 causes the hybrid vehicle 10 to run normally or evacuation running, assuming that the voltage boost by the boost circuit 20 has stopped. In the evacuation running, the hybrid vehicle 10 runs with the command torque to the motor 14 limited to a torque limit or less, or with the vehicle speed of the hybrid vehicle 10 limited to a speed limit or less. In the normal running, the hybrid vehicle 10 runs without limiting the torque of the motor 14 or the vehicle speed of the hybrid vehicle 10, with the voltage boost by the boost circuit 20 stopped. In other words, when the microcomputer 70 determines that an abnormality related to the first voltage detection circuit 30 or an abnormality related to the second voltage detection circuit 40 has occurred, the microcomputer 70 causes the HV-ECU 75 to continue running the hybrid vehicle 10 with the voltage boost by the boost circuit 20 stopped.

[0043] FIG. 5 is a time chart showing the control mode of the hybrid vehicle 10 in a normal state.

[0044] At timing t11, when the user turns on the IG-SW 12, the high-voltage battery 15 and the boost circuit 20 are connected. As a result, the voltage VL at the input point Pi becomes 250 V, and the detection voltage VLs detected by the first voltage detection circuit 30 becomes 2.5 V. Furthermore, the voltage VH at the output point Po becomes 250 V, and the detection voltage VHs detected by the second voltage detection circuit 40 becomes 2.5 V. The detection voltages VLs and VHs are greater than a lower threshold Vr1 (e.g., 2.3 V) and less than an upper threshold Vr2 (e.g., 2.7 V).

[0045] Between timings t11 and t12, i.e., within a predetermined time after IG-SW 12 is turned ON, the microcomputer 70 determines whether the absolute value of the difference between the detection voltage VHs and the detection voltage VLs is equal to or less than a predetermined value (e.g., 0.05 V). In the figure, since voltage VH = voltage VL (i.e., voltage VH ≈ voltage VL) and detection voltage VHs = detection voltage VLs (i.e., detection voltage VHs ≈ detection voltage VLs), the microcomputer 70 executes normal control.

[0046] At timing t13, the microcomputer 70 turns on the boost control and performs boosting by the boost circuit 20. This causes the voltage VH and the detected voltage VHs to increase, and at timing t14, the voltage VH becomes 500 V and the detected voltage VHs becomes 5 V. The HV-ECU 75 causes the hybrid vehicle 10 to run normally.

[0047] At timing t15, the microcomputer 70 turns off the boost control and stops boosting by the boost circuit 20. This causes the voltage VH and the detection voltage VHs to drop, and at timing t16, the voltage VH becomes 250V and the detection voltage VHs becomes 2.5V.

[0048] After timing t17, i.e., after a predetermined time has elapsed since the start of non-boost control, the microcomputer 70 determines whether the absolute value of the difference between the detected voltage VHs and the detected voltage VLs is equal to or less than a predetermined value (e.g., 0.05 V). In the figure, since the voltage VH = the voltage VL (i.e., the voltage VH ≈ the voltage VL) and the detected voltage VHs = the detected voltage VLs (i.e., the detected voltage VHs ≈ the detected voltage VLs), the microcomputer 70 executes normal control.

[0049] FIG. 6 is a time chart showing the control mode of the hybrid vehicle 10 when an abnormality occurs.

[0050] At timing t21, when the user turns on the IG-SW 12, the high-voltage battery 15 and the boost circuit 20 are connected. As a result, the voltage VL at the input point Pi becomes 250 V, and the detection voltage VLs detected by the first voltage detection circuit 30 becomes 2.5 V. Meanwhile, the voltage VH at the output point Po becomes 250 V, but the detection voltage VHs detected by the second voltage detection circuit 40 becomes 1.5 V. The detection voltage VLs is greater than the lower limit threshold Vr1 (e.g., 2.3 V) and less than the upper limit threshold Vr2 (e.g., 2.7 V). Meanwhile, the detection voltage VHs is less than the lower limit threshold Vr1 (e.g., 2.3 V).

