Hybrid vehicle

Abstract

To provide a hybrid vehicle that can identify phase short-circuit appropriately and run while cutting off a system main relay, when an abnormality occurs in a rotary electric machine part.SOLUTION: A hybrid vehicle 100 is provided with an engine 10, a rotary electric machine part 20, a battery 50, a system main relay 60, and a control device 90. The engine 10 comprises an encoder 16. The rotary electric machine part 20 comprises an inverter 80 and a diagnosing part 27. When the diagnosing part 27 diagnoses an abnormality of the rotary electric machine part 20, the control device 90 puts the system main relay 60 in a connection state to detect phase short-circuit of the inverter 80 and then puts the system main relay 60 in a non-connection state in accordance with rotation speed of the engine detected by the encoder 16. Further, the control device 90 short-circuits three-phases of the inverter 80 and makes the vehicle run on the basis of rotary drive of the engine 10.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] Patent Document 1 discloses a hybrid vehicle (hybrid electric vehicle) that includes an engine and a rotating electric machine unit (motor generator) and that suppresses the brake torque that occurs when the rotating electric machine unit fails. When a one-phase short circuit occurs in the rotating electric machine unit, this hybrid vehicle performs three-phase ON control (three-phase short circuit control) on the rotating electric machine unit to maintain the rotation speed of the rotating electric machine unit higher than a predetermined range, thereby reducing the brake torque of the rotating electric machine unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-331683 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the above technology, power is supplied from the battery to the rotating electrical machine when the system main relay is connected. In this case, power is taken from the battery via the DC-DC converter to the auxiliary battery. When the battery charge level decreases over time, the hybrid vehicle transitions to a system shutdown state (ready-off).

[0005] Furthermore, if the system main relay of a hybrid vehicle is shut off, there will be a problem in that if one phase of the rotating electrical machine section is short-circuited, the short-circuited phase cannot be identified.

[0006] The present disclosure provides a hybrid vehicle that can accurately identify a short-circuited phase when an abnormality occurs in a rotating electrical machine section, and can run with the system main relay cut off. [Means for solving the problem]

[0007] According to one aspect of the present disclosure, there is provided a hybrid vehicle having an engine and a rotating electric machine unit, the hybrid vehicle including: a battery that supplies power to the rotating electric machine unit; a system main relay that switches between connection and disconnection between the rotating electric machine unit and the battery; and a control device, wherein the engine includes an encoder that detects engine speed, and the rotating electric machine unit includes an inverter that converts DC power from the battery into three-phase AC power, and a diagnostic unit that diagnoses whether the rotating electric machine unit is normal or abnormal, and the control device controls the following steps when the diagnostic unit diagnoses an abnormality in the rotating electric machine unit: a short-circuit detection step that connects the system main relay to supply power from the battery to the inverter and detects a short circuit in a phase of the inverter; a disconnection step that, after the short-circuit detection step, detects the engine speed of the engine that has started rotational drive using the encoder and disconnects the system main relay in accordance with the engine speed; and a driving step that continues the disconnection step, short-circuits the three phases of the inverter, and drives the hybrid vehicle based on the rotational drive of the engine. [Effects of the Invention]

[0008] A hybrid vehicle according to one aspect can properly identify a short-circuited phase when an abnormality occurs in the rotating electrical machine section, and can run with the system main relay cut off. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram illustrating a schematic diagram of a hybrid vehicle drive system according to an embodiment of the present invention; [Figure 2] FIG. 2 is a diagram illustrating an example of an inverter circuit of the rotating electrical machine section. [Figure 3] 1 is a flowchart illustrating an example of a failure processing method for a hybrid vehicle. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and redundant explanations may be omitted.

[0011] 1 is a diagram that schematically shows a traveling drive system 1 of a hybrid vehicle 100 according to an embodiment. The hybrid vehicle 100 according to an embodiment is a vehicle that travels using the traveling drive system 1 that includes an engine 10 and a rotating electric machine unit 20 as drive sources. Specifically, the traveling drive system 1 is configured as a system for a one-motor hybrid (1M-HEV) that has one rotating electric machine unit 20.

[0012] The traveling drive device 1 includes an engine 10, a rotating electrical machine unit 20, a transmission unit 30, a transfer unit 40, a battery 50, an auxiliary battery 55, a system main relay 60, a DC-DC converter 70, and an inverter 80. The hybrid vehicle 100 also includes a control device 90 that controls each component of the traveling drive device 1, such as a hybrid ECU (Electronic Control Unit) 91 and an engine ECU 92.

