Hybrid vehicle

Abstract

To secure hours of use of an air conditioner, even when an abnormality occurs in a motor.SOLUTION: A hybrid vehicle is provided with: an engine; a battery; a relay through which the battery is connected to and disconnected from an electric power line; a motor which outputs power for travelling by electric power supplied by the electric power line; an air conditioner which performs air-conditioning in a vehicle compartment with electricity supplied to the electric power line; and a control device which when an abnormality occurs in the motor, makes the hybrid vehicle perform retreat-running with power from the engine and drives the air conditioner, with the relay connected to the air conditioner, when the air conditioner is required to be driven and an electricity storage ratio of the battery is above a predetermined ratio, and disconnects the relay therefrom and controls the engine, the relay and the air conditioner so that the hybrid vehicle performs retreat-running with power from the engine, when the air conditioner is not required to be driven or when the electricity storage ratio of the battery is less than the predetermined ratio.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to hybrid vehicles. [Background technology]

[0002] Conventionally, hybrid vehicles of this type have been proposed that include an engine, an automatic transmission in which an input shaft is connected to a rotating shaft connected to the output shaft of the engine via a torque converter and the output shaft is connected to drive wheels, a motor generator in which a rotor is connected to the rotating shaft, a battery, and a power control circuit (PCU) that converts the battery's power and supplies it to the motor generator (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-128280 Summary of the Invention [Problem to be solved by the invention]

[0004] In such hybrid vehicles equipped with an engine and a motor, the battery is typically connected to a power line via a relay, and the motor generator is driven by the power supplied to the power line. If an abnormality occurs in the motor generator, the relay can be shut off, allowing the vehicle to run for evacuation using power from the engine. However, in hybrid vehicles equipped with an air conditioner powered by power supplied to the power line, if the relay is shut off immediately when an abnormality occurs in the motor generator, the battery will be disconnected from the power line, making it impossible to drive the air conditioner, which could reduce comfort inside the vehicle.

[0005] The main object of the hybrid vehicle of the present disclosure is to provide a hybrid vehicle that can ensure the usage time of the air conditioner even if an abnormality occurs in the motor. [Means for solving the problem]

[0006] The hybrid vehicle of the present disclosure employs the following measures to achieve the above-mentioned main object.

[0007] The hybrid vehicle of the present disclosure comprises an engine that outputs power for driving, a battery, a relay that connects and disconnects the battery from a power line, a motor that outputs power for driving using power supplied to the power line, an air conditioning unit that conditions the air inside the vehicle using the power supplied to the power line, and a control device that controls the engine, the relay, and the air conditioning unit so that, when an abnormality occurs in the motor, if operation of the air conditioning unit is required and the battery's charge storage rate is equal to or higher than the predetermined rate, the relay is connected and the vehicle performs evacuation driving using power from the engine and drives the air conditioning unit, and if operation of the air conditioning unit is not required or the battery's charge storage rate is less than the predetermined rate, the relay is disconnected and the vehicle performs evacuation driving using power from the engine.

[0008] In the hybrid vehicle disclosed herein, if an abnormality occurs in the motor, when the air conditioning system is requested and the battery's charge storage rate is equal to or greater than a predetermined rate, the relay is connected and the vehicle runs evacuation mode using power from the engine and drives the air conditioning system. When the air conditioning system is not requested or the battery's charge storage rate is less than the predetermined rate, the relay is disconnected and the vehicle runs evacuation mode using power from the engine. This allows the vehicle to run evacuation mode using power from the engine even if an abnormality occurs in the motor, while still being able to air-condition the passenger compartment using power from the battery in response to an air-conditioning request, until the battery's charge storage rate falls below the predetermined rate. As a result, even if an abnormality occurs in the motor, the air conditioning system can be used for a certain period of time, maintaining passenger comfort. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram of a hybrid vehicle 20 according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram of a high-voltage system including a motor. [Figure 3] 10 is a flowchart illustrating an example of a control process when a motor abnormality occurs. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of the present disclosure will be described with reference to the drawings. Fig. 1 is a schematic diagram of a hybrid vehicle 20 according to this embodiment, and Fig. 2 is a schematic diagram of a high-voltage system including a motor 30. As shown in Fig. 1, the hybrid vehicle 20 according to this embodiment includes an engine 22, the motor 30, an inverter 32, a clutch K0, a power transmission device 40, a high-voltage battery 50, a low-voltage battery 55, an air conditioner 60, and a main electronic control unit (hereinafter referred to as "main ECU") 70.

