JP2018011460A - Electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably discharge smoothing capacitors in an electric vehicle.SOLUTION: An electric vehicle comprises: a motor 26 for driving wheels; a main battery 30 for supplying power to the motor 26; smoothing capacitors C1, C2 which are provided in a power supply circuit 32 which electrically connects the main battery 30 to the motor 26; a discharge control device 44 which controls the power supply circuit 32 and discharges the smoothing capacitors C1, C2; a storage capacitor 60 which is connected to the main battery 30 in parallel with the power supply circuit 32 and is charged by the main battery 30; and a DC-DC converter 36 which steps down the power charged in the storage capacitor 60 and supplies it to the discharge control device 44.SELECTED DRAWING: Figure 2

Description

  The technology disclosed in this specification relates to an electric vehicle. The term “electric vehicle” as used herein widely means an automobile having a motor for driving wheels. Although it does not specifically limit in an electric vehicle, The electric vehicle which can be recharged with external electric power, the fuel cell vehicle which has a fuel cell, the solar cell vehicle which has a solar cell, the hybrid vehicle which further has an engine, and these two or more An automobile having the following characteristics is included.

  Electric cars are known. An electric vehicle includes a motor that drives wheels and a main battery that supplies electric power to the motor. In the power supply circuit that electrically connects the main battery to the motor, for example, a smoothing capacitor is provided in addition to a converter and an inverter. The smoothing capacitor suppresses voltage fluctuation in the power supply circuit by storing electric charge. During use of the electric vehicle, the smoothing capacitor is charged with a high voltage. Therefore, for example, when an electric vehicle collides, it is required to discharge the smoothing capacitor rapidly.

  In order to discharge the smoothing capacitor rapidly, the electric vehicle can be equipped with a discharge control device. The discharge control device discharges the smoothing capacitor by controlling the power supply circuit. As an example, the discharge control device can discharge the smoothing capacitor through the motor, for example, by controlling an inverter of the power supply circuit. Alternatively, the discharge control device can discharge the smoothing capacitor by controlling a dedicated discharge circuit provided in the power supply circuit. An example of the technology described above is described in Patent Document 1.

  The discharge control device normally operates by supplying power from an auxiliary battery. However, for example, when an electric vehicle collides, an electrical failure such as a disconnection or a short circuit may occur, and as a result, the power supply from the auxiliary battery to the discharge control device may be interrupted. For this reason, the electric vehicle described in Patent Document 1 is provided with a DC-DC converter that steps down the power from the main battery and supplies it to the discharge control device. According to such a configuration, even when the power supply from the auxiliary battery to the discharge control device is interrupted, the smoothing capacitor can be discharged by continuing the power supply to the discharge control device.

JP 2014-183700 A

  As described in Patent Document 1, in an electric vehicle, it is required to discharge a smoothing capacitor even when power supply from an auxiliary battery to a discharge control device is interrupted. The present specification provides a novel technique that meets such a demand, and aims to increase the degree of design freedom of an electric vehicle.

  The present specification discloses an electric vehicle. This electric vehicle controls a motor that drives a wheel, a main battery that supplies power to the motor, a smoothing capacitor that is provided in a power supply circuit that electrically connects the main battery to the motor, and a power supply circuit. A discharge control device for discharging a smoothing capacitor, a power storage circuit connected to the main battery in parallel with the power supply circuit, and a discharge control device that steps down the power charged in the power storage capacitor and the power stored in the power storage capacitor A DC-DC converter to be supplied to

  According to the configuration described above, the power charged in the storage capacitor can be supplied to the discharge control device through the DC-DC converter. Therefore, even when the power supply from the auxiliary battery is interrupted, the discharge control device can continue to operate with the power charged in the storage capacitor. This storage capacitor is charged by the main battery. Usually, the main battery has a higher voltage than, for example, an auxiliary battery. In general, the electric power stored in the capacitor is proportional to the capacitance of the capacitor and proportional to the square of the applied voltage. Therefore, if the storage capacitor is charged by, for example, the main battery instead of the auxiliary battery, sufficient electric power can be stored in the storage capacitor even if the capacitance of the storage capacitor is reduced. Since it is possible to employ a small-sized storage capacitor, the degree of freedom in designing an electric vehicle can be increased. The high voltage power stored in the storage capacitor is stepped down to an appropriate voltage in the DC-DC converter and supplied to the discharge control device.