[0051] Between timings t21 and t22, i.e., within a predetermined time after IG-SW 12 is turned ON, the microcomputer 70 determines whether the absolute value of the difference between detection voltage VHs and detection voltage VLs is equal to or less than a predetermined value (e.g., 0.05 V). In the figure, voltage VH is equal to voltage VL, but the absolute value of the difference between detection voltage VLs and detection voltage VHs is greater than the predetermined value. Therefore, the microcomputer 70 determines that an abnormality has occurred in the first voltage detection circuit 30 or the second voltage detection circuit 40.

[0052] At timing t23, when the boost control would normally be turned ON, the microcomputer 70 turns the boost control OFF, stopping the boost operation by the boost circuit 20. After timing t23, the voltage VH is maintained at 250 V, and the detected voltage VHs is 1.5 V. After timing t23, the HV-ECU 75 causes the hybrid vehicle 10 to, for example, run to an evacuation site.

[0053] If no abnormality occurs between times t21 and t22, the microcomputer 70 turns on the boost control at time t23, causing the voltage VH and the detected voltage VHs to rise, as indicated by the dashed lines. At time t24, the voltage VH becomes, for example, 400 V, and the detected voltage VHs becomes 4 V. In other words, the voltage VH deviates from the target voltage (for example, 500 V).

[0054] Thereafter, as indicated by the dashed lines, at timing t25, the microcomputer 70 turns off the boost control and stops the boosting by the boost circuit 20. This causes the voltage VH and the detection voltage VHs to decrease, and at timing t26, the voltage VH becomes 250 V and the detection voltage VHs becomes 1.5 V.

[0055] After timing t27, i.e., after a predetermined time has elapsed since the start of non-boost control when boost control was ON, the microcomputer 70 determines whether the absolute value of the difference between the detected voltage VHs and the detected voltage VLs is equal to or less than a predetermined value (e.g., 0.05 V). In the figure, voltage VH=voltage VL, but detected voltage VLs≠detected voltage VHs, so the microcomputer 70 determines that an abnormality has occurred in the first voltage detection circuit 30 or the second voltage detection circuit 40. Thereafter, the microcomputer 70 turns off the boost control and stops the boost by the boost circuit 20. The HV-ECU 75 causes the hybrid vehicle 10 to, for example, run to an evacuation route.

[0056] The present embodiment described above in detail has the following advantages.

[0057] When the boost circuit 20 is not boosting, a current flows from the input point Pi to the output point Po via the diode 26, and the difference between the voltage VL at the input point Pi and the voltage VH at the output point Po is approximately equal to the conduction voltage of the diode 26. Therefore, when the boost circuit 20 is not boosting and the difference between the voltage VL (corresponding detected voltage VLs) detected by the first voltage detection circuit 30 and the voltage VH (corresponding detected voltage VHs) detected by the second voltage detection circuit 40 is greater than a predetermined value (e.g., equivalent to the conduction voltage of the diode 26), the microcomputer 70 can determine that an abnormality has occurred in the first voltage detection circuit 30 or the second voltage detection circuit 40. Furthermore, there is no need to newly add a first abnormality detection circuit 81 or the like to detect an abnormality in the first voltage detection circuit 30. An abnormality in the voltage detection circuits 30, 40 can be detected using the detected detected voltage VLs and the detected detected voltage VHs. Therefore, an abnormality in the voltage detection circuits 30, 40 can be detected without adding a new circuit.

[0058] The hybrid vehicle 10 runs using, as a power source, the motor 14 driven by the voltage VH output from the output point Po of the boost circuit 20. In such a hybrid vehicle 10, the motor 14 is not driven or the torque command for the motor 14 is often small until a first predetermined time (for example, one to several seconds) has elapsed since the IG-SW 12 of the hybrid vehicle 10 was turned on. In this case, boosting by the boost circuit 20 is not required, and the boost circuit 20 often does not perform boosting. Therefore, an abnormality in the voltage detection circuits 30, 40 can be detected before the first predetermined time has elapsed since the IG-SW 12 of the hybrid vehicle 10 was turned on.

