JP2006333693A - Power supply system and vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power supply system with a simple structure, where a failure occurrence rate at the time of power supply is reduced, and to provide a vehicle having the power supply system. <P>SOLUTION: The vehicle 1 is provided with a diode 50 arranged on a route supplying current to a load circuit 31 from a DC power supply BAT1 by making a direction for supplying current as a backward direction, a system main relay RLYL which is installed in parallel to the diode 50 and can switch a conduction state and a non-conduction state in accordance with a control signal, a charging circuit 33 which is connected between a load circuit 31 and the diode 50 and charges a smoothing capacitor C1 and a controller 30 controlling the system main relay RLY and the charging circuit 33. The controller 30 conducts the system main relay RLYH when a system is started and changes the system main relay RLYL to the conduction state from the non-conduction state after charging to the smoothing capacitor C1 is completed to a prescribed level by using the charging circuit 30. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a power supply system and a vehicle equipped with the same.

  In recent years, automobiles equipped with motors for propelling vehicles such as electric cars and hybrid cars have become familiar. These automobiles are equipped with a large-capacity battery and an inverter device that receives electric power from the large-capacity battery and drives a motor. Since the large capacity battery has a high voltage, it is separated from the inverter device by the system main relay when the vehicle is not operated.

  FIG. 10 is a block diagram for explaining a power supply system related to motor driving of a conventional hybrid vehicle.

  Referring to FIG. 10, high voltage battery 502 is connected to boost converter 506 by a connecting portion 504. Boost converter 506 boosts the voltage of high-voltage battery 502 and supplies the boosted voltage to inverter 508. Inverter 508 converts the DC voltage output from the boost converter into an AC voltage and provides the same to motor generator 510. Capacitors C11 and C12 are smoothing capacitors.

  In such a conventional configuration, when starting the vehicle, the system main relay SMR3 is first connected, and then the system main relay SMR1 is connected. As a result, the capacitor C11 is charged via the limiting resistor R10. Then, after the time required for charging has elapsed and the precharging of the capacitor has been completed, system main relay SMR2 is connected, and thereafter system main relay SMR1 is opened.

  Such control is performed when the system main relays SMR3 and SMR2 are turned on in a state where the capacitor C11 is not charged at all, and a large current suddenly flows and an arc is generated in the relay at this time. This is because there is a risk of welding.

  Japanese Patent Laying-Open No. 2003-61209 (Patent Document 1) discloses a DC / DC before starting to energize an inverter circuit in a vehicle equipped with a main battery and an auxiliary battery charged and discharged at a lower voltage than the main battery. It is disclosed that after a smoothing capacitor is charged from a voltage of the main battery to a voltage within a predetermined allowable voltage range by controlling the converter, the relay is closed and the main battery is connected to the inverter.

By using such a bidirectional converter to charge the smoothing capacitor from the auxiliary battery, the system main relay SMR1 and the limiting resistor R10 in FIG. 10 need not be provided.
JP 2003-61209 A JP 2000-253570 A JP-A-10-136509

  However, in the technique disclosed in Japanese Patent Laid-Open No. 2003-61209 (Patent Document 1), it is necessary to control the DC / DC converter so that the voltage on the smoothing capacitor side and the voltage on the high-voltage main battery side are substantially equal. . For this reason, accuracy is required for the control and voltage detection of the DC / DC converter, and the configuration becomes complicated.

  That is, in the technique disclosed in Japanese Patent Application Laid-Open No. 2003-61209 (Patent Document 1), the difference between the voltage on the smoothing capacitor side and the voltage on the main battery side can be large. It is necessary to constantly monitor and control the DC / DC converter so that the difference does not increase. Further, when the voltage on the smoothing capacitor side becomes larger than the voltage on the main battery side, it is necessary to cause the DC / DC converter to perform a step-down operation.

  An object of the present invention is to provide a power supply system with a simple configuration and a reduced failure occurrence rate when power is turned on, and a vehicle including the same.

  In summary, the present invention is a power supply system in which a current is supplied to a first DC power supply, a load circuit including a capacitive element, and a path for supplying current from the first DC power supply to the load circuit. Between the load circuit and the rectifying element, the rectifying element arranged in the reverse direction, a first connection circuit provided in parallel with the rectifying element and capable of switching between a conducting state and a non-conducting state according to the control signal A charging circuit connected to charge the capacitor element and a control unit controlling the connection circuit and the charging circuit are provided. The control unit changes the first connection circuit from the non-conductive state to the conductive state after the charging of the capacitive element is completed to a predetermined level.

