Power control device for on-vehicle solar panel

Abstract

A power control device (14) for an on-vehicle solar panel comprises a switch unit (20) and a control unit (24). The control unit (24) switches the switch unit (20) between a supply state and a cut-off state. The control unit (24) monitors the generated power of a solar panel (13) in a state in which a battery management system (12) is stopped, maintains the switch unit (20) in the cut-off state when the generated power of the solar panel (13) falls below a threshold value set to be greater than or equal to the power required for starting the battery management system (12), and switches the switch unit (20) to the supply state when the generated power of the solar panel (13) is greater than or equal to the threshold value.

Description

Power control device for vehicle-mounted solar panels

[0001] The present invention relates to a power control device for an on-vehicle solar panel.

[0002] Patent Document 1 discloses a solar power generation system mounted on a vehicle, in which the electric power generated by the solar power generation system is charged into a battery mounted on the vehicle.

[0003] Japanese Patent Application Laid-Open No. 2021-62841

[0004] The power generated by a solar power generation system is easily affected by sunlight conditions. When trying to operate electrical equipment when the power generated by the solar power generation system is low, the power generated by the solar power generation system alone may not be enough, and it may be necessary to draw power from the battery.

[0005] The present invention aims to provide a technology that can reduce battery power consumption in a vehicle equipped with a solar panel.

[0006] The power control device for an on-board solar panel of the present disclosure is a power control device for an on-board solar panel used in a vehicle equipped with a battery, a battery management system that receives power supplied from the battery and manages the state of the battery, and a solar panel that supplies power to the battery via a power path, and comprises: a switch unit that is provided between the solar panel and the battery and switches between a supply state in which power is supplied from the solar panel to the battery and a cut-off state in which power is cut off; and a control unit that switches the switch unit between the supply state and the cut-off state, wherein the battery management system operates when the switch unit is in the supply state and stops when the switch unit is in the cut-off state, and the control unit monitors the power generated by the solar panel when the battery management system is stopped, and maintains the switch unit in the cut-off state when the power generated by the solar panel falls below a threshold set to be equal to or higher than the power required to start the battery management system, and switches the switch unit to the supply state when the power generated by the solar panel is equal to or higher than the threshold.

[0007] According to the technology of the present disclosure, it is possible to reduce battery power consumption in a vehicle equipped with a solar panel.

[0008] Fig. 1 is a configuration diagram of an on-board system including a power control device for an on-board solar panel according to a first embodiment. Fig. 2 is a configuration diagram of an on-board system including a power control device for an on-board solar panel according to a second embodiment. Fig. 3 is a configuration diagram of an on-board system including a power control device for an on-board solar panel according to a third embodiment. Fig. 4 is a configuration diagram of an on-board system including a power control device for an on-board solar panel according to a fourth embodiment.

[0009] [Description of Embodiments of the Present Disclosure] In the following, embodiments of the present disclosure are listed and illustrated.

[0010] [1] A power control device for an on-board solar panel used in a vehicle equipped with a battery, a battery management system that receives power supplied from the battery and manages the state of the battery, and a solar panel that supplies power to the battery via a power path, comprising: a switch unit that is provided between the solar panel and the battery and that switches between a supply state in which power is supplied from the solar panel to the battery and a cut-off state in which power is cut off; and a control unit that switches the switch unit between the supply state and the cut-off state, wherein the battery management system operates when the switch unit is in the supply state and stops when the switch unit is in the cut-off state, and the control unit monitors the power generated by the solar panel when the battery management system is stopped, and maintains the switch unit in the cut-off state when the power generated by the solar panel falls below a threshold that is set to be equal to or higher than the power required to start the battery management system, and switches the switch unit to the supply state when the power generated by the solar panel is equal to or higher than the threshold.

[0011] When the power generated by the solar panel is below a threshold, the power generated by the solar panel alone is insufficient to activate the battery management system, so battery power is consumed. In this regard, the power control device maintains the switch unit in an off state when the power generated by the solar panel is below the threshold, so the battery management system is maintained in a stopped state and battery power consumption can be reduced.

