On-vehicle control device

Abstract

To provide an on-vehicle control device for suppressing overheating of a current sensor in a power control unit.SOLUTION: A power control unit has a generator inverter, a motor inverter, a boost converter, a reactor current sensor that detects a current flowing through the reactor of the boost converter, and a generator current sensor that detects the generator current. An on-vehicle control device controls the generator inverter so that the regenerative torque of the generator increases when the temperature of the reactor current sensor is more than a first predetermined temperature, and controls the boost inverter such that the voltage reacting to the generator inverter is greater when the temperature of the generator current is more than a second predetermined temperature.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] Conventionally, as this type of technology, an inverter control device has been proposed that controls an inverter device that generates a drive voltage for an AC load by the switching operation of a switching element connected to a freewheel diode (see, for example, Patent Document 1). In this inverter control device, the switching speed of the switching element is slower on the low level side of the magnitude of the current flowing through the AC load than on the high level side of the magnitude of the current, thereby making it possible to reduce the surge voltage as much as possible while suitably suppressing switching loss. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-065742 A Summary of the Invention [Problem to be solved by the invention]

[0004] Higher output is required for electric vehicles equipped with batteries, generators, and step-up inverters, and to achieve this, it is necessary to improve the heat resistance of the power control unit (PCU) that houses the inverter that drives the generator and the step-up inverter, etc. In such power control units, the current sensor is highly sensitive to heat generated by the current value, making it difficult to take measures against heat generated by the current sensor, which is prone to overheating.

[0005] The main object of the in-vehicle control device disclosed herein is to prevent overheating of the current sensor in the power control unit. [Means for solving the problem]

[0006] The vehicle control device of the present disclosure employs the following means to achieve the above-mentioned main object.

[0007] The on-board control device of the present disclosure is an on-board control device for an electric vehicle including a battery, a generator, a drive motor, a generator inverter that drives the generator, a motor inverter that drives the motor, a boost inverter attached to a power line between the battery and the generator inverter and the motor inverter, a reactor current sensor that detects a reactor current flowing in a reactor of the boost inverter, and a generator current sensor that detects a generator current flowing in the generator, and an on-board control device that controls the generator inverter, the motor inverter, and the boost inverter, When the temperature of the reactor current sensor is equal to or higher than a first predetermined temperature, the generator inverter is controlled so as to increase the regenerative torque of the generator, and when the temperature of the generator current sensor is equal to or higher than a second predetermined temperature, the boost inverter is controlled so as to increase the voltage acting on the generator inverter.

[0008] In the vehicle-mounted control device disclosed herein, when the temperature of the reactor current sensor is equal to or higher than a first predetermined temperature, the generator inverter is controlled so that the regenerative torque of the generator is increased. This allows the power generated by the generator to be increased and supplied to the motor, so that the power supplied from the boost inverter to the motor can be reduced, and the reactor current can be reduced. As a result, overheating of the reactor current sensor can be suppressed. In addition, in the vehicle-mounted control device, when the temperature of the generator current sensor is equal to or higher than a second predetermined temperature, the boost inverter is controlled so that the voltage acting on the generator inverter is increased. This allows the power generated by the generator to be reduced by increasing the power supplied from the boost inverter to the motor, and the generator current can be reduced. As a result, overheating of the generator current sensor can be suppressed. As a result, overheating of the current sensor in the power control unit can be suppressed.