  Preferably, the power supply system further includes a current detection unit that detects a current flowing through the first DC power supply. The control unit determines that charging of the capacitive element has been completed to a predetermined level when the current value detected by the current detection unit exceeds a predetermined value.

  Preferably, the rectifying element is connected between the first electrode of the first DC power supply and the load circuit. The power supply system further includes a second connection circuit connected between the second electrode of the first DC power supply and the load circuit. When the control circuit causes the load circuit to transition from the inoperable state to the operable state, the control circuit sets the first connection circuit to the non-connection state, sets the second connection circuit to the connection state, and operates the charging circuit to the capacitive element. The first connection circuit is changed from the non-conducting state to the conducting state after charging is performed to a predetermined level.

  Preferably, the charging circuit includes a second DC power supply having a power supply voltage lower than that of the first DC power supply, and a voltage conversion circuit that converts the voltage of the second DC power supply to apply to the capacitor element of the load circuit. .

  More preferably, the second DC power supply is a power storage device, the first connection circuit and the load circuit are connected at the first node, and the second connection circuit and the load circuit are at the second node. It is connected. When charging the second DC power supply, the voltage conversion circuit receives a voltage from the first and second nodes, steps down the voltage, and supplies the voltage to the second DC power supply.

  Preferably, the capacitive element is a first smoothing capacitor. The load circuit further includes a boost converter that boosts the voltage between the terminals of the first smoothing capacitor, an inverter that receives the output of the boost converter and converts it into alternating current, and a motor driven by the inverter.

  In another aspect, the present invention is a vehicle equipped with any one of the power supply systems described above.

  According to still another aspect of the present invention, a power supply system is provided on a first DC power supply, a load circuit including a capacitive element, and a path for supplying current from the first DC power supply to the load circuit, A first connection circuit that can be switched between a conductive state and a non-conductive state according to a control signal; a charging circuit that is connected between the load circuit and the rectifying element and charges the capacitor element; and the connecting circuit and the charging circuit And a control unit for controlling the above. When the charge to the capacitive element exceeds a predetermined level, the control unit discharges the charge of the capacitive element in the load circuit and returns the charge level of the capacitive element to the predetermined level, and then the first connection circuit. Is changed from the non-conductive state to the conductive state.

  Preferably, the control unit stops the operation of the charging circuit when the charging of the capacitive element exceeds a predetermined level.

Preferably, the predetermined level is a value determined according to the power supply voltage of the first DC power supply.
Preferably, the load circuit includes a boost converter connected to the capacitive element, and the control unit boosts the boost converter when the voltage between the electrodes of the capacitive element is higher than a predetermined level after completion of the precharge operation for the capacitive element by the charging circuit. To discharge the accumulated charge of the capacitor.

  More preferably, the capacitive element is a first smoothing capacitor, the boost converter boosts the voltage between the terminals of the first smoothing capacitor, and the load circuit receives the output of the boost converter and converts it into alternating current. And a motor driven by the inverter.

  In yet another aspect, the present invention is a vehicle equipped with any one of the power supply systems described above.

  According to the present invention, since the potential difference when the power is turned on is reduced with a simple configuration, the failure occurrence rate of the power supply system is reduced.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[Embodiment 1]
FIG. 1 is a circuit diagram showing a configuration of a vehicle 1 according to an embodiment of the present invention. The vehicle 1 may be any of an electric vehicle that drives wheels with a motor, a fuel cell vehicle, and a hybrid vehicle that uses a motor and an engine together for driving the vehicle.

  Referring to FIG. 1, vehicle 1 supplies a current to a DC power supply BAT1, a load circuit 31 including a smoothing capacitor C1 that is a capacitive element, and a path for supplying a current from DC power supply BAT1 to load circuit 31. A diode 50 arranged in the opposite direction, a system main relay RLYL provided in parallel with the diode 50 and switchable between a conductive state and a non-conductive state according to a control signal, and between the load circuit 31 and the diode 50 And a control circuit 30 for controlling the system main relay RLYL and the charging circuit 33. The diode 50 is connected between the negative electrode of the DC power supply BAT1 and the load circuit 31.

