Hybrid vehicle power generation system

Abstract

To provide a power generating system of a hybrid vehicle in which: a generator generates power by which a vehicle can keep traveling when error occurs in the communication with a controller; and deposition of a contactor arranged at a high voltage energization passage at the time of blockade and voltage surge of the high voltage energization passage can be prevented.SOLUTION: A hybrid vehicle 1 includes: a low voltage conducting path 21 which is connected to a generator 13 and supplies the generator 13 with the low voltage power whose voltage is lower than that of the high voltage power; and a relay 16 which is switched between a closed state where the low voltage conducting path 21 is conductive and an open state where the low voltage conducting path 21 is cut off by a controller 19. The generator 13 stops the independent power generation, when the relay 16 becomes the open state so that the low voltage conducting path 21 is cut off during an independent power generation. When the controller makes the contactor 14A switch from the closed state to the open state, the controller 19 makes the relay 16 switch from the closed state to the open state before the controller makes a contactor 14A switch from the closed state to the open state.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a power generation system for a hybrid vehicle. [Background technology]

[0002] The hybrid vehicle described in Patent Document 1 includes a high-voltage battery for driving with a relatively high voltage (e.g., approximately 500 V) and a low-voltage battery for on-board electrical equipment that stores relatively low-voltage (e.g., approximately 24 V) DC power. In the hybrid vehicle described in Patent Document 1, if a main relay provided between the battery and the motor melts, the motor inverter fails, and there is a risk of the battery being overcharged, the hybrid vehicle protects the battery from the risk of overcharging by controlling the upper limit of the engine speed through the engine control device and maintaining the motor back electromotive force at a voltage below the overcharge level. Furthermore, in the hybrid vehicle described in Patent Document 1, if communication with the motor control device and communication with the battery control device are both OFF, the upper limit of the engine speed is controlled through the engine control device, limiting the motor back electromotive force and maintaining the motor back electromotive force at a voltage below the overcharge level, thereby protecting the battery from the risk of overcharging. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-234559 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology described in Patent Document 1 does not consider preventing welding of the contactor (main relay) provided in the high-voltage current path connecting the generator (motor) and the battery, and therefore is unable to prevent welding of the contactor. Also, with the technology described in Patent Document 1, if a communication abnormality occurs in communication between the generator and the control device, the generator's generated voltage is limited by controlling the upper limit of engine speed, which could result in insufficient generated power and the vehicle being unable to continue traveling.

[0005] The present invention has been made in response to the above-mentioned problems, and aims to provide a power generation system for a hybrid vehicle that allows the generator to generate enough power to continue driving even if an abnormality occurs in communication with the control device, and that can prevent welding when a contactor installed in a high-voltage current circuit is cut off, and can prevent voltage surges in the high-voltage current circuit. [Means for solving the problem]

[0006] The present invention provides a power generation system for a hybrid vehicle, comprising: a control device; a generator that communicates with the control device, generates high-voltage power in accordance with instructions from the control device when there is no abnormality in the communication, and autonomously generates high-voltage power when there is an abnormality in the communication; a high-voltage current path connected to the generator and through which the high-voltage power generated by the generator is supplied; and a contactor that can be switched by the control device between a closed state that conducts the high-voltage current path and an open state that interrupts the high-voltage current path, a low-voltage current path connected to the generator and supplying low-voltage power having a lower voltage than the high-voltage power supplied to the high-voltage current path; and a relay that is switched by the control device to a closed state that conducts the low-voltage current path or an open state that interrupts the low-voltage current path, wherein the generator stops the autonomous power generation when the relay is opened and the low-voltage current path is interrupted during the autonomous power generation, and when switching the contactor from a closed state to an open state, the control device switches the relay from a closed state to an open state before switching the contactor from a closed state to an open state. a DC-DC converter that reduces the high-voltage power generated by the generator and supplies the reduced low-voltage power to a low-voltage system, the low-voltage current path supplies low-voltage power from the low-voltage system to the generator, the generator has a high-voltage detection unit that detects an actual generated voltage value of the high-voltage power to be generated, and during the communication abnormality, the actual generated voltage value detected by the high-voltage detection unit before the occurrence of the communication abnormality is set to a target generated voltage value to perform the autonomous power generation, the generator has a low-voltage detection unit that detects the voltage of the low-voltage power supplied from the low-voltage current path, and the generator stops the autonomous power generation if the voltage value detected by the low-voltage detection unit is equal to or lower than a threshold value during the communication abnormality. It is characterized by: [Effects of the Invention]

