JP2014042404A - Charging device, solar system, electrical system, and vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide such a configuration that allows a large current to be passed from a solar cell through loads in a short period of time.SOLUTION: An on-vehicle solar system 100 is provided for charging loads 111 and 112 with power from a solar cell module 101. The on-vehicle solar system 100 has: a capacitor 102 that accumulates the power from the solar cell module 101 and outputs the accumulated power to the loads 111 and 112; and a maximum power point tracking module for a solar cell.

Description

  The present invention relates to a charging device, a solar system, an electric system, and a vehicle for supplying electric energy from a solar cell to a load.

  Normally, automobile auxiliary equipment and electrical components are driven by electric power stored in a lead-acid battery. For this reason, the capacity | capacitance of a lead storage battery is set so that the sum total of the electric power which an auxiliary device and an electrical component consume may not exceed the power supply capability of a lead storage battery for a long time. Further, during operation of the engine, the lead storage battery is charged with electric power generated by a generator (alternator) connected to the engine. For this reason, the power generation amount of the generator is set so as not to fall below the power amount consumed by the auxiliary equipment and the electrical equipment for a long time. Thereby, the extreme fall (battery rise) of the electric energy (electric amount) which a lead storage battery can output is prevented.

  In recent years, an idling stop function for stopping an engine when the vehicle is stopped is often employed in an automobile in order to improve fuel efficiency. In this case, electric power for driving a starter for restarting the engine is usually supplied from a lead storage battery (for example, Patent Document 1).

JP 2002-31671 A (released January 31, 2002) JP-A-6-98477 (published April 8, 1994)

  However, there are many auxiliary devices and electrical components in which a large amount of current flows in a short time. For example, in many auxiliary devices and electrical components, a very large inrush current flows at start-up. Further, in the case of a 12V lead-acid battery, a current of about 100 A flows through the starter that starts the engine. A secondary battery such as a lead-acid battery deteriorates faster as the number of times a large current flows (discharges) in a short time increases.

  In particular, in the case of an idling stop vehicle, the starter drive is frequently performed after the engine is stopped, so that the above problem becomes serious. This is because the generator is stopped when the engine is stopped, and the load on the lead storage battery is large. A lead storage battery mounted on an idling stop vehicle uses a countermeasure against a large load for a short time in order to alleviate the above-mentioned problem, but such a lead storage battery is generally expensive.

  Recently, automobiles equipped with solar cell modules have been developed. For example, Patent Document 2 discloses an automobile power supply system using a solar cell module. The power supply system for automobile supplies power from a solar battery module to a load via a storage battery (secondary battery) and a control circuit.

  Therefore, it is conceivable to flow a large current from the solar cell module to the load in a short time instead of the secondary battery. If this can be realized, the number of times a large current flows from the secondary battery to the load in a short time can be reduced, and deterioration of the secondary battery can be suppressed.

  However, since the installation area of the solar cell module is limited to the dimensions of the vehicle, the output power (electric energy per unit time) is also limited. In addition, the power varies depending on weather, temperature, and the like. For this reason, it is difficult to flow a large current from the solar cell module in a short time. In fact, in Patent Document 2, the power from the storage battery is supplied to the load at the time of startup, and then the power from the solar cell module is supplied to the load. That is, in Patent Document 2, the solar cell module is not used for flowing a large current in a short time.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a configuration that allows a large current to flow from a solar cell to a load in a short time.

  A power supply device according to the present invention is a power supply device for supplying electrical energy from a solar cell to a load, and in order to solve the above-mentioned problem, the electrical energy from the solar cell is accumulated, and the accumulated electrical energy Is provided to the load.

  According to said structure, the capacitor accumulate | stores the electrical energy (electric power) produced | generated with the solar cell, and supplies the accumulated electrical energy to load. Generally, unlike a secondary battery, a capacitor can charge and discharge a large current in a short time. Therefore, the capacitor according to the present invention can flow a large current to the load in a short time using the stored electrical energy from the solar cell.

  Thereby, the frequency | count that a secondary battery sends a large current to a load for a short time can be suppressed, and as a result, deterioration of a secondary battery can be suppressed. Capacitors generally have significantly less loss and deterioration due to charging and discharging compared to secondary batteries. Therefore, the capacitor hardly deteriorates even if the number of times of flowing a large current in a short time increases.

  The power supply device according to the present invention further includes a maximum power point tracking module for the solar cell, and electrical energy from the solar cell is preferably supplied to the capacitor via the maximum power point tracking module. .

  Here, the maximum power point tracking module (hereinafter referred to as MPPT module) is a control device that can automatically follow the maximum power point, which is an optimal combination of current and voltage that can maximize the output. That is.

  Since the electric power generated by the solar cell can be efficiently supplied to the capacitor by the MPPT module, the electric power generated by the solar cell can be supplied to the load more efficiently.

  Preferably, the power supply device according to the present invention further includes a converter that converts an output voltage from the capacitor into a predetermined voltage, and electrical energy from the capacitor is output to the load via the converter. .

  Generally, when the electric energy from the capacitor is continuously output to the load, the output voltage of the capacitor is lowered. Also in a secondary battery, if a large current is passed in a short time, the output voltage will decrease even if there is a sufficient capacity for a long time. In this case, the load may not operate due to a decrease in the output voltage.

  On the other hand, according to the above configuration, the load is applied at a predetermined voltage by the converter. As a result, it is possible to prevent the load from operating due to a decrease in the output voltage. Furthermore, the capacitor can increase the amount of electric power (electric energy) per output, and as a result, the capacity can be smaller than when the converter is not provided.

  In addition, if it is an electric system characterized by including the power supply device of the said structure, the solar cell which supplies an electrical energy to this power supply device, and the load supplied with the electrical energy from the said power supply device, it is as above-mentioned. Similar effects can be achieved.

  The electric system according to the present invention may further include a secondary battery connected to a power supply line for supplying electric energy from the power supply device to the load. In this case, the electric energy from the power supply device can be supplied to the load and also to the secondary battery.

