JP2013070547A - Power conversion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power conversion device which suppresses overcharging of a battery charged by a solar cell.SOLUTION: The power conversion device includes a battery, a solar cell, a power converter for converting power from the solar cell into charging power for charging the battery, a voltage sensor for detecting a voltage of the battery, and power converter control means for controlling a power conversion stop time in which power conversion by the power converter is stopped. In the power conversion stop time, the power converter control means determines re-driving of the power converter on the basis of a detection voltage detected by the voltage sensor.

Description

  The present invention relates to a power conversion device.

  A vehicle having a solar cell, a battery, an electric control device, and a main switch that is closed only during operation of the vehicle and supplies electric current to the electric control device to operate it. The electric control device integrates the electric power charged in the battery by the solar cell while the electric control device charges the battery based on the electric power integration value by the electric power integrator when the main switch is closed. A vehicle for correcting the state is known (Patent Document 1).

JP 2006-340544 A

  However, since the current value output from the solar cell is low and the amount of change in the integrated power value for correcting the charging state is small, the charging state of the battery cannot be detected accurately, and the battery may be overcharged. there were.

  This invention provides the power converter device which suppresses the overcharge of the battery charged with a solar cell.

  The present invention includes a power converter that converts power from a solar cell into charging power for charging a battery, and the power converter is re-established based on a detection voltage detected by a voltage sensor during a power conversion stop time. The above-mentioned problem is solved by determining driving.

  According to the present invention, since the voltage of the battery is detected in a state where the battery is not charged with the power from the solar cell, and the charging power to the battery is controlled based on the detected voltage, the output from the solar cell Regardless of the amount of power, the battery can be managed, and as a result, the battery can be prevented from being overcharged.

1 is a block diagram of a vehicle including a power conversion device according to an embodiment of the present invention. It is a flowchart of the power converter device of FIG. It is a flowchart of PCS stop control of FIG. 3 is a flowchart of PCS drive resumption control in FIG. 2. It is a block diagram of the vehicle containing the power converter device which concerns on the modification of this invention. It is a flowchart of the power converter device which concerns on other embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<< First Embodiment >>
FIG. 1 is a block diagram of a vehicle including a power conversion device according to an embodiment of the invention. Hereinafter, although the example which applied the power converter device of this example to an electric vehicle is given and demonstrated, the power converter device of this example is applicable also to vehicles other than electric vehicles, such as a hybrid vehicle, for example.

  As shown in FIG. 1, the vehicle of this example includes a solar cell 1, a series / parallel switching circuit 2, an output switching circuit 3, a PCS 4, a battery 5, a charging port 6, a charger 7, and an inverter 8. A motor 9, a battery 10, a DC / DC converter 11, a current sensor 12, a voltage sensor 13, and a controller 20. The solar cells 1a and 1b are power devices that are provided on, for example, a roof panel of a vehicle and convert solar energy into electric power. The solar cell 1a and the solar cell 1b are connected to the series-parallel switching circuit 2 with their outputs independent.

  The series / parallel switching circuit 2 includes switches 2a, 2b, and 2c, and is connected between the solar cells 1a and 1b and the output switching circuit 3. The switch 2a, the switch 2b, and the switch 2c are connected in series, the P-side output line of the output of the solar cell 1a is connected to the high-potential side terminal of the switch 2c, and the N-side output of the output of the solar cell 1a The line is connected to the connection point between the switch 2a and the switch 2b, the P-side output line of the output of the solar cell 1b is connected to the connection point of the switch 2b and the switch 2c, and the N-side of the output of the solar cell 1a Are connected to the low potential side terminal of the switch 2a. When the switch 2a and the switch 2c are turned on, the solar cell 1a and the solar cell 1b are connected in parallel, and when the switch 2b is turned on, the solar cell 1a and the solar cell 1b are connected in series. The series-parallel switching circuit 2 is a circuit that switches the connection state of the solar cells 1a and 1b by switching the switches 2a to 2c on and off based on a control signal from the controller 20.