[0007] As described above, according to the present invention, a power generation system for a hybrid vehicle can be provided in which the generator can generate enough power to continue driving even if an abnormality occurs in communication with the control device, and which can prevent welding when a contactor installed in a high-voltage current circuit is cut off, and the occurrence of a voltage surge in the high-voltage current circuit. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing the configuration of a vehicle equipped with a hybrid vehicle power generation system according to one embodiment of the present invention. [Figure 2] FIG. 2 is a diagram illustrating the counter electromotive force of the generator of the power generation system of the hybrid vehicle according to one embodiment of the present invention. [Figure 3] FIG. 3 is a flowchart showing the operation of the generator of the power generation system of the hybrid vehicle according to one embodiment of the present invention. [Figure 4] FIG. 4 is a flowchart showing the operation of the control device for the power generation system of the hybrid vehicle according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] A power generation system for a hybrid vehicle according to one embodiment of the present invention includes a control device, a generator that communicates with the control device, generates high-voltage power in accordance with instructions from the control device under normal circumstances when no abnormality occurs in communication, and autonomously generates high-voltage power in the event of a communication abnormality when an abnormality occurs in communication, a high-voltage current path connected to the generator and to which the high-voltage power generated by the generator is supplied, and a contactor that can be switched by the control device to a closed state that conducts the high-voltage current path or an open state that interrupts the high-voltage current path, and the hybrid vehicle power generation system further includes a low-voltage current path connected to the generator and that supplies low-voltage power that is lower than the high-voltage power supplied to the high-voltage current path, and a relay that can be switched by the control device to a closed state that conducts the low-voltage current path or an open state that interrupts the low-voltage current path, and the generator stops autonomous power generation when the relay is opened during autonomous power generation and the low-voltage current path is interrupted, and when switching the contactor from a closed state to an open state, the control device switches the relay from a closed state to an open state before switching the contactor from a closed state to an open state. As a result, the power generation system of a hybrid vehicle according to one embodiment of the present invention allows the generator to generate enough power to continue driving even if an abnormality occurs in communication with the control device, and can prevent welding when the contactor installed in the high-voltage current circuit is cut off, or the occurrence of a voltage surge in the high-voltage current circuit. [Example]

[0010] A power generation system for a hybrid vehicle according to an embodiment of the present invention will now be described with reference to the drawings. Figures 1 to 4 are diagrams showing a power generation system for a hybrid vehicle according to an embodiment of the present invention.

[0011] 1, a hybrid vehicle 1 equipped with a hybrid vehicle power generation system according to one embodiment of the present invention includes an internal combustion engine 10, a generator 13 connected to the engine 10 via a belt 12, a high-voltage current path 20 connected to the generator 13 and supplied with high-voltage power generated by the generator 13, and a control device 19. The engine 10 has a starter 11 that starts the engine 10.

[0012] The generator 13 is connected to a crankshaft (not shown) of the engine 10 via a belt 12. The generator 13 is an ISG (Integrated Starter Generator), which is a rotating electric machine that has the functions of generating electricity using the power of the engine 10, providing power to the engine 10, and starting the engine 10. The generator 13 generates 48V power. The generator 13 is a claw-pole, magnet-wound field motor.