1 is a block diagram schematically showing the configuration of a hybrid vehicle 10 according to a first embodiment. 1 is a diagram schematically illustrating a circuit configuration of a hybrid vehicle according to a first embodiment. 3 is a time chart showing a specific example of a series of operations at the time of a collision of the hybrid vehicle 10 according to the first embodiment. The figure which shows typically the circuit structure of the hybrid vehicle 110 of Example 2. FIG. 6 is a time chart illustrating a specific example of a series of operations at the time of a collision of the hybrid vehicle 110 according to the second embodiment.

  A hybrid vehicle 10 according to a first embodiment will be described with reference to the drawings. The hybrid vehicle 10 is an example of an electric vehicle disclosed in this specification. The configuration of the hybrid vehicle 10 described below can be applied to other types of electric vehicles. As shown in FIG. 1, the hybrid vehicle 10 of the present embodiment includes a vehicle body 12 and four wheels 14 and 16 that are rotatably supported with respect to the vehicle body 12. The four wheels 14 and 16 include a pair of driving wheels 14 and a pair of driven wheels 16. The pair of drive wheels 14 are connected to the output shaft 20 via a differential gear 18. The output shaft 20 is rotatably supported with respect to the vehicle body 12. As an example, the pair of driving wheels 14 are rear wheels positioned at the rear portion of the vehicle body 12, and the pair of driven wheels 16 are front wheels positioned at the front portion of the vehicle body 12. The pair of drive wheels 14 are arranged coaxially with each other, and the pair of driven wheels 16 are also arranged coaxially with each other.

  The hybrid vehicle 10 further includes an engine 22, a generator 24 and a motor 26. The engine 22 burns fuel such as gasoline and outputs power. The engine 22 is connected to the output shaft 20 and the generator 24 via a power distribution mechanism 28. Although it is an example, the power distribution mechanism 28 in a present Example is comprised using the planetary gear mechanism. Each of the generator 24 and the motor 26 is a three-phase motor generator having a U phase, a V phase, and a W phase. The generator 24 generates power using power from the engine 22 or power from the output shaft 20. The generator can also function as a starter motor for starting the engine 22. The motor 26 is connected to the output shaft 20 and mainly functions as a traveling motor that drives the pair of drive wheels 14. The motor 26 can also function as a generator when the hybrid vehicle 10 performs regenerative braking.

  The hybrid vehicle 10 further includes a main battery 30 and a power supply circuit 32. The main battery 30 is electrically connected to the generator 24 and the motor 26 via the power supply circuit 32. The main battery 30 is a rechargeable battery and supplies power to the generator 24 and the motor 26. Further, the main battery 30 is charged with electric power generated by the generator 24 and the motor 26. Note that a relay 38 is provided between the main battery 30 and the power supply circuit 32 to electrically connect and disconnect them. Although it is an example, the rated voltage of the main battery 30 in this embodiment is about 288 volts, and the rated voltages of the generator 24 and the motor 26 are about 600 volts. That is, the rated voltage of the main battery 30 is lower than the rated voltage of the generator and motor 26. However, the specific value of the rated voltage of the main battery 30, the generator and the motor 26, and the magnitude relationship between them are not particularly limited.

  The hybrid vehicle 10 further includes a hybrid control unit 40 (HV-ECU in the drawing), an engine control unit 42 (ENG-ECU in the drawing), a motor control unit 44 (MG-ECU in the drawing), an air bag. A control unit 46 (AB-ECU in the drawing) is further provided. The engine control unit 42 is communicably connected to the engine 22 and controls the operation of the engine 22. The motor control unit 44 is communicably connected to the power supply circuit 32, and controls the operation of the generator 24 and the motor 26 by controlling the operation of the power supply circuit 32. The hybrid control unit 40 can communicate with a plurality of control units including the engine control unit 42, the motor control unit 44, and the airbag control unit 46 via the communication path 48. The overall operation of the car 10 is controlled.

  The airbag control unit 46 controls the operation of one or more airbags (not shown) provided in the hybrid vehicle 10. The airbag control unit 46 has an acceleration sensor, for example, and can detect a collision of the hybrid vehicle 10. The airbag control unit 46 activates the airbag when it detects a collision of the hybrid vehicle 10. Further, the airbag control unit 46 transmits a predetermined collision signal to a plurality of control units including the hybrid control unit 40 and the motor control unit 44 when the collision of the hybrid vehicle 10 is detected. As an example, the collision signal may be a pulse signal sequence having a predetermined period. The hybrid vehicle 10 may include another collision detection device that detects a collision of the hybrid vehicle 10 instead of or in addition to the airbag control unit 46.