[0013] The engine 10 is an internal combustion engine that has multiple cylinders and generates rotational driving force by burning fuel (gasoline) injected into each cylinder. An output shaft 11 connected to a crankshaft in the engine 10 extends to a rotating electrical machine section 20. The engine 10 is connected to an engine ECU 92, and the crankshaft and output shaft 11 are driven to rotate by the operation of spark plugs, an electronic throttle, and other components (not shown) under the control of the engine ECU 92.

[0014] The engine 10 also includes a starter motor 12 that rotates a crankshaft when the engine 10 is started, and an alternator 14 that generates electricity by receiving the rotational drive of the engine 10. For example, the starter motor 12 and the output shaft 11 of the engine 10 are connected by a gear mechanism 13. The starter motor 12 is controlled to rotate and stop based on commands from an engine ECU 92, and rotates the engine 10 via the gear mechanism 13 when the engine 10 is started. The alternator 14 is connected to the engine 10 by a pulley mechanism 15 or the like, generates electricity by using the rotational drive of the engine 10, and supplies the generated electricity to an auxiliary battery 55 that is connected to the starter motor 12.

[0015] Furthermore, the engine 10 is equipped with an encoder 16 that detects the engine speed, which is the rotation speed of the output shaft 11. The encoder 16 is connected to a control device 90 such as an engine ECU 92, and constantly transmits information about the detected engine speed.

[0016] The rotating electrical machine unit 20 is a so-called motor generator (MG), and has both a function as a motor that generates mechanical power from electric power and a function as a generator that generates electric power from mechanical power.

[0017] For example, the rotating electrical machine unit 20 includes a stator 21, a rotor 22, an electric oil pump 23, and an engine-side clutch 24. The stator 21 is provided with a coil (not shown), which is connected to an inverter 80. The rotor 22 has a permanent magnet or the like, and rotates a rotating electrical machine shaft 26 about its axis based on the supply of three-phase AC power from the inverter 80 to the coil. The electric oil pump 23 maintains the oil pressure in a hydraulic circuit (not shown) for the engine-side clutch 24 and the like when the rotating electrical machine unit 20 is started or during idling stop.

[0018] The engine-side clutch 24 switches between engagement and disengagement between the output shaft 11 of the engine 10 and the rotating electrical machine shaft 26 based on the hydraulic pressure of the hydraulic circuit. The hydraulic circuit of the engine-side clutch 24 is connected to, for example, a hybrid ECU 91, and the engagement state of the engine-side clutch 24 is switched under the control of the hybrid ECU 91.

[0019] The above-described rotating electric machine unit 20 rotates the rotating electric machine shaft 26 by controlling the drive of the inverter 80 by the control device 90. The rotating electric machine unit 20 generates a rotational driving force for traveling in the rotating electric machine shaft 26 by using the electric power supplied from the inverter 80 instead of or in addition to the engine 10. The rotating electric machine unit 20 also generates electric power by the rotational drive of the engine 10 or by using a driven force input from the drive wheels (not shown). The electric power generated by the rotating electric machine unit 20 is stored in the battery 50 via the inverter 80.

[0020] The rotating electrical machine unit 20 also has a diagnostic unit 27 that diagnoses whether the rotating electrical machine unit 20 is normal or abnormal. For example, the diagnostic unit 27 is composed of various sensors that monitor the rotating electrical machine unit 20 and a control board that processes sensor signals. Abnormalities in the rotating electrical machine unit 20 include a failure on the inverter 80 side, a failure on the control board, a failure on the resolver, etc. The diagnostic unit 27 may appropriately employ a known detection method capable of detecting a failure in the rotating electrical machine unit 20 and a configuration used for this detection method. The diagnostic unit 27 is communicably connected to the control device 90 (hybrid ECU 91) and transmits the diagnosed diagnostic information to the hybrid ECU 91 as a diagnosis code. Note that the diagnostic unit 27 is not limited to being provided in the rotating electrical machine unit 20; for example, a part or all of the diagnostic unit 27 may be provided on the control device 90 side.