  By the way, a capacitor capable of charging / discharging with a large current accumulates electric energy generated by a solar cell, supplies the accumulated electric energy to the secondary cell with a large current, and charges the secondary cell. Can do. That is, the secondary battery can be charged intermittently. As a result, the circuit related to charging only needs to be operated intermittently, so that the power consumption of the circuit related to charging can be reduced as compared with the prior art in which the circuit related to charging is continuously operated. As a result, the electric power generated by the solar cell can be efficiently supplied to the secondary battery.

  The electrical system according to the present invention further includes a secondary battery, and switching means for switching between supply of electrical energy from the power supply device to the load and supply of electrical energy from the secondary battery to the load. Also good. In this case, when the electrical energy stored in the capacitor is small, the secondary battery can supply electrical energy to the load. Can be supplied stably.

  In addition, if it is a vehicle characterized by providing the electric system of the said structure, there can exist an effect similar to the above-mentioned. The vehicle includes an automobile, a motorcycle, a bicycle, a rear car, and the like.

  By the way, the starter needs to pass a large current for a short time. Therefore, the vehicle according to the present invention further includes an internal combustion engine that is a power source of the vehicle and a starter that drives the internal combustion engine, and the load preferably includes the starter.

  The vehicle according to the present invention may further include an idling stop means for stopping the internal combustion engine when the vehicle is stopped. In this case, since the number of times of using the starter is remarkably increased, the application of the present invention is particularly effective.

  As described above, in the power supply device according to the present invention, the capacitor accumulates the electric energy generated by the solar cell, and the accumulated electric energy can be used to flow a large current to the load in a short time. Play.

1 is a block diagram showing a schematic configuration of an in-vehicle electric system mounted on an automobile according to an embodiment of the present invention. It is a flowchart which shows the flow of operation | movement of the vehicle-mounted solar system in the said vehicle-mounted electrical system. It is a flowchart which shows the flow of operation | movement of the vehicle-mounted solar system in the vehicle-mounted electric system mounted in the motor vehicle which concerns on another embodiment of this invention. It is a block diagram which shows schematic structure of the vehicle-mounted electric system mounted in the motor vehicle which concerns on other embodiment of this invention. It is a flowchart which shows the flow of operation | movement of the said vehicle-mounted electrical system. It is a circuit diagram which shows an example of the solar cell module in the said vehicle-mounted electrical system. It is a circuit diagram which shows the other example of the said solar cell module. It is a top view which shows an example of arrangement | positioning of the photovoltaic cell in the said solar cell module. It is a top view which shows the other example of arrangement | positioning of the photovoltaic cell in the said solar cell module.

[Embodiment 1]
An embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a block diagram showing a schematic configuration of an in-vehicle electric system (electric system) 1 mounted on an automobile (vehicle) according to the present embodiment.

(Outline of in-vehicle electrical system)
As shown in FIG. 1, the in-vehicle electric system 1 of this embodiment includes an in-vehicle solar system 100, loads 111 and 112, a secondary battery 113, a BMU (Battery Management Unit) 114, and an ECU (Electronic Control Unit). , Electronic control unit) 115.

  In FIG. 1, the power supply line is indicated by a thick line, and the signal line is indicated by a thin line. The in-vehicle solar system 100 and the loads 111 and 112 are connected to the power line, and further, the secondary battery 113 is connected via the BMU 114. In addition, the vehicle-mounted solar system 100, the loads 111 and 112, and the BMU 114 are connected to the signal line.

(Outline of in-vehicle solar system)
As shown in FIG. 1, the in-vehicle solar system 100 includes a solar cell module 101, a capacitor 102, a terminal 103, an MPPT module 104, a converter 105, a capacitor voltage sensor 106, and an output voltage sensor 107.

  The solar cell module 101 is composed of one or a plurality of solar cells, and converts solar energy into electric power. The solar cell module 101 supplies the generated power to the MPPT module 104.

  The MPPT module 104 automatically follows the optimum operating point so that the maximum power can be extracted from the solar cell module 101. Further, the MPPT module 104 converts the electric power from the solar cell module 101 into an appropriate voltage and supplies it to the capacitor 102.

  Further, the MPPT module 104 monitors the voltage of the capacitor 102, and determines whether or not the fully charged state in which the amount of electricity stored in the capacitor 102 has reached the allowable amount of the capacitor 102 from the voltage of the capacitor 102. to decide. When the MPPT module 104 determines that the capacitor 102 is fully charged, the MPPT module 104 stops supplying power to the capacitor 102.

  The capacitor 102 temporarily stores the power supplied from the solar cell module 101 via the MPPT module 104. Capacitor 102 supplies the stored power to converter 105.

  The converter 105 converts the voltage (DC voltage) of the DC current supplied from the capacitor 102 into a predetermined voltage (steps up or down) and outputs it to the terminal 103. A first load 111, a second load 112, and a secondary battery 113 are connected to the terminal 103.

  Capacitor voltage sensor 106 detects the voltage of capacitor 102 and is provided on the power supply line from capacitor 102 to converter 105. Capacitor voltage sensor 106 transmits the detected voltage of capacitor 102 to converter 105.

  The output voltage sensor 107 detects the output side voltage of the terminal 103 and is provided in the power line on the output side of the terminal 103. The output voltage sensor 107 transmits the detected output side voltage to the converter 105.

  The MPPT module 104, the capacitor 102, the converter 105, the terminal 103, and the voltage sensors 106 and 107 constitute a power supply device for supplying electrical energy from the solar cell module 101 to the loads 111 and 112.

(Details of in-vehicle solar system)
Next, the detail of each structure of the vehicle-mounted solar system 100 is demonstrated.