[0059] Even when a command to stop boosting is issued to the boost circuit 20, the voltage VH output from the output node Po of the boost circuit 20 does not drop instantaneously. Therefore, if the detected voltage VLs detected by the first voltage detection circuit 30 and the detected voltage VHs detected by the second voltage detection circuit 40 were compared immediately after the command to stop boosting was issued to the boost circuit 20, there is a risk of erroneously determining that an abnormality has occurred in the first voltage detection circuit 30 or the second voltage detection circuit 40. In this regard, the microcomputer 70 determines whether the absolute value of the difference between the detected voltage VHs and the detected voltage VLs is equal to or less than a predetermined value when it determines that a second predetermined time has elapsed since the start of the non-boost control. This configuration prevents erroneous determination by the microcomputer 70, enabling it to more accurately detect an abnormality in the voltage detection circuits 30 and 40.

[0060] The first voltage detection circuit 30 and the second voltage detection circuit 40 are of the same type. With this configuration, the characteristics of the magnitude of the detection voltage VLs output from the first voltage detection circuit 30 relative to the magnitude of the input detection voltage are substantially the same as the characteristics of the magnitude of the detection voltage VHs output from the second voltage detection circuit 40 relative to the magnitude of the input detection voltage. Therefore, when comparing the detection voltage VLs detected by the first voltage detection circuit 30 with the detection voltage VHs detected by the second voltage detection circuit 40, the detection voltages VLs and VHs can be compared directly. This facilitates comparison of the detected detection voltage VLs with the detected detection voltage VHs, and improves the accuracy of abnormality determination based on the comparison of these detection voltages VLs and VHs.

[0061] When the microcomputer 70 determines that an abnormality has occurred in the first voltage detection circuit 30 or the second voltage detection circuit 40, it stops the boosting by the boost circuit 20 and causes the hybrid vehicle 10 to continue running. This makes it possible to prevent the boost circuit 20 from operating in a state in which the detected voltage VLs (i.e., voltage VL) or the detected voltage VHs (i.e., voltage VH) cannot be detected normally, thereby ensuring the safety of the hybrid vehicle 10. Furthermore, the microcomputer 70 causes the hybrid vehicle 10 to continue running with the boosting by the boost circuit 20 stopped, so it is possible to continue running the hybrid vehicle 10 while ensuring the safety of the hybrid vehicle 10.

[0062] The above embodiment can be modified as follows: The same parts as those in the above embodiment are denoted by the same reference numerals and the description thereof will be incorporated herein.

[0063] The 12V voltage supplied from the auxiliary battery 16 may be supplied to the regulator 64 without being boosted by the transformer 61, and the regulator 64 may adjust the supplied voltage to 5V and output it.

[0064] Even if the power supply voltage Vd21 supplied to the first voltage detection circuit 30 is outside the recommended range, the first voltage detection circuit 30 can operate as long as it does not exceed the withstand voltage of the first voltage detection circuit 30. In this case, the magnitude of the voltage VL at the input point Pi detected by the first voltage detection circuit 30 (corresponding detected voltage VLs) will vary from the voltage VL detected by the first voltage detection circuit 30 when the power supply voltage Vd21 is within the recommended range. However, it is difficult to determine whether the power supply voltage Vd21 supplied to the first voltage detection circuit 30 is outside the recommended range from the magnitude of the voltage VL detected by the first voltage detection circuit 30 (corresponding detected voltage VLs). The same is true for the second voltage detection circuit 40.

[0065] In this regard, the microcomputer 70 may determine that the power supply voltage Vd21 supplied to the first voltage detection circuit 30 or the power supply voltage Vd22 supplied to the second voltage detection circuit 40 is outside the recommended range when the boost circuit 20 is not performing boosting and the degree of difference between the voltage VL detected by the first voltage detection circuit 30 (corresponding detected voltage VLs) and the voltage VH detected by the second voltage detection circuit 40 (corresponding detected voltage VHs) is greater than a predetermined degree. With this configuration, by comparing the detected voltage VLs detected by the first voltage detection circuit 30 and the detected voltage VHs detected by the second voltage detection circuit 40, it is possible to detect an abnormality in which the power supply voltage Vd21 supplied to the first voltage detection circuit 30 or the power supply voltage Vd22 supplied to the second voltage detection circuit 40 is outside the recommended range.