[0012] [2] A power control device for an on-vehicle solar panel as described in [1], comprising a power conversion unit that performs a step-up operation or a step-down operation on input power based on power supplied from the solar panel and supplies output power, the switch unit being provided between the power conversion unit and the battery, and when causing the power conversion unit to perform a step-up operation or a step-down operation, the control unit switches the switch unit to the supply state to enable power supply from the power conversion unit to the battery and then causes the power conversion unit to perform the step-up operation or the step-down operation.

[0013] The power control device causes the power conversion unit to perform a conversion operation after switching the switch unit to a supply state to enable power supply from the power conversion unit to the battery. Therefore, the power control device does not require a storage means such as a capacitor for storing the output power of the power conversion unit between the power conversion unit and the switch unit.

[0014] [3] The control unit controls the switch unit to the supply state when the power generated by the solar panel is greater than the power required to control the switch unit to the supply state while the battery management system is operating. A power control device for an on-board solar panel described in [1] or [2].

[0015] The power control device described above can prevent a situation in which the amount of power in the battery decreases due to the power supply from the solar panel.

[0016] [4] A power control device for an on-vehicle solar panel described in any one of [1] to [3], comprising a power conversion unit that performs a conversion operation of stepping down or stepping up the input voltage input from the solar panel side and outputting it to the battery side, the power path being provided between the power conversion unit and the battery, and having a storage unit electrically connected to the power path.

[0017] In the power control device, the power supplied from the power conversion unit to the battery is likely to be stabilized by the power storage unit storing and discharging electricity.

[0018] [5] The control unit controls the switch unit to the supply state when the power generated by the solar panel is greater than the power required to control the switch unit to the supply state when the battery management system is operating. This is a power control device for an on-board solar panel described in [4].

[0019] The power control device can avoid a situation in which the amount of power stored in the battery is reduced due to the power supply from the solar panel.

[0020] [6] A power control device for an on-vehicle solar panel described in any one of [1] to [5], comprising: a power conversion unit that performs a conversion operation of stepping down or stepping up the input voltage input from the solar panel side and outputting it to the battery side; a first conduction path different from the power path; a second conduction path provided between the first conduction path and the power conversion unit; a third conduction path provided between the first conduction path and the battery; and a diode, wherein the anode of the diode is electrically connected to the second conduction path, and the cathode of the diode is electrically connected to the first conduction path.

[0021] The power control device allows power to be supplied to the first conductive part from both the power conversion part and the battery, and can prevent backflow from the battery to the power conversion part by the diode.

[0022] [7] The power control device for an in-vehicle solar panel according to [6], wherein the control unit controls the power conversion unit so that the voltage of the anode is within a voltage range in which a current flows from the anode to the cathode.

[0023] The power control device can set a state in which power from the power converter is supplied to the first conduction path with priority over power from the battery, thereby more reliably suppressing power consumption from the battery.

[0024] [8] The battery includes a first battery and a second battery different from the first battery, and power from the solar panel is supplied to both the first battery and the second battery. A power control device for an on-vehicle solar panel described in any one of [1] to [7].

[0025] The power control device can supply power from the solar panel to both the first battery and the second battery.

[0026] [9] The power control device for an in-vehicle solar panel according to any one of [1] to [8], wherein the switch unit is made of a semiconductor.

[0027] The power control device described above can reduce power consumption compared to a case where the switch unit is configured using a mechanical circuit breaker.

[0028] [Details of the embodiments of the present disclosure] <First embodiment> 1-1. Overview of the in-vehicle system Fig. 1 shows an in-vehicle system 1 that is mounted on a vehicle. The in-vehicle system 1 includes a battery 11, a battery management system 12, a solar panel 13, and a power control device 14 for the in-vehicle solar panel (hereinafter also referred to as the power control device 14).

[0029] The battery 11 is, for example, a lead battery, a lithium ion battery, a sodium ion battery, or the like.

[0030] The battery management system 12 is a device that manages the state of the battery 11. The battery management system 12 has functions such as preventing overcharging and overdischarging of the cells that make up the battery 11, preventing overcurrent in the cells, managing the temperature of the cells, calculating the remaining battery capacity, and equalizing the cell voltages (cell balancing). The battery management system 12 is operable by receiving power supplied from the battery 11.

