JP2016086594A - Power supply system, power supply apparatus and control method for power supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply system capable of controlling operations of a plurality of distributed power sources in such a manner that an environmental burden is reduced.SOLUTION: The power supply system comprises: a storage battery 12 and a load 32 to which power is supplied; a solar cell 11 and a power generation device 33 for supplying power; a power supply apparatus (power conditioner 20) which controls power; and a current sensor 40 which makes the power generation device generate power by detecting a predetermined current. The power supply apparatus includes a control part which supplies power generated by the solar cell to the storage battery, supplies surplus power to the load and supplies power that is lacked even with the surplus power, from the power generation device to the load by controlling the current that is detected by the current sensor.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power supply system, a power supply device, and a control method for the power supply system.

  As a power conditioner of a power supply system equipped with power generation equipment such as solar cells, grid-connected operation that outputs AC power linked to a commercial power system (hereinafter abbreviated as appropriate), regardless of the system There is known one capable of independent operation that outputs AC power. As a distributed power source, a power supply system including not only a solar battery but also a power generation device or the like is known.

  Among such power conditioners, there is one that makes it possible to sell power to the grid when surplus power is generated during grid interconnection operation. For example, Patent Document 1 preferentially supplies power generated by a solar cell (solar power generation unit) to a load if power generated by a power generation device (gas power generation unit) can be sold to the system, Disclosed is a power supply system capable of economical operation, in which power from a solar cell is preferentially supplied to a load if power selling is not possible.

International Publication No. 2013/046713

  Here, in recent years, there is a demand for an electric power supply system that places importance on the environment rather than economic efficiency such as power sale and gives priority to the use of a distributed power source with a smaller burden on the environment.

  An object of the present invention made in view of the above problems is to provide a power supply system, a power supply device, and a control method for the power supply system that can control the operation of a plurality of distributed power sources so that the burden on the environment is reduced. It is to provide.

  In order to solve the above-described problems, a power supply system according to the present invention includes a storage battery and a load that receive power supply, a solar battery and a power generation device that supply the power, and a power supply device that controls the power. A power supply system comprising: a current sensor configured to generate the power generation device by detecting a predetermined current, wherein the power supply device supplies power generated by the solar cell to the storage battery, and surplus power And a control unit that controls the current detected by the current sensor to supply the load from the power generation device to the load.

  Moreover, in the power supply system according to the present invention, the power supply device further includes a first power conversion unit and a second power conversion unit different from the first power conversion unit, and receives power from the solar cell. A first path that causes the current sensor to detect the predetermined current via the first power converter and supply the load to the load; and a second path that supplies the load to the load via the second power converter. It is preferable to have a route and supply the surplus power to the load through the second route.

  Moreover, the electric power supply system which concerns on this invention WHEREIN: The said electric power supply apparatus adjusts the electric current which flows through the said 1st path | route using the said 1st electric power conversion part, The electric power supplied to the said load from the said electric power generating apparatus is provided. It is preferable to change.

  In the power supply system according to the present invention, it is preferable that the power generation device is a fuel cell, and the predetermined current is a forward current.

  Furthermore, in order to solve the above-described problems, a power supply device according to the present invention detects a storage battery and a load that receive power supply, a solar battery and a power generation device that supplies the power, and a predetermined current. A power supply device for controlling the power used in a power supply system comprising a current sensor for generating the power generation device, wherein the power generated by the solar cell is supplied to the storage battery, and surplus power is supplied to the storage battery. A control unit configured to supply the load to the load by controlling the current detected by the current sensor to be supplied to the load and detected by the current sensor even when the surplus power is insufficient.

  Furthermore, in order to solve the above-described problems, a control method for a power supply system according to the present invention includes a storage battery and a load that receive power supply, a solar battery and a power generation device that supplies the power, and the power control. A power supply system comprising: a power supply device that performs power generation by detecting a predetermined current; and a power sensor that generates power by detecting a predetermined current, the power generated by the solar cell being supplied to the storage battery, Supplying surplus power to the load; and supplying power from the power generator to the load by controlling a current detected by the current sensor for power that is also insufficient due to the surplus power. To do.

  According to the power supply system, the power supply device, and the control method for the power supply system according to the present invention, it is possible to control the operation of a plurality of distributed power supplies so as to reduce the burden on the environment.

