JP6121949B2 - Energy storage system for photovoltaic power generation - Google Patents

Description

  The present invention relates to a power storage system for solar power generation in which an output of a solar battery is grid-connected to a commercial power source and a power storage system can be easily added to a solar power generation system that does not include an existing storage battery.

Patent Document 1 discloses a solar cell module that receives light and outputs DC power, a power conditioner that converts DC power into AC power, AC power from the power conditioner, or AC power from a commercial power source. A distribution board for supplying a plurality of home loads, a plurality of sensors for measuring currents flowing to each of the plurality of home loads, a detection device to which outputs of the plurality of sensors are input, and the plurality A solar power generation system including a display device that displays the power consumption of each household load calculated based on the output from the sensor is disclosed.

The solar power generation system described in Patent Literature 1 is a solar power generation system that sells surplus power of solar power generation to a commercial power source with a configuration that does not include a storage battery.

Patent Document 2 discloses an inverter device that converts a DC voltage input from a solar cell into an alternating current and outputs it, and a distribution board that inputs a commercial power supply and branches and outputs via a branch breaker on the lower side of the main leakage breaker. In the photovoltaic power generation system comprising: a grid interconnection protection device for controlling grid interconnection of power between the commercial power source and the solar cell; and a disconnection switching device controlled by the grid interconnection protection device. There is disclosed a photovoltaic power generation system in which an electrical panel includes the grid connection protection device and the disconnection switch, and the disconnect switch is connected in parallel with the branch breaker on the lower side of the main leakage breaker.

In the photovoltaic power generation system described in Patent Document 2, as described in paragraph [0014], the power output from the solar cell is supplied to an illuminating device or an electrical wiring outlet as an emergency load at the time of a commercial power failure. The

In Patent Document 3, home electric power equipment such as an air conditioner that exhausts air in a house from one place in the house and a hot water supply device that covers hot water in the house is installed. The power facility is a power supply in which power is supplied by a solar cell system mainly composed of a storage battery for charging power obtained from a solar battery or midnight power and a controller for controlling a power charging method for the storage battery. A system is disclosed.

As described in paragraphs [0025] to [0027], the power supply system described in Patent Document 3 supplies power to a power consuming facility from a commercial power supply or from a storage battery that is supplied from a solar battery or midnight power. However, it is a system provided so that the output from the switch for power input from the commercial power supply or the storage battery is supplied to all the power consuming equipment.

JP 2014-11863 A Japanese Patent Laid-Open No. 9-182298 Japanese Patent Application Laid-Open No. 5-9539

However, although the technology described in Patent Document 1 sells the power of solar power generation to a commercial power supply, the solar power generation system is disconnected from the commercial power supply system for safety reasons such as restoration work when the commercial power supply fails. Therefore, there was a problem that an emergency power supply could not be secured.

Moreover, although the technique of patent document 2 is a solar power generation system which can supply the electric power from a solar cell to an emergency load when a commercial power supply fails, it is generally provided in a distribution board. In addition to the existing breaker, the grid connection protection device and the disconnection switchgear are provided, so that in the case of a new construction, the distribution board described in Patent Document 2 can be easily installed, but the breaker has already been installed in the distribution board. In a house where a photovoltaic power generation system that is only provided is installed, there is an existing distribution board, so if you try to introduce the photovoltaic power generation system described in Patent Document 2 that can cope with a commercial power failure Because the distribution board is different in size and form from the existing distribution board, there was a problem that the existing distribution board had to be removed and a large distribution board including wall construction had to be replaced. .

In addition, the technology described in Patent Document 3 does not describe the supply of power to an emergency power consumption facility when the commercial power source fails. If the commercial power source fails at night, the house becomes dark and unsafe. There was a problem of becoming. Furthermore, when an additional power supply system described in Patent Document 3 is to be installed in an existing photovoltaic power generation system that does not include a storage battery, there is a problem that a large additional work such as installation of a controller or the like must be performed. It was.