[0031] The solar panel 13 is configured by connecting a plurality of solar battery cells that convert light energy into electric power, and outputs electric power generated by these solar battery cells in response to irradiated light to the power control device 14. Although only one solar panel 13 is shown in Fig. 1, a plurality of such solar panels 13 are provided on the vehicle. Each of these plurality of solar panels 13 is electrically connected to the power control device 14.

[0032] The power control device 14 receives power from the solar panel 13 and can supply output power based on this power to the battery 11 .

[0033] 1-2. Basic Configuration of Power Control Device The power control device 14 includes a switch unit 20, a first diode 21, a second diode 22, a BMS activation means 23, a control unit 24, a first power path 31, a second power path 32, a first conductive path 34, a second conductive path 35, and a third conductive path 36.

[0034] The switch unit 20 is provided between the solar panel 13 and the battery 11. The switch unit 20 switches between a supply state in which power is supplied from the solar panel 13 to the battery 11 and a cut-off state in which power is cut off. The switch unit 20 is in a permissive state when in an on state and in a cut-off state when in an off state. The switch unit 20 is made of a semiconductor.

[0035] The first power path 31 is provided between the solar panel 13 and the switch unit 20. The first power path 31 corresponds to an example of a power path. The second power path 32 is provided between the switch unit 20 and the battery 11. Power is supplied from the solar panel 13 to the battery 11 via the first power path 31 and the second power path 32.

[0036] The first conductive path 34, the second conductive path 35, and the third conductive path 36 are paths different from the first power path 31 and the second power path 32. The first conductive path 34 is provided in parallel with the switch unit 20 between the solar panel 13 and the battery 11. The second conductive path 35 is provided between the first conductive path 34 and the first power path 31. The third conductive path 36 is provided between the first conductive path 34 and the second power path 32.

[0037] The anode of the first diode 21 is electrically connected to the second conductive path 35. The cathode of the first diode 21 is electrically connected to the first conductive path 34. The first diode 21 corresponds to an example of a diode.

[0038] The anode of the second diode 22 is electrically connected to the third conductive path 36. The cathode of the second diode 22 is electrically connected to the first conductive path 34.

[0039] The first conductive path 34 is connected to the BMS activation means 23, a power supply circuit (not shown), etc., and functions as a path for supplying power to the BMS activation means 23, the power supply circuit, etc. The power supply circuit generates and supplies the power necessary to drive the switch unit 20 and the control unit 24. Power from the solar panel 13 is supplied to the first conductive path 34 via the second conductive path 35. The flow of current from the first conductive path 34 to the second conductive path 35 is prevented by the first diode 21. Power from the battery 11 is supplied to the first conductive path 34 via the third conductive path 36. The flow of current from the first conductive path 34 to the third conductive path 36 is prevented by the second diode 22.

[0040] The BMS activation means 23 is configured by, for example, a communication circuit, a signal output circuit, etc. The BMS activation means 23 is electrically connected to the first conductive path 34. The BMS activation means 23 activates the battery management system 12 based on the power supplied from the first conductive path 34. The BMS activation means 23 activates the battery management system 12 when the switch unit 20 is in a supply state, and stops the battery management system 12 when the switch unit 20 is in a cut-off state. As a result, the battery management system 12 operates when the switch unit 20 is in a supply state, and stops when the switch unit 20 is in a cut-off state. The BMS activation means 23 may be configured to be controlled by the control unit 24, or may be configured not to be controlled by the control unit 24.

[0041] Whether or not the switch unit 20 is in the supply state may be determined based on the control state of the switch unit 20 by the control unit 24, or may be determined based on the voltage of the second power path 32 or the current flowing through the second power path 32. The determination of whether or not the switch unit 20 is in the supply state may be made by the BMS activation means 23, or may be made by a device other than the BMS activation means 23 (for example, the control unit 24).

[0042] The control unit 24 includes, for example, an arithmetic processing unit such as a CPU, and memories such as a ROM and a RAM.

[0043] The control unit 24 controls the switch unit 20. The control unit 24 switches the switch unit 20 between an open state and a cut-off state.