1 is a block diagram of a power supply system according to an embodiment of the present invention. It is a figure which shows the example of control of an electric power supply system. It is a flowchart explaining the control method of the electric power supply system which concerns on one Embodiment of this invention. It is a figure which shows the example of control of the electric power supply system of a comparative example.

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

(Embodiment)
First, a power supply system according to an embodiment of the present invention will be described. The power supply system according to the present embodiment includes a distributed power source that supplies power that can be sold and / or a distributed power source that supplies power that cannot be sold, in addition to the power supplied from the system (commercial power system). Prepare. A distributed power source that supplies power that can be sold is a system that supplies power by, for example, solar power generation. On the other hand, a distributed power source that supplies electric power that cannot be sold includes, for example, a storage battery system that can charge and discharge electric power, a fuel cell system that includes a fuel cell such as a SOFC (Solid Oxide Fuel Cell), and a gas that generates power from gas fuel. Such as a generator system. In the present embodiment, a solar battery as a distributed power source that supplies power that can be sold, a storage battery as a distributed power source that supplies power that cannot be sold, and a power generator that is a fuel cell or a gas generator. An example is provided.

(Configuration of power supply system)
FIG. 1 is a block diagram showing a schematic configuration of a power supply system according to an embodiment of the present invention. The power supply system according to the present embodiment includes a solar cell 11, a storage battery 12, a power conditioner 20 (power supply device), a distribution board 31, a load 32, a power generation device 33, and a current sensor 40. Prepare. Here, the power generation device 33 is configured by a fuel cell or a gas generator. The power supply system normally performs an interconnection operation with the grid, and supplies the load 32 with the power supplied from the grid and the power from each distributed power source (solar cell 11, storage battery 12, power generator 33). In addition, the power supply system performs a self-sustaining operation when there is no power supply from the system, such as at the time of a power failure, and supplies power from each distributed power source (solar cell 11, storage battery 12, power generation device 33) to the load 32. When the power supply system performs a self-sustained operation, each distributed power source (solar battery 11, storage battery 12, and power generation device 33) is disconnected from the system, and the power supply system performs a connected operation. Each distributed power supply (solar cell 11, storage battery 12, power generation device 33) is in parallel with the system.

  In FIG. 1, a solid line connecting the functional blocks represents a wiring through which power flows, and a broken line connecting the current sensor 40 and the power generation device 33 represents a flow of information to be communicated (detection signal of the current sensor 40). Here, there is a flow of control signals or information to be communicated between the control unit 25 and many functional blocks, which will be described later. Control signal and information communication may be wired communication or wireless communication. Various methods can be adopted for communication of control signals and information including each layer. For example, communication by a short-range communication method such as ZigBee (registered trademark) can be employed. In addition, various transmission media such as infrared communication and power line communication (PLC) can be used. In addition, various protocols such as ZigBee SEP 2.0 (Smart Energy Profile 2.0), ECHONET Lite (registered trademark), etc. are defined on lower layers including the physical layer suitable for each communication. A communication protocol may be operated.

  The solar cell 11 converts sunlight energy into DC power. The solar cell 11 is configured such that, for example, power generation units having photoelectric conversion cells are connected in a matrix and output a predetermined direct current (for example, 10 A). The type of solar cell 11 is not limited as long as it is capable of photoelectric conversion, such as a silicon-based polycrystalline solar cell, a silicon-based single crystal solar cell, or a thin-film solar cell such as CIGS.

  The storage battery 12 includes a storage battery such as a lithium ion battery or a nickel metal hydride battery. The storage battery 12 can supply electric power by discharging the charged electric power. Further, the storage battery 12 can charge power supplied from the power generation device 33 in addition to power supplied from the grid and the solar battery 11.

  The power conditioner 20 (power supply device) converts the DC power supplied from the solar battery 11 and the storage battery 12 and the AC power supplied from the grid and the power generation device 33, and is connected to the grid and operates independently. Operation switching control is performed. The power conditioner 20 includes an inverter 21 (first power conversion unit), interconnection operation switches 22 and 23, a self-sustaining operation switch 24, a DC / AC unit 26 (second power conversion unit), and a DC / DC unit. 27 to 29 and a control unit 25 that controls the entire power conditioner 20. In addition, you may comprise so that the interconnection operation switch 23 may be taken out of the power conditioner 20. FIG.