[0066] A high-voltage battery 15 that is designed to output a voltage within a predetermined range (e.g., 230 to 270 V) is connected to the input point Pi of the boost circuit 20. Therefore, if the boost circuit 20 is not boosting the voltage and the voltage VL (corresponding to the voltage before boosting) detected by the first voltage detection circuit 30 is outside the predetermined range, it can be assumed that an abnormality has occurred in the first voltage detection circuit 30. Furthermore, if the boost circuit 20 is not boosting the voltage and the voltage VH (corresponding to the voltage after boosting) detected by the second voltage detection circuit 40 is outside the predetermined range, it can be assumed that an abnormality has occurred in the second voltage detection circuit 40.

[0067] Therefore, the microcomputer 70 may determine that an abnormality has occurred in the first voltage detection circuit 30 or the second voltage detection circuit 40 when the voltage VL (corresponding detected voltage VLs) detected by the first voltage detection circuit 30 is outside a predetermined range (the range of detected voltages VLs corresponding to the predetermined range). Alternatively, the microcomputer 70 may determine that an abnormality has occurred in the second voltage detection circuit 40 when the voltage VH (corresponding detected voltage VHs) detected by the second voltage detection circuit 40 is outside a predetermined range (the range of detected voltages VHs corresponding to the predetermined range). The range of detected voltages VLs and VHs corresponding to the predetermined range is the range from a lower threshold Vr1 (2.3 V) to an upper threshold Vr2 (2.7 V) shown in FIGS. 5 and 6. According to the above configuration, when the microcontroller 70 determines that an abnormality has occurred in the first voltage detection circuit 30 or the second voltage detection circuit 40, it can identify whether the abnormality has occurred in the first voltage detection circuit 30 or the second voltage detection circuit 40.

[0068] The microcomputer 70 may stop the regulator 54 when it determines that an abnormality has occurred in the first voltage detection circuit 30. This configuration prevents the power supply voltage Vd21 supplied from the regulator 54 from exceeding the withstand voltage of the first voltage detection circuit 30. The microcomputer 70 may also stop the regulator 64 when it determines that an abnormality has occurred in the second voltage detection circuit 40. This configuration prevents the power supply voltage Vd22 supplied from the regulator 64 from exceeding the withstand voltage of the second voltage detection circuit 40.

[0069] The voltage VL (corresponding to the voltage before boosting) at the input point Pi detected by the first voltage detection circuit 30 contains a tolerance, so a difference occurs between the voltage VL detected by the first voltage detection circuit 30 and the true value of the voltage VL. Similarly, the voltage VH (corresponding to the voltage after boosting) at the output point Po detected by the second voltage detection circuit 40 contains a tolerance, so a difference occurs between the voltage VH detected by the second voltage detection circuit 40 and the true value of the voltage VH. The resistance values ​​of the voltage-dividing resistors r1 to r6 also contain a tolerance.

[0070] 7 , the microcomputer 70 may have a first map 71 representing the relationship between the voltage VL detected by the first voltage detection circuit 30 and the true value of the voltage VL, and a second map 72 representing the relationship between the voltage VH detected by the second voltage detection circuit 40 and the true value of the voltage VH. The first map 71 and the second map 72 may be acquired in advance, for example, during a shipping inspection of the voltage detection circuits 30, 40 and the boost circuit 20. The microcomputer 70 may determine that an abnormality related to the first voltage detection circuit 30 or the second voltage detection circuit 40 has occurred when the degree of difference between the true value of the voltage VL calculated based on the voltage VL detected by the first map 71 and the first voltage detection circuit 30 and the true value of the voltage VH calculated based on the voltage VH detected by the second map 72 and the second voltage detection circuit 40 is greater than a predetermined degree. According to this configuration, the true value of the voltage VL and the true value of the voltage VH can be compared to determine whether the voltage detection circuits 30 and 40 are abnormal, thereby improving the accuracy of the determination.

