JP5899441B2 - Power control device - Google Patents

Description

  The present invention relates to a power control device that is used in a power converter that converts DC power obtained from renewable energy such as solar cells into AC power, and stores a part of the DC power as thermal energy.

  A conventional power conversion device, for example, converts the generated power of a solar cell into AC power and then superimposes it on an indoor distribution line, and the generated power is consumed by each load L via the indoor wiring. .

  However, when using energy such as a solar battery in which generated power is not stable due to the influence of solar radiation, surplus power may be generated between the supplied power and the consumed power. Although this surplus power can be reversely flowed to the commercial power system G, there is a disadvantage that if this reverse power flow cannot be performed, it is not consumed by the load L and is wasted.

  When the reverse power flow cannot be performed, when the commercial power system G is not connected, when the commercial system is out of power, when the power conversion device is performing independent operation not linked to the commercial system, There are cases where reverse power flow to the system is restricted.

  Patent Document 1 discloses that all of the generated power is used for heating the hot water storage tank in order to use the power generated by the solar cell or surplus power without waste. In this case, power can be consumed until the hot water in the hot water tank is boiled, but the hot water in the hot water tank is only used as hot water.

  Further, Patent Document 2 describes that the contents stored in the warehouse are stored in a refrigerator or refrigerated using a Peltier element. In this case as well, the electric power generated by the solar cell is stored as cold storage or heat storage, but it can only be stored in the refrigerator or refrigerated.

Japanese Patent Laid-Open No. 10-292953 JP-A-11-325710

In the thing of patent document 1 or patent document 2, the instant fluctuation | variation of the generated electric power of a solar cell is absorbed by converting the electric power generated with the solar cell into hot water or cold energy and storing it. . However, in consideration of the conversion efficiency when converting electric power into hot water or cold heat, power loss has occurred compared to the case of directly consuming electric power.
The present invention constitutes an apparatus that can easily store power without providing additional equipment such as a storage battery when surplus power is generated while suppressing conversion loss of renewable energy such as a solar battery. is there.

  The present invention includes a DC / DC converter configured to be connectable to DC power of a power conversion device that converts DC power obtained from renewable energy such as a solar cell into AC power, and the DC / DC converter includes a Peltier element. Is connected to the Peltier element in the duct that circulates the cool air of the freezer, and the heat dissipation surface of the Peltier element is configured to exchange heat with the hot water in the hot water storage tank via the water heat exchanger. In addition, a part of the DC power obtained from the renewable energy is supplied to the Peltier element via the DC / DC converter, and at least one of the cold heat in the freezer and the hot heat in the hot water storage tank is used to provide the Peltier element. The DC power obtained from the above is supplied to the power converter via the DC / DC converter, and is generated by a solar cell or the like. It was a part of the power utilized by converting the cold / heat also those which can be used to convert the power.

  According to the present invention, a part of electric power obtained from renewable energy such as a solar cell is converted into cold / hot heat to perform cold storage / heat storage.

  Further, the present invention provides a radiator in a circulation circuit that circulates between the heat dissipation surface of the Peltier element and the hot water storage tank, and is configured to dissipate the Peltier element with the heat radiator. It can control the storage amount of warm heat.

  Further, according to the present invention, the power conversion device and the DC / DC converter can be easily connected to the refrigerator and the water heater by being housed in a single casing or integrally formed.

  In the power control apparatus of the present invention, the renewable energy obtained from the solar cell or the like is converted from DC power to AC power by the power converter and then used through the indoor wiring, and part of the power is cooled / It is converted into warm heat for storage and use, or reconverted into electric power and consumed directly by the load L.

FIG. 1 is a schematic explanatory view showing an embodiment of the present invention. FIG. 2 is an enlarged view of the vicinity of the Peltier element provided in the refrigerator shown in FIG. FIG. 2 is an explanatory diagram illustrating an example of the DC / DC converter illustrated in FIG. 1.

