JP6561803B2 - High voltage controller - Google Patents

Description

  The present invention relates to a high voltage control device that controls supply and interruption of high voltage power.

  For example, in an electric vehicle equipped with a high-voltage battery, the inverter main circuit connection switch is opened to cut off the supply of DC power from the high-voltage battery to the DC bus, and the main circuit capacitor is charged. Japanese Patent Application Laid-Open No. H10-228707 discloses that the discharged electric charge is discharged by the forced discharge circuit section.

JP 2010-193691 A

  However, in the control device described in Patent Document 1, since the electric power stored in the capacitor is passed through the forced discharge resistance of the forced discharge circuit, the forced discharge resistance may be deteriorated in some cases. There is.

  Therefore, the present invention provides a high voltage control device that can complete forced discharge processing by avoiding degradation of forced discharge resistance when it is necessary to discharge the stored power of a capacitor of a high voltage circuit. It is intended to provide.

One aspect of the invention of a high-voltage control device that solves the above problems is a high-voltage battery, an inverter that converts DC power supplied from the high-voltage battery into AC power, and DC power supplied from the high-voltage battery. Either a smoothing capacitor that smoothes the voltage of the battery and a connection state in which the high-voltage battery is connected to supply high-voltage power, or a high-voltage cutoff state in which the connection is disconnected to cut off the supply of high-voltage power A high voltage mounted on an electric vehicle comprising: a switching device for switching to a motor; an electric motor that is driven by AC power supplied from the inverter to output power; and a generator that is directly connected to the axle of the vehicle to rotate and generate electric power. The control device, when discharging the power stored in the smoothing capacitor in a high voltage cutoff state by the switch, the voltage across the electrodes of the smoothing capacitor Passive discharge using a passive discharge resistance as a limiting resistance is performed when the threshold value is equal to or higher than a preset threshold value, and when the voltage between the electrodes of the smoothing capacitor is less than the allowable threshold value, the resistance value is higher than the passive discharge resistance value. There rows forced discharge for use in limiting resistor is less forced discharge resistor, wherein when the generator is generating waits for the start of the forced discharge process power stored in the smoothing capacitor, configured to ing.

  Thus, according to one aspect of the present invention, when discharging the electric power stored in the smoothing capacitor, a high voltage control device is provided that completes the discharge process by avoiding deterioration of the forced discharge resistance. can do.

FIG. 1 is a diagram illustrating an example of a vehicle equipped with a control device for an electric vehicle according to an embodiment of the present invention, and is a block diagram illustrating a schematic overall configuration thereof. FIG. 2 is a circuit diagram showing the configuration of the inverter. FIG. 3 is a flowchart illustrating a control process (control method) for discharging the stored power of the smoothing capacitor. FIG. 4 is a graph for explaining the execution of the discharge process corresponding to the change in the storage voltage value of the smoothing capacitor.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1-4 is a figure which shows an example of the electric vehicle carrying the high voltage control apparatus which concerns on one Embodiment of this invention.

  In FIG. 1, a vehicle 1 is constructed as a hybrid vehicle that is mounted with an internal combustion engine type engine 2 and a motor generator 4 as drive sources, and travels by rotating drive wheels 5 via a transmission 3. That is, the vehicle 1 is also configured as an electric vehicle that travels with the driving force of the motor generator 4.

  The vehicle 1 is equipped with an HCU (Hybrid Control Unit) 10, an ECM (Engine Control Module) 11, and a TCM (Transmission Control Module) 12 as control systems, each of which is stored in advance in a memory. Thus, efficient driving is realized by controlling the driving of the engine 2, the transmission 3 and the motor generator 4.

  Here, in the vehicle 1, a control process in which the HCU 10 is started or stopped according to the operation of the ignition key by the driver detected by the ignition switch 9 is executed, and the HCU 10 comprehensively controls the entire vehicle 1, The ECM 11 controls the engine 2 and the TCM 12 is configured to control the transmission 3.

  The engine 2 is formed with a plurality of cylinders. The engine 2 is configured to perform a series of four strokes including an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke for each cylinder.

  The vehicle 1 has an EV (Electric Vehicle) mode in which the engine 2 is stopped and the vehicle 1 is driven by the driving force of the motor generator 4. The vehicle 1 also has an idling stop function that automatically stops the engine 2 in accordance with a preset stop condition and restarts the engine 2 in accordance with a preset restart condition.