[0021] The transmission unit 30 is configured as a stepped type having a plurality of predetermined gears, for example, and switches to an appropriate gear to reduce the rotational driving force of the rotating electric machine shaft 26. As an example, the transmission unit 30 includes a torque converter 31 and an automatic transmission unit 36.

[0022] The torque converter 31 is a fluid-type power transmission device that transmits power via a fluid. The torque converter 31 includes a pump impeller 32 on the input shaft side, a turbine runner 33 on the output shaft side, and a stator 34 that amplifies torque. The torque converter 31 transmits power via a fluid between the pump impeller 32 and the turbine runner 33. The torque converter 31 is also provided with a lock-up clutch 35 that connects the input shaft side and the output shaft side of the torque converter 31 directly or in a slip state.

[0023] The pump impeller 32 is connected to the rotating electric machine shaft 26 and rotates within the housing of the transmission unit 30 as the rotating electric machine shaft 26 rotates. The turbine runner 33 has a turbine shaft 331 at its center and rotates the turbine shaft 331 under the action of the rotation of the pump impeller 32 and the stator 34.

[0024] The lock-up clutch 35 is a hydraulic friction clutch that is frictionally engaged by being controlled by a hydraulic circuit (not shown). The operating states of the torque converter 31 include a disengaged state in which the lock-up clutch 35 is released, a semi-engaged state in which the lock-up clutch 35 is engaged with slippage, and an engaged state in which the lock-up clutch 35 is fully engaged. For example, when the lock-up clutch 35 is engaged, the pump impeller 32 and the turbine runner 33 rotate together, and the rotational drive of the rotating electric machine shaft 26 is transmitted to the automatic transmission unit 36.

[0025] The automatic transmission unit 36 ​​has a plurality of hydraulic friction engagement elements 361 and a planetary gear unit (not shown). The automatic transmission unit 36 ​​selectively establishes a plurality of gear stages by selectively engaging the plurality of friction engagement elements 361. An input shaft of the automatic transmission unit 36 ​​is connected to a turbine shaft 331 of the torque converter 31. An output shaft 37 of the automatic transmission unit 36 ​​is connected to the transfer unit 40.

[0026] Transfer unit 40 distributes and transmits the rotational driving force received from output shaft 37 of automatic transmission unit 36 ​​to the drive wheels of hybrid vehicle 100. The drive wheels of hybrid vehicle 100 may be either a pair of front wheels or a pair of rear wheels, or both a pair of front wheels and a pair of rear wheels.

[0027] Battery 50 is the main power storage device of hybrid vehicle 100, supplying stored electric power to rotating electric machine unit 20 while storing electric power regenerated from rotating electric machine unit 20. The voltage of battery 50 is set to a voltage higher than the voltage of auxiliary battery 55 in order to drive and rotate rotating electric machine unit 20. Travel drive device 1 connects battery 50 and inverter 80 of rotating electric machine unit 20 via high-voltage wiring 51.

[0028] The system main relay 60 is installed at a midpoint of the high-voltage wiring 51. The system main relay 60 is capable of communicating with the hybrid ECU 91, and switches between connection and disconnection (cutting off, disconnection) of the battery 50 in the high-voltage wiring 51 based on commands from the hybrid ECU 91. For example, the system main relay 60 is configured to have a positive relay in the positive line of the high-voltage wiring 51 and a negative relay in the negative line of the high-voltage wiring 51.

[0029] The auxiliary battery 55 is a power storage device that supplies power to various electrical and electronic devices of the hybrid vehicle 100. The auxiliary battery 55 is connected to the starter motor 12, the DC-DC converter 70, etc., and supplies power to these devices at appropriate times. The auxiliary battery 55 is also connected to the alternator 14 of the engine 10, and stores the power generated by the alternator 14.

[0030] The DC-DC converter 70 is provided on a wiring that connects the auxiliary battery 55 to a high-voltage wiring 51 that extends between the system main relay 60 and the inverter 80. In other words, the DC-DC converter 70 is electrically connected to the system main relay 60. The DC-DC converter 70 changes the voltage between the auxiliary battery 55 and the high-voltage wiring 51 to enable the transfer of power. For example, the DC-DC converter 70 boosts the supply voltage of the auxiliary battery 55 and supplies it to the high-voltage wiring 51. Alternatively, the DC-DC converter 70 reduces the voltage from the high-voltage wiring 51 and supplies it to the auxiliary battery 55.