  As shown in FIG. 1, the hybrid vehicle 10 further includes an auxiliary battery 34 and a DC-DC converter 36. The auxiliary battery 34 supplies electric power to a plurality of electric loads mounted on the hybrid vehicle 10 including, for example, the motor control unit 44. As an example, the rated voltage of the auxiliary battery 34 is 12 volts. The auxiliary battery 34 is a rechargeable battery. The auxiliary battery 34 is electrically connected to the main battery 30 via the DC-DC converter 36. The DC-DC converter 36 is a step-down converter, and steps down DC power from the main battery 30 to a voltage suitable for charging the auxiliary battery 34, thereby charging the auxiliary battery 34.

  The electrical structure of the hybrid vehicle 10 will be described in detail with reference to FIG. The power supply circuit 32 includes a step-up / step-down converter 50, a first inverter 52, and a second inverter 54. The step-up / down converter 50 is a DC-DC converter capable of stepping up and stepping down, and each of the first inverter 52 and the second inverter 54 is a three-phase inverter. The power supply circuit 32 electrically connects the main battery 30 to the generator 24 via the buck-boost converter 50 and the first inverter 52. As a result, the AC power generated by the generator 24 is converted into DC power by the first inverter 52, then stepped down by the step-up / down converter 50, and supplied to the main battery 30. That is, the main battery 30 is charged. On the other hand, when the generator 24 functions as a starter motor, DC power from the main battery 30 is boosted by the step-up / down converter 50, converted to AC power by the first inverter 52, and supplied to the generator 24. Is done. Similarly, the power supply circuit 32 electrically connects the main battery 30 to the motor 26 via the buck-boost converter 50 and the second inverter 54. Thus, the DC power from the main battery 30 is boosted by the step-up / step-down converter 50, converted to AC power by the second inverter 54, and supplied to the motor 26. On the other hand, when the motor 26 functions as a generator, AC power generated by the motor 26 is converted into DC power by the second inverter 54, and then stepped down by the step-up / down converter 50 and supplied to the main battery 30. Is done. Hereinafter, a circuit portion VL that connects the main battery 30 and the step-up / down converter 50 may be referred to as a battery-side circuit VL, and a voltage in the battery-side circuit VL may be referred to as a VL voltage. Normally, if the relay 38 is not electrically opened, the VL voltage is equal to the output voltage of the main battery 30.

  The specific configuration of the step-up / down converter 50 is not particularly limited. As an example, the buck-boost converter 50 in this embodiment includes an inductor L1, an upper arm switching element Q13, a lower arm switching element Q14, and drive circuits 50a and 50b. Although not shown, a diode is connected in antiparallel to each of the upper arm switching element Q13 and the lower arm switching element Q14. The drive circuits 50a and 50b switch the upper arm switching element Q13 and the lower arm switching element Q14, respectively, according to a control signal from the motor control unit 44. The step-up / down converter 50 functions as a step-up converter when the lower arm switching element Q14 is intermittently turned on, and functions as a step-down converter when the upper arm switching element Q13 is intermittently turned on.

  The specific configurations of the first inverter 52 and the second inverter 54 are not particularly limited. Although it is an example, the 1st inverter 52 in a present Example has several switching element Q1-Q6 and the drive circuit 52a. Although not shown, a diode is connected in antiparallel to each of the switching elements Q1 to Q6. The drive circuit 52a switches each of the plurality of switching elements Q1 to Q6 in accordance with a control signal from the motor control unit 44. In the first inverter 52, the DC power from the step-up / down converter 50 is converted into AC power by selectively turning on and off the plurality of switching elements Q1 to Q6. The first inverter 52 functions as a full-wave rectifier circuit that converts AC power from the generator 24 into DC power, for example, in a state where all the switching elements Q1 to Q6 are turned off.

  Similarly, the second inverter 54 includes a plurality of switching elements Q7 to Q12 and a drive circuit 54a. Although not shown, a diode is connected in antiparallel to each of the switching elements Q7 to Q12. The drive circuit 54a switches each of the switching elements Q7 to Q12 in response to a control signal from the motor control unit 44. Also in the second inverter 54, the DC power from the step-up / down converter 50 is converted into AC power by selectively turning on and off the plurality of switching elements Q7 to Q12. The first inverter 52 functions as a full-wave rectifier circuit that converts AC power from the motor 26 into DC power, for example, with all the switching elements Q7 to Q12 being turned off.