  Control device 30 changes system main relay RLYL from the non-conductive state to the conductive state after charging of smoothing capacitor C1 is completed to a predetermined level at the time of system startup.

  The vehicle 1 further includes a current sensor 11 that detects a current IB flowing through the DC power supply BAT1. Control device 30 determines that charging of smoothing capacitor C1 has been completed to a predetermined level when current value IB detected by current sensor 11 exceeds a predetermined value.

  Vehicle 1 further includes a system main relay RLYH connected between the positive electrode of DC power supply BAT1 and load circuit 31.

  When the control device 30 causes the load circuit 31 to transition from the inoperable state to the operable state, first, the system main relay RLYL is disconnected and the system main relay RLYH is connected. Then, after charging circuit 33 is operated to charge smoothing capacitor C1 to a predetermined level, system main relay RLYL is changed from the non-conductive state to the conductive state.

  The charging circuit 33 converts the power supply voltage Vcc of the DC power supply BAT2 and the DC power supply BAT2 that are lower than the DC power supply BAT1 into an auxiliary battery, and the step-up / step-down DC / DC applied between the electrodes of the smoothing capacitor C1. DC converter 42 and a load circuit 46 that operates with the voltage of DC power supply BAT2 are included.

  The step-up / step-down DC / DC converter 42 steps down the voltage between the terminals of the smoothing capacitor C1 and supplies it to the DC power source BAT2 as the charging voltage when the DC power source BAT2, which is an auxiliary battery, drops in the vehicle operation state due to discharge. .

  Load circuit 31 further includes a boost converter 12 that boosts the voltage across terminals of smoothing capacitor C1, inverter 14 that receives the output of boost converter 12 and converts it into alternating current, and motor generator M1 that is driven by inverter 14. .

  DC power supply BAT1 includes a plurality of battery cells 6 and 8 connected in series, and a safety switch 4 and a fuse 2 connected between the battery cells. The safety switch 4 is normally connected, but is set to an open state when the cover of the battery case is opened.

  The voltage between the positive electrode and the negative electrode of the DC power supply BAT1 is monitored by the voltage sensor 10, and the measured voltage value VB is transmitted to the control device 30. The voltage between the electrodes of the smoothing capacitor C <b> 1 is monitored by the voltage sensor 21, and the measured voltage value VL is transmitted to the control device 30.

  Boost converter 12 includes a reactor L1 having one end connected to the positive electrode of DC power supply BAT1 via system main relay RLYH, an IGBT element Q1 having an emitter connected to the other end of the reactor, and a collector at the other end of reactor L1. IGBT element Q2 to which is connected. The emitter of IGBT element Q2 is connected to the negative electrode of DC power supply BAT1 through system main relay RLYL.

  Boost converter 12 further has a diode element D1 connected in a forward direction from the emitter to the collector between the collector and emitter of IGBT element Q1, and a direction from the emitter to the collector between the collector and emitter of IGBT element Q2. And a diode element D2 connected as a forward direction.

  A smoothing capacitor C2 is provided between the collector of the IGBT element Q1 and the emitter of the IGBT element Q2. The voltage across the smoothing capacitor C2 is monitored by the voltage sensor 13. From the voltage sensor 13, the measured voltage value VH is transmitted to the control device 30.

  The motor generator M1 is provided with a current sensor (not shown), and the current flowing through the motor generator M1 is detected as a motor current value MCRT and output to the control device 30.

  Control device 30 outputs a control signal PWU for boosting, a control device PWD for instructing step-down, and an operation detection signal CSDN to the boost converter. Further, control device 30 converts drive instruction PWMI for converting a DC voltage, which is the output of boost converter 12 to inverter 14, into an AC voltage for driving motor generator M1, and an AC voltage generated by motor generator M1. A regenerative instruction PWMC that is converted into a DC voltage and returned to the boost converter 12 side is output.

  FIG. 2 is a flowchart showing a control structure of a program executed by the control device 30 of FIG. This process is called and executed from the main routine every predetermined time or whenever a predetermined condition is satisfied.