[0071] The voltage VL (corresponding to the voltage before boosting) at the input point Pi detected by the first voltage detection circuit 30 varies depending on the ambient temperature of the first voltage detection circuit 30, so a difference occurs between the voltage VL detected by the first voltage detection circuit 30 and the true value of the voltage VL depending on the temperature. Similarly, the voltage VH (corresponding to the voltage after boosting) at the output point Po detected by the second voltage detection circuit 40 varies depending on the ambient temperature of the second voltage detection circuit 40, so a difference occurs between the voltage VH detected by the second voltage detection circuit 40 and the true value of the voltage VH depending on the temperature.

[0072] 1, the first voltage detection circuit 30 may include a first temperature sensor 34 that detects the temperature around the first voltage detection circuit 30. The second voltage detection circuit 40 may include a second temperature sensor 44 that detects the temperature around the second voltage detection circuit 40. As shown in FIG. 8, the microcomputer 70 may have a third map 73 that represents the relationship between the voltage VL detected by the first voltage detection circuit 30, the temperature detected by the first temperature sensor 34, and the true value of the voltage VL, and a fourth map 74 that represents the relationship between the voltage VH detected by the second voltage detection circuit 40, the temperature detected by the second temperature sensor 44, and the true value of the voltage VH. The third map 73 and the fourth map 74 can be obtained in advance, for example, during a shipping inspection of the voltage detection circuits 30, 40 and the boost circuit 20. The microcomputer 70 may determine that an abnormality has occurred in the first voltage detection circuit 30 or the second voltage detection circuit 40 when the degree of difference between the true value of the voltage VL calculated based on the third map 73, the voltage VL detected by the first voltage detection circuit 30, and the temperature detected by the first temperature sensor 34 and the true value of the voltage VH calculated based on the fourth map 74, the voltage VH detected by the second voltage detection circuit 40, and the temperature detected by the second temperature sensor 44 is greater than a predetermined degree. With this configuration, the true value of the voltage VL and the true value of the voltage VH can be compared to determine an abnormality in the voltage detection circuits 30 and 40, taking into account the influence of the ambient temperatures of the first voltage detection circuit 30 and the second voltage detection circuit 40, thereby improving the accuracy of the determination.

[0073] It is also possible to determine whether the degree of difference between the voltage VL (corresponding detected voltage VLs) detected by the first voltage detection circuit 30 and the voltage VH (corresponding detected voltage VHs) detected by the second voltage detection circuit 40 is greater than a predetermined degree as follows. That is, the microcomputer 70 can determine that the degree of difference is greater than a predetermined degree when the value of the ratio between the detected voltage VLs and the detected voltage VHs is outside the range from a lower limit value less than 1 to an upper limit value greater than 1. The lower limit value is, for example, 0.9, and the upper limit value is, for example, 1.1.

[0074] The first voltage detection circuit 30 and the second voltage detection circuit 40 may be of different types. That is, the characteristics of the magnitude of the detection voltage VLs outputted relative to the magnitude of the voltage to be detected inputted to the first voltage detection circuit 30 may be different from the characteristics of the magnitude of the detection voltage VHs outputted relative to the magnitude of the voltage to be detected inputted to the second voltage detection circuit 40. For example, when the voltage to be detected inputted to the first voltage detection circuit 30 varies from 0 to 250 V, the detection voltage VLs may vary from 0 to 5 V, and when the voltage to be detected inputted to the second voltage detection circuit 40 varies from 0 to 500 V, the detection voltage VHs may vary from 0 to 5 V. Even in this case, when the boost circuit 20 is not performing boosting and the difference between the voltage VL (the voltage converted from the detected voltage VLs) detected by the first voltage detection circuit 30 and the voltage VH (the voltage converted from the detected voltage VHs) detected by the second voltage detection circuit 40 is greater than a predetermined degree (e.g., equivalent to the conduction voltage of the diode 26), the microcomputer 70 can determine that an abnormality has occurred in the first voltage detection circuit 30 or the second voltage detection circuit 40. Note that the predetermined degree is not limited to the degree equivalent to the conduction voltage of the diode 26, but may be any degree greater than the conduction voltage of the diode 26, such as several times the conduction voltage of the diode 26.