[0009] In such an on-board control device disclosed herein, the motors may be two motors, a first motor that outputs power to a first drive shaft and a second motor that outputs power to a second drive shaft, the motor inverters may be two inverters, a first inverter that drives the first motor and a second inverter that drives the second motor, the electric vehicle may include a first motor current sensor that detects a first motor current flowing to the first motor and a second motor current sensor that detects a second motor current flowing to the second motor, and the on-board control device may control the first inverter and the second inverter so that the torque of the first motor decreases and the torque of the second motor increases when the temperature of the first motor current sensor is equal to or higher than a third predetermined temperature, and control the first inverter and the second inverter so that the torque of the first motor increases and the torque of the second motor decreases when the temperature of the second motor current sensor is equal to or higher than a fourth predetermined temperature. When the temperature of the first motor current sensor is equal to or higher than a third predetermined temperature, the vehicle control device controls the first inverter and the second inverter so that the torque of the first motor decreases and the torque of the second motor increases, thereby reducing the first motor current and preventing overheating of the first motor current sensor. When the temperature of the second motor current sensor is equal to or higher than a fourth predetermined temperature, the vehicle control device controls the first inverter and the second inverter so that the torque of the first motor increases and the torque of the second motor decreases, thereby reducing the second motor current and preventing overheating of the second motor current sensor. As a result, overheating of the current sensor in the power control unit can be prevented. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic configuration diagram of an electric vehicle 20 equipped with an on-board control device according to an embodiment. [Diagram 2] 10 is a flowchart showing an example of a temperature sensor overheating suppression process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Next, a mode (embodiment) for carrying out the present disclosure will be described. Fig. 1 is a configuration diagram showing an outline of the configuration of an electric vehicle 20 equipped with an on-board control device as one embodiment of the present disclosure. As shown in the figure, the electric vehicle 20 of the embodiment includes a battery 22, a system main relay (SMR) 24, a power control unit 30, a generator 40, a first motor 42, a second motor 44, and an electronic control unit 50.

[0012] The battery 22 is configured as, for example, a lithium ion secondary battery, and is connected to a boost converter 32 of the power control unit 30 via a low-voltage power line. The system main relay 24 is attached to the low-voltage power line that connects the battery 22 and the boost converter 32.

[0013] The power control unit 30 includes a boost converter 32, a reactor current sensor 33 that detects a reactor current IL flowing in a reactor (not shown) of the boost converter 32, a generator inverter 34, a generator current sensor 35 that detects a three-phase generator current IGuvw flowing in the generator 40, a first motor inverter 36, a first motor current sensor 37 that detects a three-phase first motor current I1uvw flowing in the first motor 42, a second motor inverter 38, and a second motor current sensor 39 that detects a three-phase second motor current I2uvw flowing in the second motor 44.

[0014] The boost converter 32 is connected to a low-voltage power line connected to the battery 22 and a high-voltage power line connected to each of the inverters 34, 36, 38, and is configured as a well-known boost converter having two transistors as switching elements, two diodes connected in parallel to each of the two transistors, and a reactor. A reactor current sensor 33 is attached to the positive line of the low-voltage power line to which the reactor of the boost converter 32 is connected. A temperature sensor 33a is attached to the reactor current sensor 33 to detect its temperature T(IL).

[0015] The generator inverter 34, the first motor inverter 36, and the second motor inverter 38 are used to drive the generator 40, the first motor 42, and the second motor 44, and are connected to the boost converter 32 via a high-voltage power line. Each of the inverters 34, 36, and 38 is configured as a well-known inverter circuit having six switching elements (transistors) and six diodes connected in parallel to each of the six switching elements.

[0016] The generator 40, the first motor 42, and the second motor 44 are configured as, for example, a synchronous generator motor, and have a rotor with a permanent magnet embedded in the rotor core, and a stator with a three-phase coil wound around the stator core. The generator 40 is connected, for example, to an output shaft of the engine, or to a planetary gear connected to the output shaft of the engine and a drive shaft. The first motor 42 is connected, for example, to a front-wheel drive shaft connected to the front wheels. The second motor 44 is connected, for example, to a rear-wheel drive shaft connected to the rear wheels.

[0017] A generator current sensor 35 is attached to the three-phase power line between the generator inverter 34 and the generator 40, and a temperature sensor 35a is attached to the generator current sensor 35 to detect its temperature T(IG). A first motor current sensor 37 is attached to the three-phase power line between the first motor inverter 36 and the first motor 42, and a temperature sensor 37a is attached to the first motor current sensor 37 to detect its temperature T(I1). A second motor current sensor 39 is attached to the three-phase power line between the second motor inverter 38 and the second motor 44, and a temperature sensor 39a is attached to the second motor current sensor 39 to detect its temperature T(I2).