[0044] 1-3. Functions and Effects of the Power Control Device The control unit 24 monitors the power generated by the solar panel 13 when the battery management system 12 is stopped. The control unit 24 maintains the switch unit 20 in the cut-off state when the power generated by the solar panel 13 falls below a threshold set to be equal to or greater than the power required to start the battery management system 12. The control unit 24 switches the switch unit 20 to the supply state when the power generated by the solar panel 13 is equal to or greater than the threshold.

[0045] When the power generated by the solar panels 13 is below a threshold, the power generated by the solar panels 13 alone is insufficient to activate the battery management system 12, and therefore power is consumed from the battery 11. In this regard, the power control device 14 maintains the shut-off state when the power generated by the solar panels 13 is below the threshold, so the battery management system 12 is maintained in a stopped state and power consumption from the battery 11 can be reduced.

[0046] When the battery management system 12 is operating, the control unit 24 controls the switch unit 20 to the supply state if the power generated by the solar panel 13 is greater than the power required to control the switch unit 20 to the supply state. Therefore, the power control device 14 can avoid a situation in which the power of the battery 11 is reduced due to the power supply from the solar panel 13. <Second Embodiment> In the second embodiment, the same components as in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0047] 2-1. Overview of the In-Vehicle System Fig. 2 shows an in-vehicle system 201 mounted on a vehicle. The in-vehicle system 201 includes a battery 211, a battery management system 12, a solar panel 13, and a power control device 214 for the in-vehicle solar panel (hereinafter also referred to as the power control device 214).

[0048] The battery 211 includes a first battery 211A and a second battery 211B. The first battery 211A is a high-voltage battery with a higher output voltage than the second battery 211B. The first battery 211A is configured as, for example, a lithium-ion battery or a sodium-ion battery. The output voltage of the first battery 211A is, for example, 400V or 800V.

[0049] The second battery 211B is a low-voltage battery having a lower output voltage than the first battery 211A. The second battery 211B is configured as, for example, a lead battery or a lithium-ion battery. The output voltage of the second battery 211B is, for example, 12 V or 24 V.

[0050] The battery management system 12 manages the state of at least one of the first battery 211A and the second battery 211B. The battery management system 12 is operable by receiving power supplied from the first battery 211A and by receiving power supplied from the second battery 211B.

[0051] The power control device 214 receives power from the solar panel 13 and can supply output power based on this power to the first battery 211A and the second battery 211B. The power control device 214 has a function of controlling the power input from the solar panel 13 and can perform voltage step-down and voltage step-up operations internally.

[0052] 2-2. Basic Configuration of Power Control Device As with the power control device 14 of the first embodiment, the power control device 214 includes a switch unit 20, a first diode 21, a second diode 22, a BMS activation means 23, a control unit 24, a first power path 31, a second power path 32, a first conductive path 34, a second conductive path 35, and a third conductive path 36. Furthermore, the power control device 214 includes a power conversion unit 25, a charging unit 26, a step-down unit 27, a power storage unit 28, a third power path 37, and a fourth power path 38.

[0053] The switch unit 20 is provided between the solar panel 13 and the battery 211. The switch unit 20 switches between a supply state in which power is supplied from the solar panel 13 to the battery 211 and a cut-off state in which power is cut off.

[0054] The first power path 31 is provided between the solar panel 13 and the switch unit 20. The first power path 31 corresponds to an example of a power path. The second power path 32 is provided between the switch unit 20 and the battery 11. The third power path 37 is provided between the second power path 32 and the first battery 211A. The fourth power path 38 is provided between the second power path 32 and the second battery 211B. Power is supplied from the solar panel 13 to the first battery 211A via the first power path 31, the second power path 32, and the third power path 37. Power is supplied from the solar panel 13 to the second battery 211B via the first power path 31, the second power path 32, and the fourth power path 38.

[0055] The power conversion unit 25 is provided individually corresponding to each solar panel 13. The power conversion unit 25 is provided between the solar panel 13 and the first power path 31. The power conversion unit 25 is configured to include an MPPT circuit. The MPPT circuit is configured, for example, by a DC-DC converter. The DC-DC converter is configured, for example, by including a semiconductor switching element. The power conversion unit 25 performs a conversion operation of stepping down or stepping up the input voltage input from the solar panel 13 side and outputting it to the battery 211 side. The power conversion unit 25 supplies output power to the first power path 31.