  The engine 2 is connected to an integrated starter generator (ISG) 20 and a starter 21. The ISG 20 is connected to the crankshaft 18 of the engine 2 via a belt 22 or the like. The ISG 20 has a function of an electric motor that starts the engine 2 by rotating by being supplied with electric power, and a function of a generator that converts the rotational force input from the crankshaft 18 into electric power.

  The vehicle 1 includes an ISGCM (Integrated Starter Generator Control Module) 13 as a control system, and the ISGCM 13 controls driving of the ISG 20 according to a control program stored in advance in a memory.

  The ISG 20 functions as an electric motor so as to restart the engine 2 from a stopped state by the idling stop function. The ISG 20 can assist the traveling of the vehicle 1 by functioning as an electric motor.

  The starter 21 includes a motor and a pinion gear (not shown). The starter 21 rotates the crankshaft 18 by rotating the motor to give the engine 2 a starting torque. As described above, the engine 2 is started by the starter 21 and restarted by the ISG 20 from the stop state by the idling stop function.

  The transmission 3 shifts and transmits the driving torque output from the engine 2, and rotates the driving wheels 5 via a drive shaft (axle) 23. The transmission 3 includes a rotation speed (the number of rotations) of the drive shaft 23 of each of the left and right drive wheels 5 and a clutch 26 constituted by a normally-meshing type transmission mechanism 25 composed of a parallel shaft gear mechanism, a normally closed dry clutch. ) And an actuator (not shown).

  The transmission 3 is configured as a so-called AMT (Automated Manual Transmission). In the transmission mechanism 25 that is driven by an actuator in accordance with sensor information of a vehicle speed sensor (not shown) that detects the rotational speed (rotational speed) of the drive shaft 23. The shift stage is switched and the clutch 26 is engaged / disengaged. The differential mechanism 27 receives the power output by the speed change mechanism 25 and transmits it to the left and right drive shafts 23.

  The motor generator 4 is connected to the differential mechanism 27 via a power transmission mechanism 28 such as a chain. The motor generator 4 functions as an electric motor.

  Thus, the vehicle 1 is constructed in a parallel hybrid system that can use the power of both the engine 2 and the motor generator 4 for driving the vehicle, and the power output by at least one of the engine 2 and the motor generator 4. It comes to run by.

  The motor generator 4 also functions as a generator, and generates power when the vehicle 1 is coasting or decelerating.

  Here, the motor generator 4 has a structure that is directly connected to the drive shaft 23 via a differential mechanism 27 and a power transmission mechanism 28, and rotates at the same time when the drive wheels 5 rotate. The motor generator 4 may be connected to any part of the power transmission path from the engine 2 to the drive wheel 5 so as to be able to transmit power, and is not necessarily connected to the differential mechanism 27.

  Further, the vehicle 1 includes a first power storage device 30, a low voltage power pack 32 including a second power storage device 31, a high voltage power pack 34 including a third power storage device 33, a high voltage cable 35, and a low voltage cable. 36.

  The first power storage device 30, the second power storage device 31, and the third power storage device 33 are composed of rechargeable secondary batteries. The second power storage device 31 is a power storage device that can store higher power and higher energy density than the first power storage device 30. The second power storage device 31 can be charged in a shorter time than the first power storage device 30. The first power storage device 30 and the second power storage device 31 are low voltage batteries in which the number of cells and the like are set so as to generate an output voltage of about 12V. In this embodiment, the 1st electrical storage apparatus 30 consists of lead batteries, and the 2nd electrical storage apparatus 31 consists of lithium ion batteries. The second power storage device 31 may be a nickel hydride storage battery.

  Third power storage device 33 constitutes a high voltage battery by setting the number of cells and the like so as to generate a higher voltage than first power storage device 30 and second power storage device 31. The 3rd electrical storage apparatus 33 consists of nickel hydride storage batteries, for example.

  The high voltage power pack 34 includes an inverter 50, an INVCM 14, and a high voltage BMS 16 in addition to the third power storage device 33, and is formed in a high voltage circuit. The high voltage power pack 34 is connected to the motor generator 4 via a high voltage cable 35 so that electric power can be supplied.

  The vehicle 1 is provided with a general load 37 and a protected load 38 as electric loads. The general load 37 and the protected load 38 are electric loads other than the starter 21 and the ISG 20.