[0018] The electronic control unit 50 is configured as a microcomputer for driving and controlling the generator 40, the first motor 42, and the second motor 44. The electronic control unit 50 receives inputs of the reactor current IL from the reactor current sensor 33, the reactor current sensor temperature T(IL) from the temperature sensor 33a, the generator current IGuvw from the generator current sensor 35, the generator current sensor temperature T(IG) from the temperature sensor 35a, the first motor current I1uvw from the first motor current sensor 37, the first motor current sensor temperature T(I1) from the temperature sensor 37a, the second motor current I2uvw from the second motor current sensor 39, the second motor current sensor temperature T(I2) from the temperature sensor 39a, the rotational positions of the generator 40, the first motor 42, and the second motor 44, and the like. The electronic control unit 50 outputs a drive control signal to the system main relay 24, a switching control signal to the boost converter 32, and switching control signals to the generator inverter 34, the first motor inverter 36, and the second motor inverter 38.

[0019] The electronic control unit 50 transmits information required for vehicle driving control to the driving electronic control unit (not shown) through communication with the driving electronic control unit, and receives torque commands Tg*, Tm1*, Tm2* of the generator 40, the first motor 42, and the second motor 44 from the driving electronic control unit. The electronic control unit 50 sets the boost ratio of the boost converter 32 based on the torque commands Tg*, Tm1*, Tm2* of the generator 40, the first motor 42, and the second motor 44, and controls the switching of the switching elements of the boost converter 32, controls the switching of the switching elements of the generator inverter 34 based on the torque command Tg* and the generator current IGuvw of the generator 40, controls the switching of the switching elements of the first motor inverter based on the torque command Tm1* and the first motor current I1uvw of the first motor 42, and controls the switching of the switching elements of the second motor inverter based on the torque command Tm2* and the second motor current I2uvw of the second motor 44.

[0020] Next, a description will be given of the operation of the electric vehicle 20 of the embodiment configured as described above, in particular the operation of the electronic control unit 50 when suppressing overheating of the temperature sensors 33a, 35a, 37a, 39a. Fig. 2 is a flowchart showing an example of a temperature sensor overheat suppression process executed by the electronic control unit 50. This process is repeatedly executed at predetermined time intervals.

[0021] When the temperature sensor overheating suppression process is executed, the electronic control unit 50 first determines whether the reactor current sensor temperature T(IL) detected by the temperature sensor 33a is equal to or higher than the first predetermined temperature Tref1 (step S100). The first predetermined temperature Tref1 may be a temperature slightly lower than the maximum allowable temperature of the reactor current sensor 33. When it is determined that the reactor current sensor temperature T(IL) is equal to or higher than the first predetermined temperature Tref1, the regenerative torque of the generator 40 is increased to be greater than the torque command Tg* (step S110). When the regenerative torque of the generator 40 is increased, the generated power by the generator 40 increases, and the power supplied from the generator 40 to the first motor 42 and the second motor 44 increases. Therefore, the power supplied from the boost converter 32 to the first motor 42 and the second motor 44 can be reduced, and the reactor current IL can be reduced. As a result, overheating of the reactor current sensor 33 can be suppressed. On the other hand, when it is determined that the reactor current sensor temperature T(IL) is lower than the first predetermined temperature Tref1, the regenerative torque of the generator 40 is set to the normal torque, i.e., the torque command Tg* (step S120). This allows the regenerative torque of the generator 40 to be returned to the normal state when it has been increased.

[0022] Next, it is determined whether the generator current sensor temperature T(IG) detected by the temperature sensor 35a is equal to or higher than the second predetermined temperature Tref2 (step S130). The second predetermined temperature Tref2 may be a temperature slightly lower than the maximum allowable temperature of the generator current sensor 35, and may be different from or equal to the first predetermined temperature Tref1. When it is determined that the generator current sensor temperature T(IG) is equal to or higher than the second predetermined temperature Tref2, the boost rate of the boost converter 32 is increased (step S140). When the boost rate of the boost converter 32 is increased, the power supplied from the boost converter 32 to the first motor 42 and the second motor 44 increases, and the power supplied from the generator 40 to the first motor 42 and the second motor 44 decreases. Therefore, the power generated by the generator 40 can be reduced, and the generator current IGuvw can be reduced. As a result, overheating of the generator current sensor 35 can be suppressed. On the other hand, when it is determined that the generator current sensor temperature T(IG) is lower than the second predetermined temperature Tref2, the boost rate of the boost converter 32 is set to the normal boost rate (step S150). This allows the boost rate of the boost converter 32, when increased, to be returned to the normal rate.