[0011] The engine 22 is configured as an internal combustion engine that outputs power using hydrocarbon fuel such as gasoline or diesel. A transmission shaft 35 is connected to a crankshaft 23 of the engine 22 via a clutch K0. The clutch K0 is, for example, a hydraulically driven friction clutch, and connects and disconnects the engine 22 and the transmission shaft 35. A starter motor 24 for cranking the engine 22 and an alternator 25 for generating electricity using power from the engine 22 are also connected to the crankshaft 23 of the engine 22.

[0012] The operation of the engine 22 is controlled by an engine electronic control unit 26 (hereinafter referred to as engine ECU). Signals from various sensors for controlling the operation of the engine 22 are input to the engine ECU 26. Examples of the signals input to the engine ECU 26 include the crank angle θcr of the crankshaft 23 from the crank position sensor 23a. The engine ECU 26 outputs various control signals for controlling the operation of the engine 22. Examples of the signals output from the engine ECU 26 include control signals to a throttle valve and spark plugs (not shown), a control signal to the starter motor 24, and a control signal to the alternator 25.

[0013] The motor 30 is configured as, for example, a synchronous generator motor having a rotor to which a permanent magnet is attached and a stator around which a three-phase coil is wound. The rotor of the motor 30 is attached to a transmission shaft 35. As shown in FIG. 2, the inverter 32 is connected to a high-voltage battery 50 via a high-voltage power line 51. The inverter 32 has a plurality of (six) transistors T as switching elements and a plurality of (six) diodes D connected in anti-parallel to each transistor T. The motor 30 is rotationally driven by applying a three-phase AC current to each phase coil from the high-voltage power line 51 by switching each transistor T of the inverter 32. The motor 30 is also a generator motor, and the power generated by the motor 30 is rectified by the diodes D and supplied to the high-voltage power line 51.

[0014] The power transmission device 40 includes a torque converter 41 and an automatic transmission 44. The torque converter 41 is configured as a typical fluid transmission device with a lock-up clutch. The torque converter 41 is connected to the crankshaft 23 of the engine 22 via a clutch KO and is connected to the rotor of the motor 30. The torque converter 41 amplifies the torque of a transmission shaft 35 connected to an input shaft 42 of the automatic transmission 44, or transmits the torque directly without amplifying it. The automatic transmission 44 is connected to the input shaft 42 and an output shaft 43. The output shaft 43 is connected to a drive shaft 47 that is connected to rear wheels 49a, 49b via a rear differential gear 48. The automatic transmission 44 has multiple planetary gears and multiple hydraulically driven friction engagement elements (clutches, brakes). The automatic transmission 44 transmits power between the input shaft 42 and the output shaft 43 by engaging and disengaging the multiple friction engagement elements to form forward gears (e.g., first through sixth gears) and reverse gears.

[0015] The high-voltage battery 50 is, for example, a lithium-ion battery or a nickel-metal hydride battery having a rated voltage of 48 V, and is connected to a high-voltage power line 51 that is connected to the inverter 32. A system main relay 52 is attached to the high-voltage power line 51, and the high-voltage battery 50 can be disconnected by turning off the system main relay 52. ​​The high-voltage power line 51 is also equipped with high-voltage load circuits, such as an inverter 61 that drives a compressor 62 of an air conditioner 60 that conditions the passenger compartment 21, a DC / DC converter 54 that steps down the power of the high-voltage power line 51 and supplies it to a low-voltage power line 56, and an inverter (not shown) that supplies AC power (AC power of up to 1500 W or 2400 W) to an electrical load connected to an AC outlet equipped in the vehicle. A smoothing capacitor 53 is also attached to the high-voltage power line 51.

[0016] As shown in Fig. 1, the air conditioner 60 includes a refrigeration cycle consisting of a compressor 62, a condenser 63, an expansion valve 64, and an evaporator 65, a blower 66 that blows air cooled by heat exchange with the evaporator 65 of the refrigeration cycle to the outlet 21a of the passenger compartment 21, and an air conditioner electronic control unit (hereinafter referred to as air conditioner ECU) 68. The compressor 62 is driven by an inverter 61 connected to the high-voltage power line 51. As shown in Fig. 2, the inverter 61 has multiple transistors T similar to those of the inverter 32. The compressor 62 is driven to rotate by switching on and off the transistors T of the inverter 61. The air conditioning ECU 68 receives inputs such as a switch signal from an on / off switch 67a attached to an operation panel 67 for turning the air conditioning on and off, a set temperature T* from a set temperature switch 67b also attached to the operation panel 67 for setting the temperature inside the passenger compartment 21, and an occupant room temperature Tin from a temperature sensor 67c attached to the operation panel 67 for detecting the temperature inside the passenger compartment 21. The air conditioning ECU 68 also outputs drive signals to the compressor 62 and the blower 66. Based on the input signals, the air conditioning ECU 68 controls the drive of the compressor 62, the blower 66, etc. so that the occupant room temperature Tin becomes the set temperature T*.