  The output switching circuit 3 includes switches 3a, 3b, 3c, and 3d, and is connected between the series-parallel switching circuit 2, the low-voltage battery 10, and the PCS 4. The switches 3a and 3b, and the switches 3c and 3d constitute relay switches. When the switch 3a and the switch 3b are turned on, the power output from the solar cells 1a and 1b is input to the PCS 4 via the series-parallel switching circuit 2, and when the switch 3c and the switch 3d are turned on, the power is output from the solar cells 1a and 1b. The output electric power is input to the solar cell 10 via the series / parallel switching circuit 2. As will be described later, since the PCS 4 is connected to the battery 5, when the switch 3 a and the switch 3 b are turned on, the power output from the solar cells 1 a and 1 b can be supplied to the battery 5. That is, the output switching circuit 3 is a circuit that supplies the output from the solar cells 1a and 1b to the battery 5 via the PCS 4 by switching on and off of the switches 3a to 3d based on a control signal from the battery control unit 20. And the circuit which supplies the output from solar cell 1a, 1b to the battery 10 is switched.

  The PCS (Power Conversion System) 4 is a power conversion system including a conversion circuit that converts power output from the solar cells 1a and 1b, and MPPT (Maximum Power Point Tracking) that follows the maximum power point of the solar cells 1a and 1b. : Maximum power follow-up control). The PCS 4 is connected between the output switching circuit 3 and the battery 5, boosts the power output from the solar cells 1 a and 1 b, and supplies the boosted power to the battery 5 as charging power for the battery 5. For example, the PCS 4 is provided with a step-up chopper, a rectifier circuit, a DC / DC converter, and the like. The transistors included in the boost chopper are switched on and off based on a switching signal from the controller 20. When the duty ratio of the switching waveform of the transistor is set by the controller 20, the PCS 4 operates the operating point of the input voltage of the PCS 4 while maintaining the output voltage from the conversion circuit substantially constant, and the solar cell 1a. The generated power of 1b is controlled. The high-voltage circuit including the PCS 4 and the battery 5 is an insulating circuit that can insulate the low-voltage circuit from each other.

  The battery 5 is composed of a plurality of secondary batteries, serves as a driving source for the vehicle, and is a high-voltage battery as compared with a battery 10 described later. The battery 5 is connected to the PCS 4 and is connected to the motor 9 via the inverter 8. The battery 5 is a battery that can be charged with electric power from an external power source, and is connected to the charging port 6 via the charger 7. The charging port 6 is a charging port that can be connected to a charging connector from the outside, and is connected to the charger 7 via wiring. The charging connector is connected to a power source of a commercial power system such as a household AC power source.

  The charger 7 has an input side connected to the charging port 6 and an output side connected to the battery 5. The charger 3 converts electric power from the external power source into charging electric power for charging the battery 5 and supplies the electric power to the battery 5 to charge the battery 5. Charge control of the charger 5 is performed by the controller 20. The charger 7 is connected to the battery 10 via the DC / DC converter 11 and charges the battery 10 based on a control signal from the controller 20.

  The inverter 8 includes a plurality of switching elements such as insulated gate bipolar transistors (IGBT), and includes a smoothing capacitor and the like. The inverter 8 performs PWM control of the switching element based on the switching signal transmitted from the controller 20, thereby converting DC power supplied from the battery 5 into AC power and providing it to each phase of the motor 9. Further, the inverter 8 converts electric power supplied from the motor 9 by regeneration of the motor 9 and supplies it to the battery 5. The motor 9 is a three-phase AC motor, for example, and is connected to the inverter 8.

  The battery 10 includes a plurality of secondary batteries, serves as a power source for operating auxiliary equipment such as a vehicle headlight and audio equipment, and is a battery having a lower voltage than the battery 5. The battery 10 is connected to the DC / DC converter 11 and the output switching circuit 3. The battery 10 is charged with electric power supplied from the solar cells 1a and 1b and electric power from an external power source. The battery 10 is connected to the battery 5 through the DC / DC converter 11 and is charged by supplying the battery 5 with electric power. The DC / DC converter 11 is connected between the battery 5 and the battery 10 and between the charger 7 and the battery 10. The DC / DC converter 11 converts the power from the battery 5 and supplies it to the battery 10. Is converted into power and supplied to the battery 10. The DC / DC converter 11 switches the conduction state between the battery 10, the battery 5, and the charger 7 based on the control signal transmitted from the controller 20.

  The current sensor 12 and the voltage sensor 13 are sensors that respectively detect the current and voltage of the battery 5, and are connected to the battery 5. The detection value of each sensor is transmitted to the controller 20, and the controller 20 manages the state of the battery 5 based on the detection value.