Examples of solar cells constituting the solar cell module 101 include a silicon single crystal cell, a silicon polycrystalline cell, an amorphous silicon cell, a compound semiconductor cell (GaAs-based, InGaAs-based, CIS (Cu In Se-based), etc.), organic A thin film solar cell, a dye-sensitized solar cell, etc. can be used. The rated power generation amount of the solar cell module 101 can be set to, for example, 50 W to 1 kW. Cell region of the solar cell module 101 corresponding to the rated power generation amount, for example, when using a silicon solar cell conversion efficiency of 20%, a 0.25m ² ~5m ^2.

  The output voltage of the solar cell module 101 can be set to 2.5V to 100V, for example. In addition, when the voltage of load 111 * 112 and the secondary battery 113 is 12V, it is preferable to set it as 5V-20V near this.

  The solar cell module 101 is most preferably installed on the roof of the automobile. However, the solar cell module 101 may be divided into a hood and a door.

  The MPPT module 104 automatically follows the optimum operating point in order to efficiently transmit the power generated by the solar cell module 101. The MPPT module 104 also has a built-in converter function for converting a DC voltage in order to apply an appropriate voltage to the capacitor 102.

  Note that the MPPT module 104 is not necessarily required if the output voltage of the solar cell module 101 is set so as not to apply an excessive voltage to the capacitor 102. In this case, a backflow prevention circuit such as a diode may be provided instead of the MPPT module 104.

  As the capacitor 102, a large-capacity electric double layer capacitor can be used. The rated voltage of the capacitor 102 can be set to 2.5V to 100V. In addition, when the voltage of load 111 * 112 and the secondary battery 113 is 12V, it is preferable to set it as 5V-20V close | similar to this.

  The capacity of the capacitor 102 can be set to 5F to 1000F, for example, when the rated voltage of the capacitor 102 is 15V. When capacitors with a rated voltage of 2.5V are connected in series and the rated voltage is set to 15V, six capacitors of 30F to 6000F may be connected in series.

  As described above, the converter 105 boosts or steps down the DC voltage from the capacitor 102 to a predetermined voltage. Although the output voltage of the capacitor 102 varies depending on the amount of accumulated charge, the converter 105 can output a predetermined voltage. The output voltage of converter 105 is preferably about 14.5 V when the voltage of secondary battery 113 is a 12 V lead acid battery.

  The input / output power of the converter 105 is set depending on what loads 111 and 112 are driven. For example, when the load 111 or 112 includes a starter, the load is preferably 1 kW or more.

  In the present embodiment, when the capacitor 102 is in a fully charged state and it is necessary to supply power to at least one of the loads 111 and 112, the converter 105 uses the above voltage for the power supplied from the capacitor 102. Is converted (step-up or step-down) and output to the terminal 103. On the other hand, the converter 105 pauses the conversion of the voltage and the output to the terminal 103 when the capacitor 102 is being charged, or when it is not necessary to supply power to the loads 111 and 112. At this time, the converter 105 hardly consumes power. Furthermore, when the automobile is parked, it is not necessary to activate the in-vehicle ECU 115 to control the converter 105.

  Whether the capacitor 102 is being charged or fully charged can be determined by the converter 105 receiving and monitoring the voltage of the capacitor 102 from the capacitor voltage sensor 106. Whether or not it is necessary to supply power to at least one of the loads 111 and 112 is determined by the converter 105 receiving the output side voltage of the terminal 103 from the output voltage sensor 107 and monitoring it. Can do.

  The terminal 103 is provided to supply power from the capacitor 102 to the loads 111 and 112. This terminal 103 defines the boundary between the vehicle-mounted solar system 100 and the outside. Therefore, the vehicle-mounted solar system 100 may be removable at the terminal 103 or may not be removable. Further, the terminal 103 may have a clear shape as a terminal or may not have a clear shape. Further, converter 105 (capacitor 102 when converter 105 is omitted), loads 111 and 112, and secondary battery 113 may be directly connected via a power supply line. In this case, any part of the power supply line becomes the terminal 103.

(Other configurations)
In the present embodiment, the in-vehicle solar system 100 is used to supply power to the loads 111 and 112 connected to the in-vehicle solar system 100 to operate, but further to charge the secondary battery 113. May be used.

  The first load 111 connected to the terminal 103 of the in-vehicle solar system 100 is, for example, a starter that starts an engine (internal combustion engine). Normally, the starter consumes about 1 kW of power. When the drive voltage is 12V, the drive current reaches nearly 100A. In the case of an idling stop vehicle, the time for driving the starter is about 0.5 seconds. When starting the engine manually, the starter may be driven for a longer time.

  The second load 112 connected to the terminal 103 of the vehicle-mounted solar system 100 is, for example, various auxiliary devices and electrical components other than the starter. Examples of auxiliaries and electrical components include ignition systems, headlights, brake lights, direction indicators, ECUs, blower fans, electric air conditioners (air conditioners), stereos, navigation, and the like.

  The secondary battery 113 currently uses a 12 V lead acid battery, but may be a lead acid battery, a nickel hydride battery, a lithium ion battery, or the like of other voltages.

  The BMU 114 controls and protects the secondary battery 113. That is, charging / discharging of the secondary battery 113 is controlled by the BMU 114.

  The ECU 115 performs overall control of various devices in the in-vehicle electrical system 1. Specifically, the ECU 115 collects information from the various devices, and instructs the operation of the various devices based on the collected information. In the example of FIG. 1, the ECU 115 collects the information and gives an instruction for the operation with respect to the converter 105, the loads 111 and 112, and the BMU 114.

(Operation of in-vehicle solar system)
The operation of the in-vehicle solar system 100 having the above configuration will be described with reference to FIG. FIG. 2 is a flowchart showing an operation flow of the converter 105 in the in-vehicle solar system 100.

  As shown in FIG. 2, converter 105 first acquires the voltage value of output voltage sensor 107 (S100), and whether or not the acquired voltage value of output voltage sensor 107 is equal to or less than a first predetermined value. Is determined (S101). This first predetermined value is for determining the necessity of power transmission to the loads 111 and 112. When the voltage value of the output voltage sensor 107 is larger than the first predetermined value, it is determined that power transmission from the in-vehicle solar system 100 to the loads 111 and 112 is unnecessary, and the process returns to step S100 and the above operation is repeated. .