[0017] The low-voltage battery 55 is a lead-acid battery having a rated voltage lower than that of the high-voltage battery 50, for example, a rated voltage of 12V, and is connected to a low-voltage power line 56 that is connected to the starter motor 24 and alternator 25.

[0018] DC / DC converter 54 is connected to high-voltage power line 51 and low-voltage power line 56. DC / DC converter 54 steps down the power on high-voltage power line 51 and supplies it to low-voltage power line 56, and steps up the power on low-voltage power line 56 and supplies it to high-voltage power line 51. DC / DC converter 54 normally steps down the power on high-voltage power line 51 and supplies it to low-voltage power line 56.

[0019] The main ECU 70 includes a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports. The main ECU 70 receives signals from various sensors via the input ports. For example, the main ECU 70 receives signals related to the status of the motor 30, the high-voltage battery 50, the low-voltage battery 55, and the powertrain 40. These signals include, for example, the rotational position θm of the motor 30 received from a rotational position sensor 30a attached to the rotor of the motor 30, the phase currents Iv and Iw of the motor 30 received from current sensors 30b attached to the respective phase coils of the motor 30, the coil temperature tm of the motor 30 received from a temperature sensor 30c attached to the stator of the motor 30, the current Ib of the high-voltage battery 50 received from a current sensor 50a attached to the output terminal of the high-voltage battery 50, the rotational speed Nin of the input shaft 42 of the automatic transmission 44 received from a rotational speed sensor 42a attached to the input shaft 42, and the rotational speed Nout of the output shaft 43 of the automatic transmission 44 received from a rotational speed sensor 43a attached to the output shaft 43 of the automatic transmission 44. The main ECU 70 calculates the rotation speed Nm of the motor 30 based on the rotation position θm of the motor 30, and calculates the charge storage percentage SOC, which is the ratio of the remaining capacity to the total capacity of the high-voltage battery 50, based on the integrated value of the current Ib of the high-voltage battery 50. The main ECU 70 also receives as input an ignition signal IG from an ignition switch 80, a shift position SP, which is the operating position of a shift lever 81, from a shift position sensor 82, an accelerator pedal position AP, which is the depression amount of an accelerator pedal 83, from an accelerator pedal position sensor 84, a brake pedal position BP, which is the depression amount of a brake pedal 85, from a brake pedal position sensor 86, and a vehicle speed V from a vehicle speed sensor 87.

[0020] The main ECU 70 outputs various control signals via an output port. For example, the main ECU 70 outputs control signals to the system main relay 52, the inverter 32, the clutch K0, and the automatic transmission 44. The main ECU 70 also communicates with the engine ECU 26 and the air conditioning ECU 68, exchanging control signals and data with them.

[0021] The operation of the hybrid vehicle 20 of this embodiment configured as described above will now be described. The main ECU 70 sets a required torque Td* for driving based on the accelerator pedal position AP, the brake pedal position BP, and the vehicle speed V, and controls the engine 22, the motor 30, the clutch K0, and the automatic transmission 44 so that the vehicle drives at the set required torque Td*.

[0022] Next, an operation when an abnormality is detected in the motor 30 will be described. FIG. 3 is a flowchart showing an example of a motor abnormality control process executed by the main ECU 70. This process is executed when an abnormality is detected in the motor 30. Examples of abnormalities in the motor 30 include element abnormalities such as overcurrent or overheating of a switching element of the inverter 32, and sensor abnormalities such as a failure of the rotational position sensor 30a or a failure of the current sensor 30b. When an abnormality in the motor 30 is detected, for example, the main ECU 70 shuts off the gate of the inverter 32. When the main ECU 70 detects a short circuit in a switching element as the abnormality in the motor 30, the main ECU 70 performs three-phase ON control, in which all switching elements of the upper arm are turned on if the short-circuited switching element is in the upper arm, and all switching elements of the lower arm are turned on if the short-circuited switching element is in the lower arm.