  Referring to FIG. 1 and FIG. 2, when the processing is started, control device 30 detects whether or not the driver switches the ignition switch from the off state to the on state by monitoring signal IGON in step S1. To do. If this switching has not occurred, the process proceeds to step S8 and control returns to the main routine again. On the other hand, when this switching is detected, the process proceeds to step S2.

  In step S2, control device 30 switches system main relay RLYH from the non-conductive state to the conductive state. In step S3, the DC / DC converter 42 starts a boosting operation. Subsequently, in step S4, it is determined whether or not the battery current value IB sent from the current sensor 11 exceeds the threshold value I0. If the battery current value IB has not yet exceeded the threshold value, the process returns to step S3 and the boosting operation of the DC / DC converter is maintained.

  On the other hand, if the current value IB exceeds the threshold value I0 in step S4, the process proceeds to step S5. In step S5, control device 30 instructs DC / DC converter 42 to stop the operation. Subsequently, the process proceeds to step S6, and the control device 30 changes the setting of the system main relay RLYL from the non-conductive state to the conductive state. Subsequently, in step S7, the control device 30 lights an indicator (Ready-on) to notify the driver that the vehicle is in an operable state. When the process of step S7 ends, the process proceeds to step S8, and control is returned to the main routine.

  FIG. 3 is an operation waveform diagram for explaining the operation when the flowchart of FIG. 2 is executed.

  Referring to FIG. 3, first, as an initial state, system main relays RLYH and RLYL are both non-conductive, and DC / DC converter 42 is in an operation stop state. At this time, the battery current value IB is 0 amperes, and the voltage value VL indicating the voltage between the terminals of the smoothing capacitor C1 is 0 volts.

  When the driver operates the ignition switch at time t0, this is detected (step S1 in FIG. 2), and at this time, the system main relay RLYH transitions from the non-conductive state to the conductive state at time t1 (step S2).

  Subsequently, at time t2, the control device 30 starts the boosting operation of the DC / DC converter 42. In response to this, charging of the smoothing capacitor C1 is started and the voltage value VL starts to gradually increase.

  When voltage value VL exceeds battery voltage VB of DC power supply BAT1 at time t3, a forward current of diode 50 flows and current also flows from DC / DC converter 42 to DC power supply BAT1. When this current exceeds threshold value I0 at time t4, control device 30 stops the DC / DC converter (step S5 in FIG. 2).

  At time t5, control device 30 switches system main relay RLYL from the non-conducting state to the conducting state, and the vehicle enters an operable state in which precharging has been completed.

FIG. 4 is a diagram showing a modification of the flowchart of FIG.
The flowchart of FIG. 4 is obtained by replacing the order of steps S5 and S6 in the flowchart of FIG. 2, and the other parts are the same as those in FIG.

  FIG. 5 is an operation waveform diagram for explaining the operation when the flowchart of FIG. 4 is executed.

Since the operation up to time t3 in FIG. 5 is the same as the operation described in FIG. 3, description thereof will not be repeated.
When the voltage between the terminals of the smoothing capacitor C1 exceeds the battery voltage value VB at time t3, the battery current value IB starts increasing from 0 amperes. At time t4A, when battery current value IB exceeds threshold value I0, system main relay RLYL is controlled from the non-conductive state to the conductive state in step S6 of FIG.

  At time t5A, the operation of the DC / DC converter 42 is stopped, and the battery current value IB becomes 0 amperes again. Here, the driver lights up the indicator that the smoothing capacitor C1 has been precharged. To inform.

  It should be noted that no current exceeding a certain current value flows between times t4A and t5A. This is because the current is limited to some extent because the capability of the DC / DC converter 42 is limited.

FIG. 6 is a circuit diagram for explaining a modification of the configuration shown in FIG.
In place of providing the diode 50 in FIG. 1, a diode 50A may be provided in parallel with the system main relay RLYH as shown in FIG. At this time, the forward direction of the diode 50A is the forward direction from the smoothing capacitor C1 to the DC power supply BAT1. Even in such a configuration, the control of the flowcharts shown in FIGS. 2 and 4 can be applied.