  The DC / DC units 27 to 29 are for boosting or stepping down the DC power at the previous stage of the inverter 21. For example, the DC / DC unit 27 boosts the DC power from the solar cell 11 to a certain voltage and supplies it to the inverter 21. Further, the DC / DC unit 28 boosts the DC power from the storage battery 12 to a certain voltage and supplies it to the inverter 21. The DC / DC unit 28 steps down the DC voltage from the inverter 21, the DC / DC unit 27, or the DC / DC unit 29 and supplies it to the storage battery 12. The DC / DC unit 29 is provided, for example, for drawing power from the power generation device 33 through the DC / AC unit 26.

  The inverter 21 (first power conversion unit) is a bidirectional inverter, which converts DC power supplied from the solar battery 11 and the storage battery 12 into AC power, and AC power supplied from the system. Convert to DC power.

  The interconnecting operation switches 22 and 23 and the self-supporting operation switch 24 are each configured by a relay, a transistor, and the like, and are on / off controlled. As illustrated, the self-sustaining operation switch 24 is disposed between the power generation device 33 and the storage battery 12. The interconnecting operation switches 22 and 23 and the independent operation switch 24 are switched synchronously so that both are not simultaneously turned on (or off). More specifically, when the interconnection operation switches 22 and 23 are turned on, the autonomous operation switch 24 is turned off synchronously, and when the interconnection operation switches 22 and 23 are turned off, the autonomous operation switch 24 is turned on synchronously. It becomes. Synchronous control of the interconnection operation switches 22 and 23 and the independent operation switch 24 is realized by hardware by branching the wiring of the control signal to the interconnection operation switches 22 and 23 to the independent operation switch 24. Needless to say, the ON and OFF states for the same control signal can be set separately for each switch. Further, the synchronous control of the interconnection operation switches 22 and 23 and the independent operation switch 24 can be realized by software by the control unit 25.

  The DC / AC unit 26 (second power conversion unit) enables the AC power generated by the power generation device 33 to be converted into DC power and supplied to the storage battery 12. In the present embodiment, the DC / AC unit 26 is a bidirectional power conversion unit that can convert DC power from the solar cell 11 into AC power. Here, when the DC / AC unit 26 is a bidirectional power conversion unit, the power conditioner 20 includes a DC / DC unit 29 that is a bidirectional converter, or a configuration in which the DC / DC unit 29 is omitted. (See FIG. 2). Note that the DC / AC unit 26 can be provided outside the power conditioner 20. In this case, the power conditioner 20 includes an input / output terminal that receives DC power input / output from an external DC / AC unit.

  The control unit 25 is composed of, for example, a microcomputer, and is based on the state such as an increase in system voltage or a power failure, etc., the inverter 21, the interconnecting operation switches 22, 23, the independent operation switch 24, the DC / AC unit 26, the DC / The operation of each unit such as the DC units 27 to 29 is controlled. The control unit 25 switches the interconnection operation switches 22 and 23 on and the independent operation switch 24 off during the interconnection operation. In addition, the control unit 25 switches the interconnection operation switches 22 and 23 off and the autonomous operation switch 24 on during the independent operation.

  The distribution board 31 distributes the power supplied from the grid during the grid operation to a plurality of branches and distributes it to the load 32. In addition, the distribution board 31 distributes the power supplied from a plurality of distributed power sources (solar cell 11, storage battery 12, power generation device 33) to a plurality of branches and distributes the load 32. Here, the load 32 is a power load that consumes power. For example, various electric appliances such as air conditioners, microwave ovens, and televisions used in homes, air conditioners and lighting equipment used in commercial and industrial facilities, and the like. Machine, lighting equipment, etc.

  The power generation device 33 is configured by a fuel cell or a gas generator. A fuel cell includes a cell that generates direct-current power through a chemical reaction with oxygen in the air using hydrogen, an inverter that converts the generated direct-current power into 100V or 200V AC power, and other accessories. Prepare. Here, the fuel cell as the power generation device 33 is a system that enables supply of AC power to the load 32 without using the power conditioner 20, and is always designed to be connected to the power conditioner 20. The system may be a versatile system. The gas generator generates power with a gas engine using a predetermined gas or the like as fuel.