  The controller 20 includes a switching circuit control unit 21, a PCS control unit 22, an SOC estimation unit 23, a memory 24, and a battery controller 25. The controller 20 is a circuit that controls the entire power conversion device of this example. The battery 5 and the battery 10 are charged by the solar cells 1a and 1b. The battery 5 and the battery 10 are charged from an external power source. Power supply control with the battery 10, drive control of the motor 9, and the like are performed.

  The switching circuit control unit 21 is a circuit that controls on and off of the switches 2a to 2c included in the series / parallel switching circuit 2, and the solar cell 1a and the solar cell 1b are connected in parallel and in series. Perform switching control. The switching circuit control unit 21 is a circuit that controls on and off of the switches 3 a to 3 d included in the output switching circuit 3, and outputs the output from the solar cells 1 a and 1 b to the battery 5 or to the battery 10. Control to switch the output.

  The PCS control unit 22 is a control unit that controls the PCS 4 and sets the drive time and stop time of the PCS 4. The PCS control unit 22 detects an input voltage input to the PCS 4 from the solar cells 1 a and 1 b from a voltage sensor (not shown) connected to the input side of the PCS 4, and stores the detected voltage in the memory 24.

  The SOC estimating unit 23 estimates the state of charge of the battery 5 based on the detection voltage of the voltage sensor 5. Note that the SOC estimation control by the SOC estimation unit 23 will be described later. The battery controller 25 manages the SOC of the battery 5 and the SOC of the battery 10 so as to prevent overcharge and overdischarge of the battery 5 and the battery 10. The battery controller 25 manages the state of the battery 5 based on the SOC estimated by the 80 percent estimation unit 23. When managing the battery 10, the battery controller 25 calculates an integrated current value from, for example, a sensor (not shown) that detects an input / output current of the battery 10, and calculates an SOC from the integrated current value.

In the battery controller 25, an upper limit value indicating the full charge of the battery 5 and the battery 10 is set in advance, and SOC ₀ and SOC ₁ are set. The upper limit value (SOC ₀ ) is a value indicating the upper limit of the SOC of the battery 5 when the battery 5 is charged by the external power source via the charger 7. The upper limit (SOC ₁₎ is in the case of charging the battery 5 solar cell 1a, by 1b, is a value indicating the upper limit of the SOC of the battery 5. The battery controller 25 transmits a control signal to the controller 20 in order to prevent the battery 5 from being overcharged when the SOC of the battery 5 becomes higher than the upper limit value (SOC ₀ ) during charging by the external power source. Then, the controller 20 ends the charging of the battery 5.

In the battery controller 25, an upper limit value indicating the full charge of the battery 10 is set in advance, and SOC ₂ is set. The upper limit value (SOC ₂ ) is a value indicating the upper limit of the SOC of the battery 10. When charging the battery 10, when the SOC of the battery 10 becomes higher than the upper limit value (SOC ₂ ), the battery controller 25 transmits a control signal to the controller 20 to prevent the battery 10 from being overcharged. Ends the charging of the battery 10.

  The battery controller 25 is preset with a threshold value indicating the lower limit value of the capacity of the battery 5, and manages the battery 5 and the battery 10 so that the capacity of the battery does not become lower than the lower limit value. Prevent over-discharge.

  Next, the control content of the power converter of this example will be described. First, charging by an external power source will be described. When the controller 20 detects that the charging connector is connected to the charging port 6, the controller 20 starts control for charging the battery 5 with the external power source. The controller 20 controls the charger 7, converts electric power supplied from the external power source into electric power suitable for charging the battery 5, and supplies the electric power to the battery 5. When the battery 20 is charged by the external power source, the controller 20 turns off the switches 3a and 3b by the switching circuit control unit 21 to turn off the DC / DC converter 11 and outputs from the charger 7. Is not input to the solar cells 1a and 1b.

  The controller 20 calculates the SOC of the battery 5 from the detection voltage of the voltage sensor 13 and the detection current of the current sensor 12 while the battery 5 is being charged, and manages the SOC of the battery 5. When the battery 5 is charged by an external power source, the SOC calculation method may be calculated from, for example, the integrated value of the detected current.

When the SOC of the battery 5 becomes higher than the SOC ₀ , the battery controller 25 determines that the capacity of the battery 5 has reached full charge, and the controller 20 controls the charger 7 to end the charging of the battery 5. .