  By adopting the configuration and control as described above, the difference between the battery voltage VB and the voltage VL between the terminals of the smoothing capacitor C1 does not increase even if the operation of the DC / DC converter is continued. Control of the converter 42 is facilitated. This is because the voltage difference between them is only the forward voltage of the diode 50. As a result, the voltage when the system main relay RLYL is on can be reduced. That is, an inexpensive system main relay having a smaller maximum contact allowable voltage at the time of ON can be used.

  Further, by detecting that the precharge of the smoothing capacitor C1 is completed by the current sensor 11 provided in the high voltage side power supply, the sameness of the voltage values VB and VL detected by the voltage sensors 10 and 21 is monitored. There is little monitoring burden. That is, an inexpensive voltage sensor with a lower accuracy of the voltage sensor can be used.

  In addition, although the example which uses the current sensor 11 was shown as a method of detecting charging of the smoothing capacitor C1, the detection may be performed by using the voltage values VB and VL detected by the voltage sensors 10 and 21, respectively. . Also in this case, since the voltage value VL does not become larger than the voltage value VB beyond the forward voltage of the diode 50, the monitoring burden and the control burden are reduced as compared with the conventional case.

[Embodiment 2]
When the smoothing capacitor is precharged by the DC / DC converter, the diode 50 is provided in the first embodiment to prevent the voltage of the smoothing capacitor from rising too much. In order to prevent the voltage of the smoothing capacitor from rising too much without providing a diode, it is conceivable to lower the smoothing capacitor in the step-down operation of the DC / DC converter.

  However, there is a delay in control response from the detection of the capacitor voltage VL to the control of the DC / DC converter in the same way as the capacitor voltage may be raised too much in the boost operation. There is also a risk of lowering too much.

  Normally, the control start / stop command is issued to the DC / DC converter in anticipation of this control response delay. However, since the boosting time and the like vary depending on the state of charge of the battery, the control response delay is completely predicted. Is difficult.

  FIG. 7 is a circuit diagram showing a configuration of vehicle 100 according to the second embodiment. The vehicle 100 may be any of an electric vehicle that drives wheels with a motor, a fuel cell vehicle, and a hybrid vehicle that uses a motor and an engine together for driving the vehicle.

  The configuration of the vehicle 100 is different from the configuration of the vehicle 1 described with reference to FIG. 1 in that the diode 50 is deleted and another control is performed in the control device 30, but the configuration of other parts is different. Since vehicle 100 is similar to vehicle 1, description thereof will not be repeated.

  FIG. 8 is a flowchart showing the structure of the control program executed in the second embodiment.

  FIG. 9 is an operation waveform diagram for explaining the operation when the flowchart of FIG. 8 is executed. This process is called and executed from the main routine every predetermined time or whenever a predetermined condition is satisfied.

  Referring to FIGS. 8 and 9, when the process is started, control device 30 in FIG. 7 monitors signal IGON in step S <b> 11 to determine whether the driver switches the ignition switch from the off state to the on state. Is detected. If this switching has not occurred, the process proceeds to step S20 and control returns to the main routine again. On the other hand, when this switching occurs as shown at time t10 and the control device 30 detects the switching, the process proceeds to step S12.

  In step S12, as shown at time t11, control device 30 switches system main relay RLYH from the non-conductive state to the conductive state. In step S13, as shown at time t12, the DC / DC converter 42 starts a boosting operation.

  Subsequently, in step S14, it is determined whether or not | VL−VB | <Vth is satisfied, where Vth is a predetermined threshold value, VL is the voltage of the capacitor C1, and VB is the battery voltage. If this equation does not hold, the process returns to step S13 again and the step-up operation of the DC / DC converter is maintained. Between time t12 and time t13, | VL−VB | <Vth, and therefore, control device 30 causes DC / DC converter 42 to continue the boosting operation.

  If voltage VL becomes larger than VB−Vth at time t13, | VL−VB | <Vth is not established in step S14, and the process proceeds to step S15. In step S15, the control device 30 instructs the DC / DC converter 42 to stop the operation.

  However, since there is a control response delay, the time when the DC / DC converter 42 actually stops its operation is time t14. Therefore, as a result of DC / DC converter 42 performing the boosting operation from time t13 to t14, voltage VL exceeds VB + Vth.