  On the other hand, when the voltage value of output voltage sensor 107 is equal to or lower than the first predetermined value, converter 105 acquires the voltage value of capacitor voltage sensor 106 (S102), and the acquired voltage value of capacitor voltage sensor 106 is obtained. Is greater than or equal to a second predetermined value (S103). The second predetermined value is for determining whether sufficient electric power is stored in the capacitor 102. When the voltage value of the capacitor voltage sensor 106 is smaller than the second predetermined value, it is determined that the power transmission from the in-vehicle solar system 100 to the loads 111 and 112 is insufficient, and the process returns to step S100 and the above operation is performed. repeat.

  On the other hand, when the voltage value of capacitor voltage sensor 106 is equal to or greater than the second predetermined value, converter 105 starts power transmission from capacitor 102 to loads 111 and 112 (S104).

  Next, converter 105 acquires the voltage value of output voltage sensor 107 (S105), and determines whether or not the acquired voltage value of output voltage sensor 107 is equal to or greater than a third predetermined value (S106). . This third predetermined value is for determining whether or not the necessity of power transmission to the loads 111 and 112 has been eliminated and whether or not the voltage of the loads 111 and 112 is abnormal. When the voltage value of the output voltage sensor 107 is equal to or greater than the third predetermined value, it is determined that power transmission from the in-vehicle solar system 100 to the loads 111 and 112 is no longer necessary, and the capacitors 102 to the loads 111 and 112 The power transmission is stopped (S109), and then the process returns to step S100 to repeat the above operation.

  On the other hand, when the voltage value of output voltage sensor 107 is smaller than the third predetermined value, converter 105 acquires the voltage value of capacitor voltage sensor 106 (S107), and the acquired voltage value of capacitor voltage sensor 106 is obtained. Is less than or equal to a fourth predetermined value (S108). This fourth predetermined value is for determining whether sufficient electric power remains in the capacitor 102. If the voltage value of the capacitor voltage sensor 106 is larger than the fourth predetermined value, it is determined that sufficient power remains in the capacitor 102, the process returns to step S105, and the above operation is repeated. On the other hand, if the voltage value of the capacitor voltage sensor 106 is equal to or less than the fourth predetermined value, it is determined that sufficient power does not remain in the capacitor 102, the power transmission is stopped (S109), and then the step is performed. Returning to S100, the above operation is repeated.

  Note that the order of the operations in steps S100 and S101 related to the output voltage sensor 107 and the operations in steps S102 and S103 related to the capacitor voltage sensor 106 may be interchanged. Similarly, the operations of steps S105 and S106 related to the output voltage sensor 107 and the operations of steps S107 and S108 related to the capacitor voltage sensor 106 may be interchanged. Further, the first predetermined value and the third predetermined value may be the same. Similarly, the second predetermined value and the fourth predetermined value may be the same.

  As described above, the in-vehicle solar system 100 according to the present embodiment converts solar energy into electric power and supplies the electric power to the in-vehicle loads 111 and 112, and converts the solar energy into electric power. The battery module 101 includes a capacitor 102 that stores electric power supplied from the solar cell module 101, and a terminal 103 that supplies electric power from the capacitor 102 to loads 111 and 112 and the secondary battery 113.

  According to the above configuration, charging / discharging with a large current is possible, and a large current can be passed through the loads 111 and 112 from the capacitor 102 with almost no limit on the number of charging / discharging in a short time. As a result, the number of times the secondary battery 113 allows a large current to flow through the loads 111 and 112 can be suppressed, and as a result, deterioration of the secondary battery 113 can be suppressed.

  Furthermore, the electric power stored in the capacitor 102 is supplied from the solar cell module 101 and is not supplied from the generator connected to the engine. Therefore, the fuel efficiency of the automobile equipped with the in-vehicle solar system 100 can be improved.

  Since the electric power generated by the solar cell module 101 is proportional to the total area of the solar cells, a large current cannot be obtained when the mounting area is limited as in an automobile. Moreover, the electric power generated by the solar cell module 101 always varies depending on the amount of solar radiation. Once the electric power generated by the solar cell module 101 is stored in the capacitor 102, a large current can be extracted from the capacitor 102. Therefore, it is possible to achieve both improvement in automobile fuel efficiency and suppression of deterioration of the secondary battery 113.

  In the present embodiment, an MPPT module 104 having a maximum power point tracking function is provided between the solar cell module 101 and the capacitor 102. Thereby, since the electric power generated by the solar cell module 101 can be efficiently supplied to the capacitor 102, the electric power generated by the solar cell module 101 can be supplied to the loads 111 and 112 more efficiently. As a result, it is possible to further improve the fuel consumption or power consumption of the automobile.

  In the present embodiment, a converter that converts a voltage is provided between the capacitor 102 and the terminal 103. Thereby, even if the voltage from the capacitor 102 decreases due to the discharge from the capacitor 102, the vehicle-mounted solar system 100 applies the loads 111 and 112 at a predetermined voltage by the converter 105. It is possible to prevent 112 from becoming inoperable. Furthermore, the capacitor 102 can increase the amount of electric power per output, and as a result, can have a smaller capacity than the case where the converter 105 is not provided.

(Operation example 1)
Next, a first operation example of the in-vehicle solar system 100 will be described.

  Here, as an example, the rated voltage of the solar cell module 101 is 5 V, the rated power generation amount is 50 W, the rated voltage of the capacitor 102 is 15 V, and the capacitance is 20 F.

  The on-vehicle solar cell module 101 converts solar energy into electric power, and charges the capacitor 102 via the MPPT module 104. The MPPT module 104 automatically follows the optimum operating point in order to efficiently supply the power generated by the solar cell module 101. In addition, the MPPT module 104 boosts the voltage of the power received from the solar cell module 101 to 15 V and charges the capacitor 102.

