Motor control apparatus

Abstract

To provide a motor control apparatus, which can be downsized, including a circuit for detecting a connection defect of a connector.SOLUTION: A motor control apparatus comprises a sensor board including a sensor for detecting a current, which flows to a motor, and a motor control board connected to the sensor board via a connector. The motor control board includes: a variable power source which is connected to the sensor via a power supply line passing the connector; an output detection circuit connected to the sensor via a sensor output line passing the connector; a resistive element inserted into a first wire connecting the sensor output line and a ground; and a switch inserted into the first wire. The sensor board includes a device which is inserted into a second wire connecting the power supply line and the sensor output line and conducted in a case where a voltage between the power supply line and the sensor output line is equal to or higher than a predetermined voltage.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a motor control device. [Background technology]

[0002] Many motor control devices perform feedback control by detecting the current flowing through the motor and determining the next current to be passed through the motor based on the detected current. Such motor control devices include a sensor for detecting the current flowing through the motor and an output detection circuit for detecting the output of the sensor.

[0003] In some implementations, the sensor board with the sensor may be separate from the motor control board with the output detection circuit. The motor control board is connected to the sensor board via a connector. The connector may develop poor contact due to vibration, thermal history, and other factors. Poor contact in the connector can adversely affect the feedback control of the motor.

[0004] Patent Document 1 proposes a dedicated detection circuit for detecting poor connections in connectors. This detection circuit has a dedicated signal line that passes through the connector from one board to another. A poor connection in the connector is detected by a change in the current flowing in this signal line. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 9-148035 Summary of the Invention [Problem to be solved by the invention]

[0006] The detection circuit disclosed in Patent Document 1 is a dedicated circuit for detecting poor connections in connectors. Such dedicated circuits increase the number of pins in the connector, which hinders efforts to reduce the size of motor control devices.

[0007] An object of the present disclosure is to provide a motor control device that can be miniaturized and that includes a circuit that detects poor connection of a connector. [Means for solving the problem]

[0008] A motor control device according to one aspect of the present disclosure includes a sensor board having a sensor for detecting a current flowing through a motor, and a motor control board connected to the sensor board via a connector. The motor control board includes a variable power supply connected to the sensor via a power line passing through the connector, an output detection circuit connected to the sensor via a sensor output line passing through the connector, a resistive element inserted in a first wiring connecting the sensor output line to ground, and a switch inserted in the first wiring. The sensor board includes a device inserted in a second wiring connecting the power line and the sensor output line, which is conductive when a voltage between the power line and the sensor output line is equal to or higher than a predetermined voltage. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide a motor control device that can be miniaturized and that includes a circuit for detecting a poor connection of a connector. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a system diagram of a vehicle according to one embodiment of the present disclosure. [Figure 2] 1 is a circuit diagram of a motor control device according to an embodiment of the present disclosure. [Figure 3] FIG. 4 is a circuit diagram illustrating a motor current detection state according to an embodiment of the present disclosure. [Figure 4] FIG. 10 is a circuit diagram illustrating a connector connection failure detection state according to an embodiment of the present disclosure. [Figure 5] 3 is a flowchart of a control procedure executed by a vehicle control device according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings.

[0012] As shown in Fig. 1, vehicle C includes an inverter 1, a motor 2, a battery 6, a control device 4, and a charging device 8. Vehicle C of this embodiment is an electric vehicle in which battery 6 is charged by charging device 8 and motor 2 is rotated by the power of battery 6. Vehicle C of this embodiment also includes a power supply device 10 that can supply power from battery 6 to an external device. Vehicle C may be a plug-in hybrid electric vehicle (PHEV) or a battery electric vehicle (BEV) that can be externally charged or externally supplied with power.

[0013] The inverter 1 receives DC power from a battery 6, converts the DC power into, for example, three-phase AC power, and supplies the three-phase AC power to a motor 2. The motor 2 is, for example, a three-phase AC motor. The battery 6 is, for example, a lithium-ion battery. The control device 4 is electrically connected to the inverter 1 and controls the inverter 1. In this embodiment, a motor control device 21 is included in the inverter 1 and the control device 4.