The present invention was devised in view of these problems. In a house where an existing photovoltaic power generation system without a storage battery is installed, the existing distribution board can be diverted without removing the existing distribution board. In such a state, an additional storage system can be installed to supply power only to the emergency load, to all power consumption facilities, or to a power generation system for solar power generation that can supply power to any power consumption facility. The issue is to provide.

The power storage system 1 for photovoltaic power generation according to claim 1 converts the direct current output of the solar battery 4 into alternating current through the power conditioner 20 and connects it to the commercial power source 3 to input the commercial power source 3. A DC / DC converter 6 that converts the DC voltage of the solar cell 4 into another DC voltage is added to the existing photovoltaic power generation system 40 having the distribution board 5 that branches and outputs the trunk line on the input side into a plurality of circuits. A wiring 50 extending from the DC / DC converter 6, a storage battery 9 provided downstream of the DC / DC converter 6, and a storage battery inserted between the storage battery 9 and the DC / DC converter 6. 9, a charge / discharge controller 7 that performs charge / discharge control, a DC / AC inverter 8 that is disposed downstream of the charge / discharge controller 7 and converts direct current to alternating current, and the DC / AC inverter And a selector switch 10 disposed on the downstream side of the switch 8 for switching the input side contacts a and b with the input side as two contacts a and b including the contact b with the DC / AC inverter 8 and the output side as one terminal c. The power storage device 2 having wirings 51 and 52 extending from the input side 1 contact a and the output side 1 terminal c of the changeover switch 10 is connected to the DC / DC converter 6. 50 is connected to the wiring between the solar cell 4 and the power conditioner 20, and the wirings 51 and 52 extended from the changeover switch 10 are connected in a circuit form in which they are inserted into the trunk line or branch circuit of the distribution board 5. In addition, it is characterized by being additionally installed.

A storage system 1 for photovoltaic power generation according to a second aspect is the power distribution system according to the first aspect, wherein the wirings 51 and 52 connected to the changeover switch 10 by the wirings 51 and 52 extending from the power storage device 2 to the outside are divided into power distribution units. In the case of a circuit configuration inserted in a branch circuit that outputs to the emergency load 30 in the panel 5, when the commercial power source 3 is energized, the power from the commercial power source 3 or the solar cell 4 is supplied to the emergency load 30 side. When the commercial power supply 3 fails, the changeover switch 10 is preferentially switched so as to supply the power from the storage battery 9 charged by the power supply from the solar battery 4 to the emergency load 30 side.

A power storage system 1 for photovoltaic power generation according to a third aspect is the power distribution system according to the first aspect, wherein the wirings 51 and 52 connected to the changeover switch 10 by the wirings 51 and 52 extending to the outside from the power storage device 2 In the case of a circuit configuration in which the commercial power source 3 in the panel 5 is inserted into the main line supplying power, the power from the commercial power source 3 or the solar battery 4 is supplied to the main line of the distribution panel 5 when the commercial power source 3 is energized. When the commercial power source 3 is out of power, the changeover switch 10 is preferentially switched so that the power from the storage battery 9 charged by the power supply from the solar battery 4 is supplied to the main line of the distribution board 5.

A power storage system 1 for photovoltaic power generation according to a fourth aspect is the power distribution system according to the first aspect, wherein the wirings 51 and 52 connected to the changeover switch 10 by the wirings 51 and 52 extending from the power storage device 2 to the outside are divided into power distribution units. In the case of a circuit configuration in which the commercial power source 3 in the panel 5 is inserted into the main line that feeds power, the power from the commercial power source 3 or the solar battery 4 is supplied to the main line of the distribution panel 5 when the solar cell 4 generates power. When the solar battery 4 cannot generate power, the switch 10 is switched so as to supply the power from the storage battery 9 charged by the power supply from the solar battery 4 to the main line of the distribution board 5, and the voltage of the storage battery 9 is discharged. When the power supply voltage drops, the commercial power source 3 is preferentially switched by the changeover switch 10.