  The protected load 38 is an electric load that always requires a stable power supply. The protected load 38 includes, for example, a stability control device 38A that prevents a side slip of the vehicle 1, an electric power steering control device 38B that electrically assists an operating force of a steering wheel (not shown), and a headlight 38C. . The protected load 38 also includes instrument panel lamps and meters (not shown) and a car navigation system.

  The general load 37 is an electric load that is temporarily used without requiring stable power supply as compared with the protected load 38. The general load 37 includes, for example, a wiper (not shown) and an electric cooling fan that blows cooling air to the engine 2.

  The low voltage power pack 32 includes switches 40 and 41 and a low voltage BMS 15 in addition to the second power storage device 31. First power storage device 30 and second power storage device 31 are connected to starter 21, ISG 20, general load 37 as an electrical load, and protected load 38 via low voltage cable 36 so as to be able to supply power. Yes. The first power storage device 30 and the second power storage device 31 are electrically connected in parallel to the protected load 38.

  The switch 40 is provided in the low voltage cable 36 between the second power storage device 31 and the protected load 38. The switch 41 is provided in the low voltage cable 36 between the first power storage device 30 and the protected load 38.

  The vehicle 1 includes an INVCM (Invertor Control Module) 14, a low voltage BMS (Battery Management System) 15, and a high voltage BMS 16 as a control system, each of which is an inverter according to a control program stored in advance in a memory. 50 drive and charging / discharging of the 1st electrical storage apparatus 30, the 2nd electrical storage apparatus 31, and the 3rd electrical storage apparatus 33 are controlled.

  The INVCM 14 controls the inverter 50 to mutually convert AC power applied to the high voltage cable 35 and DC power applied to the third power storage device 33. For example, when powering the motor generator 4, the INVCM 14 converts the DC power discharged by the third power storage device 33 into AC power by the inverter 50 and supplies the AC power to the motor generator 4. Further, when regenerating motor generator 4, INVCM 14 converts AC power generated by motor generator 4 into DC power by inverter 50 and charges third power storage device 33.

  The low voltage BMS 15 controls charging / discharging of the second power storage device 31 and power supply to the protected load 38 by controlling opening and closing of the switches 40 and 41. When the engine 2 is stopped due to idling stop, the low voltage BMS 15 is stabilized to the protected load 38 from the high power and high energy density second power storage device 31 by closing the switch 40 and opening the switch 41. It is designed to supply power.

  When the engine 2 is started by the starter 21 and when the engine 2 stopped by the idling stop control is restarted by the ISG 20, the low voltage BMS 15 opens the switch 41 and opens the switch 41. Electric power is supplied from the power storage device 30 to the starter 21 or the ISG 20. When the switch 40 is closed and the switch 41 is opened, power is also supplied from the first power storage device 30 to the general load 37.

  The high voltage BMS 16 manages the state such as the remaining capacity of the third power storage device 33. The high voltage BMS 16 is controlled by the HCU 10 so as to cooperate with the INVCM 14 to efficiently drive the motor generator 4.

  As described above, the first power storage device 30 supplies at least electric power to the starter 21 and the ISG 20 as starters for starting the engine 2. The second power storage device 31 supplies at least power to the general load 37 and the protected load 38.

  The second power storage device 31 is connected so as to be able to supply power to both the general load 37 and the protected load 38. However, the second power storage device 31 preferentially supplies power to the protected load 38 that always requires stable power supply. Thus, the switches 40 and 41 are controlled by the low voltage BMS 15.

  As described above, the low voltage BMS 15 is protected while taking into consideration the charging state (remaining charge amount) of the first power storage device 30 and the second power storage device 31, and the operation requests to the general load 37 and the protected load 38. Prioritizing stable operation of the load 38, the switches 40 and 41 are appropriately controlled.

  The vehicle 1 is laid with CAN communication lines 48 and 49 for forming an in-vehicle LAN (Local Area Network) conforming to a standard such as CAN (Controller Area Network). The HCU 10 is connected to the INVCM 14 and the high voltage BMS 16 by a CAN communication line 48. The HCU 10, the INVCM 14 and the high voltage BMS 16 mutually transmit and receive signals such as control signals via the CAN communication line 48. The HCU 10 is connected to the ECM 11, the TCM 12, the ISGCM 13, and the low voltage BMS 15 by a CAN communication line 49. The HCU 10, ECM 11, TCM 12, ISGCM 13, and low voltage BMS 15 mutually transmit and receive signals such as control signals via the CAN communication line 49.