  When the process of step S15 ends, control device 30 determines whether or not | VL−VB | <Vth is satisfied in step S16. If this expression does not hold, it is determined that the voltage VL has become too high by the boosting operation of the DC / DC converter 42, and the boosting converter 12 is caused to perform the boosting operation in order to consume the charge of the capacitor C1. When boost converter 12 performs a boost operation, the charge of capacitor C1 is transferred to capacitor C2, and voltage VL decreases.

  Note that the step-up operation of step-up converter 12 in step S17 is a single control different from the normal control. The single control is not repeating the switching of the transistor Q2, but conducting the transistor Q2 for a predetermined time and then turning it off according to the voltage.

  When the transistor Q2 is turned on in a pulse state while the transistor Q1 is kept off, first, when the transistor Q2 is turned on, the positive electrode of the capacitor C1, the reactor L1, the collector of the transistor Q2, the emitter of the transistor Q2, the negative electrode of the capacitor C1 Current flows in the order of. When the transistor Q2 transitions from the conductive state to the non-conductive state, in order to release the energy accumulated in the reactor L1, the positive electrode of the capacitor C1, the reactor L1, the diode D1, the positive electrode of the capacitor C2, the negative electrode of the capacitor C2, A current flows through this path in the order of the negative electrode of the capacitor C1. As a result, the charge of the capacitor C1 is transferred to the capacitor C2.

  Depending on the constants of the smoothing capacitors C1 and C2 and the reactor L1, for example, according to the circuit simulation performed by the present inventor, the transistor Q2 is conducted about 10 μs in a single operation with C1 = 300 μF, C2 = 1000 μF, and the reactor L1 = 200 μH. When it is made non-conductive after being made, the voltage VL of the capacitor C1 decreases by 5.7V, and the voltage VH of the capacitor C2 increases by 1.7V. In order to make finer voltage adjustment to the voltage VL, the conduction period of the transistor Q2 at the time of single control may be made shorter.

  As a result of the single control as described above, voltage VL decreases with the operation of the boost converter as shown at times t15 to t16.

  The DC / DC converter 42 operates upon receiving an UP / DN command from the control device 30. The control device 30 does not directly control the switching element like the boost converter 12. Since the DC / DC converter 42 has a response delay with respect to the UP / DN command, it is difficult to slightly increase or decrease the voltage. It can be improved by shortening the response delay, but it is not easy to realize.

  Thus, although a response delay occurs in the DC / DC converter, the control accuracy of the voltage VL can be made smaller than that in the DC / DC converter by controlling the boost converter one time.

  Then, in step S16 again, it is determined whether or not | VL−VB | <Vth is satisfied. Since | VL−VB | <Vth is satisfied at time t16, the process proceeds to step S18.

  In step S18, as shown at time t17, control device 30 changes the setting of system main relay RLYL from the non-conductive state to the conductive state. Subsequently, in step S19, the control device 30 lights the indicator (Ready-on) to notify the driver that the vehicle is in an operable state. When the process of step S19 ends, the process proceeds to step S20, and control is returned to the main routine.

  As described above, in the second embodiment, the charge of the smoothing capacitor C1 on the input side of the boost converter 12 is moved to the smoothing capacitor C2 side on the output side of the boost converter 12. Since the difference between the voltage VL and the voltage VB can be reduced by driving the load circuit, the bidirectional DC / DC converter 42 can be easily controlled.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 is a circuit diagram showing a configuration of a vehicle 1 according to an embodiment of the present invention. It is the flowchart which showed the control structure of the program performed with the control apparatus 30 of FIG. FIG. 3 is an operation waveform diagram for explaining an operation when the flowchart of FIG. 2 is executed. It is the figure which showed the modification of the flowchart of FIG. FIG. 5 is an operation waveform diagram for explaining an operation when the flowchart of FIG. 4 is executed. It is a circuit diagram for demonstrating the modification of the structure shown in FIG. FIG. 4 is a circuit diagram showing a configuration of a vehicle 100 according to a second embodiment. 6 is a flowchart showing a structure of a control program executed in the second embodiment. It is an operation | movement waveform diagram for demonstrating operation | movement when the flowchart of FIG. 8 is performed. It is a block diagram for demonstrating the power supply system regarding the motor drive of the conventional hybrid vehicle.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,100 Vehicle, 2 fuse, 4 safety switch, 6,8 battery battery case, 10, 13, 21 voltage sensor, 11 current sensor, 12 boost converter, 14 inverter, 30 control apparatus, 31 load circuit, 33 charging circuit , 42 DC / DC converter, 46 load circuit, 50, 50A diode, BAT1, BAT2 DC power supply, C1, C2, C11, C12 capacitor, D1 diode element, D2 diode element, L1 reactor, M1 motor generator, Q1, Q2 IGBT Element, RLYH, RLYL System main relay.