  Next, charging of the solar cells 1a and 1b will be described. When charging the battery 5, the controller 20 switches the solar cells 1 a, 1 b into a series connection state by turning on the switch 2 b and turning off the switches 2 a, 2 c by the switching circuit control unit 21. In addition, the controller 20 turns on the switches 3a and 3b and turns off the switches 3c and 3d by the switching circuit control unit 21, and inputs the outputs of the solar cells 1a and 1b in the serial connection state to the PCS 4. Thereby, the loss at the time of the power conversion in PCS4 is reduced by making the output voltage from solar cell 1a, 1b high, and reducing the input current to PCS4.

  The controller 20 causes the PCS control unit 22 to drive the PCS 4 so that the power generation point of the solar cells 1a and 1b approaches the maximum power generation power point by MPPT control. Then, the controller 20 supplies the power output from the PCS 4 to the battery 5.

  The controller 20 performs control to stop the PCS 4 at a predetermined cycle during charging control of the battery 5. That is, the PCS control unit 22 is preset with a PCS4 drive time and a PCS4 power conversion stop time. By repeating the drive time and the power conversion stop time, the PCS 4 is driven periodically. PCS4 is stopped. When the PCS 4 is driven, power is output from the PCS 4 and the battery 5 is charged. On the other hand, when the PCS 4 is stopped, power conversion by the PCS 4 is stopped, no power is output from the PCS 4, and the battery 5 is not charged.

  Then, the controller 20 acquires the detected voltage of the battery 5 from the voltage sensor 13 during the power conversion stop time, and the SOC estimation unit 23 estimates the SOC of the battery 5. The SOC estimation unit 23 stores a map indicating the correlation between the open circuit voltage of the battery 5 and the SOC of the battery. During the power conversion stop time, power is not supplied to the battery 5, and the battery 5 is in a no-load state. Therefore, the voltage detected by the voltage sensor 13 corresponds to an open circuit voltage. Therefore, the SOC estimation unit 23 estimates the SOC of the battery 5 by referring to the stored map from the detected voltage during the power conversion stop time.

  Further, the controller 20 stores the input voltage to the PCS 4 in the memory 24 when switching from the drive time to the power conversion stop time. That is, the controller 20 stores the input voltage of the PCS 4 in the memory 24 immediately before the power conversion stop time.

The controller 20 compares the estimated SOC of the SOC estimation unit 23 with the SOC ₁ by the battery controller 25, and determines that the battery 5 can be continuously charged when the estimated SOC is lower than the SOC ₁ , The PCS 4 drive time is started and the PCS 4 is re-driven. At the time of re-driving, the controller 20 drives the PCS 4 by MPPT control based on the input voltage stored in the memory 24. As a result, when performing MPPT control, the PCS control unit 22 does not have to search for the maximum power point from the initial driving state of the PCS 4, thereby shortening the search time. Then, when the set drive time has elapsed, the controller 20 again stops the PCS 4 and estimates the SOC of the battery.

On the other hand, when the estimated SOC based on the detected voltage during the power conversion stop time is higher than SOC ₁ by the battery controller 25, the controller 20 determines that the battery 5 has reached full charge, and the solar cell 1a. The charging control of the battery 5 by 1b is terminated.

  When the battery 5 has reached full charge, the controller 20 charges the battery 10 with the solar cells 1a and 1b. When the controller 20 charges the battery 10, the switching circuit control unit 21 turns off the switch 2b, turns on the switches 2a and 2c, and switches the solar cells 1a and 1b to a parallel connection state. In addition, the controller 20 turns on the switches 3 c and 3 d and turns off the switches 3 a and 3 b by the switching circuit control unit 21, and inputs the outputs of the solar cells 1 a and 1 b in a series connection state to the battery 10. Since the output from the solar cells 1a and 1b is input to the battery 10 without being subjected to voltage conversion or the like, loss during power conversion is reduced.

The controller 20 manages the SOC of the battery 10 by the battery controller 25 while the battery 10 is being charged. When the SOC becomes higher than SOC ₂ , the controller 20 determines that the battery 10 has reached full charge, and the solar cell. The charging control of the battery 10 by 1a and 1b is terminated.