[0031] The inverter 80 converts the DC power supplied from the battery 50 into three-phase AC power and supplies it to the rotating electrical machine unit 20. The inverter 80 also converts the AC power generated by the rotating electrical machine unit 20 into DC power and supplies it to the battery 50. This allows the battery 50 to store the power output from the inverter 80.

[0032] 2 is a diagram illustrating a circuit of inverter 80 of rotating electrical machine unit 20. As shown in Fig. 2, rotating electrical machine unit 20 divides the coil wound around stator 21 (see Fig. 1) into three phases, U-phase, V-phase, and W-phase, which are connected by a Y-connection. Therefore, inverter 80 has a U-phase line 81 connected to the U-phase, a V-phase line 83 connected to the V-phase, and a W-phase line 85 connected to the W-phase. Note that rotating electrical machine unit 20 may also have a configuration in which the U-phase, V-phase, and W-phase are connected by a Δ-connection.

[0033] The inverter 80 includes a U-phase drive unit 82 connected to a U-phase line 81, a V-phase drive unit 84 connected to a V-phase line 83, and a W-phase drive unit 86 connected to a W-phase line 85. The U-phase drive unit 82 includes, for example, an IGBT (Insulated Gate Bipolar Transistor) and two arms in which diodes are connected in parallel between the collector and emitter of the IGBT. The U-phase drive unit 82 is configured by connecting these two arms (upper arm and lower arm) in series with the U-phase line 81 in between. The same applies to the V-phase drive unit 84 and the W-phase drive unit 86. Note that the elements configuring the arms are not limited to IGBTs and diodes, and various elements may be used. For example, transistors, power MOSFETs, etc. may be used instead of the IGBTs.

[0034] The inverter 80 also has a control board that turns on / off the gates of each IGBT. By controlling the on / off timing of each IGBT using the control board, the inverter 80 forms the waveforms of three-phase AC power consisting of U, V, and W phases.

[0035] Furthermore, inverter 80 includes current sensors 87 that can separately detect the current in U-phase line 81, the current in the V-phase line, and the current in the W-phase line. Current sensors 87 are connected to a control board or control device 90 of inverter 80, and transmit the detected current values ​​for each of the U-phase, V-phase, and W-phase.

[0036] Each IGBT of the inverter 80 described above shorts out when its collector current increases and becomes an overcurrent exceeding a predetermined value. In the case of a single-phase short circuit, in which one phase of the U-phase drive unit 82, V-phase drive unit 84, or W-phase drive unit 86 is shorted, the shorted phase can be identified by observing changes in the waveform of the three-phase AC current detected by the current sensor 87. Therefore, the diagnostic unit 27 of the rotating electrical machine unit 20 shown in FIG. 1 can diagnose an abnormality based on the occurrence of a single-phase short circuit in the inverter 80 by acquiring the current value of the current sensor 87 over time.

[0037] However, a one-phase short circuit in the inverter 80 can be identified by connecting the system main relay 60 and supplying power from the battery 50 to the inverter 80. However, as described above, if the system main relay 60 continues to be connected when there is an abnormality in the inverter 80, power will be taken out from the battery 50 via the DC-DC converter 70 and sent to the auxiliary battery 55. If the charge level of the battery 50 decreases due to the continuous power supply from the battery 50, the hybrid vehicle 100 will transition to a system stop state (ready-off).

[0038] Therefore, in the hybrid vehicle 100 according to the embodiment, when an abnormality occurs in the rotating electrical machine section 20, the control device 90 switches the system main relay 60 between connected and disconnected at an appropriate timing, thereby enabling identification of a one-phase short circuit and evacuation driving.

[0039] The hybrid ECU 91 and engine ECU 92 of the control device 90 are electronic circuits having a processor, memory, input / output interface, communication interface, etc. (not shown). The processor is one or a combination of a central processing unit (CPU), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a circuit made up of multiple discrete semiconductors, etc. The memory includes a main storage device made up of semiconductor memory such as random access memory (RAM) and read only memory (ROM), and an auxiliary storage device made up of a disk, semiconductor memory (flash memory), etc.

[0040] The hybrid ECU 91 mainly controls the configuration related to the combination of the engine 10 and the rotating electrical machine unit 20 by having a processor read and process programs stored in a memory. The hybrid ECU 91 is connected to, for example, the hydraulic circuit of the engine-side clutch 24 of the rotating electrical machine unit 20, the ECU of the battery 50, the control unit of the system main relay 60, the control unit of the DC-DC converter 70, and the control unit of the inverter 80. The hybrid ECU 91 operates each of the connected components by outputting commands to each of the connected components at appropriate timing.