  The power generation device 33 generates power while the corresponding current sensor 40 detects a forward power flow (current in the power purchase direction, corresponding to the predetermined current of the present invention), and follows the power consumption of the load 32 during power generation. Perform load following operation or rated operation with a predetermined rated power value. The power generation device 33 in the stopped state is activated when the current sensor 40 detects a forward flow. The tracking range during the load following operation is, for example, 0.5 to 3.0 kW, and the rated power value during the rated operation is, for example, 3.0 kW. The power generation device 33 performs a load following operation (for example, 0.5 to 3.0 kW) that follows the power consumption of the load 32 during the interconnection operation, and the rated operation based on the load following operation or the rated power value during the independent operation. It is good also as what performs.

  The current sensor 40 detects a current flowing between the system and the power generation device 33. In Japan, it is stipulated that the power generated by the power generation device 33 cannot be sold. Therefore, when the current sensor 40 detects a reverse power flow (current in the power selling direction) to the grid side, the power generation device 33 generates power. Stop. While the current sensor 40 detects a forward power flow, the power generation device 33 performs power generation in a load following operation or a rated operation on the assumption that power can be supplied to the load 32 from itself.

  When the power supply system performs the interconnection operation, the switches of the power conditioner 20 are controlled such that the interconnection operation switches 22 and 23 are on and the independent operation switch 24 is off.

  During the interconnected operation, AC 100 V (or 200 V) is supplied from the system and is supplied to the load 32. When the charging of the storage battery 12 has not been completed, the power conditioner 20 charges the storage battery 12 by converting AC power from the system into DC power. In addition, the power conditioner 20 can convert the generated power of the solar cell 11 into AC power and reversely flow into the system, or sell surplus power. Further, the power conditioner 20 may output the power from the grid and the power from the distributed power source (solar battery 11, storage battery 12) to the load 32. In this case, since the forward flow (current in the power purchase direction) from the grid flows through the current sensor 40, the power generation device 33 generates power and supplies power to the load 32 through the distribution board 31.

  When the power supply system performs the autonomous operation, the switches of the power conditioner 20 are controlled such that the interconnection operation switches 22 and 23 are off and the autonomous operation switch 24 is on.

  During the independent operation, the power conditioner 20 supplies the power of the distributed power source (solar cell 11 and storage battery 12) to the load 32 via the independent operation switch 24. Since the current sensor 40 detects a forward power flow (current in the power purchase direction), the power generation device 33 can execute power generation in a load following operation or a rated operation.

  Here, the solar cell 11 and the power generation device 33 included in the power supply system are compared from the viewpoint of burden on the environment. As long as there is sunlight, the solar cell 11 can generate electric power substantially infinitely. On the other hand, the power generation device 33 uses gas to extract hydrogen if it is a fuel cell, for example, and uses gas as fuel for a gas engine if it is a gas generator, for example. That is, the power generation device 33 needs to use a resource called gas. Therefore, in consideration of the burden on the environment, there is a user's request that the power from the solar cell 11 is preferentially supplied to the load 32 regardless of whether power can be sold to the system or not. In the control of the power supply system of the present embodiment described below, the power from the solar cell 11 can be preferentially supplied to the load 32. In the following description, the case of self-sustained operation will be described as an example. However, it is possible to give priority to the power supply from the solar cell 11 by the same method during the interconnected operation.

(Outline of control)
FIG. 2 is a diagram illustrating a control example of the power supply system during the self-sustaining operation in which priority can be given to the power supply from the solar cell 11. As shown in FIG. 2, the power conditioner 20 has two paths for supplying power from the solar cell 11 to the load 32. One path is the path A (first path) passing through the inverter 21, point a in FIG. 2 (output of the inverter 21), and the self-sustaining operation switch 24. The other route is a route B (second route) passing through the DC / AC unit 26. In the present embodiment, for example, the power conditioner 20 preferentially supplies the power generated by the solar cell 11 to the storage battery 12 and supplies the surplus power thereafter to the load 32. Then, the power conditioner 20 causes the power generation device 33 to supply the load 32 with power that is insufficient due to the surplus power. Therefore, in this embodiment, the solar cell 11 is used preferentially over the power generator 33. At this time, the power conditioner 20 uses both the path A and the path B to supply the power from the solar cell 11 to the load 32. Here, the names of the route A and the route B are not limited to the wiring inside the power conditioner 20, but are used for all the wirings up to substantially the same range as the wiring through which the power flows. . For example, although the current sensor 40 exists outside the power conditioner 20, in the following description, the current sensor 40 detects a current flowing through the path A. FIG. 2 shows the power conditioner 20 having a configuration in which the DC / DC unit 29 is omitted. In addition, in the following, for the sake of easy understanding, description will be made using specific power values, but the values shown are merely examples and are not limited to such values.