[0014] 2, the motor control device 21 includes a sensor board 11 and a motor control board 12 connected via a connector 13. The connector 13 includes a power supply line Lp, a sensor output line Ls, and a ground line Lg. In this embodiment, the connector 13 has a contact resistance R1 on the sensor output line Ls.

[0015] The sensor substrate 11 includes a sensor 14 and a device D1.

[0016] The sensor 14 detects a current Ia flowing through a wiring Wa connecting the inverter 1 and the motor 2. FIG. 2 shows only the a-phase of three-phase AC including the a-phase, b-phase, and c-phase. In this embodiment, the sensor 14 includes an annular magnetic core 15 having a gap, a Hall element 16 disposed in the gap of the annular magnetic core 15, and an operational amplifier 17 that differentially amplifies the output of the Hall element 16. The operational amplifier 17 outputs a signal current corresponding to the current Ia to a sensor output line Ls. The sensor 14 is not limited to this, and may be, for example, a circuit that differentially amplifies the voltage across a shunt resistor using an operational amplifier.

[0017] The device D1 is inserted into the second wiring L2 connected between the power supply line Lp and the sensor output line Ls. The device D1 has the characteristic of being conductive when the voltage between the power supply line Lp and the sensor output line Ls is equal to or higher than a predetermined voltage. The device D1 is a device that has the function of passing current when the voltage exceeds a desired voltage, and is, for example, a Zener diode or a constant voltage power supply. In this embodiment, the device D1 is a diode, more specifically, a Zener diode. In this embodiment, the predetermined voltage is the breakdown voltage (Zener voltage) of the Zener diode.

[0018] The motor control board 12 includes a variable power supply 18, an output detection circuit 19, an inverter control unit 20, a switch SW, a resistor R2, and a resistor R3.

[0019] The variable power supply 18 is connected to the sensor 14 via a power line Lp. In this embodiment, the variable power supply 18 can selectively output at least a first voltage V1 and a second voltage V2 higher than the first voltage V1. The first voltage V1 is lower than a predetermined voltage (Zener voltage) of the device D1, for example, 5 V. The second voltage V2 is higher than the predetermined voltage (Zener voltage) of the device D1, for example, 12 V.

[0020] The output detection circuit 19 is connected to the sensor 14 via the sensor output line Ls. The output detection circuit 19 detects the voltage generated in the sensor output line Ls and generates a detection signal S1 according to the detected voltage.

[0021] The inverter control unit 20 controls the inverter 1 based on the detection signal S1 so that a desired current is supplied to the motor 2.

[0022] The switch SW is inserted into the first wiring L1 that connects the sensor output line Ls and the ground. The switch SW closes (ON) or opens (OFF) in response to an instruction from the control device 4. The switch SW includes, for example, a transistor and a driver circuit that drives the transistor.

[0023] The resistive element R2 is inserted into the first wiring L1. When the switch SW is closed, the resistive element R2 forms a voltage divider circuit together with the contact resistance R1 of the connector 13, generating a voltage in the sensor output line Ls that can be detected by the output detection circuit 19. The resistive element R2 may have a resistance value similar to the expected contact resistance R1. For example, the resistive element R2 may have a resistance value that is 1 to 100 times the contact resistance R1.

[0024] The resistor R3 is inserted into the third wiring L3 that connects the sensor output line Ls to ground. The resistor R3 generates a voltage in the sensor output line Ls that can be detected by the output detection circuit 19 by passing a signal current output from the operational amplifier 17 through the resistor R3. The resistor R3 may have a resistance value greater than that of the resistor R2. For example, the resistor R3 may have a resistance value 100 times or more that of the resistor R2.