[0075] Furthermore, the voltage-dividing resistors r1 to r6 connected to the input point Pi may be different from the voltage-dividing resistors r1 to r6 connected to the output point Po. Even in this case, the microcomputer 70 only needs to determine whether the degree of difference between the voltage VL detected by the first voltage detection circuit 30 (the voltage converted from the detected voltage VLs) and the voltage VH detected by the second voltage detection circuit 40 (the voltage converted from the detected voltage VHs) is greater than a predetermined degree. The voltage-dividing resistors r1 to r6 connected to the input point Pi may also be incorporated inside the first voltage detection circuit 30. The voltage-dividing resistors r1 to r6 connected to the output point Po may also be incorporated inside the second voltage detection circuit 40.

[0076] The high-voltage battery 15 (corresponding to a battery) may output a voltage in a predetermined range lower than 230 to 270 V, or may output a voltage in a predetermined range higher than 230 to 270 V. The microcomputer 70 may also control the switching elements 23, 25 of the boost circuit 20 so that the voltage VH output from the output point Po of the boost circuit 20 becomes a target voltage lower than 500 V or a target voltage higher than 500 V.

[0077] The above-described embodiment and modifications may be combined within the scope of possible combinations.

[0078] Characteristic configurations extracted from the above-described embodiments and modifications will be described below. [Configuration 1] An abnormality detection device (70) for detecting an abnormality in a first voltage detection circuit (30) for detecting a pre-boost voltage, which is a voltage at an input point (Pi) of a boost circuit (20), and a second voltage detection circuit (40) for detecting a post-boost voltage, which is a voltage at an output point (Po) of the boost circuit, the boost circuit has a forward diode (26) connecting the input point and the output point, boosts the voltage input to the input point and outputs it from the output point; The abnormality detection device for a voltage detection circuit determines that an abnormality has occurred in the first voltage detection circuit or the second voltage detection circuit when the boost circuit is not performing the boost and the difference between the pre-boost voltage detected by the first voltage detection circuit and the post-boost voltage detected by the second voltage detection circuit is greater than a predetermined degree. [Configuration 2] The abnormality detection device for a voltage detection circuit according to configuration 1, wherein when the boost circuit is not performing the boosting, the abnormality detection device includes a period from when a start switch (12) of a vehicle (10) equipped with a rotating electric machine (14) driven by the voltage output from the output point of the boost circuit as a power source to when a first predetermined time has elapsed. [Configuration 3] 3. The abnormality detection device for a voltage detection circuit according to configuration 1 or 2, wherein, when the boost circuit is not performing the boost, the period includes a period after a second predetermined time has elapsed since a command to stop the boost circuit is output to the boost circuit. [Configuration 4] A battery (15) that is designed to output a voltage within a predetermined range is connected to the input point of the boost circuit, The abnormality detection device determining that an abnormality has occurred in the first voltage detection circuit or the second voltage detection circuit, and if the pre-boost voltage detected by the first voltage detection circuit is outside the predetermined range, determining that an abnormality has occurred in the first voltage detection circuit; An abnormality detection device for a voltage detection circuit according to any one of configurations 1 to 3, which determines that an abnormality has occurred in the first voltage detection circuit or the second voltage detection circuit, and determines that an abnormality has occurred in the second voltage detection circuit when the boosted voltage detected by the second voltage detection circuit is outside the predetermined range. [Configuration 5] 5. The voltage detection circuit abnormality detection device according to any one of configurations 1 to 4, wherein the first voltage detection circuit and the second voltage detection circuit are of the same type. [Configuration 6] the abnormality detection device has a first map (71) that represents a relationship between the pre-boost voltage detected by the first voltage detection circuit and a true value of the pre-boost voltage, and a second map (72) that represents a relationship between the post-boost