  The power supply circuit 32 further includes a first smoothing capacitor C1 and a second smoothing capacitor C2. The first smoothing capacitor C1 is located between the main battery 30 and the buck-boost converter 50, and the second smoothing capacitor C2 is between the buck-boost converter 50 and the first inverter 52 and It is located between the pressure converter 50 and the second inverter 54. Each of the first smoothing capacitor C <b> 1 and the second smoothing capacitor C <b> 2 suppresses voltage fluctuations in the power supply circuit 32 by accumulating electric charges. For example, the first smoothing capacitor C <b> 1 suppresses fluctuations in the DC voltage output from the buck-boost converter 50 to the main battery 30. The second smoothing capacitor C <b> 2 suppresses fluctuations in the DC voltage output from the buck-boost converter 50 to the first inverter 52 and the second inverter 54. The power supply circuit 32 may include only one of the first smoothing capacitor C1 and the second smoothing capacitor C2, or may further include another smoothing capacitor. Depending on the configuration of the power supply circuit 32, the number and position of the smoothing capacitors can be changed as appropriate.

  As shown in FIG. 3, the auxiliary battery 34 is electrically connected to a plurality of electrical loads 56 via fuses 58, and supplies electric power for operating them. As described above, the auxiliary battery 34 is electrically connected to the main battery 30 via the DC-DC converter 36 and is charged by the electric power from the main battery 30. A current limiting circuit 66 is provided between the DC-DC converter 36 and the auxiliary battery 34. The current limiting circuit 66 includes elements such as a fuse, a relay, and a semiconductor switch. For example, a ground fault (to the ground potential) in a circuit (hereinafter referred to as an auxiliary voltage circuit VA) that connects the auxiliary battery 34 and the electric load 56, for example. When the short circuit occurs, the energization of the auxiliary voltage circuit VA from the DC-DC converter 36 is prohibited or restricted. The output side of the DC-DC converter 36 is also connected to the motor control unit 44 via the conductive path 64. Thereby, the DC-DC converter 36 can directly supply electric power to the motor control unit 44. Here, the conductive path 64 extends from between the DC-DC converter 36 and the current limiting circuit 66. Therefore, the DC-DC converter 36 can supply power to the motor control unit 44 without being affected by the current limiting circuit 66.

  A storage capacitor 60 and a backflow prevention diode 62 are provided on the input side of the DC-DC converter 36. The storage capacitor 60 is connected to the main battery 30 in parallel with the power supply circuit 32 and is charged by the main battery 30. The backflow prevention diode 62 is interposed between the storage capacitor 60 and the battery side circuit VL. For example, when a ground fault occurs in the battery side circuit VL, the power charged in the storage capacitor 60 is transferred to the battery side circuit. Prevents supply to VL. According to such a configuration, even when the power supply from the main battery 30 to the DC-DC converter 36 is interrupted, the power charged in the storage capacitor 60 is supplied to the motor control unit 44 via the DC-DC converter 36. can do.

  The specific configuration of the DC-DC converter 36 is not particularly limited. Although it is an example, the DC-DC converter 36 in this embodiment includes a plurality of switching elements Q15 to Q18, a transformer T1, two diodes D1 and D2, an inductor L2, a capacitor C3, a drive circuit 36a, A power generation circuit 36b and a control circuit 36c are provided. The drive circuit 36a selectively switches the plurality of switching elements Q15 to Q18 in accordance with a control signal from the control circuit 36c. The power generation circuit 36b is connected to the conductive path 64 and supplies power from the conductive path 64 to the drive circuit 36a and the control circuit 36c. The DC power from the main battery 30 is converted into single-phase AC power by the plurality of switching elements Q15 to Q18, and is stepped down by the transformer T1. The single-phase AC power stepped down by the transformer T1 is rectified by the two diodes D1 and D2, then rectified by the inductor L2 and the capacitor C3, and output to the auxiliary battery 34 and the motor control unit 44.

  The configuration of the hybrid vehicle 10 has been described above. Next, main operations of the hybrid vehicle 10 will be described. During use of the hybrid vehicle 10, the smoothing capacitors C1 and C2 are charged with a high voltage. Therefore, for example, when the hybrid vehicle 10 collides, it is required to discharge the smoothing capacitors C1 and C2 rapidly. Therefore, the hybrid vehicle 10 is configured to be able to execute a discharge process when a collision of the hybrid vehicle 10 is detected. The discharge process is executed by the motor control unit 44 and controls the power supply circuit 32 to discharge the smoothing capacitors C1 and C2. The motor control unit 44 is an example of a discharge control device that executes a discharge process, and the hybrid vehicle 10 may include another discharge control device that executes the discharge process instead of the motor control unit 44. In the discharge process in this embodiment, the smoothing capacitors C1 and C2 can be discharged through the motor 26 mainly by controlling the step-up / step-down converter 50 and the second inverter 54 of the power supply circuit 32. However, as another embodiment, the motor control unit 44 or another discharge control device may discharge the smoothing capacitors C1 and C2 by controlling a dedicated discharge circuit provided in the power supply circuit 32.