[0023] When the motor abnormality control process is executed, the main ECU 70 (CPU) first determines whether the engine 22 is stopped (step S100). If the main ECU 70 determines that the engine 22 is stopped, it sends a control signal to the engine ECU 26 to have the starter motor 24 crank and start the engine 22 (step S102). If the main ECU 70 determines that the engine 22 is not stopped but is running, it prohibits the engine ECU 26 from intermittently stopping the engine 22 (step S104).

[0024] Next, the main ECU 70 determines whether air conditioning of the passenger compartment 21 by the air conditioner 60 is requested (air conditioning on) (step S106), and whether the power storage percentage SOC of the high-voltage battery 50 is equal to or greater than a predetermined percentage α (step S108). If the main ECU 70 determines that air conditioning is requested and that the power storage percentage SOC is equal to or greater than the predetermined percentage α, it sends a control signal to the engine ECU 26 to keep the system main relay 52 on and controls the power transmission device 40 to run using power from the engine 22 (step S110), and then returns to step S106.

[0025] On the other hand, if the main ECU 70 determines in step S106 that air conditioning is not required, or if it determines in step S108 that the power storage percentage SOC of the high-voltage battery 50 is less than the predetermined percentage α even if air conditioning is required, it determines that operation of the air conditioner 60 is unnecessary or that the power storage percentage SOC of the high-voltage battery 50 is insufficient to operate the air conditioner 60, and turns off the system main relay 52 to disconnect the high-voltage battery 50 from the high-voltage power line 51 (step S112). Here, the system main relay 52 is turned off after, for example, forcibly upshifting the automatic transmission 44 to reduce the rotation speed Nin of the input shaft 42 and thereby reducing the back electromotive force of the motor 30 connected to the input shaft 42. The main ECU 70 also discharges the charge stored in the smoothing capacitor 53 and performs processing to confirm that the system main relay 52 has been normally turned off (is not welded) based on whether the voltage VH of the smoothing capacitor 53 has become less than the predetermined voltage. Then, the main ECU 70 transmits a control signal to the engine ECU 26 to drive using power from the engine 22 (evacuation driving), and controls the power transmission device 40 (step S114), and ends the motor abnormality control process. Note that if the main ECU 70 determines that the system main relay 52 is not normally turned off, it turns off the system without performing evacuation driving.

[0026] In the hybrid vehicle 20 of the present embodiment described above, if an abnormality occurs in the motor 30, when operation of the air conditioner 60 is required and the power storage percentage SOC of the high-voltage battery 50 is equal to or greater than the predetermined percentage α, the system main relay 52 remains on and the vehicle performs evacuation running using power from the engine 22 and air conditioning in the passenger compartment 21 using the air conditioner 60. When operation of the air conditioner 60 is not required or the power storage percentage SOC of the high-voltage battery 50 is less than the predetermined percentage α, the system main relay 52 is turned off and the vehicle performs evacuation running using power from the engine 22. As a result, even if an abnormality occurs in the motor 30, evacuation running can be performed using power from the engine 22 and air conditioning in the passenger compartment 21 using power from the high-voltage battery 50 until the power storage percentage SOC of the high-voltage battery 50 falls below the predetermined percentage α. As a result, even if an abnormality occurs in the motor 30, the air conditioner 60 can be used for a sufficient period of time to maintain comfort in the passenger compartment 21.

[0027] The above describes the forms for implementing the present disclosure 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 implemented in various forms within the scope that does not deviate from the gist of the present disclosure. [Industrial Applicability]

[0028] The present disclosure is applicable to the hybrid vehicle manufacturing industry and the like. [Explanation of symbols]

[0029] 20 Hybrid vehicle, 22 Engine, 30 Motor, 50 High voltage battery, 51 High voltage power line, 52 System main relay, 60 Air conditioning unit, 70 Main electronic control unit (main ECU).

Claims

[Claim 1] An engine that outputs power for driving; A battery, a relay for connecting and disconnecting the battery and the power line; a motor that outputs power for running using the power supplied to the power line; an air conditioning device that conditions the air inside the vehicle cabin using the power supplied to the power line; a control device that controls the engine, the relay, and the air conditioner so that, when an abnormality occurs in the motor, if operation of the air conditioner is required and the charge storage rate of the battery is equal to or greater than the predetermined rate, the engine, the relay, and the air conditioner are driven while the vehicle runs on power from the engine with the relay connected, and if operation of the air conditioner is not required or the charge storage rate of the battery is less than the predetermined rate, the relay is disconnected and the vehicle runs on power from the engine; A hybrid vehicle equipped with

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