[0013] The hybrid vehicle 1 is equipped with a high-voltage battery 14, which is a Li (lithium ion) battery having a plurality of cells, and which stores and discharges 48 V of electric power. A high-voltage current path 20 connects the generator 13 and the high-voltage battery 14.

[0014] The hybrid vehicle 1 has a contactor 14A. The contactor 14A is provided in the high-voltage battery 14. The contactor 14A is switched by a control device 19 between a closed state that connects a high-voltage current path 20 and an open state that interrupts the high-voltage current path 20. The high-voltage battery 14 is provided with a BMS (Battery Management System) 14B. The BMS 14B has functions such as preventing overcharging, over-discharging, and overcurrent of the cells, managing the cell temperature, determining whether or not there is an abnormality in the cells, and calculating the state of charge (SOC). The BMS 14B switches the contactor 14A between an open state and a closed state in accordance with instructions from the control device 19.

[0015] The hybrid vehicle 1 includes low-voltage current paths 21, 22, and 27 through which 12V low-voltage power is supplied. The low-voltage current path 27 connects the DC-DC converter 15 and the lead battery 17. The low-voltage current path 22 connects the low-voltage current path 27 and the 12V components 18. The low-voltage current path 21 connects the low-voltage current path 27 and the generator 13. Therefore, the low-voltage current path 21 supplies the generator 13 with low-voltage power that is lower in voltage than the high-voltage power supplied to the high-voltage current path 20. More specifically, the low-voltage current path 21 supplies the generator 13 with low-voltage power from the low-voltage system of the hybrid vehicle 1.

[0016] Hybrid vehicle 1 includes, as a low-voltage system, lead battery 17 that stores and generates 12V electric power, and 12V components 18 connected to lead battery 17 via low-voltage current paths 27 and 22. 12V components 18 are electrical components that operate on 12V electric power. Low-voltage current path 21 supplies 12V low-voltage electric power to generator 13.

[0017] The hybrid vehicle 1 includes a relay 16. The relay 16 is provided in a low-voltage current path 21. The relay 16 is switched by a control device 19 between a closed state in which the low-voltage current path 21 is connected and an open state in which the low-voltage current path 21 is disconnected.

[0018] Hybrid vehicle 1 includes DC-DC converter 15. DC-DC converter 15 is connected to high-voltage current path 20 and low-voltage current path 27. DC-DC converter 15 steps down the high-voltage power generated by generator 13 and supplies the stepped-down low-voltage power to a low-voltage system. The low-voltage power output by DC-DC converter 15 charges lead battery 17. Therefore, DC-DC converter 15 steps down the high-voltage power of 48 V supplied from generator 13 via high-voltage current path 20 to low-voltage power of 14 V and supplies the stepped-down low-voltage power to lead battery 17 via low-voltage current path 27.

[0019] The hybrid vehicle 1 is equipped with ground wires 23 and 24. The ground wire 23 connects a negative terminal (not shown) of the lead battery 17 to the DC-DC converter 15. The ground wire 24 connects the negative terminal of the lead battery 17 to the generator 13.

[0020] The hybrid vehicle 1 includes a communication line 25 for communication between the control device 19 and the generator 13 via a CAN (Controller Area Network), and a communication line 26 for communication between the control device 19 and the high-voltage battery 14 via the CAN. The generator 13 communicates with the control device 19 via the communication line 25. The BMS 14B of the high-voltage battery 14 communicates with the control device 19 via the communication line 26.

[0021] The control device 19 is composed of an ECU (Electronic Control Unit) including a microcomputer equipped with a CPU, RAM, ROM, input / output interface, etc. The CPU uses the temporary storage function of the RAM and performs signal processing according to a program pre-stored in the ROM. Various control constants, various maps, etc. are pre-stored in the ROM.

[0022] The generator 13 communicates with the control device 19 and generates high-voltage power in accordance with instructions from the control device 19 under normal circumstances when no abnormalities occur in the communication.