The power storage system 1 for photovoltaic power generation according to claim 1 does not require the removal work of the existing distribution board 5, can use the existing distribution board 5, and does not have an existing storage battery It is possible to install the power storage device 2 capable of storing electric power generated by solar power generation at low cost and early by simple construction.

The power storage system 1 for solar power generation according to claim 2 has the same effect as that of claim 1, and power supply from the solar cell 4 is cut off when the commercial power source 3 is cut off, but is stored by solar power generation. Further, the power from the storage battery 9 can be used to stably supply power to the emergency load 30 such as a communication device such as a telephone or a fax machine or an emergency lighting device.

The power storage system 1 for solar power generation according to claim 3 has the same effect as that of claim 1, and power supply from the solar cell 4 is cut off when the commercial power source 3 is powered off, but is stored by solar power generation. Using the power from the storage battery 9, communication equipment such as telephones and fax machines, emergency loads 30 such as emergency lighting fixtures, and loads 31, 32, 33, 34 such as lighting, refrigerators, air conditioners, etc. 35 has an effect that power can be supplied stably.

The power storage system 1 for solar power generation according to claim 4 has the same effect as that of claim 1 and is stored by solar power generation when it is difficult to generate power from the solar cell 4 at night, rainy weather, snowfall, cloudiness, and the like. In addition, the power from the storage battery 9 can be selected and fed by the changeover switch 10 to reduce the power cost.

It is a schematic explanatory drawing of the electrical storage system for solar power generation in the case of the form which inserted and connected the wiring to the branch circuit of the distribution board of this invention. It is a schematic explanatory drawing of the electrical storage system for solar power generation in the case of the form of having inserted and connected with the main line of the distribution board of this invention. It is an outline explanatory view of a photovoltaic power generation system before introduction of a power storage system for photovoltaic power generation of the present invention.

The power storage system 1 for photovoltaic power generation according to the present invention converts the direct current output of the solar battery 4 into alternating current via the power conditioner 20 and connects it to the commercial power source 3 to input the commercial power source 3 to the input side. A DC / DC converter 6 that converts the DC voltage of the solar cell 4 into another DC voltage, and a DC / DC converter 6 that includes a distribution board 5 that branches and outputs the main line into a plurality of circuits, and the DC The wiring 50 extended from the DC / DC converter 6, the storage battery 9 provided on the downstream side of the DC / DC converter 6, and charging / discharging of the storage battery 9 inserted between the storage battery 9 and the DC / DC converter 6 A charge / discharge controller 7 that performs control, a DC / AC inverter 8 that is arranged downstream from the charge / discharge controller 7 to convert direct current into alternating current, and under the DC / AC inverter 8 The changeover switch 10 for switching the input side contacts a and b with the input side as two contacts a and b including the contact b with the DC / AC inverter 8 and the output side as one terminal c, and the changeover switch The power storage device 2 provided with wirings 51 and 52 respectively extending from one input side 1 contact point a and the output side 1 terminal c, and the wiring 50 extended from the DC / DC converter 6 as a solar cell. 1 and FIG. 2 is connected to the wiring between the power switch 4 and the power conditioner 20, and wirings 51 and 52 extending from the changeover switch 10 are inserted into the trunk of the distribution board 5. Then, it is connected and installed at the location C shown in FIG. 2 or at the location B shown in FIG.

As shown in FIG. 3, the existing photovoltaic power generation system 40 includes solar cells 4, a DC / AC conversion inverter that converts DC power into AC power that is the same as system power, and solar power when there is an abnormality on the system side such as a power failure. And a power conditioner 20 having a grid interconnection protection device for safely stopping the power generation system.

As shown in FIG. 3, in the existing distribution board 5, a solar cell breaker 22 is inserted into the circuit from the solar cell 4, and a main circuit breaker 21 is inserted into the main line from the commercial power source 3. Branch breakers 23, 24, 25, 26, 27, and 28 are inserted in branch circuits that are branched according to loads in the house such as communication devices, lighting fixtures, electrical outlets, televisions, refrigerators, and washing machines. . And it is output to each load 30, 31, 32, 33, 34, 35.