voltage detected by the second voltage detection circuit and a true value of the post-boost voltage, The abnormality detection device for a voltage detection circuit according to any one of configurations 1 to 5, wherein the abnormality detection device determines that an abnormality has occurred in the first voltage detection circuit or the second voltage detection circuit when the degree of difference between the true value of the pre-boost voltage calculated based on the first map and the pre-boost voltage detected by the first voltage detection circuit and the true value of the post-boost voltage calculated based on the second map and the post-boost voltage output from the second voltage detection circuit is greater than the predetermined degree. [Configuration 7] the first voltage detection circuit includes a first temperature sensor (34) that detects the ambient temperature of the first voltage detection circuit; the second voltage detection circuit includes a second temperature sensor (44) that detects the ambient temperature of the second voltage detection circuit; the abnormality detection device has a third map (73) that represents a relationship between the pre-boost voltage detected by the first voltage detection circuit, the temperature detected by the first temperature sensor, and a true value of the pre-boost voltage, and a fourth map (74) that represents a relationship between the post-boost voltage detected by the second voltage detection circuit, the temperature detected by the second temperature sensor, and a true value of the post-boost voltage, The abnormality detection device for a voltage detection circuit according to any one of configurations 1 to 5, wherein the abnormality detection device determines that an abnormality related to the first voltage detection circuit or an abnormality related to the second voltage detection circuit has occurred when the degree of difference between the true value of the pre-boost voltage calculated based on the third map, the pre-boost voltage detected by the first voltage detection circuit, and the temperature detected by the first temperature sensor, and the true value of the post-boost voltage calculated based on the fourth map, the post-boost voltage detected by the second voltage detection circuit, and the temperature detected by the second temperature sensor is greater than the predetermined degree. [Configuration 8] the abnormality detection device is applied to a vehicle equipped with a rotating electric machine as a power source, the rotating electric machine being driven by a voltage output from the output point of the boost circuit, The abnormality detection device for a voltage detection circuit described in any one of configurations 1 to 7, wherein when it is determined that an abnormality has occurred in the first voltage detection circuit or the second voltage detection circuit, the abnormality detection device stops the voltage boost by the boost circuit and continues running the vehicle. [Configuration 9] The abnormality detection device for a voltage detection circuit described in any one of configurations 1 to 8, wherein the abnormality detection device determines that the power supply voltage supplied to the first voltage detection circuit or the power supply voltage supplied to the second voltage detection circuit is outside a recommended range when the boost circuit is not performing the boost and the difference between the pre-boost voltage detected by the first voltage detection circuit and the post-boost voltage detected by the second voltage detection circuit is greater than a predetermined degree. [Explanation of symbols]

[0079] 20...Boost circuit, 26...Diode, 30...First voltage detection circuit, 40...Second voltage detection circuit, 70...Microcomputer, Pi...Input point, Po...Output point.

Claims

1. An abnormality detection device (70) for detecting an abnormality in a first voltage detection circuit (30) for detecting a pre-boost voltage, which is the voltage at an input point (Pi) of a boost circuit (20), and a second voltage detection circuit (40) for detecting a post-boost voltage, which is the voltage at an output point (Po) of the boost circuit, the boost circuit has a forward diode (26) connecting the input point and the output point, boosts the voltage input to the input point and outputs it from the output point; The abnormality detection device for a voltage detection circuit determines that an abnormality has occurred in the first voltage detection circuit or the second voltage detection circuit when the boost circuit is not performing the boost and the difference between the pre-boost voltage detected by the first voltage detection circuit and the post-boost voltage detected by the second voltage detection circuit is greater than a predetermined degree.