  The motor control unit 44 normally operates by supplying power from the auxiliary battery 34. However, when the hybrid vehicle 10 collides, an electrical failure such as a disconnection or a short circuit may occur, and as a result, the power supply from the auxiliary battery 34 to the motor control unit 44 may be interrupted. If the power supply to the motor control unit 44 is interrupted, the motor control unit 44 may not be able to complete the discharge process. In this regard, in the hybrid vehicle 10 of the present embodiment, the electric power charged in the storage capacitor 60 can be supplied to the motor control unit 44 through the DC-DC converter 36. Therefore, the motor control unit 44 can continue to operate with the electric power charged in the storage capacitor 60 even when the power supply from the auxiliary battery 34 is interrupted.

  The storage capacitor 60 is charged by the main battery 30. Main battery 30 has a higher voltage than auxiliary battery 34. In general, the electric power stored in the capacitor is proportional to the capacitance of the capacitor and proportional to the square of the applied voltage. Therefore, when the storage capacitor 60 is charged by, for example, the main battery 30 instead of the auxiliary battery 34, sufficient power is supplied to the storage capacitor 60 even if the capacitance of the storage capacitor 60 is reduced. Can be stored. Since it is possible to employ the storage capacitor 60 having a small size, the degree of freedom in designing the hybrid vehicle 10 can be increased. The high voltage power stored in the storage capacitor 60 is stepped down to an appropriate voltage in the DC-DC converter 36 and supplied to the motor control unit 44 via the conductive path 64.

  As described above, the backflow prevention diode 62 is provided between the storage capacitor 60 and the battery side circuit VL. Thereby, even when a ground fault occurs in the battery side circuit VL, energization from the storage capacitor 60 to the battery side circuit VL is prevented, and power supply from the storage capacitor 60 to the motor control unit 44 can be continued. A current limiting circuit 66 is provided between the DC-DC converter 36 and the auxiliary battery 34. Thereby, for example, when a ground fault occurs in the auxiliary machine voltage circuit VA, energization from the DC-DC converter 36 to the auxiliary battery 34 side can be prohibited or restricted. Thereby, useless discharge of the electric power charged in the storage capacitor 60 is prevented or suppressed.

  A specific example of the above-described series of flows will be described with reference to FIG. As shown in FIG. 3, it is assumed that a collision of the hybrid vehicle 10 occurs at time t1 (see A1 in the figure). In this case, the hybrid vehicle 10 is physically deformed by the external force due to the collision until the collision is completed at time t2. Usually, the time from time t1 to t2 is at most 100 milliseconds. During the period from time t1 to time t2, a ground fault may occur in the battery side circuit VL due to physical deformation of the hybrid vehicle 10 (see A2). In this case, power supply from the main battery 30 to the DC-DC converter 36 is interrupted. However, when the power charged in the storage capacitor 60 is discharged through the DC-DC converter 36 (see A3), the power supply to the motor control unit 44 is continued (see A5), and the motor control unit 44 Can continue operation (see A6). The motor control unit 44 can detect a collision of the hybrid vehicle 10 based on, for example, a collision signal from the airbag control unit 46 and can start the discharge process.

  Further, during the period from time t1 to time t2, a ground fault may occur in the auxiliary voltage circuit VA due to physical deformation of the hybrid vehicle 10 (see A4). In this case, the supply voltage from the DC-DC converter 36 to the auxiliary voltage circuit VA decreases the supply voltage to the motor control unit 44 (see A5). However, when the current limiting circuit 66 is activated, energization from the DC-DC converter 36 to the auxiliary voltage circuit VA is prohibited or restricted, whereby the supply voltage to the motor control unit 44 is quickly recovered. Thus, the operation of the motor control unit 44 can be continued while avoiding the supply voltage to the motor control unit 44 being lower than the minimum operating voltage (for example, 8 volts) of the motor control unit 44. Thereafter, the hybrid vehicle 10 often performs inertial movement due to skidding or the like during the period from time t2 to time t3. Usually, the time from time t2 to t3 is 30 seconds at the longest. In this embodiment, the hybrid vehicle 10 is designed so that the time from the stop of the hybrid vehicle 10 at time t3 to the completion of the discharge process at time t4 is less than 5 seconds. Note that time t4 when the discharge process is completed may be earlier than time t3 when the hybrid vehicle 10 stops.