[0025] As shown in FIG. 3, while the motor 2 is running, the motor control device 21 detects the magnitude of the current Ia flowing through the motor 2. Specifically, the variable power supply 18 outputs a first voltage V1 in response to an instruction from the control device 4. Additionally, the switch SW opens (OFF) in response to an instruction from the control device 4. Because the first voltage V1 is lower than the predetermined voltage of the device D1, the device D1 is non-conductive. The operational amplifier 17 receives power from the variable power supply 18 and outputs a signal current corresponding to the current Ia to the sensor output line Ls. The resistor element R3 generates a voltage corresponding to the signal current in the sensor output line Ls. The output detection circuit 19 detects the voltage of the sensor output line Ls and outputs a detection signal S1 corresponding to the detected voltage. At this time, the detection signal S1 reflects the magnitude of the current Ia flowing through the motor 2.

[0026] Meanwhile, as shown in FIG. 4, while the motor 2 is stopped, the motor control device 21 detects the magnitude of the contact resistance R1 of the connector 13. Specifically, the variable power supply 18 receives an instruction from the control device 4 to output a second voltage V2. In addition, the switch SW receives an instruction from the control device 4 to close (ON). Because the second voltage V2 is higher than the predetermined voltage of the device D1, the device D1 becomes conductive. The resistive element R2 and the contact resistance R1 form a voltage divider circuit, generating a voltage in the sensor output line Ls that corresponds to the ratio of the contact resistance R1 to the resistive element R2. The output detection circuit 19 detects the voltage of the sensor output line Ls and outputs a detection signal S1 that corresponds to the detected voltage. At this time, the detection signal S1 reflects the magnitude of the contact resistance R1 of the connector 13.

[0027] In this way, the motor control device 21 partially shares the motor current detection circuit, which detects the current Ia flowing through the motor 2, and the contact resistance detection circuit, which detects the contact resistance R1 of the connector 13. The connector 13 has a power supply line Lp, a sensor output line Ls, and a ground line Lg running through it. These lines were not added specifically for the contact resistance detection circuit. The contact resistance detection circuit of this embodiment does not increase the number of pins on the connector 13, and contributes to the miniaturization of the motor control device 21.

[0028] In this embodiment, the device D1 is a diode. A diode does not require a control line to switch between conductive and non-conductive states, so the number of pins of the connector 13 does not increase.

[0029] 5, upon receiving the start of the vehicle C (S101), the control device 4 detects the magnitude of the contact resistance R1 of the connector 13 while the motor 2 is stopped (S102). Specifically, the control device 4 instructs the variable power supply 18 to output the second voltage V2 and supplies an instruction to the motor control device 21 to turn on the switch SW. In response to this instruction, the motor control device 21 supplies a detection signal S1 indicating the magnitude of the contact resistance R1 of the connector 13 to the control device 4. The control device 4 measures the contact resistance R1 of the connector 13 based on the detection signal S1.

[0030] If the magnitude of the contact resistance R1 of the connector 13 is normal (S103: YES), the control device 4 proceeds to normal operation (S104). The normal operation includes, for example, detecting the current Ia flowing through the motor 2 and performing feedback control to determine the current to be flowed through the motor 2 in accordance with this current Ia.

[0031] On the other hand, if the magnitude of the contact resistance R1 of the connector 13 is abnormal (S103: NO), the control device 4 determines whether the magnitude of the contact resistance R1 is within a predetermined range (S105). For example, even if the magnitude of the contact resistance R1 is abnormal, if it is within a certain allowable range, the control device 4 can properly detect the current Ia flowing through the motor 2 by correcting the detection signal S1. The control device 4 determines whether the contact resistance R1 is within the predetermined range by determining whether it is within such an allowable range. In this embodiment, the predetermined range is, for example, a range in which the correction rate is between 10% and 20%.

[0032] If the magnitude of the contact resistance R1 is within a predetermined range (S105: YES), the control device 4 determines to correct the detection signal S1 in accordance with the magnitude of the contact resistance R1 (S106) and proceeds to normal operation (S104). The control device 4 may have a map that associates the magnitude of the contact resistance R1 with a correction factor for the detection signal S1, and may determine the correction factor for the detection signal S1 from the magnitude of the contact resistance R1 by referring to this map. The inverter control unit 20 may estimate the current Ia flowing through the motor 2 using this correction factor.