[0056] The charging unit 26 is provided between the first power path 31 and the switch unit 20. The charging unit 26 performs a charging operation of boosting the voltage input from the power conversion unit 25 and outputting the boosted voltage to the battery 211. The charging unit 26 is configured, for example, by a DC-DC converter. The DC-DC converter is configured, for example, to include a semiconductor switching element. The charging unit 26 boosts the power supplied from the first power path 31 and supplies the boosted power to the battery 211.

[0057] The step-down unit 27 is provided between the second power path 32 and the third power path 37 and the fourth power path 38 and the third conductive path 36. The step-down unit 27 performs a step-down operation of stepping down the voltage input from the second power path 32 and the third power path 37 side and outputting the voltage to the fourth power path 38 and the third conductive path 36 side. The step-down unit 27 is configured, for example, by a DC-DC converter. The DC-DC converter is configured, for example, to include a semiconductor switching element. The step-down unit 27 steps down the power supplied from the second power path 32 and the third power path 37 side and supplies the power to the second battery 211B via the fourth power path 38.

[0058] The solar panel 13 described above supplies the generated power to the first battery 211A via the first power path 31, the second power path 32, and the third power path 37. The solar panel 13 also supplies the generated power to the second battery 211B via the first power path 31, the second power path 32, and the fourth power path 38.

[0059] When the power conversion unit 25 performs a conversion operation, the charging unit 26 performs a charging operation, and the switch unit 20 is in an allowable state, power is supplied from the solar panel 13 to the first battery 211A. When the power conversion unit 25 performs a conversion operation, the charging unit 26 performs a charging operation, the step-down unit 27 performs a step-down operation, and the switch unit 20 is in an allowable state, power is supplied from the solar panel 13 to the second battery 211B.

[0060] The power storage unit 28 is configured by, for example, a capacitor. One end of the power storage unit 28 is electrically connected to the first power path 31. The other end of the power storage unit 28 is electrically connected to the ground. The power storage unit 28 functions as a smoothing capacitor that smoothes the output voltage of the power conversion unit 25.

[0061] The first conductive path 34, the second conductive path 35, and the third conductive path 36 are paths different from the first power path 31, the second power path 32, the third power path 37, and the fourth power path 38. The first conductive path 34 is provided in parallel with the switch unit 20 between the solar panel 13 and the battery 211. The second conductive path 35 is provided between the first conductive path 34 and the first power path 31. The third conductive path 36 is provided between the first conductive path 34 and the second power path 32 and the step-down unit 27. The third conductive path 36 is provided between the first conductive path 34 and the fourth power path 38.

[0062] The control unit 24 controls the power conversion unit 25. The control unit 24 performs maximum power point tracking control on the power conversion unit 25. The maximum power point tracking control is a control that varies the operating point of the solar panel 13 so that the input power from the solar panel 13 becomes the maximum power point.

[0063] The control unit 24 controls the charging unit 26. The control unit 24 performs charging control to cause the charging unit 26 to perform a charging operation.

[0064] The control unit 24 controls the step-down unit 27. The control unit 24 performs step-down control to make the step-down unit 27 perform a step-down operation.

[0065] The control unit 24 performs maximum power point tracking control on the power conversion unit 25, performs charging control on the charging unit 26, and controls the switch unit 20 to the supply state, whereby power is supplied from the solar panel 13 to the first battery 211A.

[0066] The control unit 24 performs maximum power point tracking control on the power conversion unit 25, performs charging control on the charging unit 26, performs step-down control on the step-down unit 27, and controls the switch unit 20 to a supply state, thereby supplying power from the solar panel 13 to the second battery 211B.

[0067] 2-3. Functions and Effects of the Power Control Device The control unit 24 monitors the power generated by the solar panel 13 when the battery management system 12 is stopped. The control unit 24 maintains the switch unit 20 in the cut-off state when the power generated by the solar panel 13 falls below a threshold set to be equal to or greater than the power required to start the battery management system 12. The control unit 24 switches the switch unit 20 to the supply state when the power generated by the solar panel 13 is equal to or greater than the threshold. Specifically, when the power generated by the solar panel 13 is equal to or greater than the threshold, the control unit 24 switches the switch unit 20 to the supply state, performs maximum power point tracking control on the power conversion unit 25, performs charging control on the charging unit 26, and performs step-down control on the step-down unit 27.