  FIG. 1 is an explanatory view showing an embodiment of the present invention. Reference numeral 1 denotes a solar cell module, which is composed of a plurality of solar cells. Moreover, it is not restricted to the solar cell module 1, The electric power using renewable energy, such as the electric power by wind power generation and wave power generation, can be used. Reference numeral 2 denotes a power converter, which converts DC power supplied from the solar cell module 1 into AC power having the same frequency as that of the AC power of the power grid G and then supplies the AC power to the indoor current breaker 3 after conversion. . The AC power supplied from the power converter 2 is supplied to the load L via the current breaker 3 and the indoor wiring.

  The power converter 2 operates so that the power generated by the solar cell module 1 is maximized, and supplies AC power to the current breaker 3 without exceeding the power. When the electric power consumed by the load L connected to the current breaker 3 is lower than the electric power generated by the solar cell module 1, it is possible to install a power selling meter and reverse the surplus power to the power system G. When the power sale price at the time of this power sale is low, it is more advantageous to self-consume indoors. Therefore, in this embodiment, the explanation will be made in the state without the power sale function. Moreover, the same state is obtained even in a state where the power failure and the connection to the power system G are interrupted.

  When such surplus power is generated, the power conversion device 2 shifts the optimum operating point of the solar cell module 1 so as to prevent the solar cell module 1 from generating power for the surplus power. The power generation efficiency of the solar cell module 1 is suppressed. In the present invention, the surplus power is supplied to the Peltier element, and the solar cell module 1 is generated at the optimum operating point.

  Reference numeral 4 denotes a DC / DC converter, which is connected to a direct current power line connecting the solar cell module 1 and the power conversion device 2 to flow the surplus power. The magnitude of this surplus power is the power consumed by the load L or the load L when the reverse power flow state starts to occur in the power system G with respect to the generated power obtained from the product of the output voltage and output current of the solar cell module 1. After controlling the step-up ratio in a range not exceeding the generated power of the solar cell module 1 on the input side so as to supply electric power in a state where the current supplied to no longer increases, the step-up ratio of the DC / DC converter 4 is changed to the sun. Control is performed so that the generated power of the battery module 1 reaches the optimum operating point, and the difference between the power generated by the solar cell module 1 and the power supplied to the load L is set to pass through the DC / DC converter 4. Is. Note that this series of control is performed by the control unit of the power converter 2, and the DC / DC converter 4 may be built in the casing of the power converter 2, or may be configured integrally with the outside. It may be provided.

  The DC / DC converter 4 is a converter that boosts the DC voltage bidirectionally, and supplies a part of the power corresponding to the surplus with respect to the load L of the power generated by the solar cell module 1 to the Peltier element 5 or The electric power obtained from the Peltier element 5 is supplied to the wiring for direct current power connecting the solar cell module 1 and the power conversion device 2. When it is necessary to adjust the voltage applied to the Peltier element 5, a constant voltage circuit or the like may be further provided between the DC / DC converter 4 and the Peltier element 5. The part of power supplied to the Peltier element 5 is not limited to the amount of power corresponding to such surplus power, but may be a certain amount of power or a certain amount of power relative to the generated power of the solar cell module 1. Is.

  If the current flowing through the DC / DC converter 4 is detected and the step-up ratio is controlled so that the power based on this current becomes a set value, a constant power is supplied to the Peltier element 5. This power may be set according to a predetermined ratio from the rated output of the Peltier element 5 or the generated power of the solar cell module 1.

  When energized, one of the Peltier elements 5 acts as a heat absorbing surface (cooling surface), and the other acts as a heat radiating surface (heating surface). The cooling surface 5 a is provided facing the duct for supplying cold air to the freezer compartment F of the refrigerator 6, and the heating surface 5 b is provided connected to the water heat exchanger 7.