  Note that since the voltage of the capacitor 102 increases with the accumulation of electric charges, the charging efficiency can be further improved by changing the output voltage of the MPPT module 104 in accordance with the voltage of the capacitor 102.

  The time from when the capacitor 102 is not charged to the fully charged state is 90 seconds when the solar cell module 101 is outputting as rated. Furthermore, when the output voltage of the MPPT module 104 is changed in accordance with the voltage of the capacitor 102, it is 45 seconds. When the capacitor 102 is fully charged, the MPPT module 104 stops operating.

  The electric power stored in the capacitor 102 is supplied as necessary to drive the first load 111 that is a starter. Preferably, in an automobile having an idling stop function, the starter is driven when starting the engine to cancel the idling stop state.

  When the electric power stored in the capacitor 102 is used, the voltage is converted into, for example, 12V by the converter 105. Although the voltage of the capacitor 102 decreases as the accumulated charge (electric energy) is lost, the voltage output by the converter 105 can be kept constant.

  The electric power output from the converter 105 is supplied to the first load 111 that is a starter through the terminal 103. The maximum power stored in the capacitor 102 is 2.25 kWs when the voltage is 15V and the capacitance is 20F. Therefore, if the starter consumes 1 kW of power, the starter can be driven for about 2 seconds. This is enough time to restart the engine.

  When driving of the first load 111 that is a starter is completed, the output of the converter 105 is stopped, and charging from the solar cell module 101 to the capacitor 102 is resumed.

  In the first operation example, the vehicle-mounted solar system 100 supplies power to drive a starter that requires a large amount of power for a short time. The capacitor 102 can be easily charged and discharged with a large current as compared with the secondary battery 113, and the number of times of charging and discharging is almost unlimited. Therefore, as compared with the case where the first load 111 is driven by the secondary battery 113, the effect of preventing the voltage drop and deterioration of the secondary battery becomes remarkable.

  In particular, when the vehicle on which the in-vehicle solar system 100 is mounted has an idling stop function, the number of times the starter is used becomes very large, and the effect of preventing the voltage drop and deterioration of the secondary battery is particularly remarkable.

(Operation example 2)
Next, a second operation example of the in-vehicle solar system 100 will be described. In the following description, the difference from the first operation example will be described, and the description of the same will be omitted.

  Here, as an example, the rated voltage of the solar cell module 101 is 10 V, the rated power generation amount is 200 W, the rated voltage of the capacitor 102 is 15 V, and the capacitance is 200 F.

  The time from when the capacitor 102 is not charged to the fully charged state is 225 seconds when the solar cell module 101 is outputting as rated. Furthermore, when the output voltage of the MPPT module 104 is changed in accordance with the voltage of the capacitor 102, it is 112.5 seconds. When the capacitor 102 is fully charged, the MPPT module 104 stops operating.

  The electric power stored in the capacitor 102 is supplied as necessary to operate the second load 112 which is various auxiliary devices and electrical components. Furthermore, the electric power stored in the capacitor 102 may be supplied to drive the first load 111 that is a starter. Preferably, in an automobile having an idling stop function, the second load 112 is operated during idling stop. The second load 112 may be operated not only during idling stop but during normal traveling.

  The electric power output from the converter 105 is supplied to the second load 112 which is an auxiliary device and an electrical component through the terminal 103. The maximum power stored in the capacitor 102 is 22.5 kWs when the voltage is 15 V and the capacitance is 200 F. Therefore, if the power consumption of the second load 112 is 250 W, the second load 112 can be driven for 90 seconds. If the second load 112 is driven when idling is stopped, in many cases, power at idling can be supplemented.

  When the driving of the second load 112 is completed, the output of the converter 105 is stopped, and charging from the solar cell module 101 to the capacitor 102 is resumed.

(Operation example 3)
Next, a third operation example of the in-vehicle solar system 100 will be described. In the following description, the difference from the first operation example will be described, and the description of the same will be omitted.

  Here, as an example, the rated voltage of the solar cell module 101 is 10 V, the rated power generation amount is 200 W, the rated voltage of the capacitor 102 is 15 V, and the capacitance is 200 F.

  The time from when the capacitor 102 is not charged to the fully charged state is 225 seconds when the solar cell module 101 is outputting as rated. Furthermore, when the output voltage of the MPPT module 104 is changed in accordance with the voltage of the capacitor 102, it is 112.5 seconds. When the capacitor 102 is fully charged, the MPPT module 104 stops operating.

  The electric power stored in the capacitor 102 drives at least one of the first load 111 that is a starter and the second load 112 that is various auxiliary devices and electrical components, and also charges the secondary battery 113. . The maximum power stored in the capacitor 102 is 22.5 kWs when the voltage is 15 V and the capacitance is 200 F.

  When the driving of the first load 111, the operation of the second load 112, and the charging of the secondary battery 113 are finished, the output of the converter 105 is stopped and the charging of the capacitor 102 from the solar cell module 101 is resumed. .

  In this operation example, the vehicle-mounted solar system 100 charges the secondary battery 113. Usually, since the electric power of the secondary battery 113 is supplied by a generator using the power of the engine, the in-vehicle solar system 100 can remarkably improve the fuel consumption of the automobile by charging the secondary battery 113. it can.

  Since the electric power generated by the solar cell module 101 is temporarily stored in the capacitor 102, the secondary battery 113 can be charged with a larger current (electric power) than the electric current (electric power) generated by the solar cell module 101. In addition, the secondary battery 113 can be charged intermittently. Therefore, since the operation time of the converter 105 can be shortened, the electric power generated by the solar cell module 101 can be efficiently supplied to the secondary battery 113.