  Here, as shown in FIG. 2, the inverter 50 includes switching elements 51u to 51w and 61u to 61w connected to the three-phase full-wave bridge 50B. The switching elements 51u to 51w and 61u to 61w include diodes 53u to 53w. , 54u to 54w are reversely connected. The inverter 50 supplies three-phase alternating current to each of the coils 4 u to 4 w for each UVW phase of the motor generator 4 by PWM control of the switching elements 51 u to 51 w and 61 u to 61 w by the control signal from the INVCM 14. Function as an electric motor. The inverter 50 is configured to charge the third power storage device 33 by full-wave rectifying the AC power generated by the motor generator 4 functioning as a generator by the diodes 53 u to 53 w and 54 u to 54 w.

  In the inverter 50, a smoothing capacitor 55, a passive discharge resistor 57, and a forced discharge resistor 67 are connected in parallel to the preceding stage of the three-phase full-wave bridge 50 </ b> B on the third power storage device 33 side.

  Smoothing capacitor 55 functions to stabilize and smooth the voltage value supplied to three-phase full-wave bridge 50 </ b> B by storing the DC power discharged from third power storage device 33 and discharging the stored power. The storage of the smoothing capacitor 55 is started when the ignition switch 9 detects ignition on by the driver and the HCU 10 is activated to start the vehicle 1 as a whole in a running preparation state.

  The passive discharge resistor 57 is always connected to the smoothing capacitor 55 to form a discharge circuit. The passive discharge resistor 57 is set to a high resistance value so as to suppress the stored power discharged from the smoothing capacitor 55 to a minute current. That is, the passive discharge resistor 57 functions as a limiting resistor that restricts the stored power in the smoothing capacitor 55 from being discharged with a large capacity.

  The passive discharge resistor 57 receives high voltage stored power discharged from the smoothing capacitor 55 when the supply of high voltage stored power discharged from the third power storage device 33 to the smoothing capacitor 55 is interrupted. A circuit (so-called passive discharge circuit) that reduces the voltage value of the stored electric power stored in the smoothing capacitor 55 to reduce the voltage is formed by performing so-called passive discharge processing.

  The forced discharge resistor 67 is installed so as to be connected to or disconnected from the smoothing capacitor 55 via the connection relay 68. The forced discharge resistor 67 is set to a resistance value lower than that of the passive discharge resistor 57, and discharges the stored power in the smoothing capacitor 55 with a larger current than the discharge using the passive discharge resistor 57. That is, the forced discharge resistor 67 also functions as a limiting resistor that limits large-capacity discharge of the stored power in the smoothing capacitor 55.

  The connection relay 68 is connected in series to the forced discharge resistor 67, and the forced discharge state (connection state) in which the high voltage power in the smoothing capacitor 55 is supplied to the forced discharge resistor 67 to forcibly discharge, and the discharge is cut off. As will be described later, switching control is performed by the INVCM 14 cooperating with the HCU 10 so as to select one of the discharge cut-off state (disconnected state).

  When the HCU 10 determines that it is necessary to discharge the stored electric power in the smoothing capacitor 55, the forced discharge resistor 67 is connected to the connection relay 68 to form a discharge circuit. The stored electric power stored in 55 is energized together with the passive discharge resistor 57 to consume the discharge current. For example, the power consumption at the forced discharge resistor 67 is started when the ignition switch 9 detects the ignition off by the driver and the HCU 10 executes the stop process for shifting the entire vehicle 1 to a stop (restart standby) state. Is done.

  In the disconnected state, the connection relay 68 blocks the discharge circuit via the forced discharge resistor 67 and prohibits the stored power in the smoothing capacitor 55 from being discharged to the forced discharge resistor 67.

  The inverter 50 includes a voltage sensor 56 that detects a voltage value between the electrodes of the smoothing capacitor 55, a current sensor 66 that detects a current value input to and output from the smoothing capacitor 55, the third power storage device 33, and the smoothing capacitor 55. And an interruption relay (switcher) 58 disposed between the two. The interruption relay 58 is switch-controlled by the INVCM 14 that cooperates with the HCU 10 based on the detection information of the voltage sensor 56 and the current sensor 66.