  Next, the control procedure of the power converter of this example will be described with reference to FIG. FIG. 2 is a flowchart showing a control procedure of the power conversion apparatus of this example. In step S1, the controller 20 acquires information related to charging the battery 5 and the battery 10, such as the connection state of the charging connector to the charging port 6 and the power generation state of the solar cells 1a and 1b. In step S2, the controller 20 detects whether or not the battery 5 is being charged by an external power source based on the connection state of the charging port 6, the control state of the charger 7, and the like. In step S <b> 3, when charging by the external power supply is in progress, the battery controller 25 detects the current of the battery 5 from the current sensor 12.

In step S4, the battery controller 25 calculates the SOC of the battery 5 by integrating the detected current in step S3. In step S5, the battery controller 25 compares the SOC in step S4 with the SOC ₀ and detects whether or not the battery 5 has reached full charge. If the calculated SOC is SOC ₀ or less, the process returns to step S3. If the calculated SOC is higher than SOC ₀ , the process proceeds to step S6.

Returning to step S2, if charging by an external power source is not being performed, in step S21, the controller 20 controls the series-parallel switching circuit 2 by the switching circuit control unit 21 so that the solar cells 1a and 1b are in a series state. The output switching circuit 3 is controlled to switch to a circuit that inputs the output of the solar cells 1a and 1b to the PCS 4, and the PCS 4 is driven by the MPPT control by the PCS control unit 22 to start charging the battery 5. Further, when driving the PCS 4, the PCS control unit 22 sets a timer (not shown) to zero and starts counting for measuring the driving time. In step S22, the PCS control unit 22 compares the counting timer (T) with a threshold time (T ₀ ) corresponding to the driving time. When the timer (T) is smaller than the threshold time (T ₀ ), it is within the driving time, so in step S221, the timer (T) is incremented and the process returns to step S22. On the other hand, if the timer (T) is equal to or greater than the threshold time (T), the process proceeds to step S23. Thereby, the controller 20 charges the battery 5 with the set drive time for every predetermined period.

In step S23, when the drive time (T ₀ ) has elapsed, the PCS control unit 22 transitions to the power conversion stop time, and performs PCS stop control as shown in FIG. FIG. 3 is a flowchart showing a control procedure of PCS stop control. In step S231, the PCS control unit 22 transmits to the PCS 4 a command signal for stopping the circuit. The PCS 4 that has received the command signal stops driving the circuit. In step S232, when the PCS 4 stops driving the circuit, the PCS 4 detects an input voltage immediately before the stop by a sensor (not shown) and transmits it to the controller 20. The PCS control unit 22 detects the input voltage of the PCS 4 from the signal from the PCS 4. In step S233, the PCS control unit 22 stores the detected input voltage in the memory 24, and proceeds to step S24.

In step S24, SOC estimation unit 23 detects the voltage of battery 5 during the power conversion stop time from the detection value of current sensor 12. In step S25, the SOC estimation unit 23 estimates the SOC of the battery 5 by referring to the detected voltage in the map. In step S26, battery controller 25 compares the estimated SOC, and SOC _1. When the estimated SOC is equal to or lower than SOC ₁ , the battery controller 25 determines that the battery has not reached full charge, and the PCS control unit 22 performs PCS drive resumption control as shown in FIG. 4 (step S27).

  FIG. 4 is a flowchart showing a control procedure of PCS drive resumption control. In step S271, the PCS control unit 22 reads the input voltage stored in step S233 from the memory 24. In step S272, the PCS control unit 22 searches for the maximum power point of the solar cells 1a and 1b for performing MPPT control based on the read input voltage, and sets conditions for driving the PCS 4. In step S273, the PCS control unit 22 transmits a signal including the driving condition set in step S272 to the PCS 4, and the PCS 4 re-drives the circuit under the driving condition, and returns to step S21. Thereby, the PCS control unit 22 re-drives the PCS 4 after the elapse of the power conversion stop time, and starts counting the drive time.

Returning to step S26, if the estimated SOC is higher than SOC ₁ , it is determined that the battery 5 has reached full charge. In step S6, the controller 20 controls the series-parallel switching circuit 2 using the switching circuit control unit 21. Is controlled so that the solar cells 1a and 1b are in a parallel state, the output switching circuit 3 is controlled to switch the output of the solar cells 1a and 1b to the battery 10 and charging of the battery 10 is started. In step S7, the battery controller 25 detects the current of the battery 10 from the current sensor 12 (not shown). In step S8, the battery controller 25 calculates the SOC of the battery 10 by integrating the detected current in step S7. In step S9, the battery controller 25 compares the SOC in step S7 with the SOC _2, and detects whether or not the battery 10 has reached full charge. If the calculated SOC is less than or equal to SOC ₂ , the process returns to step S7. If the calculated SOC is higher than SOC ₂ , the control of this example is terminated, assuming that the battery 10 has reached full charge.