  The refrigerator 6 is a general-purpose refrigerator composed of three temperature zones of a refrigerator compartment R, a vegetable compartment V, and a freezer compartment F. An evaporator E1 for the refrigerator compartment R / vegetable compartment V and an evaporator E2 for the freezer compartment F are provided. The arrow 8 indicates the flow of cold air for the refrigerator compartment R / vegetable room V circulated by a blower (not shown), and the arrow 9 is circulated by a blower (not shown). The flow of the cold air of the freezer compartment F is shown. The cooling surface of the Peltier element 5 is provided in the duct through which the cool air supplied to the freezer compartment F flows, and the cool air in the duct can be cooled. Alternatively, when the Peltier element 5 is not energized, the Peltier element 5 is cooled by cold air.

  The evaporator E2 is designed so that the temperature in the freezer compartment is minus 20 degrees, whereas the temperature of the cooling surface 5a of the Peltier element 5 is lower than the evaporator temperature, for example, minus 40 degrees. it can. The food stored in the freezer compartment F is better as the temperature in the freezer compartment F is lower, and can store more cold energy. In addition, if the temperature of the cooling surface 5a of the Peltier element 5 is minus 20 degrees or less and lower than the temperature of the air cooled by the evaporator E2, the effect of cold storage can be obtained more.

  The water in the water heat exchanger 7 provided on the heating surface 5b of the Peltier element 5 is heated and then supplied to the upper part of the hot water storage tank 10 via a radiator 11 having a blower (not shown). A circulation circuit is formed that recirculates from the lower part to the water heat exchanger. The pump 12 supplies hot water heated by the water heat exchanger 7 to the upper part of the hot water storage tank 10, and the pump 13 conversely circulates hot water in the upper part of the hot water storage tank to the heat exchanger side.

  When the Peltier element 5 is energized, the cold air cooled by the cooling surface 5a cools the temperature in the freezer compartment to a temperature lower than the normal refrigerator operation temperature, and the hot water heated by the heating surface 5b of the Peltier element 5 is The hot water storage tank 10 is supplied. The temperature of the hot water supplied to the hot water storage tank 10 is controlled by changing the circulation amount of the pump 12, and is controlled to be, for example, about 90 degrees before boiling. When the temperature of the hot water in the hot water storage tank 10 output from the lower part of the hot water storage tank 10 exceeds this set temperature, the heat storage in the hot water storage tank 10 cannot be performed, so the blower attached to the radiator 11 is operated. Dissipate heat to the atmosphere. This heat radiation is performed so as to correspond to the amount of heat obtained from the heat radiation surface 5 b of the Peltier element 5. Furthermore, when the temperature in the freezer compartment F becomes minus 40 degrees or less, energization to the Peltier element 5 is further stopped, and cold storage and heat storage are ended.

  As for the operation of the hot water storage, for example, if a refrigeration cycle that operates CO2 (carbon dioxide) in a supercritical state is used as a refrigerant, hot water of about 90 degrees can be directly boiled. Heating by the Peltier element 5 is performed in an auxiliary manner, and the power required for the operation of the refrigeration cycle can be saved. When the electric heater is used as a heat source or when a refrigeration cycle using a chlorofluorocarbon refrigerant is used, the temperature of hot water in the hot water storage tank 10 may be set to about 65 degrees. The temperature of the hot water to be heated is set to a temperature of about 65 degrees.

  Thus, when supplying electric power to the Peltier element 5, heat absorption and heat dissipation can be performed simultaneously, and loss during conversion can be suppressed. Further, if the DC / DC converter is operated to the side where power is supplied to the DC power line, and at the same time circulation of cold air and circulation of hot water by the pump 13 are performed, the generated power generated by the heat transfer in the Peltier element 5 is boosted and supplied can do. In this case, the larger the temperature difference between the heat absorbing surface and the heat radiating surface, the larger the generated power, but considering the deterioration of the stored product in the freezer compartment F, the Peltier until the temperature in the freezer compartment F rises to about minus 20 degrees. Power generation by the element 5 can be continued. Note that further power generation can be performed without considering deterioration of stored products such as in an emergency.