[0041] The engine ECU 92 mainly controls the operation of the engine 10 and components linked to the operation of the engine 10 by having a processor read and process programs stored in memory. The engine ECU 92 is connected to sensors related to the control of the engine 10 (such as an accelerator opening sensor 93 that detects the accelerator operation by the user), and rotates the engine 10 in response to the user's operation and commands from the hybrid ECU 91. The engine ECU 92 is also connected to, for example, control units for the electronic throttle and spark plugs of the engine 10, a driver for the starter motor 12, a control unit for the alternator 14, and a control unit for the transmission unit 30. The engine ECU 92 operates each component by outputting commands to each component connected to it at appropriate timing.

[0042] Although the control device 90 according to the embodiment includes the hybrid ECU 91 and the engine ECU 92, these ECUs may be integrated into an electronic circuit. Alternatively, the control device 90 may be configured to include a plurality of ECUs obtained by further dividing the hybrid ECU 91 and the engine ECU 92.

[0043] Hereinafter, processing (failure processing method) when a failure in the rotating electrical machine unit 20 in the hybrid vehicle 100 is detected will be described with reference to Fig. 3. Fig. 3 is a flowchart showing an example of the failure processing method for the hybrid vehicle 100.

[0044] In the failure handling method for hybrid vehicle 100, control device 90 (hybrid ECU 91, engine ECU 92) sequentially controls the processing flow of steps S101 to S113 shown in FIG.

[0045] The hybrid ECU 91 of the control device 90 monitors the state of the rotating electric machine unit 20 using the diagnosis unit 27, and monitors whether or not an abnormality has occurred in the rotating electric machine unit 20 (step S101). As described above, abnormalities in the rotating electric machine unit 20 include a failure on the inverter 80 side (including one-phase short circuit), a failure of the control board, a failure of the resolver, etc. If the hybrid ECU 91 does not detect an abnormality in the rotating electric machine unit 20 (step S101: NO), it repeats this step S101. On the other hand, if the hybrid ECU 91 detects an abnormality in the rotating electric machine unit 20 (step S101: YES), it proceeds to step S102.

[0046] In step S102, the hybrid ECU 91 outputs a command to the inverter 80 based on the detection of an abnormality in the rotating electrical machine unit 20 to shut off (turn off) the gates of the IGBTs of the inverter 80 (step S102). This stops the supply of three-phase AC power from the inverter 80 to the rotating electrical machine unit 20.

[0047] When starting the hybrid vehicle 100, the engine ECU 92 of the control device 90 then operates the starter motor 12 based on a command from the hybrid ECU 91 to start the engine 10 (step S103). At this time, the hybrid vehicle 100 prohibits intermittent operation by the engine 10 and the rotating electric machine unit 20, and drives only the engine 10. Note that when the hybrid vehicle 100 is started and running using the rotating electric machine unit 20, the control device 90 performs a push start instead of starting the engine 10 using the starter motor 12 in response to the occurrence of an abnormality in the rotating electric machine unit 20. In a push start, for example, the engine 10 is cranked using the inertia of the tires with the engine-side clutch 24 and the lock-up clutch in the on state.

[0048] Thereafter, the engine ECU 92 sets an upper limit of the engine speed of the engine 10 in response to the abnormality of the rotating electrical machine unit 20, and performs speed limit control to rotate the engine 10 up to this upper limit of the engine speed (step S104). As the engine speed increases, the transmission unit 30 forcibly performs an upshift.

[0049] Then, the hybrid ECU 91 connects the system main relay 60 while the gates of the IGBTs of the inverter 80 are cut off, supplies power from the battery 50 to the inverter 80, and determines whether an overcurrent is occurring in the inverter 80 (step S105). As described above, if an overcurrent is occurring in the inverter 80, there is a possibility that a one-phase short circuit has occurred, in which any one of the U phase, V phase, or W phase of the inverter 80 is short-circuited. Alternatively, there is a possibility that the inverter 80 has a two-phase short circuit or a three-phase short circuit in addition to a one-phase short circuit.