  This effect is particularly remarkable when the sunlight is weak or the installation area is small and the output of the solar cell module 101 is small. For example, when the output of the solar cell module 101 is 50 W, the power consumption of the converter 105 is 30 W, and the generated power is supplied to the loads 111 and 112 as they are, 60% of the output of the solar cell module 101 is consumed by the converter 105. It will be lost as electric power. However, if 1 kW of power is supplied from the capacitor 102 to the loads 111 and 112, the loss due to the power consumption of the converter 105 becomes 3%.

[Embodiment 2]
Next, another embodiment of the present invention will be described with reference to FIG. The in-vehicle electric system in the automobile according to the present embodiment is different from the in-vehicle electric system 1 shown in FIG. 1 in that the output voltage sensor 107 is omitted, and the other configurations are the same. For this reason, the block diagram which shows schematic structure of the vehicle-mounted electrical system 1 of this embodiment is abbreviate | omitted. In addition, the same code | symbol is attached | subjected to the structure which has the function similar to the structure demonstrated in the said embodiment, and the description is abbreviate | omitted.

  In the in-vehicle electrical system 1 shown in FIG. 1, the converter 105 receives the output side voltage of the terminal 103 from the output voltage sensor 107 and monitors whether or not it is necessary to supply power to the loads 111 and 112. It is done by doing. On the other hand, in the in-vehicle electrical system 1 of the present embodiment, the converter 105 determines whether or not it is necessary to supply power to the loads 111 and 112 based on an instruction from the ECU 115.

  Operation | movement of the vehicle-mounted solar system 100 in the vehicle-mounted electrical system 1 of this embodiment is demonstrated with reference to FIG. FIG. 3 is a flowchart showing the operation flow of the converter 105 in the in-vehicle solar system 100. The operation of the converter 105 shown in FIG. 3 is different from the operation of the converter 105 shown in FIG. 2 in that a step S110 is provided instead of steps S100 and S101, and a step instead of steps S105 and S106 is performed. The other operations are the same except that S111 is provided.

  As shown in FIG. 3, converter 105 first waits until power transmission from vehicle-mounted solar system 100 to loads 111 and 112 is instructed by ECU 115 (S <b> 111). When the power transmission is instructed, steps S102 and S103 are performed. If the voltage value of the capacitor voltage sensor 106 is smaller than the second predetermined value, it is determined that the power transmission is not sufficient. Then, it returns to step S110 and repeats the said operation | movement.

  On the other hand, when the voltage value of capacitor voltage sensor 106 is equal to or greater than the second predetermined value, converter 105 determines that the power transmission is sufficient, and transmits power from capacitor 102 to loads 111 and 112. Start (S104).

  Next, converter 105 determines whether or not stop of power transmission is instructed from ECU 115 (S111). When the stop of the power transmission is instructed, the power transmission from the capacitor 102 to the loads 111 and 112 is stopped (S109), and then the process returns to step S110 to repeat the above operation.

  On the other hand, if the ECU 115 is not instructed to stop the power transmission, steps S107 and S108 are performed. If the voltage value of the capacitor voltage sensor 106 is larger than the fourth predetermined value, sufficient power is supplied to the capacitor 102. Is determined to remain, the process returns to step S111, and the above operation is repeated. On the other hand, if the voltage value of the capacitor voltage sensor 106 is equal to or less than the fourth predetermined value, it is determined that sufficient power does not remain in the capacitor 102, the power transmission is stopped (S109), and then the step is performed. Returning to S100, the above operation is repeated.

  As described above, converter 105 can perform or stop power transmission to loads 111 and 112 based on an instruction from ECU 115 without providing output voltage sensor 107.

[Embodiment 3]
Next, another embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a block diagram showing a schematic configuration of the in-vehicle electric system in the automobile according to the present embodiment. In addition, the same code | symbol is attached | subjected to the structure which has the function similar to the structure demonstrated in the said embodiment, and the description is abbreviate | omitted.

(Configuration of in-vehicle electrical system)
The in-vehicle electric system 2 of this embodiment is different from the in-vehicle electric system 1 shown in FIG. 1 in that an in-vehicle solar system 200 is provided instead of the in-vehicle solar system 100, and the in-vehicle solar system 200 and the loads 111 and 112. The point that a switch (switching means) 211 is provided between the secondary battery 113 and the secondary battery 113 is different from the point that a switch controller 212 that controls the switch 211 is provided. The in-vehicle solar system 200 of the present embodiment is different from the in-vehicle solar system 100 shown in FIG. 1 in that the converter 105 and the output voltage sensor 107 are omitted, and the other configurations are the same. For this reason, the capacitor 102 is directly connected to the terminal 103 without going through the converter.

  The switch 211 switches the connection destination of the first load 111 to either the in-vehicle solar system 200 side or the secondary battery 113 side. Moreover, the vehicle-mounted solar system 200 is configured not to be connected to the second load 112 and the secondary battery 113 due to the presence of the switch 211. Therefore, the first load 111 is supplied with power from either the in-vehicle solar system 200 or the secondary battery 113, while the second load 112 is not supplied with power from the in-vehicle solar system 200. Electric power is supplied only from the secondary battery 113.

  The switch controller 212 controls switching of the switch 211 based on an instruction from the ECU 115 and a voltage value from the capacitor voltage sensor 106 of the vehicle-mounted solar system 200.

(Operation of in-vehicle electrical system)
The operation of the in-vehicle electrical system 2 having the above configuration will be described with reference to FIG. FIG. 5 is a flowchart showing an operation flow of the switch controller 212 in the in-vehicle electrical system 2.

  As shown in FIG. 5, the switch controller 212 first switches the switch 211 to the secondary battery 113 side (S200). As a result, power is supplied from the secondary battery 113 to the first load 111 via the BMU 114 and the switch 211. That is, the power supply source to the first load 111 is the secondary battery 113.

  Next, the switch controller 212 determines whether power transmission from the in-vehicle solar system 200 to the first load 111 is instructed by the ECU 115 (S201). If the power transmission is not instructed, the process returns to step S200 and the above operation is repeated.