2. 2. The abnormality detection device for a voltage detection circuit according to claim 1, wherein when the boost circuit is not performing the boosting, the abnormality detection device includes a period from when a start switch (12) of a vehicle (10) equipped with a rotating electric machine (14) driven by the voltage output from the output point of the boost circuit as a power source to when a first predetermined time has elapsed since the start switch (12) was turned on.

3. 3. The abnormality detection device for a voltage detection circuit according to claim 1, wherein, when the boost circuit is not performing the boost, the period includes a period after a second predetermined time has elapsed since a command to stop the boost circuit is output to the boost circuit.

4. A battery (15) that is designed to output a voltage within a predetermined range is connected to the input point of the boost circuit, The abnormality detection device determining that an abnormality has occurred in the first voltage detection circuit or the second voltage detection circuit, and if the pre-boost voltage detected by the first voltage detection circuit is outside the predetermined range, determining that an abnormality has occurred in the first voltage detection circuit; 3. The voltage detection circuit abnormality detection device according to claim 1, wherein the device determines that an abnormality has occurred in the first voltage detection circuit or the second voltage detection circuit, and determines that an abnormality has occurred in the second voltage detection circuit when the boosted voltage detected by the second voltage detection circuit is outside the predetermined range.

5. 3. The voltage detection circuit abnormality detection device according to claim 1, wherein the first voltage detection circuit and the second voltage detection circuit are of the same type.

6. the abnormality detection device has a first map (71) that represents a relationship between the pre-boost voltage detected by the first voltage detection circuit and a true value of the pre-boost voltage, and a second map (72) that represents a relationship between the post-boost voltage detected by the second voltage detection circuit and a true value of the post-boost voltage, 3. The abnormality detection device for a voltage detection circuit according to claim 1, wherein the abnormality detection device determines that an abnormality has occurred in the first voltage detection circuit or the second voltage detection circuit when a degree of difference between a true value of the pre-boost voltage calculated based on the first map and the pre-boost voltage detected by the first voltage detection circuit and a true value of the post-boost voltage calculated based on the second map and the post-boost voltage output from the second voltage detection circuit is greater than the predetermined degree.

7. the first voltage detection circuit includes a first temperature sensor (34) that detects the temperature around the first voltage detection circuit; the second voltage detection circuit includes a second temperature sensor (44) that detects the ambient temperature of the second voltage detection circuit; the abnormality detection device has a third map (73) that represents a relationship between the pre-boost voltage detected by the first voltage detection circuit, the temperature detected by the first temperature sensor, and a true value of the pre-boost voltage, and a fourth map (74) that represents a relationship between the post-boost voltage detected by the second voltage detection circuit, the temperature detected by the second temperature sensor, and a true value of the post-boost voltage, 3. The abnormality detection device for a voltage detection circuit according to claim 1, wherein the abnormality detection device determines that an abnormality related to the first voltage detection circuit or an abnormality related to the second voltage detection circuit has occurred when a degree of difference between a true value of the pre-boost voltage calculated based on the third map, the pre-boost voltage detected by the first voltage detection circuit, and the temperature detected by the first temperature sensor, and a true value of the post-boost voltage calculated based on the fourth map, the post-boost voltage detected by the second voltage detection circuit, and the temperature detected by the second temperature sensor is greater than the predetermined degree.

8. the abnormality detection device is applied to a vehicle equipped with a rotating electric machine as a power source, the rotating electric machine being driven by a voltage output from the output point of the boost circuit, 3. The abnormality detection device for a voltage detection circuit according to claim 1, wherein when the abnormality detection device determines that an abnormality has occurred in the first voltage detection circuit or the second voltage detection circuit, the abnormality detection device stops the voltage boost by the boost circuit and allows the vehicle to continue running.

9. 3. The abnormality detection device for a voltage detection circuit according to claim 1, wherein the abnormality detection device determines that the power supply voltage supplied to the first voltage detection circuit or the power supply voltage supplied to the second voltage detection circuit is outside a recommended range when the boost circuit is not performing the boost and the difference between the pre-boost voltage detected by the first voltage detection circuit and the post-boost voltage detected by the second voltage detection circuit is greater than a predetermined degree.

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