[0050] Therefore, if an overcurrent is occurring (step S105: YES), the hybrid ECU 91 proceeds to step S106. In step S106, the hybrid ECU 91 supplies power from the battery 50 to the inverter 80, and identifies the phase (including the upper arm or the lower arm) that is short-circuited in one phase based on the switching of the inverter 80 at that time and the detection information of the current sensor 87. Alternatively, the hybrid ECU 91 may identify each phase of the two-phase short circuit, a three-phase short circuit, etc. of the inverter 80 in conjunction with step S106.

[0051] On the other hand, if no overcurrent is occurring (step S105: NO), it means that an abnormality other than a short circuit in a phase of the inverter 80 has occurred in the rotating electrical machine unit 20. Therefore, the hybrid ECU 91 proceeds to step S107 without performing step S106 of identifying the short-circuited phase. As described above, steps S105 and S106 correspond to the short-circuit detection process of the present disclosure.

[0052] The control device 90 (e.g., the engine ECU 92) then acquires the engine speed from the encoder 16 of the engine 10, estimates the back electromotive force from the engine speed, and determines whether the back electromotive force has fallen below a predetermined value (step S107). The estimated back electromotive force is linked to the brake torque of the rotating electrical machine unit 20. When the inverter 80 is short-circuited in one phase, if the rotating electrical machine shaft 26 of the rotating electrical machine unit 20 continues to rotate, the brake torque increases according to the rotation speed of the rotating electrical machine shaft 26. Immediately after starting the engine 10, the engine speed and the rotation speed of the rotating electrical machine shaft 26 are the same. Therefore, it can be said that the brake torque of the rotating electrical machine unit 20 increases according to the engine speed. On the other hand, when the inverter 80 is short-circuited in three phases, the brake torque of the rotating electrical machine unit 20 is large when the rotation speed of the rotating electrical machine shaft 26 is low, but conversely, it decreases when the rotation speed is high (see also FIG. 2 of JP 2007-331683 A, prior art).

[0053] The predetermined value for monitoring the back electromotive force may be set to, for example, a value at which the brake torque changes between an increase in a one-phase short circuit and a decrease in a three-phase short circuit. In other words, when the back electromotive force of the rotating electrical machine unit 20 becomes smaller than the predetermined value, it means that the brake torque of the rotating electrical machine unit 20 can be suppressed even if the engine speed increases.

[0054] If the back electromotive force is equal to or greater than the predetermined value (step S107: NO), the hybrid ECU 91 repeats step S107 to continue monitoring the engine speed. On the other hand, if the back electromotive force becomes smaller than the predetermined value, the process proceeds to step S108. The back electromotive force of the rotating electrical machine unit 20 may be estimated by detecting the rotation speed of the rotating electrical machine shaft 26 using a resolver (not shown) provided in the rotating electrical machine unit 20. However, since an abnormality in the rotating electrical machine unit 20 may also be due to a malfunction of the resolver as described above, the back electromotive force can be more accurately estimated by using the engine speed.

[0055] In step S108, the hybrid ECU 91 disconnects the system main relay 60. This cuts off the power supply from the battery 50 to the rotating electrical machine unit 20. The above steps S107 and S108 correspond to the cut-off step of the present disclosure.

[0056] Then, with the system main relay 60 disconnected, the control device 90 controls the drive and stop of the DC-DC converter 70 and checks for welding of the system main relay 60 (step S109). That is, in the welding check of the system main relay 60, welding of each of the positive and negative relays is inspected by supplying power from the auxiliary battery 55 via the DC-DC converter 70 without using power from the battery 50. The method of checking for welding of the system main relay 60 can be, for example, the method disclosed in Japanese Patent Laid-Open No. 2020-99129 (therefore, detailed description thereof will be omitted in this disclosure).

[0057] The hybrid ECU 91 determines whether the system main relay 60 is welded by the welding check (step S110). If the hybrid ECU 91 determines that the system main relay 60 is welded (step S110: NO), the process proceeds to step S111.

[0058] In step S111, the control device 90 stops activation of the system main relay 60 based on the fact that the system main relay 60 is welded, and ends the processing flow of the failure handling method. This is because if the system main relay 60 is welded, the hybrid vehicle 100 may not be able to run properly.

[0059] On the other hand, if the welding check finds no welding in the system main relay 60 (step S109: YES), the hybrid ECU 91 proceeds to step S112. In step S112, the hybrid ECU 91 executes the three-phase ON control of the inverter 80 while continuing the disconnection of the system main relay 60 in step S108.