  The interruption relay 58 and the connection relay 68 are switches that switch between a connection state that allows passage of current and a disconnection state that blocks passage of current, such as a contact switch type, a relay switch type, and a diode switch type. Any may be sufficient, and it should just install in consideration of a current capacity, a withstand voltage, lifetime, etc.

  The interruption relay 58 is arranged between the third power storage device 33 and the smoothing capacitor 55, and a high voltage application state (connection state) capable of supplying the high voltage power discharged from the third power storage device 33 to the downstream side. The INVCM 14 performs switching control so as to select any one of a high voltage cut-off state (cut-off state) that cuts off the supply.

  When the ignition switch 9 generates a stop request for detecting the ignition off by the driver, the HCU 10 cooperates with the INVCM 14 to open the cutoff relay 58 (disconnected state) to discharge the third power storage device 33. The electric power stored in the smoothing capacitor 55 is stopped and discharged to the forced discharge resistor 67 to be consumed.

  As a result, the HCU 10 discharges the stored power stored in the smoothing capacitor 55 to the forced discharge resistor 67 to reduce the voltage value and reduce the voltage.

  In addition, the HCU 10 cooperates with the INVCM 14 to close the shut-off relay 58 (connected state) and discharge from the third power storage device 33 when the travel preparation request for the ignition switch 9 to detect ignition on by the driver is generated. The smoothing capacitor 55 is boosted to a predetermined voltage.

  As a result, the HCU 10 stores the discharge power from the third power storage device 33 in the smoothing capacitor 55 and stabilizes (smooths) the voltage value of the power supplied to the motor generator 4 via the three-phase full-wave bridge 50B. ).

  The HCU 10 generates a discharge process execution command when receiving various detection information set in advance as the execution timing of the control process for discharging the stored electric power in the smoothing capacitor 55, thereby generating the third power storage device 33. Is turned off and a control process for discharging the stored power in the smoothing capacitor 55 of the inverter 50 is executed.

  For example, when the vehicle 1 is stopped, the HCU 10 has a predetermined condition that the third power storage device 33 is disconnected from the inverter 50 and the smoothing capacitor 55 is discharged. When the maintenance of the electrical system including the device 33 and the inverter 50 is detected from the control information and sensor information, or when an external force exceeding the extent that the insulation case of the electrical system is deformed while the vehicle 1 is stopped is applied. When an acceleration sensor (not shown) or the like detects this, a discharge process execution command is generated.

  Then, when the HCU 10 determines that it is necessary to discharge the stored power in the smoothing capacitor 55 based on the discharge processing execution command, the HCU 10 switches the cutoff relay 58 to the disconnected state and sets the high voltage cutoff state. Is performed to discharge the high-voltage stored power in the smoothing capacitor 55, and further, a process of forming the discharge circuit including the forced discharge resistor 67 by switching the connection relay 68 from the disconnected state to the connected state is performed. It has become.

  As a result, the HCU 10 connects the smoothing capacitor 55 to the smoothing capacitor 55 via the connection relay 68 in addition to the passive discharging resistor 57 when it is necessary to discharge the stored electric power of the smoothing capacitor 55, thereby The stored electric power in the smoothing capacitor 55 can be discharged in a short time with a large capacity current via the passive discharge resistor 57 and the forced discharge resistor 67. That is, the HCU 10 constitutes a high voltage control device in which the electric vehicle in the present embodiment is mounted as a device main body.

  At this time, when the voltage value between the electrodes of the smoothing capacitor 55 received from the voltage sensor 56 is equal to or higher than a preset allowable threshold value, the HCU 10 maintains the disconnection state of the connection relay 68 and the forced discharge resistor 67. The forced discharge using only the passive discharge resistor 57 as the limiting resistor is performed with the power being disconnected.

  Further, when the voltage value between the electrodes of the smoothing capacitor 55 received from the voltage sensor 56 is less than the set allowable threshold value, the HCU 10 switches the connection relay 68 to the connected state so as to add the forced discharge resistance 67 to the limiting resistance. The forced discharge is performed by causing the forced resistance discharge 67 and the passive discharge resistance 57 to discharge and consume the high-voltage stored power in the smoothing capacitor 55.