[0023] Here, if the generator 13 is configured to stop generating power when an abnormality occurs in the communication between the control device 19 and the generator 13, the hybrid vehicle 1 may be unable to continue traveling due to a lack of power. Therefore, in this embodiment, the generator 13 autonomously generates high-voltage power when an abnormality occurs in communication with the control device 19 via the communication line 25. In other words, when there is a communication abnormality in communication with the control device 19, the generator 13 performs autonomous power generation in accordance with control content that is preset in the generator 13. This allows the hybrid vehicle 1 to continue generating power through autonomous power generation and travel to a service center where repairs, etc. can be performed.

[0024] On the other hand, if the contactor 14A is switched from the closed state to the open state while high-voltage power is being applied to the high-voltage current path 20, the contactor 14A may be welded due to arc discharge, or a voltage surge (load dump) may occur in the high-voltage current path 20. In order to prevent the contactor 14A from welding or a voltage surge in the high-voltage current path 20, it is desirable to switch the contactor 14A to the open state while the generator 13 is stopped from generating power. On the other hand, when there is an abnormality in communication with the generator 13, the control device 19 cannot control the generator 13 to stop autonomous power generation.

[0025] Therefore, in this embodiment, the generator 13 is configured to stop autonomous power generation if the relay 16 is opened during autonomous power generation and the low-voltage current path 21 is interrupted. When the low-voltage current path 21 is interrupted, the supply of low-voltage power to the generator 13 stops and the power supply to the control unit of the generator 13 is cut off, so the power supply unit to the field coil inside the generator 13 is turned off and the generator 13 stops generating power.

[0026] When the control device 19 changes the contactor 14A from a closed state to an open state in response to a request from the BMS 14B of the high-voltage battery 14, the control device 19 changes the relay 16 from a closed state to an open state before changing the contactor 14A from a closed state to an open state. In other words, the control device 19 changes the contactor 14A from a closed state to an open state after changing the relay 16 from a closed state to an open state.

[0027] The generator 13 is equipped with a high-voltage detection unit 13A that detects the actual generated voltage value of the high-voltage power to be generated. The actual generated voltage value is the voltage actually generated by the generator 13 when it is generating electricity. During a communication abnormality, the generator 13 performs autonomous power generation by setting the actual generated voltage value detected by the high-voltage detection unit 13A before the communication abnormality occurred as the target generated voltage value. This allows the generated voltage at the time of the communication abnormality to be maintained even during autonomous power generation, enabling extended driving to a service center. The target generated voltage is the target generated voltage of the generator 13. Note that if the generator 13 is generating electricity at or above the center (approximately 60%) of the normal use range of the open circuit voltage (OCV) of the high-voltage battery 14 when the communication abnormality occurs, the target generated voltage is set to a predetermined value (constant) stored inside the generator 13, rather than the actual generated voltage value at the time the communication abnormality occurred. This prevents the wasteful consumption of fuel beyond that required for extended travel to a service center due to an increase in mechanical load caused by the generation of excess power, even if a communication abnormality occurs during high regeneration of the generator 13.

[0028] The generator 13 includes a low-voltage detection unit 13B that detects the voltage of the low-voltage power supplied from the low-voltage current path 21. When the DC-DC converter 15 is functioning normally, the normal voltage of the low-voltage current path 27 connected to the DC-DC converter 15 is equal to or higher than the threshold value during normal power generation (14 V in this embodiment). On the other hand, when the DC-DC converter 15 is not functioning normally and power supply to the low-voltage current path 27 is stopped, the normal voltage of the low-voltage current path 27 is lower than 14 V. Therefore, when a communication abnormality occurs, the generator 13 stops autonomous power generation if the voltage value detected by the low-voltage detection unit 13B is equal to or lower than the threshold value (10 V in this embodiment). When a communication abnormality occurs and a cell is faulty, the control device 19 preferably switches the relay 16 from the closed state to the open state.