  In FIG. 1, reference numeral 14 denotes a heat source machine that houses a refrigeration cycle, and hot water heated by the refrigeration cycle is supplied from the upper part of the hot water storage tank 10. Reference numeral 15 denotes a city water supply port, and water is poured every time hot water in the hot water storage tank 10 is supplied from the upper hot water supply port 16.

  Thus, using a part of the electric power generated by the solar cell module 1, the temperature reduction of the freezer compartment F and the hot water supply of the hot water storage tank 10 can be performed at the same time, for example, surplus power can be stored / stored. Cold storage / heat storage can be used as it is. Alternatively, it can be converted into electric power for use.

  FIG. 3 is a circuit diagram showing an example of a DC / DC converter. In this figure, terminals A and B are connected to a DC power line connecting the solar cell module 1 and the power converter 2, and terminals C and D are connected to a Peltier element 5. When the relay contacts R1 and R2 are closed (relay contacts R3 and R4 are open), the reactor 20, the switching element 21, the diode 22, and the capacitor 23 constitute a booster circuit, and the voltage between the terminals A and B is The voltage is boosted to a predetermined voltage and then applied to the Peltier element 5 from the terminals C and D. Since this booster circuit can use a general-purpose type circuit that controls the ON duty within one period with a predetermined period of ON / OFF of the switching element 21, a detailed description of the operation is omitted. If the value of the current supplied to the Peltier element 5 is measured (current detector is not shown) and the step-up ratio is controlled so that the supplied DC power becomes a set value, the amount of heat absorbed / heat released by the Peltier element 5 is controlled. be able to.

  When the relay contacts R3 and R4 are closed (the relay contacts R1 and R2 are open), the reactor 24, the switching element 25, the diode 26, and the capacitor 27 constitute a booster circuit, and the voltage between the terminals C and D is After boosting to a predetermined voltage, the voltage is applied from the terminals A and B to the wiring for DC power. If the current value output from the Peltier element 5 is measured (current detector is not shown) and the step-up ratio is controlled so that the DC power supplied to the wiring becomes the set value, the power generation amount of the Peltier element 5 is controlled. be able to. Since the operation of this booster circuit is the same as that of the booster circuit, description thereof is omitted.

  The present invention can be applied to devices that efficiently use renewable energy such as solar cells.

DESCRIPTION OF SYMBOLS 1 Solar cell module 2 Power converter 3 Indoor breaker 4 DC / DC converter 5 Peltier element 5a Cooling surface 5b Heating surface 7 Hydrothermal exchanger 8 Refrigeration cold air circulation direction 9 Refrigeration cold air circulation direction 10 Hot water storage tank 11 Radiator 12 Pump 13 Pump 14 Heat source machine 15 City water supply port 16 Hot water supply port 20 Reactor 21 Switching element 22 Diode 23 Capacitor 24 Reactor 25 Switching element 26 Diode 27 Capacitor

Claims (3)

A DC / DC converter configured to be connectable to the DC power of the power conversion device that converts DC power obtained from renewable energy such as a solar cell into AC power;
A peltier element is connected to the DC / DC converter by wiring, and a heat absorption surface of the peltier element is desired in a duct for circulating cold air in a freezer, and a heat radiation surface of the peltier element is provided in a hot water storage tank via a water heat exchanger. It is configured to exchange heat with hot water, and a part of direct current power obtained from the renewable energy is supplied to the Peltier element via the DC / DC converter, and at least in the cold or hot water storage tank in the freezer A power control apparatus having a configuration in which direct current power obtained from the Peltier element is supplied to the power converter via the DC / DC converter using any one of the above-mentioned heats.   2. The electric power according to claim 1, wherein a radiator is provided in a circulation circuit that circulates between a heat radiation surface of the Peltier element and a hot water storage tank, and the Peltier element is radiated by the radiator. Control device. The power control apparatus according to claim 2, wherein the power conversion apparatus and the DC / DC converter are housed in a single casing or configured integrally.

Images