  As described above, in this example, the circuit drive of the PCS 4 is stopped during the power conversion stop time, and the re-drive of the PCS 4 is determined based on the detected voltage detected by the voltage sensor 12 during the power conversion stop time. . Thereby, this example can detect the voltage of the battery 5 being charged by the solar cells 1a and 1b when there is no load. Since it is determined that the PCS 4 is redriven based on the voltage, it is possible to prevent the battery 5 from exceeding the upper limit value and to prevent the battery 5 from being overcharged.

  Unlike this example, when charging of the battery 5 is controlled by calculating the SOC of the battery 5 from the integrated value of the detected current of the battery 5 during charging by the solar cells 1a, 1b, the solar cells 1a, 1b Since the current value output from is weak, the SOC of the battery 5 cannot be accurately detected, and the battery 5 may be overcharged. Further, in order to detect a weak change in the output current from the solar cells 1a and 1b, it may be possible to increase the resolution of the sensor, but there is a problem when the cost of the current sensor 12 increases.

  In this example, after stopping the PCS 4 being driven, the voltage of the battery 5 is detected, and based on the detected voltage, it is determined whether to re-drive the PCS 4 and whether to continue charging the battery 5. Therefore, the detection accuracy of the state of the battery 5 can be increased, and overcharging of the battery 5 can be prevented.

  Further, in this example, the SOC of the battery 5 is estimated based on the detected voltage detected by the voltage sensor 12 during the power conversion stop time, and the re-driving of the PCS 4 is prohibited when the estimated SOC is higher than the SOC1. To do. Thereby, the detection accuracy of SCO of a battery can be raised and the overcharge of the battery 5 can be prevented.

  Further, in this example, the SOC of the battery 5 is estimated based on the detected voltage detected by the voltage sensor 12 during the power conversion stop time, and the PCS 4 is re-driven when the estimated SOC is lower than the SOC1. Thereby, when the charge amount of the battery 5 is insufficient, the charging by the solar cells 1 a and 1 b can be continued by re-driving the PCS 4.

Further, in this example, when the estimated SOC is higher than SOC ₁ , the power of the solar cells 1a and 1b is switched to a circuit that supplies the battery 10 and the battery 10 is charged by the solar cells 1a and 1b. Thereby, the battery 10 can be directly charged by the generated power of the solar cells 1a and 1b, and a decrease in the amount of charge of the battery 10 that can occur during long-time parking and suspension can be prevented. Further, since the control is started by supplying power from the battery 10 during driving of the vehicle, it is possible to avoid the inability to start the battery 10 due to a decrease in the charge amount.

In this example, the PCS 4 is driven after the power conversion stop time based on the input voltage stored in the memory 24 immediately before the power conversion stop time. Thereby, based on the power point of the solar cells 1a and 1b before the PCS 4 is stopped, power generation can be resumed. Also,
When performing MPPT control, the time for searching for the maximum power point from the initial operating state can be saved, so that power generation at the maximum power point can be performed quickly, and the power generation efficiency can be increased.

  In this example, as shown in FIG. 5, the series-parallel switching circuit 2 may be omitted. FIG. 5 is a block diagram of a vehicle including a power conversion device according to a modification of this example.

  The PCS 4 corresponds to the “power converter” of the present invention, the PCS control unit 22 is the “power converter control means”, the SOC estimation unit 23 is the “SOC estimation means”, the series-parallel switching circuit 2 and the output switching The circuit 3 is a “switching circuit”, the switching circuit control unit 21 is a “switching circuit control unit”, the memory 24 is a “storage unit”, the battery 5 is a “high voltage battery”, and the battery 10 is a “low voltage battery”. It corresponds to.

<< Second Embodiment >>
FIG. 6 is a flowchart showing a control procedure of the power conversion apparatus according to another embodiment of the invention. This example differs from the first embodiment in that the battery 10 is charged by the solar cells 1a and 1b while the power conversion is stopped. Since the other configuration is the same as that of the first embodiment described above, the description thereof is incorporated.