  On the other hand, when the power transmission is instructed, the switch controller 212 performs steps S202 and 203 similar to steps S102 and S103 shown in FIG. 2, and the voltage value of the capacitor voltage sensor 106 is the second predetermined value described above. If it is smaller than that, it is determined that the power transmission is not sufficient, and the process returns to step S200 to repeat the above operation.

  On the other hand, when the voltage value of the capacitor voltage sensor 106 is equal to or greater than the second predetermined value, the switch controller 212 determines that the power transmission is sufficient, and switches the switch 211 to the capacitor 102 side ( S204). As a result, electric power is supplied from the capacitor 102 to the first load 111 via the terminal 103 and the switch 211. That is, the power supply source to the first load 111 is the capacitor 102.

  Next, the switch controller 212 determines whether or not the ECU 115 is instructed to stop the power transmission (S206). When the stop of the power transmission is instructed, the process returns to step S200 and the above operation is repeated. As a result, the power supply source to the first load 111 returns from the vehicle-mounted solar system 200 to the secondary battery 113.

  On the other hand, when the stop of the power transmission is not instructed from the ECU 115, the switch controller 212 performs the steps S202 and 203 similar to the steps S102 and S103 shown in FIG. If it is larger than the fourth predetermined value, it is determined that sufficient electric power remains in the capacitor 102, the process returns to step S206, and the above operation is repeated. That is, the in-vehicle solar system 200 maintains the power supply source to the first load 111.

  On the other hand, if the voltage value of the capacitor voltage sensor 106 is equal to or lower than the fourth predetermined value, it is determined that sufficient power does not remain in the capacitor 102, the process returns to step S200, and the above operation is repeated. As a result, the power supply source to the first load 111 returns from the vehicle-mounted solar system 200 to the secondary battery 113.

(Operation example)
Hereinafter, an operation example of the vehicle-mounted solar system 200 shown in FIGS. 4 and 5 will be described. In addition, it is the same as that of the vehicle-mounted solar system 100 shown in FIG. 1 until the electric power generated in the solar cell module 101 is charged into the capacitor 102 via the MPPT module 104.

  Here, as an example, the rated voltage of the solar cell module 101 is 5 V, the rated power generation amount is 50 W, the rated voltage of the capacitor 102 is 15 V, and the capacitance is 40 F.

  The time from when the capacitor 102 is not charged to the fully charged state is 180 seconds when the solar cell module 101 is outputting as rated. Furthermore, when the output voltage of the MPPT module 104 is changed in accordance with the voltage of the capacitor 102, it is 90 seconds. When the capacitor 102 is fully charged, the MPPT module 104 stops operating.

  The electric power stored in the capacitor 102 is supplied to drive the first load 111 that is a starter as necessary. Preferably, in a vehicle having an idling stop function, the starter is driven when the engine is started to release the idling stop state.

  When the electric power stored in the capacitor 102 is used, the switch 211 is switched so that the first load 111 is connected to the vehicle-mounted solar system 200. At this time, the second load 112 and the secondary battery 113, which are various auxiliary devices and electrical components, are disconnected from the first load 111.

  The electric power output from the capacitor 102 is supplied to the first load 111 that is a starter via the terminal 103. The maximum amount of power stored in the capacitor 102 is 4.5 kWs when the voltage is 15V and the capacitance is 40F. Assuming that the first load 111 is driven until the voltage of the capacitor 102 reaches 10 V, the power supplied to the first load 111 is 2.5 kWs. In this embodiment, although the voltage for driving the starter varies, the amount of power is sufficient to start the engine.

  When driving of the first load 111 that is a starter is completed, the switch 211 is switched, the vehicle-mounted solar system 200 and the first load 111 are disconnected, and charging of the capacitor 102 from the solar cell module 101 is resumed.

  In the above configuration, it is not necessary to provide a converter between the capacitor 102 and the terminal 103.

(Circuit example of solar cell module)
In addition, various things can be considered as a circuit and arrangement | positioning of the photovoltaic cell in the photovoltaic module 101 of the said embodiment.

  FIG. 6 is a circuit diagram of the solar cell module 10 which is an example of the solar cell module 101. The illustrated diode symbol indicates one solar battery cell 11. The illustrated solar cell module 10 has a configuration in which a plurality (24 in the illustrated example) of solar cells 11 are connected in series. When the solar battery cell 11 is a silicon solar battery, the output voltage is about 12V. The output voltage can be changed by changing the number of solar cells 11.

  In the example of the solar cell module 10 shown in FIG. 6, when no sunlight is incident on one solar cell 11, the solar cell module 10 is not affected even if sunlight is incident on all other solar cells 11. The output will be zero. Even when the intensity of sunlight incident on one solar battery cell 11 is reduced, the current that can be passed through the solar battery cell 11 is limited, and thus the output of the solar battery module 10 is significantly reduced. Such a situation may occur due to partial shade, dirt on the surface of the solar battery cell 11 and adhesion of foreign matter.

  An example of a solar cell module that avoids such problems is shown in FIG. FIG. 7 is a circuit diagram of a solar cell module 20 which is another example of the solar cell module 101. The illustrated solar cell module 20 includes a plurality (eight in the illustrated example) of parallel connection units in which a plurality (eight in the illustrated example) of the solar cells 11 are connected in parallel. This is a configuration of a series-parallel connection unit in which R8 is connected in series.

  In the solar cell module 20 illustrated in FIG. 7, even when no sunlight is incident on one solar cell 11, the other seven solar cells 11 belonging to the same parallel connection unit can pass current. Therefore, the output need only be reduced to 7/8 of the ideal state. Therefore, it is possible to suppress a decrease in the output of the solar cell module due to the partial shade.

  In addition, in the example of FIG. 7, although the structure connected in series and parallel by the 8 * 8 photovoltaic cell 11 is shown, the number of parallel connections and the number of series connections are not this limitation. Further, a larger-scale solar cell module 101 may be formed by connecting a plurality of configurations shown in FIG. 7 in parallel or in series.