As shown in FIG. 1 or 2, the power storage device 2 is interposed between the solar cell 3 and the distribution board 5. The power storage device 2 includes a DC / DC converter 6 that converts a DC voltage into another DC voltage, a wiring 50 that extends from the DC / DC converter 6, a storage battery 9, the storage battery 9, and a DC / DC A charge / discharge controller 7 which is inserted between the DC converter 6 and performs charge / discharge control of the storage battery 9; a DC / AC inverter 8 which is disposed downstream from the charge / discharge controller 7 and converts direct current into alternating current; A changeover switch 10 disposed on the downstream side of the DC / AC inverter 8 and wirings 51 and 52 respectively extending from an input side one contact a and an output side one terminal c of the changeover switch 10 are provided.

On the input side of the power storage device 2, a wiring 50 extending to the outside from the DC / DC converter 6 is connected to the solar cell 4 at the location A shown in FIG. 1 or 2 and connected in parallel with the power conditioner 20. A circuit is formed. Thereby, if the electric power of the solar cell 4 is always generated without being affected by the power failure of the commercial power 3 and without being affected by the power conditioner 20 of the solar power generation system 40, Power is supplied.

The DC / DC converter 6 converts the electric power of the solar battery 4 into a direct current voltage of the storage battery 9 although it is a direct current voltage. For example, 400 V from the solar battery 4 is converted into 12 to 24 V of the storage battery 9. Thereby, the storage battery 9 can be charged.

The charge / discharge controller 7 is inserted in the wiring between the DC / DC converter 6 and the storage battery 9 on the solar battery 4 side which is the input side, and is connected to the storage battery 9 and the DC / DC on the existing distribution board 5 side which is the output side. The battery 9 is inserted into the wiring between the AC inverter 8 and the state of the storage battery 9 is monitored. When the storage battery 9 is fully charged, charge / discharge control of the storage battery 9 is performed such that the charging current from the solar battery 4 is cut off.

The DC / AC inverter 8 converts the direct current voltage of the storage battery 9 into an alternating current voltage so as to have the same electric power as that of the commercial power supply 3. For example, the DC voltage 24V from the storage battery 9 is converted into the AC voltage 100V of the commercial power source 3.

As shown in FIG. 1 or FIG. 2, a selector switch 10 and outlets 11 and 12 that can be used in an emergency are arranged in a circuit on the downstream side of the DC / AC inverter 8 and on the output side. The changeover switch 10 is configured to switch the input side contacts a and b by setting the output side as one terminal c and the input side as two contacts a and b. A wiring from the DC / AC inverter 8 is connected to one contact b on the input side of the changeover switch 10, and a wiring 51 extending from the other input side contact a and the output side terminal c to the outside of the power storage device 2, 52 is connected to the circuit of the distribution board 5 in the form of a circuit inserted in the trunk line or branch circuit in the distribution board 5.

As shown in FIG. 1, the wirings 51, 52 connected to the changeover switch 10 by the wirings 51, 52 extending to the outside from the power storage device 2 are used as branch circuits that output to the emergency load 30 in the distribution board 5. In the case of the inserted circuit configuration, when the commercial power source 3 is energized, the power from the commercial power source 3 or the solar cell 4 is supplied to the emergency load 30 side, and during the commercial power source 3 power failure, the power from the solar cell 4 is supplied. Control is performed so that the changeover switch 10 is switched preferentially so as to supply power from the storage battery 9 charged by power feeding to the emergency load 30 side.