  The controller 20 stops the PCS 4 when the PCS control unit 22 transits from the drive time to the power conversion stop time, and the switching circuit control unit 21 controls the series / parallel switching circuit 2 to control the solar cells 1a and 1b. In parallel, the output switching circuit 3 is controlled to switch to a circuit that inputs the outputs of the solar cells 1a and 1b to the battery 10, and charging of the battery 10 is started. Thereby, the battery 10 can be charged with the generated power of the solar cells 1a and 1b during the power conversion stop time.

  Next, the control procedure of the power conversion device of this example will be described with reference to FIG. FIG. 6 is a flowchart showing a control procedure of the power conversion apparatus of this example. Of the steps shown in FIG. 6, the description of steps having the same control content as the step shown in FIG. 1 is omitted.

  After performing the PCS stop control in step S23, in step S231, the switching circuit control unit 21 controls the series / parallel switching circuit 2 and the output switching circuit 3 so that the solar cells 1a and 1b are connected in parallel. Then, the electric power of the solar cells 1a and 1b is supplied to the battery 10. Further, the battery controller 25 manages the state of charge of the battery 10 during the charging in step S231, as in the first embodiment.

  As described above, this example switches to a circuit that supplies the output from the solar cells 1 a and 1 b to the battery 10 during the power conversion stop time. Thereby, it is possible to directly charge the battery 10 with the power generated by the solar cells 1a and 1b even during the power conversion stop time, and to prevent a decrease in the amount of charge of the battery 10 that can occur during long-time parking and suspension. Can do. In addition, since the control is started by supplying power from the battery 10 during driving of the vehicle, it is possible to avoid the inability to start the battery 10 due to a decrease in the charge amount.

DESCRIPTION OF SYMBOLS 1a, 1b ... Solar cell 2 ... Series-parallel switching circuit 2a, 2b, 2c ... Switch 3 ... Output switching circuit 3a, 3b, 3c, 3d ... Switch 4 ... PCS
DESCRIPTION OF SYMBOLS 5 ... Battery 6 ... Charge port 7 ... Charger 8 ... Inverter 9 ... Motor 10 ... Battery 11 ... DC / DC converter 12 ... Current sensor 13 ... Voltage sensor 20 ... Controller 21 ... PCS control part 22 ... SOC estimation part 23 ... Switching Circuit control unit 24 ... Memory 25 ... Battery controller

Claims (6)

Battery,
Solar cells,
A power converter that converts power from the solar cell into charge power for charging the battery;
A voltage sensor for detecting the voltage of the battery;
Power converter control means for controlling a power conversion stop time for stopping power conversion by the power converter;
The power converter control means includes
A power conversion device that determines whether or not to redrive the power converter based on a detection voltage detected by the voltage sensor during the power conversion stop time. SOC estimation means for estimating the SOC of the battery based on the detected voltage detected by the voltage sensor during the power conversion stop time,
The power converter control means includes
When the SOC estimated by the SOC estimation means is higher than an upper limit SOC indicating an upper limit value of the SOC of the battery, re-driving of the power converter is prohibited. The power converter control means includes
The power converter according to claim 2, wherein when the SOC estimated by the SOC estimating means is lower than an upper limit SOC indicating an upper limit value of the SOC of the battery, the power converter is re-driven. A switching circuit that switches between a circuit that supplies the output of the solar cell to a high-voltage battery included in the battery, and a circuit that supplies the output of the solar cell to a low-voltage battery included in the battery;
Switching circuit control means for controlling the switching circuit,
The switching circuit control means includes
When the SOC estimated by the SOC estimation means is higher than the upper limit SOC indicating the upper limit value of the SOC of the battery, the output from the solar cell is switched to a circuit that supplies the low voltage battery. The power converter of Claim 2 or 3. A switching circuit that switches between a circuit that supplies the output of the solar cell to a high-voltage battery included in the battery, and a circuit that supplies the output of the solar cell to a low-voltage battery included in the battery;
Switching circuit control means for controlling the switching circuit,
The switching circuit control means includes
The power conversion device according to any one of claims 1 to 3, wherein the output from the solar cell is switched to a circuit that supplies the low-voltage battery during the power conversion stop time. The power converter control means includes
A storage unit for storing an input voltage from the solar cell to the power converter;
The said power converter is driven after the said power conversion stop time based on the input voltage memorize | stored in the said memory | storage part immediately before the said power conversion stop time, The any one of Claims 1-5 characterized by the above-mentioned. The power converter device described in 1.

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