[0029] The configuration and power generation characteristics of the generator 13 will be described with reference to Fig. 2. In Fig. 2, the vertical axis represents the open circuit voltage (OCV) of the high-voltage battery 14 (referred to as LiB voltage_OCV in the figure), and the horizontal axis represents the state of charge (referred to as SOC, abbreviated as State of Charge in the figure) of the high-voltage battery 14. In this embodiment, a normal use range of the state of charge is set for the high-voltage battery 14.

[0030] A back electromotive force generated by the magnets in the generator 13 acts on the high-voltage battery 14. Therefore, the magnet amount and magnetic circuit of the generator 13 are set so that the back electromotive force generated by the magnets when the engine 10 is rotating at the maximum engine speed (when the generator 13 is rotating at the maximum speed) is the lower limit of the open circuit voltage in the normal operating range of the high-voltage battery 14. The back electromotive force generated by the magnets of the generator 13 exists within a back electromotive force range. The upper limit of this back electromotive force range is set to be the lower limit of the open circuit voltage in the normal operating range of the high-voltage battery 14.

[0031] In FIG. 1 , when a cell of the high-voltage battery 14 fails and a communication abnormality with the generator 13 occurs, the control device 19 opens the relay 16 to stop the supply of low-voltage power to the generator 13 through the low-voltage current path 21. By stopping the supply of low-voltage power, the power supply to the field coil of the generator 13 is turned off, and the generator 13 stops generating power. Furthermore, even if a back electromotive force is generated due to the rotation of the engine 10, the voltage is set to a value below the voltage value in the normal specification range of the high-voltage battery 14, so no current flows through the high-voltage battery 14 with a failed cell. Therefore, when a cell of the high-voltage battery 14 fails and a communication abnormality with the generator 13 occurs, no current is passed through the cell of the high-voltage battery 14, thereby protecting the high-voltage battery 14.

[0032] The operation of the generator 13 when a communication abnormality occurs will be described with reference to Figure 3. In Figure 3, the generator 13 determines in step S1 whether communication via CAN (referred to as CAN communication in the figure) is in an abnormal state, and if not in an abnormal state, performs normal control in step S8 and ends the current operation. Normal control is control in which the control device 19 and the generator 13 communicate with each other, and the generator 13 generates high-voltage power in accordance with instructions from the control device 19.

[0033] If the communication is abnormal in step S1, the generator 13 determines whether the voltage value of the low-voltage current path is equal to or lower than a threshold in step S2. If the generator 13 determines that the voltage value is not equal to or lower than the threshold in step S2, the generator 13 determines whether a target generation voltage has been set in step S3.

[0034] If the target power generation voltage has not been set in step S3, the generator 13 acquires the actual power generation voltage value in step S4. Then, the generator 13 sets the target power generation voltage to the actual power generation voltage value in step S5. Then, the generator 13 starts autonomous power generation in step S6.

[0035] If the generator 13 determines in step S2 that the voltage value is equal to or lower than the threshold value, it stops power generation in step S7. Note that even during autonomous power generation when a communication abnormality occurs with the control device 19, the generator 13 stops autonomous power generation if it determines that the voltage value is equal to or lower than the threshold value.

[0036] The operation of the control device 19 when a communication abnormality occurs will be described with reference to Figure 4. In Figure 4, the control device 19 determines in step S11 whether or not communication via CAN (referred to as CAN communication in the figure) is in an abnormal state, and if not in an abnormal state, performs normal control in step S15 and ends the current operation. Normal control is control in which the control device 19 and the generator 13 communicate with each other, and the generator 13 generates high-voltage power in accordance with instructions from the control device 19.

[0037] If the communication with the generator 13 is in an abnormal state in step S11, the control device 19 determines in step S12 whether or not welding of the contactor 14A or a failure of a cell of the high-voltage battery 14 has occurred.

[0038] If the control device 19 determines in step S12 that the contactor 14A has welded or a cell of the high-voltage battery 14 has failed, the control device 19 opens the relay 16 in step S13, and ends the current operation.