[0068] When the power generated by the solar panel 13 is below the threshold, the power generated by the solar panel 13 alone is insufficient to activate the battery management system 12, and therefore power is consumed from the battery 211. In this regard, the power control device 214 keeps the switch unit 20 in an off state when the power generated by the solar panel 13 is below the threshold, so the battery management system 12 is maintained in a stopped state and power consumption from the battery 211 can be suppressed.

[0069] Furthermore, when causing the power conversion unit 25 to perform a step-up operation or a step-down operation, the control unit 24 switches the switch unit 20 to a supply state, thereby enabling the power conversion unit 25 to supply power to the battery 211, and then causes the power conversion unit 25 to perform the step-up operation or the step-down operation. In other words, the power control device 214 switches the switch unit 20 to a supply state, thereby enabling the power conversion unit 25 to supply power to the battery 211, and then causes the power conversion unit 25 to perform the conversion operation. Therefore, the power control device 214 does not require a storage means such as a capacitor for storing the output power of the power conversion unit 25 between the power conversion unit 25 and the switch unit 20.

[0070] The power storage unit 28 is electrically connected to the first power path 31. Therefore, the power supplied from the power conversion unit 25 to the battery 211 is likely to be stabilized by the power storage unit 28 storing and discharging electricity.

[0071] When the battery management system 12 is operating, if the power generated by the solar panel 13 is greater than the power required to control the switch unit 20 to a supply state, perform maximum power point tracking control on the power conversion unit 25, perform charging control on the charging unit 26, and perform step-down control on the step-down unit 27, the control unit 24 controls the switch unit 20 to a supply state, performs maximum power point tracking control on the power conversion unit 25, perform charging control on the charging unit 26, and perform step-down control on the step-down unit 27. Therefore, the power control device 214 can avoid a situation in which the power supply from the solar panel 13 conversely reduces the power of the battery 211.

[0072] The control unit 24 controls the power conversion unit 25 so that the voltage of the anode of the first diode 21 falls within a voltage range in which current flows from the anode to the cathode of the first diode 21. Specifically, the control unit 24 controls the power conversion unit 25 so that the output voltage of the power conversion unit 25 is greater than a voltage VA calculated by the following equation (1): VA=VB-VT2+VT1 (Equation (1)) where VB is the voltage of the third conduction path 36, VT1 is the voltage drop of the first diode 21, and VT2 is the voltage drop of the second diode 22. As a result, power from the power conversion unit 25 is supplied to the first conduction path 34 with priority over power from the battery 211. This allows the power control device 214 to more reliably suppress power consumption from the battery 211.

[0073] Third Embodiment In the third embodiment, an example will be described in which the second battery 211B described in the second embodiment is not installed. Note that in the third embodiment, the same components as those in the second embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0074] 3, the in-vehicle system 301 of the third embodiment includes a battery 311, a battery management system 12, a solar panel 13, and a power control device 314 for the in-vehicle solar panel (hereinafter also referred to as the power control device 314). The battery 311 has the same configuration as the first battery 211A described in the second embodiment.

[0075] The power control device 314 differs from the power control device 214 of the second embodiment in that the second battery 211B described in the second embodiment is not connected, but is otherwise common. The operation of the power control device 314 is the same as the operation of the power control device 214 of the second embodiment.

[0076] Fourth Embodiment In the fourth embodiment, an example will be described in which the first battery 211A described in the second embodiment is not installed. Note that in the fourth embodiment, the same components as those in the second embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0077] 4, the in-vehicle system 401 of the fourth embodiment includes a battery 411, a battery management system 12, a solar panel 13, and a power control device 414 for the in-vehicle solar panel (hereinafter also referred to as the power control device 414). The battery 411 has the same configuration as the second battery 211B described in the second embodiment.

[0078] The power control device 414 differs from the power control device 214 of the second embodiment in that the first battery 211A described in the second embodiment is not connected, but is otherwise common. The operation of the power control device 414 is the same as the operation of the power control device 214 of the second embodiment.