[0060] In this three-phase ON control, the inverter 80 turns on (releases) the gates of the IGBTs of the three phases (U phase, V phase, W phase) under the control of the control board, thereby creating a three-phase short-circuit state. As a result, the inverter 80 suppresses the brake torque of the rotating electrical machine unit 20 during evacuation running, allowing the hybrid vehicle 100 to run stably.

[0061] Through the above processing flow, the control device 90 ends the processing for the failure of the rotating electrical machine unit 20 and transitions to a state in which the hybrid vehicle 100 can perform evacuation traveling (step S112). Note that the above steps S111 and S112 correspond to the traveling step of the present disclosure.

[0062] During evacuation running, hybrid vehicle 100 can generate electricity with alternator 14 based on the rotational drive of engine 10, and charge auxiliary battery 55. Hybrid vehicle 100 can run until it runs out of fuel by generating electricity with alternator 14 and by rotating engine 10.

[0063] As described above, the hybrid vehicle 100 according to this embodiment can accurately identify the short-circuited phase when an abnormality occurs in the rotating electrical machine unit 20 by performing the short-circuit detection process, the disconnection process, and the running process using the control device 90, and can run by disconnecting the system main relay 60. Specifically, in the short-circuit detection process, when the diagnostic unit 27 diagnoses an abnormality in the rotating electrical machine unit 20, the system main relay 60 is connected to supply power from the battery 50 to the inverter 80, and a phase short circuit of the inverter 80 is detected. This allows the hybrid vehicle 100 to smoothly identify the short-circuited phase when, for example, one phase is short-circuited in the inverter 80. Furthermore, in the disconnection process following the short-circuit detection process, the encoder 16 detects the engine speed of the engine 10, which has been started to be driven by the starter motor 12, and the system main relay 60 is disconnected in accordance with the detected engine speed. This prevents power from being drawn from the battery 50 to the auxiliary battery 55. Furthermore, in the running process, while the disconnection process is continued, the gates of three phases of the inverter 80 are turned on to create a three-phase short-circuit state, and the vehicle runs based on the rotational drive of the engine 10. As a result, the hybrid vehicle 100 can perform evacuation running by rotating the engine 10 and generating electricity with the alternator 14 until the fuel runs out. Moreover, since the braking torque of the rotating electrical machine unit 20 is suppressed by the three-phase ON control, the hybrid vehicle 100 can ensure high running performance during evacuation running.

[0064] The hybrid vehicle 100 is not limited to the configuration of the above-described embodiment, and various modifications are possible. For example, the hybrid vehicle 100 is not limited to a one-motor hybrid, and may be a traveling drive device equipped with a plurality of motor generators (rotating electric machine unit 20), such as a two-motor hybrid.

[0065] The hybrid vehicle 100 according to the presently disclosed embodiment is illustrative in all respects and not restrictive. The embodiment may be modified and improved in various ways without departing from the spirit and scope of the appended claims. The features described in the above-described embodiments may be configured differently and may be combined within a consistent range. [Explanation of symbols]

[0066] 10 Engine 12 Starter motor 16 Encoders 20 Rotating Electric Machinery Department 27 Diagnostic Department 50 Battery 60 System Main Relay 80 inverter 90 Control device 100 Hybrid Vehicles

Claims

[Claim 1] A hybrid vehicle equipped with an engine and a rotating electrical machine unit, a battery that supplies power to the rotating electrical machine unit; a system main relay that switches between connection and disconnection between the rotating electrical machine unit and the battery; a control device; The engine is equipped with an encoder for detecting engine speed, the rotating electrical machine unit includes an inverter that converts DC power from the battery into three-phase AC power, and a diagnostic unit that diagnoses whether the rotating electrical machine unit is normal or abnormal, a short-circuit detection step of connecting the system main relay to supply power from the battery to the inverter when the diagnosis unit has diagnosed an abnormality in the rotating electrical machine unit, and detecting a short circuit in a phase of the inverter, a disconnection step of detecting the engine speed of the engine that has started to rotate after the short-circuit detection step by the encoder and disconnecting the system main relay in accordance with the detected engine speed; a running process in which the three phases of the inverter are short-circuited while the shut-off process is continued, and the vehicle is run based on the rotational drive of the engine. Hybrid vehicle.

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