[0039] If the control device 19 determines in step S12 that there is no welding of the contactor 14A or a failure of a cell of the high-voltage battery 14, it determines in step S14 whether there is a request from the BMS 14B of the high-voltage battery 14 to open the contactor 14A.

[0040] If there is no request to open contactor 14A in step S14, control device 19 ends this operation. If there is a request to open contactor 14A in step S14, control device 19 opens relay 16 before opening contactor 14A in step S13, and then ends this operation. That is, in step S13, control device 19 first opens relay 16, and then opens contactor 14A.

[0041] As described above, in this embodiment, the hybrid vehicle 1 includes the low-voltage current path 21 connected to the generator 13 and supplying low-voltage power that is lower in voltage than the high-voltage power to the generator 13, and the relay 16 that is switched by the control device 19 to a closed state that conducts the low-voltage current path 21 or an open state that interrupts the low-voltage current path 21. If the relay 16 is opened during autonomous power generation and the low-voltage current path 21 is interrupted, the generator 13 stops autonomous power generation. When changing the contactor 14A from a closed state to an open state, the control device 19 changes the relay 16 from a closed state to an open state before changing the contactor 14A from a closed state to an open state.

[0042] As a result, even if an abnormality occurs in communication with the control device 19, the generator 13 can autonomously generate enough power to enable the hybrid vehicle 1 to continue traveling. Therefore, even when a communication abnormality occurs, the driver can drive the hybrid vehicle 1 and increase the opportunities to bring it to a service workshop.

[0043] Furthermore, by changing the relay 16 from a closed state to an open state before changing the contactor 14A from a closed state to an open state, the contactor 14A can be opened when the autonomous power generation of the generator 13 has stopped and high-voltage power is not being supplied to the high-voltage current circuit 20, thereby preventing welding of the contactor 14A provided in the high-voltage current circuit 20 when it is cut off and preventing a voltage surge (load dump) in the high-voltage current circuit 20.

[0044] As a result, even if an abnormality occurs in communication with the control device 19, the generator 13 can generate enough electricity to continue driving, and welding when the contactor 14A provided in the high-voltage current circuit 20 is cut off and the occurrence of a voltage surge in the high-voltage current circuit 20 can be prevented.

[0045] In addition, in this embodiment, the hybrid vehicle 1 is equipped with a DC-DC converter 15 that steps down the high-voltage power generated by the generator 13 and supplies the stepped-down low-voltage power to the low-voltage system, the low-voltage current path 21 supplies low-voltage power from the low-voltage system to the generator 13, the generator 13 is equipped with a high-voltage detection unit 13A that detects the actual generation voltage value of the high-voltage power it generates, and during a communication abnormality, the actual generation voltage value detected by the high-voltage detection unit 13A before the occurrence of the communication abnormality is set to the target generation voltage value to perform autonomous power generation.

[0046] As a result, during a communication abnormality, the actual generated voltage value before the communication abnormality occurred is set to the target generated voltage, so that the target generated voltage can be set to an appropriate voltage value, preventing overcharging and over-discharging of the low-voltage system.

[0047] Furthermore, when the contactor 14A is welded, the supply of current to the contactor 14A can be minimized, which reduces the possibility of damaging the contactor 14A and reducing the possibility of the contactor 14A becoming red hot.

[0048] In addition, in this embodiment, the generator 13 is equipped with a low-voltage detection unit 13B that detects the voltage of the low-voltage power supplied from the low-voltage current path 21, and the generator 13 stops autonomous power generation when the voltage value detected by the low-voltage detection unit 13B is below a threshold value during a communication abnormality.

[0049] As a result, when DC-DC converter 15 stops supplying low-voltage power to the low-voltage system, generator 13 stops autonomous power generation, reducing the engine load and suppressing fuel and power consumption, thereby extending the driving distance and enabling the vehicle to travel to a dealer or repair shop. Also, if DC-DC converter 15 malfunctions, stopping the supply of power to DC-DC converter 15 reduces the possibility of DC-DC converter 15 becoming red-hot, etc.