  Here, as the allowable threshold value, the voltage value between the electrodes when the capacity of the stored power in the smoothing capacitor 55 is such that no deterioration occurs even when the forced discharge resistor 67 is energized is preliminarily stored in the memory of the HCU 10. Set it to.

  As a result, the HCU 10 performs passive discharge only by the high-resistance passive discharge resistor 57 when the voltage value between the electrodes of the smoothing capacitor 55 is larger than the allowable threshold value, and between the both ends of the smoothing capacitor 55. Low voltage can be achieved. Further, the HCU 10 performs a forced discharge by adding a low-resistance forced discharge resistor 67 to the passive discharge resistor 57 when the voltage value between the electrodes of the smoothing capacitor 55 is less than the allowable threshold value, and performing a forced discharge. The voltage between both ends of the smoothing capacitor 55 can be made low in time.

  At this time, when the HCU 10 determines that the discharge processing of the stored power in the smoothing capacitor 55 is necessary based on the discharge processing execution command, the motor generator 4 functions as a generator, and the regenerative power is It is determined based on the sensor information of the current sensor 66 whether or not the third power storage device 33 is supplied via the phase full wave bridge 50B, and the smoothing capacitor 55 The discharge processing of the stored power is controlled.

  For example, when the HCU 10 determines that the discharge processing of the stored power in the smoothing capacitor 55 is necessary based on the discharge processing execution command, the motor generator 4 rotates and functions as a generator, so that the regenerative power is reduced to the smoothing capacitor. When the power is supplied to 55, the connection relay 68 is maintained in a disconnected state to wait for execution of a process for forcibly discharging the stored power in the smoothing capacitor 55.

  The HCU 10 also monitors the presence or absence of regenerative power supplied to the smoothing capacitor 55 even after starting the process of discharging the stored power in the smoothing capacitor 55 by switching the connection relay 68 to the connected state. When the power supply to 55 is confirmed, the connection relay 68 is returned to the disconnected state, and the execution of the process of discharging the stored power in the smoothing capacitor 55 is interrupted (stopped).

  Thus, the HCU 10 rotates as the motor generator 4 directly connected to the drive shaft 23 functions as a generator. Therefore, when the regenerative power is supplied to the smoothing capacitor 55 and charged, the HCU 10 Execution of a process for forcibly discharging power can be avoided. For this reason, the smoothing capacitor 55 can avoid the discharge process from being performed for a long period of time in parallel with the charging and discharging, and the current flows to the forced discharge resistor 67 and the like for a long period of time. Can be prevented.

  Here, in the present embodiment, the presence or absence of energy supply to the smoothing capacitor 55 (whether or not the motor generator 4 generates power) is determined based on the sensor information of the current sensor 66, but the present invention is not limited to this. The rotation speed (number of rotations) of the motor generator 4 may be detected and determined. The presence or absence of energy supply to the smoothing capacitor 55 is determined based on whether or not the current value detected by the current sensor 66 exceeds a preset threshold value, or the rotation of the motor generator 4 detected by the vehicle speed sensor. The determination may be made based on whether or not the speed exceeds a preset threshold value.

  Specifically, the HCU 10 executes the control process shown in the flowchart of FIG. 3 according to the control program stored in the memory when discharging the stored power in the smoothing capacitor 55 based on the discharge process execution command. It has become.

  First, the HCU 10 stops the vehicle 1 based on sensor information of a vehicle speed sensor (not shown) that detects the rotational speed of the drive shaft 23 when executing the discharge process of the stored power of the smoothing capacitor 55 based on the discharge process execution command. It is confirmed whether or not the vehicle is in the middle (step S11). If the vehicle is not stopped, the control process is terminated.

  In step S <b> 11, the HCU 10 that has confirmed that the vehicle 1 is stopped has the cut-off relay 58 disconnected and the smoothing capacitor 55 is disconnected from the third power storage device 33 by the control process based on the discharge process execution command. It is confirmed whether or not a high voltage cutoff state in which application of high voltage power is cut off (step S12). If the high voltage cutoff state is not established, this control process is terminated.

  In step S 12, the HCU 10 that has confirmed that the smoothing capacitor 55 is in the high-voltage cutoff state has the regenerative power energy generated by the rotation of the motor generator 4 based on the input / output current value to the smoothing capacitor 55 detected by the current sensor 66. Whether or not the supply is stopped is repeatedly confirmed (step S13), and the process waits until the rotation of the motor generator 4 is stopped and the supply of energy to the smoothing capacitor 55 is stopped.