(At the start of autonomous operation)
First, the power conditioner 20 confirms that the solar cell 11 is generating power, and supplies the power from the solar cell 11 to the load 32 via the path A. In the example of FIG. 2, it is assumed that the solar cell 11 generates 3.5 kW, which is the upper limit of power that can be generated. Further, it is assumed that the power required for the load 32 is 1 kW.

(Start of operation of power generator)
The power supply system includes a current sensor 40 that detects a current flowing through the path A. When the power supply from the solar battery 11 is started, the current sensor 40 detects a forward power flow, so that the power generation device 33 that has been stopped is activated and starts operation. The power conditioner 20 is set so that the power generator 33 performs rated operation at the start of independent operation. In the example of FIG. 2, it is assumed that the power generation device 33 can generate a maximum power generation amount of 3 kW during rated operation.

(Distribution of power from solar cells)
The control unit 25 of the power conditioner 20 adjusts the output of the inverter 21 so that necessary power is supplied to the load 32. And the control part 25 of the power conditioner 20 controls so that the surplus electric power which does not need to be supplied to the load 32 by the path | route A flows among the electric power which the solar cell 11 generated. In the example of FIG. 2, the control unit 25 of the power conditioner 20 causes most of the power from the solar cell 11 to be supplied to the load 32 through the path B. However, the control unit 25 of the power conditioner 20 causes the current sensor 40 to detect a forward power flow so that the current for causing the power generation device 33 to generate power flows through the path A. For example, the power conditioner 20 may distribute only 50 W of the power of the solar battery 11 to the path A and the remaining power to the path B. In the following description, since the power distributed to the route A is very small, for the sake of simplicity of explanation, it is assumed that 3.5 kW of power is distributed to the route B.

  Here, in the example of FIG. 2, since the power generation device 33 can generate more power than the power required for the load 32, the power distributed to the path A may be zero. However, in this case, since the current sensor 40 does not detect a forward power flow, the power generator 33 that has been activated once stops. When the power generation device 33 stops and cools down, it takes time until the power is again extracted from the power generation device 33, and the power cannot be extracted when necessary. Therefore, it is preferable to distribute power to the path A so that the current for detecting the forward flow of the current sensor 40 flows. When the power supply system includes a hot water storage tank that stores hot water generated by heat during operation of the power generation apparatus 33, the power generation apparatus 33 may stop when the hot water storage tank is full. At this time, it is preferable that the control unit 25 of the power conditioner 20 distributes power to the path A and controls the hot water storage tank not to be full.

(Charging the storage battery)
The power conditioner 20 controls the DC / DC unit 28 so that the storage battery 12 is charged by the electric power of the solar battery 11 in the path B. In the example of FIG. 2, it is assumed that the power required for charging the storage battery 12 is 3.0 kW. In addition, 3.5 kW of power is distributed to the path B as described above. Since the power conditioner 20 supplies 3.0 kW of the electric power of the solar battery 11 to the storage battery 12, the surplus power thereafter, that is, the electric power that can be supplied to the load 32 through the path B is 0.5 kW. At this time, the solar cell 11 generates power that is the upper limit of power that can be generated, but the load 32 needs to be further supplied with 0.5 kW. Therefore, next, the power conditioner 20 performs control to supply the load 32 from the power generation device 33 with the power that is insufficient due to the surplus power of the solar cell 11.

(Control of power generator)
Here, the power generation device 33 performs rated operation and generates the maximum power generation amount of 3 kW, which greatly exceeds the power of 0.5 kW necessary for the load 32. Therefore, the power conditioner 20 controls the power generation device 33 to perform load following operation so that 0.5 kW of power is supplied from the power generation device 33 to the load 32. Specifically, the control unit 25 of the power conditioner 20 adjusts the output of the inverter 21 and controls (changes) the forward current detected by the current sensor 40. Since the power generated by the power generation device 33 also changes in accordance with the detection result of the current sensor 40, the power conditioner 20 can supply 0.5 kW of power from the power generation device 33 to the load 32. At this time, the power conditioner 20 suppresses the operation of the power generation apparatus 33 as much as possible by causing the solar cell 11 to generate the upper limit of the power that can be generated while supplying the necessary power to the load 32. Therefore, consumption of gas fuel used by the power generation device 33 can be suppressed.