[0050] In this embodiment, the hybrid vehicle 1 includes a high-voltage battery 14 having a plurality of cells, and a high-voltage current path 20 connects the generator 13 and the high-voltage battery 14. When a communication abnormality occurs and a cell fails, the control device 19 switches the relay 16 from a closed state to an open state.

[0051] As a result, if a communication abnormality occurs and a cell of the high-voltage battery 14 fails, the relay 16 is switched to a closed state, causing the generator 13 to stop autonomous power generation, thereby protecting the high-voltage battery 14.

[0052] In this embodiment, during a communication abnormality, the generator 13 performs autonomous power generation by setting the actual generated voltage value detected by the high voltage detection unit 13A before the occurrence of the communication abnormality to the target generated voltage value.

[0053] In addition, if the high-voltage battery 14 is generating power at or above the center of its normal operating range (for example, 60%), the generator 13 may set the target power generation voltage to a constant stored inside the generator 13 during a communication abnormality.

[0054] Although autonomous power generation basically maintains the state at the time of the communication abnormality, if a communication abnormality occurs while the generator 13 is in high regeneration mode, the excess power generation increases the mechanical load and wastes fuel. By setting the target power generation voltage to a constant held inside the generator 13, it is possible to extend the life of the vehicle.

[0055] While an embodiment of the present invention has been disclosed, it will be apparent to one skilled in the art that modifications may be made thereto without departing from the scope of the present invention, and it is intended that all such modifications and equivalents be included in the following claims. [Explanation of symbols]

[0056] 1 Hybrid vehicle 13. Generator 13A high voltage detector 13B Low voltage detection section 14 High Voltage Battery 14A contactor 15 DC-DC converter 16 Relay 19 Control device 20 High voltage current circuit 21 Low voltage current circuit

Claims

1. a control device; a generator that communicates with the control device, generates high-voltage power in accordance with instructions from the control device during normal times when no abnormality occurs in the communication, and autonomously generates high-voltage power during a communication abnormality when an abnormality occurs in the communication; a high-voltage current path connected to the generator and supplied with high-voltage power generated by the generator; a contactor that is switched by the control device to a closed state that conducts the high-voltage current path or an open state that interrupts the high-voltage current path, a low-voltage current path connected to the generator and configured to supply low-voltage power to the generator, the low-voltage power having a voltage lower than that of the high-voltage power supplied to the high-voltage current path; a relay that is switched by the control device to a closed state that conducts the low-voltage current path or an open state that interrupts the low-voltage current path, the generator stops the autonomous power generation when the relay is opened and the low-voltage current path is interrupted during the autonomous power generation; When the control device changes the contactor from a closed state to an open state, the control device changes the relay from a closed state to an open state before changing the contactor from a closed state to an open state, a DC-DC converter that reduces the high-voltage power generated by the generator and supplies the reduced low-voltage power to a low-voltage system; the low-voltage current path supplies low-voltage power from the low-voltage system to the generator; the generator includes a high-voltage detection unit that detects an actual generated voltage value of high-voltage power to be generated, and during the communication abnormality, the actual generated voltage value detected by the high-voltage detection unit before the occurrence of the communication abnormality is set as a target generated voltage value to perform the autonomous power generation; the generator includes a low-voltage detection unit that detects the voltage of the low-voltage power supplied from the low-voltage current path, The power generation system for a hybrid vehicle, wherein the generator stops the autonomous power generation when the voltage value detected by the low voltage detection unit is equal to or lower than a threshold value during the communication abnormality.

2. A high-voltage battery having a plurality of cells, the high-voltage current path connects the generator and the high-voltage battery; 2. The power generation system for a hybrid vehicle according to claim 1, wherein the control device switches the relay from a closed state to an open state when the communication abnormality occurs and the cell is faulty.

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