[0033] If the magnitude of the contact resistance R1 is outside the predetermined range (S105: NO), the control device 4 proceeds to a fail-safe process (S107). The fail-safe process includes, for example, limiting the output of the motor 2.

[0034] In this embodiment, the motor control device 21 detects the magnitude of the contact resistance R1 of the connector 13 while the motor 2 is stopped, i.e., during a period when it is not necessary to detect the magnitude of the current Ia flowing through the motor 2. Therefore, the detection of the contact resistance R1 of the connector 13 does not adversely affect the operation of the motor 2.

[0035] In this embodiment, the motor control device 21 corrects the detected current Ia if the contact resistance R1 is within a predetermined range. The motor control device 21 performs feedback control using the corrected current Ia, thereby achieving more accurate motor control.

[0036] In this embodiment, the motor control device 21 proceeds to a fail-safe process if the contact resistance R1 is outside a predetermined range. The motor control device 21 contributes to the safety of the vehicle C by the fail-safe process.

[0037] As described above, according to the present disclosure, it is possible to provide a motor control device 21 that can be miniaturized and that includes a circuit for detecting a connection failure of the connector 13.

[0038] <Other embodiments>

[0039] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments, and various modifications are possible within the scope of the gist of the invention. In particular, the multiple modifications described in this specification can be arbitrarily combined as necessary.

[0040] (a) In the above embodiment, the motor 2 is a traction motor, but the present disclosure is not limited to this. The motor 2 may be, for example, a motor used in an air conditioning compressor, a water pump, or the like.

[0041] (b) In the above embodiment, the motor control device 21 is included in the inverter 1 and the control device 4, but the present disclosure is not limited to this. The motor control device 21 may be included only in the inverter 1, or only in the control device 4. Furthermore, the control device 4 may be included in the inverter 1.

[0042] (c) In the above embodiment, the motor control device 21 detects the magnitude of the contact resistance R1 of the connector 13 when the vehicle C starts, but the present disclosure is not limited to this. The motor control device 21 may also detect the magnitude of the contact resistance R1 of the connector 13 while the motor 2 is stopped, for example, while the motor 2 is stopped at a traffic light. [Explanation of symbols]

[0043] 1: Inverter, 2: Motor, 4: Control device, 11: Sensor board, 12: Motor control board, 13: Connector, 14: Sensor, 18: Variable power supply, 19: Output detection circuit, 21: Motor control device, Lp: Power line, Ls: Sensor output line, L1: First wiring, L2: Second wiring, R1: Contact resistor, R2: Resistive element, SW: Switch, D1: Device

Claims

1. a sensor board having a sensor for detecting a current flowing through the motor; a motor control board connected to the sensor board via a connector, The motor control board a variable power supply connected to the sensor via a power line passing through the connector; an output detection circuit connected to the sensor via a sensor output line passing through the connector; a resistive element inserted in a first wiring connecting the sensor output line and ground; a switch inserted in the first wiring, The sensor substrate includes: a device that is inserted into a second wiring that connects the power supply line and the sensor output line, and that becomes conductive when a voltage between the power supply line and the sensor output line is equal to or higher than a predetermined voltage; Motor control device.

2. the device is a diode. The motor control device according to claim 1 .

3. a control device that closes the switch while the motor is stopped and measures the contact resistance of the connector based on the output of the output detection circuit when the switch is closed; The motor control device according to claim 1 .

4. The control device opening the switch while the motor is running and measuring the motor current based on the output of the output detection circuit when the switch is open; correcting the measured motor current based on the contact resistance of the connector when the contact resistance of the connector is within a predetermined range; The motor control device according to claim 3 .

5. The control device If the contact resistance of the connector is outside a predetermined range, a fail-safe process is performed.

5. The motor control device according to claim 3 or 4.

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