Claims (13)

A first DC power supply;
A load circuit including a capacitive element;
A rectifying element arranged on the path for supplying current from the first DC power supply to the load circuit, with the direction of supplying current being reverse;
A first connection circuit provided in parallel with the rectifying element and capable of switching between a conductive state and a non-conductive state according to a control signal;
A charging circuit connected between the load circuit and the rectifying element and charging the capacitive element;
A controller for controlling the connection circuit and the charging circuit;
The said control part is a power supply system which changes a said 1st connection circuit from a non-conduction state to a conduction | electrical_connection state after the charge to the said capacitive element is completed to a predetermined level. A current detector for detecting a current flowing through the first DC power supply;
The power supply system according to claim 1, wherein the control unit determines that charging of the capacitive element has been completed to the predetermined level when a current value detected by the current detection unit exceeds a predetermined value. The rectifying element is connected between a first electrode of the first DC power source and the load circuit,
The power supply system includes:
A second connection circuit connected between the second electrode of the first DC power source and the load circuit;
The control unit sets the first connection circuit to a non-connection state, sets the second connection circuit to a connection state, and operates the charging circuit when the load circuit is transitioned from an inoperable state to an operable state. The power supply system according to claim 1 or 2, wherein the first connection circuit is changed from a non-conducting state to a conducting state after charging the capacitive element to the predetermined level. The charging circuit is
A second DC power supply having a power supply voltage lower than that of the first DC power supply;
4. The power supply system according to claim 1, further comprising: a voltage conversion circuit that converts the voltage of the second DC power supply and applies the voltage to the capacitive element of the load circuit. The second DC power source is a power storage device;
The first connection circuit and the load circuit are connected at a first node;
The second connection circuit and the load circuit are connected at a second node,
5. The voltage conversion circuit according to claim 4, wherein when the second DC power supply is charged, the voltage conversion circuit receives a voltage from the first and second nodes, steps down the voltage, and supplies the voltage to the second DC power supply. Power system. The capacitive element is a first smoothing capacitor;
The load circuit includes a boost converter that boosts a voltage between terminals of the first smoothing capacitor;
An inverter that receives the output of the boost converter and converts it into alternating current;
The power supply system according to claim 1, further comprising a motor driven by the inverter.   A vehicle equipped with the power supply system according to any one of claims 1 to 6. A first DC power supply;
A load circuit including a capacitive element;
A first connection circuit provided on a path for supplying a current from the first DC power supply to the load circuit, and capable of switching between a conductive state and a non-conductive state according to a control signal;
A charging circuit connected between the load circuit and the rectifying element and charging the capacitive element;
A controller for controlling the connection circuit and the charging circuit;
When the charge to the capacitive element exceeds a predetermined level, the control unit discharges the charge of the capacitive element in the load circuit and returns the charge level of the capacitive element to the predetermined level. A power supply system that changes the first connection circuit from a non-conductive state to a conductive state.   The power supply system according to claim 8, wherein the control unit stops the operation of the charging circuit when charging of the capacitive element exceeds a predetermined level.   The power supply system according to claim 8 or 9, wherein the predetermined level is a value determined according to a power supply voltage of the first DC power supply. The load circuit is
Including a boost converter connected to the capacitive element;
The controller drives the boost converter to discharge the accumulated charge of the capacitive element when the inter-electrode voltage of the capacitive element is higher than the predetermined level after the precharge operation for the capacitive element by the charging circuit is completed. The power supply system according to any one of claims 8 to 10. The capacitive element is a first smoothing capacitor;
The boost converter boosts a voltage between terminals of the first smoothing capacitor;
The load circuit is
An inverter that receives the output of the boost converter and converts it into alternating current;
The power supply system according to claim 11, further comprising a motor driven by the inverter.   A vehicle equipped with the power supply system according to any one of claims 8 to 12.

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