  Next, the hybrid vehicle 110 according to the second embodiment will be described with reference to FIGS. 4 and 5. As shown in FIG. 4, in the hybrid vehicle 110 of the second embodiment, a second storage capacitor 70 and a second backflow prevention diode 72 are added as compared to the hybrid vehicle 10 of the first embodiment. The second storage capacitor 70 has one end connected to the conductive path 64 and the other end grounded. That is, the second storage capacitor 70 is connected to the DC-DC converter 36 in parallel with the motor control unit 44. Thereby, the second storage capacitor 70 is charged by the electric power from the DC-DC converter 36 and supplies the electric power to the motor control unit 44 when the electric power from the DC-DC converter 36 is interrupted. be able to. The second backflow prevention diode 72 is provided between the second storage capacitor 70 and the auxiliary voltage circuit VA. For example, when a ground fault occurs in the auxiliary voltage circuit VA, the second storage capacitor 70 is charged. The supplied power is prevented from being supplied to the auxiliary voltage circuit VA.

  The time chart of FIG. 5 shows a specific example of a series of operations at the time of a collision of the hybrid vehicle 110 of the second embodiment, like the time chart of FIG. 3 according to the first embodiment. Each chart A1 to A7 in FIG. 5 shows the same index or state as each chart A1 to A7 in FIG. 3, and redundant description is omitted here. 3 and FIG. 5, in the example shown in FIG. 5, regarding the voltage of the auxiliary battery 34 (see A4), the period P1 from when the current limiting circuit 66 is activated to when the operation is completed is long. It has become. During this period P1, the power output from the DC-DC converter 36 is also supplied to the auxiliary voltage circuit VA in which a ground fault has occurred. Therefore, if this period becomes long, the supply voltage to the motor control unit 44 may fall below the minimum operating voltage (for example, 8 volts) of the motor control unit 44 only with the electric power output from the DC-DC converter 36. In this regard, in the hybrid vehicle 110 of the second embodiment, the second storage capacitor 70 and the second backflow prevention diode 72 are provided, and power is supplied from the charged second storage capacitor 70 to the motor control unit 44. . Thereby, even if the period P1 becomes comparatively long, the supply voltage to the motor control unit 44 is prevented from falling below the minimum operating voltage. Here, since the period P1 described above is assumed to be 100 milliseconds at the longest, the capacity to be charged by the second storage capacitor 70 may be sufficiently smaller than that of the storage capacitor 60. Therefore, a relatively small capacitor can be adopted as the second storage capacitor 70.

  Several specific examples have been described in detail above, but these are merely examples and do not limit the scope of the claims. For example, the motor control unit 44 described in the embodiment is an example of the discharge processing apparatus described in the claims, but the discharge processing apparatus is not limited thereto. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical matters grasped from the disclosure content of the present specification are listed below. The technical items described below are independent technical items, and exhibit technical usefulness alone or in various combinations.

10, 110: Hybrid vehicle 20: Output shaft 22: Engine 24: Generator 26: Motor 28: Power distribution mechanism 30: Main battery 32: Power supply circuit 34: Auxiliary battery 36: DC-DC converter 40: Hybrid control unit 42: Engine control unit 44: Motor control unit 46: Airbag control unit 50: Buck-boost converter 52: First inverter 54: Second inverter 60: Storage capacitor 62: Backflow prevention diode 64: Conductive path 66: Current limiting circuit 70 : Second storage capacitor 72: second backflow prevention diode 110: hybrid vehicle C1: first smoothing capacitor C2: second smoothing capacitor VA: auxiliary voltage circuit VL: battery side circuit

Claims (1)

An electric vehicle,
A motor that drives the wheels;
A main battery for supplying power to the motor;
A smoothing capacitor provided in a power supply circuit that electrically connects the main battery to the motor;
A discharge control device for controlling the power supply circuit to discharge the smoothing capacitor;
A storage capacitor connected to the main battery in parallel with the power supply circuit and charged by the main battery;
A DC-DC converter that steps down the power charged in the storage capacitor and supplies it to the discharge control device;
Electric car with

Images