[0079] <Other Embodiments> The present invention is not limited to the embodiments described above and illustrated in the drawings, and the following embodiments are also included within the technical scope of the present invention. Furthermore, various features of the above-mentioned embodiments and the embodiments to be described later may be combined in any manner as long as they are not contradictory.

[0080] In the above-described fourth embodiment, at least one of the charging unit 26 and the step-down unit 27 does not necessarily have to be provided.

[0081] It should be noted that the embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is not limited to the embodiments disclosed herein, and is intended to include all modifications within the scope indicated by the claims or within the scope equivalent to the claims.

[0082] DESCRIPTION OF SYMBOLS 1...In-vehicle system 11...Battery 12...Battery management system 13...Solar panel 14...Power control device 20...Switch unit 21...First diode (diode) 22...Second diode 23...BMS activation means 24...Control unit 25...Power conversion unit 26...Charging unit 27...Step-down unit 28...Storage unit 31...First power path (power path) 32...Second power path 34...First conduction path 35...Second conduction path 36...Third conduction path 37...Third power path 38...Fourth power path 201...In-vehicle system 211...Battery 211A...First battery 211B...Second battery 214...Power control device 301...In-vehicle system 311...Battery 314...Power control device 401...In-vehicle system 411...Battery 414...Power control device

Claims

1. A power control device for an on-board solar panel used in a vehicle equipped with a battery, a battery management system that receives power supplied from the battery and manages the state of the battery, and a solar panel that supplies power to the battery via a power path, comprising: a switch unit that is provided between the solar panel and the battery and switches between a supply state in which power is supplied from the solar panel to the battery and a cut-off state in which power is cut off; and a control unit that switches the switch unit between the supply state and the cut-off state, wherein the battery management system operates when the switch unit is in the supply state and stops when the switch unit is in the cut-off state, and the control unit monitors the power generated by the solar panel when the battery management system is stopped, and maintains the switch unit in the cut-off state when the power generated by the solar panel falls below a threshold that is set to be equal to or higher than the power required to start up the battery management system, and switches the switch unit to the supply state when the power generated by the solar panel is equal to or higher than the threshold.

2. A power control device for an on-vehicle solar panel as described in claim 1, comprising a power conversion unit that performs a step-up operation or a step-down operation on input power based on the power supplied from the solar panel and supplies output power, the switch unit being provided between the power conversion unit and the battery, and when causing the power conversion unit to perform the step-up operation or the step-down operation, the control unit switches the switch unit to the supply state to enable power supply from the power conversion unit to the battery and then causes the power conversion unit to perform the step-up operation or the step-down operation.

3. A power control device for an on-vehicle solar panel as described in claim 1, wherein the control unit controls the switch unit to the supply state when the power generated by the solar panel is greater than the power required to control the switch unit to the supply state while the battery management system is operating.

4. A power control device for an on-vehicle solar panel as described in claim 1, comprising a power conversion unit that performs a conversion operation of stepping down or stepping up an input voltage input from the solar panel side and outputting the input voltage to the battery side, the power path being provided between the power conversion unit and the battery, and having a storage unit electrically connected to the power path.

5. A power control device for an on-vehicle solar panel as described in claim 4, wherein the control unit controls the switch unit to the supply state when the power generated by the solar panel is greater than the power required to control the switch unit to the supply state while the battery management system is operating.

6. A power control device for an on-vehicle solar panel as described in claim 1 or claim 4, comprising: a power conversion unit that performs a conversion operation of stepping down or stepping up an input voltage input from the solar panel side and outputting the input voltage to the battery side; a first conductive path different from the power path; a second conductive path provided between the first conductive path and the power conversion unit; a third conductive path provided between the first conductive path and the battery; and a diode, the anode of the diode being electrically connected to the second conductive path, and the cathode of the diode being electrically connected to the first conductive path.

7. The power control device for an on-vehicle solar panel according to claim 6, wherein the control unit controls the power conversion unit so that the voltage of the anode is within a voltage range in which a current flows from the anode to the cathode.

8. A power control device for an on-vehicle solar panel described in any one of claims 1 to 5, wherein the battery includes a first battery and a second battery different from the first battery, and power from the solar panel is supplied to both the first battery and the second battery.

9. A power control device for an in-vehicle solar panel according to any one of claims 1 to 5, wherein the switch section is made of a semiconductor.

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