(Control method of power supply system)
FIG. 3 is an example of a flowchart illustrating a method for controlling the power supply system according to the present embodiment. First, the control unit 25 of the power supply system determines whether or not the solar cell 11 is generating power (step S1). For example, if the solar cell 11 is not generating power at night or the like (No in step S1), the control unit 25 sets the power generation device 33 to perform load following power generation (power generation by load following operation) (step S9). Finish. At this time, the power required by the load 32 is supplied only from the power generation device 33. However, if the solar cell 11 is generating electric power (Yes in step S1), the control unit 25 proceeds to step S2 and performs the following control so that the solar cell 11 is used preferentially over the power generation device 33. Do.

  The control unit 25 sets the power generation device 33 to perform rated power generation (power generation by rated operation), adjusts the output of the inverter 21, and supplies the shortage (electric power required by the load 32 and the power generation device 33. (Difference with electric power) is supplied from the solar cell 11 through the path A (step S2). Here, as in the example of FIG. 2, even when the power at the rated power generation of the power generation device 33 exceeds the power required by the load 32, the control unit 25 sets the point a (see FIG. 2). Control so that the flowing current does not become zero. As described above, this is to prevent the current sensor 40 from detecting a forward power flow and stopping the power generation apparatus 33 once started.

  If there is no surplus in the power supplied to solar cell 11, that is, if all of the power generated by solar cell 11 is supplied to load 32 via path A (No in step S <b> 3), control unit 25 ends the process. If there is a surplus in the power supplied to the solar cell 11 (Yes in step S3), the control unit 25 proceeds to step S4.

  If there is a battery charging command (Yes in step S4), the control unit 25 uses the path B to charge the storage battery 12 with the surplus power supplied from the solar battery 11 (step S5), and proceeds to step S6. On the other hand, when there is no battery charging command, for example, when the storage battery 12 is sufficiently charged and charging is not necessary (No in step S4), the process proceeds to step S6. If there is more surplus in the power supplied to the solar cell 11 (Yes in step S6), the process proceeds to step S7. If there is no surplus in the power supplied to the solar battery 11, that is, if the power of all the paths B is used for charging the storage battery 12 (No in step S6), the process is terminated.

  The control part 25 supplies the surplus electric power of the solar cell 11 to the load 32 using the path | route B (step S7). Then, by the processing in step S7, more power than necessary for the load 32 is supplied to the load 32, so that the power generation amount of the power generator 33 is controlled. Specifically, the control unit 25 controls the output of the inverter 21 to suppress the power generation amount of the power generation device 33 (step S8). As described above, since the power generated by the power generation device 33 also changes in accordance with the current detected by the current sensor 40, the power conditioner 20 suppresses the current flowing through the point a (see FIG. 2), thereby reducing the power generation device 33. Power generation can be suppressed.

(effect)
Here, with reference to FIG. 4, the effect of the power supply system of this embodiment is demonstrated, showing the power supply system of a comparative example. In the configuration of the power supply system of the comparative example, the DC / AC unit 26 may not be a bidirectional power conversion unit. However, the other parts are the same as those in FIG. 1, and the same elements are denoted by the same reference numerals and the description thereof is omitted.

  Even in the power supply system of the comparative example, first, the power conditioner 20 controls the power of the solar cell 11 to be supplied to the load 32 via the inverter 21 and the self-sustaining operation switch 24. Since the current sensor 40 detects a forward power flow, the power generation device 33 that has been stopped is activated to start operation, and the power generation device 33 starts power generation in a rated operation. The power conditioner 20 charges the storage battery 12 with the surplus power of the solar battery 11.

  In the power supply system of the comparative example, when the power generation device 33 generates power in the rated operation, power supply to the load 32 is started. And the surplus electric power of the electric power generating apparatus 33 is supplied to the storage battery 12 via the DC / AC part 26, the DC / DC part 29, and the DC / DC part 28, and the storage battery 12 is charged. That is, the storage battery 12 is charged with the electric power from the solar battery 11 and the power generation device 33.