This will be described with reference to FIG. When the commercial power source 3 is energized, the change-over switch 10 is connected to the contact a and the terminal c, so that the power from the commercial power source 3 or the solar cell 4 is supplied in the direction indicated by the dotted line in FIG. Supplied. On the other hand, when the commercial power supply 3 is out of power, the contact point b and the terminal c are connected to the changeover switch 10, so that the power from the storage battery 9 charged by the power supply from the solar battery 4 is supplied in the direction indicated by the solid line in FIG. The changeover switch 10 is preferentially switched so as to be supplied to the emergency load 30 side. As a result, even when the commercial power supply 3 is out of power, if you select and wire the load you want to use in an emergency from the load of telephones, lighting fixtures, electrical outlets, TVs, etc. Can always be used without any influence. If the capacity | capacitance of the storage battery 9 is made into the capacity | capacitance which can satisfy | fill the request | requirement load, all the loads in a house can also be made usable.

Next, as shown in FIG. 2, the trunk lines 51, 52 connected to the changeover switch 10 by the wirings 51, 52 extending from the power storage device 2 to the outside are fed with the commercial power supply 3 in the distribution board 5. In the case of the circuit configuration inserted in the storage battery 9, the usage mode of the storage battery 9 differs depending on whether the commercial power source 3 is out of power or when the power generation of the solar cell 4 is difficult.

First, when the commercial power source 3 is energized, the power from the commercial power source 3 or the solar cell 4 is supplied to the main line of the distribution board 5, and when the commercial power source 3 is powered down, it is charged by power feeding from the solar cell 4. Control is performed so that the changeover switch 10 is switched preferentially so as to supply power from the storage battery 9 to the main line of the distribution board 5.

This will be described with reference to FIG. When the commercial power source 3 is energized, the change-over switch 10 is connected to the contact a and the terminal c, so that the power from the commercial power source 3 or the solar cell 4 is supplied in the direction indicated by the dotted line in FIG. , 32, 33, 34, 35 side. On the other hand, when the commercial power supply 3 is out of power, the contact b and the terminal c are connected to the changeover switch 10, so that the power from the storage battery 9 charged by the power supply from the solar battery 4 is supplied in the direction indicated by the solid line in FIG. Then, the selector switch 10 is preferentially switched so as to be supplied to all the loads 30, 31, 32, 33, 34, and 35. Thereby, all the loads 30, 31, 32, 33, 34, and 35 can be always used without influence at the time of electricity supply or a power failure.

Next, when the solar cell 4 is generating power, power is supplied in the same way as when the commercial power source 3 is energized. However, when it is difficult to generate power from the solar cell 4 such as at night, rainy weather, snowfall, or cloudiness, The changeover switch 10 is set to supply power from the commercial power supply 3 with priority. Accordingly, since the contact point a and the terminal c are connected to the changeover switch 10, the power from the commercial power source 3 is supplied in the direction indicated by the dotted line in FIG. 2 and all the loads 30, 31, 32, 33, 34, and 35 are on the side. To be supplied. However, this increases the cost because the power stored in the power storage device 2 is not used.

Therefore, a manual operation button (not shown) of the changeover switch 10 is provided, the contact b and the terminal c are connected by the manual operation of the changeover switch 10, and the electric power from the storage battery 9 charged by the power supply from the solar battery 4 is illustrated. 2 is supplied in the direction indicated by the solid line and supplied to all the loads 30, 31, 32, 33, 34, and 35. As a result, when the solar battery 4 becomes difficult to generate power at night or the like, the power from the storage battery 9 of the power storage device 2 is used without using the commercial power supply 3, so that the cost can be suppressed.

However, when the solar battery 4 becomes difficult to generate power, if the power from the storage battery 9 of the power storage device 2 is continuously supplied without supplying the power of the commercial power supply 3, the discharge of the storage battery 9 proceeds and the voltage of the storage battery 9 becomes The load 30, 31, 32, 33, 34, 35 falls below a predetermined voltage that is the minimum level at which the load can be used. Therefore, a voltage measuring means (not shown) is provided in the storage battery 9, and when the voltage measuring means reaches the predetermined voltage, the voltage measuring means contacts the input side of the changeover switch 10 with respect to the changeover switch 10. Control is performed so as to switch from b to contact a, contact a of the changeover switch and terminal c are connected, and power from the commercial power supply 3 is supplied to the loads 30, 31, 32, 33, 34, and 35 side. .