[0023] Next, it is determined whether the first motor current sensor temperature T(I1) detected by the temperature sensor 37a is equal to or higher than the third predetermined temperature Tref3 (step S160). The third predetermined temperature Tref3 may be a temperature slightly lower than the maximum allowable temperature of the first motor current sensor 37, and may be different from or equal to the first predetermined temperature Tref1 or the second predetermined temperature Tref2. When it is determined that the first motor current sensor temperature T(I1) is equal to or higher than the third predetermined temperature Tref3, the torque of the second motor 44 is increased to be greater than the torque command Tm2* (step S170). When the torque of the second motor 44 is increased, the torque of the first motor 42 is reduced, and the power supplied to the first motor 42 from the boost converter 32 and the generator inverter 34 is reduced. Therefore, the first motor current I1uvw can be reduced, and overheating of the first motor current sensor 37 can be suppressed. On the other hand, when it is determined that the first motor current sensor temperature T(I1) is lower than the third predetermined temperature Tref3, the torque of the second motor 44 is set to the normal torque command Tm2* (step S180). This allows the torque of the second motor 44, when increased, to be returned to the normal state.

[0024] Then, it is determined whether the second motor current sensor temperature T(I2) detected by the temperature sensor 39a is equal to or higher than the third predetermined temperature Tref3 (step S190). The fourth predetermined temperature Tref4 may be a temperature slightly lower than the maximum allowable temperature of the second motor current sensor 39, and may be different from or equal to the first predetermined temperature Tref1, the second predetermined temperature Tref2, and the third predetermined temperature Tref3. When it is determined that the second motor current sensor temperature T(I2) is equal to or higher than the fourth predetermined temperature Tref4, the torque of the first motor 42 is increased to be greater than the torque command Tm1* (step S200). When the torque of the first motor 42 is increased, the torque of the second motor 44 is reduced, and the power supplied to the second motor 44 from the boost converter 32 and the generator inverter 34 is reduced. Therefore, the second motor current I2uvw can be reduced, and overheating of the second motor current sensor 39 can be suppressed. On the other hand, when it is determined that the second motor current sensor temperature T(I2) is lower than the fourth predetermined temperature Tref4, the torque of the first motor 42 is set to the normal torque command Tm1* (step S180). This allows the torque of the first motor 42, when increased, to be returned to the normal state.

[0025] The present disclosure has been described above using embodiments, but the present disclosure is not limited to these embodiments in any way, and it goes without saying that the present disclosure can be embodied in various forms without departing from the gist of the present disclosure. [Industrial Applicability]

[0026] The present disclosure can be used in the manufacturing industry of in-vehicle control devices, etc. [Explanation of symbols]

[0027] 20 electric vehicle, 30 power control unit, 32 boost converter, 34 generator inverter, 36 first motor inverter, 38 second motor inverter, 50 electronic control unit.

Claims

1. A battery; A generator, A drive motor; a power control unit including a generator inverter for driving the generator, a motor inverter for driving the motor, a step-up inverter attached to a power line between the battery and the generator inverter and the motor inverter, a reactor current sensor for detecting a reactor current flowing in a reactor of the step-up inverter, and a generator current sensor for detecting a generator current flowing in the generator; an on-vehicle control device for controlling the generator inverter, the motor inverter, and a boost inverter; The vehicle-mounted control device in an electric vehicle comprising: When the temperature of the reactor current sensor is equal to or higher than a first predetermined temperature, the generator inverter is controlled so that a regenerative torque of the generator is increased; when the temperature of the generator current sensor is equal to or higher than a second predetermined temperature, the step-up inverter is controlled so that a voltage acting on the generator inverter becomes large.

2. An in-vehicle control device comprising:

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