  As a result, the HCU 10 prohibits the discharge process of the smoothing capacitor 55 when the driving wheel 5 rotates even if the vehicle 1 is erroneously detected as being stopped due to a failure of the vehicle speed sensor or the like. Thus, it is possible to avoid the parallel discharge and charging of the stored electric power in the smoothing capacitor 55, and it is possible to prevent the energization of the forced discharge resistor 67 from being continued unnecessarily.

  In step S13, the HCU 10 that has confirmed that the smoothing capacitor 55 is not in the energy supply state checks whether or not the voltage value of the stored power of the smoothing capacitor 55 detected by the voltage sensor 56 is less than a preset allowable threshold value. (Step S14).

  In step S14, the HCU 10 that has confirmed that the large capacity power is being stored between the electrodes of the smoothing capacitor 55 at a voltage value equal to or higher than the set allowable threshold value, the passive discharge resistor 57 is maintained with the connection relay 68 maintained in a disconnected state. As a limiting resistor, whether or not the passive discharge for discharging the stored power in the smoothing capacitor 55 is started (step S15), and then the process returns to step S14 to determine whether the voltage value of the stored power in the smoothing capacitor 55 has decreased to less than the set allowable threshold. The process of confirming whether or not is repeated.

  As a result, the HCU 10 can avoid deteriorating the entire amount of large-capacity stored power in the smoothing capacitor 55 by energizing the low-resistance forced discharge resistor 67. Here, since the passive discharge resistor 57 is set to have a higher resistance value than the forced discharge resistor 67, the durability against the energization of the stored power in the smoothing capacitor 55 is excellent.

  In step S14, the HCU 10 that has confirmed that the storage power is a small capacity with a voltage value between the electrodes of the smoothing capacitor 55 that is less than the set allowable threshold, switches the connection relay 68 from the disconnected state to the connected state, and performs passive discharge. The forced discharge resistor 67 is connected in parallel as the limiting resistor to the resistor 57, and the forced discharge for discharging the stored power in the smoothing capacitor 55 is started (step S16). Thereafter, the timer function provided is activated to count the elapsed time from the start of the forced discharge process (step S17).

  Thereafter, the HCU 10 confirms whether or not the voltage value of the stored power of the smoothing capacitor 55 detected by the voltage sensor 56 has been lowered to a value less than a preset stop threshold (step S18), and between the electrodes of the smoothing capacitor 55 If the stored power discharge process has been completed with a voltage value less than the set stop threshold, a post-process to end the forced discharge process is executed (step S21), and this control process ends.

  In step S18, the HCU 10 that has confirmed that the discharge process of the stored power has not yet ended with the voltage value between the electrodes of the smoothing capacitor 55 being equal to or higher than the set stop threshold, has started from the start of the forced discharge process counted by the timer function. It is confirmed whether or not the processing time limit that has been set in advance has passed (step S19). If the time for the forced discharge processing has passed the setting processing time limit, the process proceeds to step S21. A post-process for ending the forced discharge process is executed, and this control process is ended.

  In step S 19, the HCU 10 that has confirmed that the time required for the forced discharge process has not passed the set process limit time, is based on the input / output current value to the smoothing capacitor 55 detected by the current sensor 66. It is confirmed whether or not the rotation is restarted for some reason and the regenerative power energy is supplied (step S20).

  In step S20, the HCU 10 confirming that the motor generator 4 is stopped and the energy supply to the smoothing capacitor 55 is stopped returns to step S18 and repeats the same processing.

  In step S20, the HCU 10 confirming that the motor generator 4 has been rotated and the energy supply to the smoothing capacitor 55 has been resumed proceeds to step S21, and performs post-processing to end the forced discharge process. This control process is terminated. In step S20, when it is confirmed that the energy supply to the smoothing capacitor 55 has been resumed, the same process may be repeated by returning to step S13.

  As a result, the HCU 10 reduces the capacity of the large-capacity stored power in the smoothing capacitor 55 by passive discharge by passing the discharge to the passive discharge resistor 57 as a limiting resistor, and then the forced discharge resistor 67 and the passive discharge connected in parallel. The forced discharge can be continuously consumed by switching to the limiting resistor with the resistor 57.