(Solar cell module arrangement example)
FIG. 8 is a plan view showing an example of the arrangement of the solar battery cells 11 in the solar battery module 20 having the configuration shown in FIG. In FIG. 8, the solar cells 11 are square and are arranged in an 8 × 8 matrix. In FIG. 8, the eight solar cells 11 constituting the parallel connection unit R1 shown in FIG. 7 are indicated by the number 1, the eight solar cells 11 constituting the parallel connection unit R2 are indicated by the number 2, The same applies hereinafter. In FIG. 8, rectangular shadows A, B, and C are indicated by broken lines as an example of partial shade.

  When the shadow A is formed on the solar cell module 20 shown in FIG. 8, in each of the parallel connection units R1 to R8, only one of the eight solar cells 11 is a shadow. Accordingly, the output of the solar cell module 20 only needs to be reduced to 7/8 of the ideal state. The same applies when the shadow B is formed on the solar cell module 20 shown in FIG.

  On the other hand, when the shadow C is formed on the solar cell module 20 shown in FIG. 8, all the eight solar cells 11 constituting the parallel connection unit R1 are shaded. For this reason, the output of the solar cell module 20 will be zero. As described above, with respect to each of the parallel connection units R1 to R8, in the arrangement in which all the solar cells constituting the parallel connection unit are arranged on the same straight line, the solar battery module 20 against the shadow extending long in the straight direction. Output will be significantly smaller.

  An example of a solar cell module that avoids such problems is shown in FIG. FIG. 9 is a plan view showing another example of the arrangement of the solar battery cells 11 in the solar battery module 20 having the configuration shown in FIG. Compared to the solar cell module 20 shown in FIG. 8, the solar cell module 20 shown in FIG. 9 has all the solar cells 11 constituting the parallel connection unit aligned in a straight line for each of the parallel connection units R1 to R8. The solar battery cell 11 is arrange | positioned so that it may not happen. In FIG. 9, rectangular shadows D, E, and F are shown by broken lines as an example of partial shade.

  When the shadow D is formed on the solar cell module 20 shown in FIG. 9, only one of the eight solar cells 11 becomes a shadow in each of the parallel connection units R1 to R8. Accordingly, the output of the solar cell module 20 only needs to be reduced to 7/8 of the ideal state. The same applies when the shadow F is formed on the solar cell module 20 shown in FIG.

  On the other hand, when the shadow E is formed on the solar cell module 20 shown in FIG. 9, each of the four parallel connection units R1, R3, R5, and R7 is only two of the eight solar cells 11. Becomes a shadow. Accordingly, the output of the solar cell module 20 only needs to be reduced to 6/8 of the ideal state.

  As described above, in the arrangement example of the solar battery cell 11 shown in FIG. 9, the output of the solar battery module 20 with respect to the shadow extending long in a specific direction is significantly reduced as compared with the arrangement example of the solar battery cell 11 shown in FIG. 8. Can be prevented.

  That is, by arranging so that all the solar cells 11 constituting the parallel connection unit do not line up in a straight line, the output of the solar cell module 20 is greatly reduced with respect to partial shade extending in a specific direction. Can be suppressed. Therefore, it is possible to more efficiently prevent the output of the solar cell module 20 from being reduced when there is dirt or deposits on the surface of the solar cell 11.

  Note that the arrangement of the solar cells 11 shown in FIG. 9 is merely an example, and an arbitrary arrangement in which all the solar cells 11 constituting the parallel connection unit are not arranged in a straight line can be selected.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  For example, in the above-described embodiment, the present invention is applied to the in-vehicle electric systems 1 and 2 mounted on an automobile. However, the present invention can be applied to an in-vehicle electric system mounted on a motorcycle, a bicycle, and a rear car. . Furthermore, the present invention can be applied to any electric system that charges a secondary battery with electric energy generated by a solar battery, such as a mobile phone equipped with a solar battery and a photovoltaic power generation facility.

  As described above, in the power supply device according to the present invention, the capacitor accumulates the electric energy generated by the solar cell, and can use the accumulated electric energy to flow a large current to the load in a short time. The present invention can be applied to any power supply device that supplies electric energy generated by the solar cell to a load.

1.2 In-vehicle electrical system (electrical system)
10/20 Solar cell module 11 Solar cell 100/200 In-vehicle solar system 101 Solar cell module 102 Capacitor 103 Terminal 104 MPPT module 105 Converter 106/107 Voltage sensor 111/112 Load 113 Secondary battery 114 BMU
115 ECU
211 switch (switching means)
212 Switch controller

Claims (9)

A power supply device for supplying electrical energy from a solar cell to a load,
A power supply device comprising a capacitor for accumulating electric energy from the solar cell and outputting the accumulated electric energy to the load. Further comprising a maximum power point tracking module for the solar cell;
2. The power supply device according to claim 1, wherein electrical energy from the solar cell is supplied to the capacitor through the maximum power point tracking module. A converter for converting the output voltage from the capacitor into a predetermined voltage;
The power supply apparatus according to claim 1, wherein electrical energy from the capacitor is output to the load via the converter. The power supply device according to any one of claims 1 to 3,
A solar cell for supplying electrical energy to the power supply;
An electrical system comprising: a load supplied with electrical energy from the power supply device.   The electric system according to claim 4, further comprising a secondary battery connected to a power supply line for supplying electric energy from the power supply device to the load. A secondary battery,
The electric system according to claim 4, further comprising switching means for switching between supply of electric energy from the power supply device to the load and supply of electric energy from the secondary battery to the load.   A vehicle comprising the electrical system according to any one of claims 4 to 6. An internal combustion engine as a power source of the vehicle;
A starter for driving the internal combustion engine,
The vehicle according to claim 7, wherein the load includes the starter.   The vehicle according to claim 8, further comprising an idling stop means for stopping the internal combustion engine when the vehicle is stopped.

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