  In the power supply system of the comparative example, the power generator 33 is operated with priority. Therefore, when the power conditioner 20 determines that the storage battery 12 can be charged even if the power supply from the solar battery 11 is reduced, the power conditioner 20 adjusts the supplied power by suppressing the operation of the solar battery 11. That is, in the power supply system of the comparative example, the operation of the solar cell 11 can be suppressed while the power generation device 33 performs the rated operation.

  On the other hand, as described above, in the power supply system of this embodiment, power supply from the solar cell 11 is prioritized, and the operation of the power generation device 33 is suppressed as much as possible. Therefore, consumption of gas fuel used by the power generation device 33 can be suppressed. In other words, the power supply system, the power conditioner 20, and the control method of the power supply system according to the present embodiment can control the operation of a plurality of distributed power sources (solar cells 11, power generation devices 33) so as to reduce the burden on the environment. It is.

  Further, as described above, the power conditioner 20 of the power supply system of the present embodiment includes the path A that passes through the inverter 21 and the path B that passes through the DC / AC unit 26 different from the inverter 21. Only the current A is detected by the current sensor 40. For this reason, the power supply path from the solar cell 11 to the load 32 is changed to the path B while the start method of the power generation device 33 similar to the power supply system of the comparative example is executed using the path A. Thus, the path A can be used for power generation control of the power generation device 33. That is, as compared with the power supply system of the comparative example, a power supply system with less burden on the environment can be realized only by changing the DC / AC unit 26 to a bidirectional power conversion unit.

  Although the present invention has been described based on the drawings and examples, it should be noted that those skilled in the art can easily make various modifications and corrections based on the present disclosure. Therefore, it should be noted that these variations and modifications are included in the scope of the present invention. For example, functions included in each member, each means, each step, etc. can be rearranged so as not to be logically contradictory, and a plurality of means, steps, etc. can be combined or divided into one. Is possible.

11 Solar battery 12 Storage battery 20 Power conditioner (power supply equipment)
21 Inverter (first power converter)
22, 23 Interconnection operation switch 24 Independent operation switch 25 Control unit 26 DC / AC unit (second power conversion unit)
27, 28, 29 DC / DC section 31 Distribution board 32 Load 33 Power generator 40 Current sensor

Claims (6)

A storage battery and a load that receive power supply, a solar cell and power generation device that supplies the power, a power supply device that controls the power, and a current sensor that generates the power generation device by detecting a predetermined current. A power supply system comprising:
The power supply device is:
The power generated by the solar cell is supplied to the storage battery, surplus power is supplied to the load, and the current detected by the current sensor is controlled from the power generation device by controlling the current deficient due to the surplus power. A power supply system comprising: a control unit that supplies power to a load. The power supply device is:
A first power converter, and a second power converter different from the first power converter,
A first path for causing the current sensor to detect the predetermined current via the first power converter and supplying the power to the load via the first power converter and the second power converter. A second path for supplying the load;
The power supply system according to claim 1, wherein the surplus power is supplied to the load through the second path. The power supply device is:
The power supply system according to claim 2, wherein the power supplied from the power generation device to the load is changed by adjusting a current flowing through the first path using the first power conversion unit.   4. The power supply system according to claim 1, wherein the power generation device is a fuel cell, and the predetermined current is a forward current. 5. Used in a power supply system comprising a storage battery and a load that receive power supply, a solar battery and power generation device that supplies the power, and a current sensor that generates the power generation device by detecting a predetermined current. A power supply device for controlling the power,
The power generated by the solar cell is supplied to the storage battery, surplus power is supplied to the load, and the current detected by the current sensor is controlled from the power generation device by controlling the current deficient due to the surplus power. A power supply device comprising: a control unit that supplies power to a load. A storage battery and a load that receive power supply, a solar cell and power generation device that supplies the power, a power supply device that controls the power, and a current sensor that generates the power generation device by detecting a predetermined current. A method for controlling a power supply system comprising:
Supplying the power generated by the solar cell to the storage battery and supplying surplus power to the load;
And controlling the current detected by the current sensor from the power generation device to the load by controlling the current detected by the surplus power to the load.

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