  Therefore, as shown in FIG. 4, the smoothing capacitor 55 has a passive discharge resistance when a large amount of stored electric power is stored so as to be deteriorated if the forced discharge resistance 67 is energized and discharged. By energizing 57 and discharging, it is possible to discharge the large-capacity stored power until it reaches the small-capacity stored power without exceeding the energized capacity of the forced discharge resistor 67. The smoothing capacitor 55 is switched to a discharge process in which a forced discharge resistor 67 is connected in parallel to a passive discharge resistor 57 after discharging to a storage capacity at which the voltage between the electrodes is less than the allowable threshold value. For example, the voltage can be reduced to about DC13V of the lead storage battery of the first power storage device 30 in a short time.

  As described above, in the present embodiment, when the stored power in the smoothing capacitor 55 has a large capacity so that the inter-electrode voltage value exceeds the allowable threshold value, the discharge process is performed by the passive discharge energizing the passive discharge resistor 57. It is possible to avoid the deterioration of the forced discharge resistor 67.

  For this reason, even when the stored power of the smoothing capacitor 55 needs to be discharged suddenly, it is possible to avoid the deterioration of the forced discharge resistor 67 and complete the discharging process of the smoothing capacitor 55.

  While embodiments of the invention have been disclosed, it will be apparent to those skilled in the art that changes may be made without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims.

1 Vehicle 2 Engine 4 Motor generator (electric motor, generator)
9 Ignition switch 10 HCU (control unit)
14 INVCM
16 High voltage BMS
23 Drive shaft (axle)
27 Differential mechanism 28 Power transmission mechanism 33 Third power storage device (high voltage battery)
34 High Voltage Power Pack 50 Inverter 55 Smoothing Capacitor 56 Voltage Sensor 57 Passive Discharge Resistor 58 Break Relay (Switch)
66 Current sensor 67 Forced discharge resistor 68 Connection relay

Claims (2)

Connecting the high voltage battery, an inverter that converts DC power supplied from the high voltage battery into AC power, a smoothing capacitor that smoothes the voltage of DC power supplied from the high voltage battery, and the high voltage battery And a switching device for switching to either a connected state in which high-voltage power can be supplied or a high-voltage cut-off state in which the connection is cut off to cut off the supply of high-voltage power, and driven by AC power supplied from the inverter A high-voltage control device mounted on an electric vehicle comprising: an electric motor that outputs power and a generator that is directly connected to the axle of the vehicle to rotate and generate electric power ;
When discharging the power stored in the smoothing capacitor at the time of a high voltage cutoff state by the switch,
When the voltage between the electrodes of the smoothing capacitor is equal to or higher than a preset allowable threshold value, passive discharge using a passive discharge resistor as a limiting resistor is performed,
Wherein when the inter-electrode voltage of the smoothing capacitor is less than the allowable threshold, have rows forced discharge using the passive discharge resistor forced discharge resistance is less resistance than the limiting resistor,
A high-voltage control device that waits for the start of forced discharge processing of the electric power stored in the smoothing capacitor when the generator is generating power . Connecting the high voltage battery, an inverter that converts DC power supplied from the high voltage battery into AC power, a smoothing capacitor that smoothes the voltage of DC power supplied from the high voltage battery, and the high voltage battery And a switching device for switching to either a connected state in which high-voltage power can be supplied or a high-voltage cut-off state in which the connection is cut off to cut off the supply of high-voltage power, and driven by AC power supplied from the inverter A high-voltage control device mounted on an electric vehicle comprising: an electric motor that outputs power and a generator that is directly connected to the axle of the vehicle to rotate and generate electric power;
When discharging the power stored in the smoothing capacitor at the time of a high voltage cutoff state by the switch,
When the voltage between the electrodes of the smoothing capacitor is equal to or higher than a preset allowable threshold value, passive discharge using a passive discharge resistor as a limiting resistor is performed,
When the voltage between the electrodes of the smoothing capacitor is less than the allowable threshold, performing a forced discharge using a forced discharge resistor having a resistance value smaller than that of the passive discharge resistor as a limiting resistor,
A high-voltage control device that stops the forced discharge process of the power when the generator generates power when discharging the power stored in the smoothing capacitor in a high-voltage cutoff state by the switch .