Thereby, when it becomes difficult for the solar cell 4 to generate power, the power supply from the commercial power source 3 is suppressed to the minimum, and the power is not generated in the loads 30, 31, 32, 33, 34, and 35. can do.

As another effect, for example, when the effect of selling surplus power of solar power generation to a commercial power source has been reduced, the solar battery 4 can generate power by additionally installing the power storage system 1 for solar power generation according to the present invention. The power storage 9 is charged while supplying power to the distribution board 5 without selling the power from the solar cell 4 when the solar cell 4 is difficult to generate power. It is possible to minimize the power cost by supplying the power from the storage battery 9 to the minimum.

DESCRIPTION OF SYMBOLS 1 Power storage system 2 for photovoltaic power generation 2 Power storage device 3 Commercial power supply 4 Solar battery 5 Distribution board 6 DC / DC converter 7 Charge / discharge controller 8 DC / AC inverter 9 Storage battery 10 Changeover switch 11 Outlet 12 Outlet 20 Power conditioner 21 Main breaker 22 Solar cell breaker 23 Branch breaker 24 Branch breaker 25 Branch breaker 26 Branch breaker 27 Branch breaker 28 Branch breaker 30 Emergency load 31 Load 32 Load 33 Load 34 Load 35 Load 40 Solar power generation system 50 Wiring 51 Wiring 52 Wiring

Claims (4)

A distribution board that converts the DC output of a solar cell into AC via a power conditioner and connects it to a commercial power supply, inputs the commercial power supply, branches the main trunk on the input side into multiple circuits, and outputs the distribution board To the existing solar power generation system
A DC / DC converter that converts the DC voltage of the solar cell into another DC voltage;
Wiring extending from the DC / DC converter;
A storage battery provided downstream of the DC / DC converter;
A charge / discharge controller inserted between the storage battery and the DC / DC converter and performing charge / discharge control of the storage battery;
A DC / AC inverter disposed downstream from the charge / discharge controller for converting direct current to alternating current;
A selector switch disposed on the downstream side of the DC / AC inverter, wherein the input side is a two-contact including a contact with the DC / AC inverter and the output side is a terminal and the input-side contact is switched;
A power storage device comprising wiring extending from one input side contact and one output side terminal of the changeover switch;
A circuit in which wiring extending from the DC / DC converter is connected to wiring between a solar cell and a power conditioner, and wiring extending from the changeover switch is inserted into a main line or branch circuit of a distribution board A storage system for photovoltaic power generation, which is connected in a form and additionally installed.   In the case of a circuit configuration in which wiring connected to the changeover switch with wiring extending outside from the power storage device is inserted into a branch circuit that outputs to an emergency load in the distribution board, Supply power from the power supply or solar battery to the emergency load side, and preferentially supply power from the storage battery charged by power supply from the solar battery to the emergency load side during a commercial power outage The power storage system for photovoltaic power generation according to claim 1, wherein the changeover switch is switched.   In the case of a circuit configuration in which the wiring connected to the changeover switch with the wiring extending from the power storage device to the outside is inserted into the main line that feeds the commercial power in the distribution board, the commercial power or The power from the solar battery is supplied to the main line of the distribution board, and in the event of a commercial power failure, the power from the storage battery charged by the power supply from the solar battery is preferentially supplied to the main line of the distribution board. The power storage system for photovoltaic power generation according to claim 1, wherein the changeover switch is switched.   In the case of a circuit configuration in which wiring connected to the changeover switch with wiring extending outside from the power storage device is inserted into a main line that feeds commercial power in the distribution board, at the time of solar cell power generation, Supply power from the solar battery to the main board of the distribution board, and switch to supply power from the storage battery charged by power supply from the solar battery to the main line of the distribution board when the solar battery cannot generate electricity The storage system for photovoltaic power generation according to claim 1, wherein the storage system is switched by a switch, and when the voltage of the storage battery decreases due to discharge, the switch is preferentially switched to a commercial power source by the switch.

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