Distributed power system

Abstract

To provide a distributed power supply system capable of supplying power to three-phase and single-phase loads during stand-alone operation.SOLUTION: A distributed power supply system includes a distributed power supply for supplying power during stand-alone operation to single-phase and three-phase loads that receive power supply from a commercial power system. The distributed power supply system includes a first power conversion device for converting power output from a first distributed power supply to three-phase power to supply power to the three-phase load during stand-alone operation and a single-phase power supply part for supplying single-phase power to the single-phase load during stand-alone operation.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a distributed power source system including a power conversion device that is connected to a commercial power system and can supply power from a distributed power source to a three-phase load during independent operation.

Background Art

[0002] Conventionally, a distributed power source system has been proposed in which a distributed power source such as a storage battery or a solar cell is installed and supplies power to a three-phase load in a three-phase three-wire system during connection to a commercial power system and during independent operation. In addition, for customers who desire power supply to a single-phase load during independent operation, a distributed power source system that supplies three-phase three-wire AC power during grid-connected operation and supplies single-phase three-wire or single-phase two-wire AC power during independent operation has been proposed (see, for example, Patent Document 1).

[0003] However, in such a distributed power source system, there has been a problem that power can be supplied only to a three-phase load or a single-phase load during independent operation.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a distributed power source system capable of supplying power to a three-phase load and a single-phase load during independent operation.

Means for Solving the Problems

[0006] In order to solve the above problems, the present invention is A distributed power source system including a single-phase load and a three-phase load that receive power supply from a commercial power system, and a distributed power source that supplies power during self-operation, During self-operation, a first power conversion device that converts the power output from the first distributed power source into three-phase power and supplies it to the three-phase load, During self-operation, a single-phase power supply unit that supplies single-phase power to the single-phase load, characterized by comprising.

[0007] According to this, during self-operation, the three-phase power converted from the power output from the first distributed power source is supplied to the three-phase load by the first power conversion device, and the single-phase power is supplied to the single-phase load by the single-phase power supply unit. As the distributed power source and the first distributed power source, various power sources such as storage batteries, solar cells, and fuel cells can be applied. Also, during grid-connected operation, the first power conversion device may convert the power output from the first distributed power source into three-phase power and supply it to the three-phase load, or convert it into single-phase power and supply it to the single-phase load.

[0008] Also, in the present invention, As the single-phase power supply unit, a transformer provided between the first power conversion device and the single-phase load is provided, During self-operation, the primary side of the transformer is connected to any two of the three-phase power lines that supply the three-phase power from the first power conversion device to the three-phase load in a three-phase three-wire system, and the A single-phase power line for supplying the single-phase power to the single-phase load in a single-phase three-wire system may be connected to the secondary side.

[0009] In this way, during self-operation, the power output from the first distributed power source is converted into three-phase power in a three-phase three-wire system by the first power conversion device and supplied to the three-phase load through three three-phase power lines. Then, by connecting the primary side of the transformer to any two of the three three-phase power lines and connecting a single-phase power line in a single-phase three-wire system to the secondary side of this transformer, single-phase power can be supplied to the single-phase load during self-operation through the single-phase power line.

[0010] Also, in the present invention, As the single-phase power supply unit, a second power conversion device is provided that converts the power output from the second distributed power source into the single-phase three-wire single-phase power and supplies it to the single-phase load. During self-operation, any two of the three-phase power lines that supply the three-phase power from the first power conversion device to the three-phase load in a three-phase three-wire system may be connected to two voltage lines of the single-phase power lines that supply the single-phase power from the second power conversion device to the single-phase load in a single-phase three-wire system.

[0011] In this way, power can be exchanged between the first distributed power source connected to the first power conversion device that supplies three-phase power to the three-phase load in a three-phase three-wire system and the second distributed power source connected to the second power conversion device that supplies single-phase power to the single-phase load in a single-phase three-wire system. When both the first distributed power source and the second distributed power source are storage batteries, the two storage batteries can be utilized evenly.

[0012] Also, in the present invention, As the first distributed power source, either one of a storage battery and a third distributed power source having a power generation function is provided. As the second distributed power source, the other of the storage battery and the third distributed power source may be provided.

[0013] In this way, when the power generated by the third distributed power source is surplus for the single-phase load or the three-phase load, the storage battery can be charged. Here, the storage battery may be a storage battery for an EV. Also, the third distributed power source having a power generation function may be a solar cell or a fuel cell, but is not limited thereto.

Advantages of the Invention

[0014] According to the present invention, a distributed power source system capable of supplying power to a three-phase load and a single-phase load during self-operation can be provided.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Mode for Carrying Out the Invention

[0016] 〔Application Example〕 Hereinafter, application examples of the present invention will be described with reference to the drawings.

[0017] FIG. 1 is a diagram showing the schematic configuration of a distributed power system 1 according to an application example of the present invention.

[0018] The distributed power system 1 includes a first power conditioner 20a having a three-phase three-wire output connected to a storage battery 11a. The first power conditioner 20a has a first inverter 10a having three-phase three-wire output terminals 101a, 101b, and 101c.

[0019] During the interconnection operation, relays SW6a, 6b, and 6c are connected to the system 1a side, and single-phase three-wire single-phase power is supplied from the system 1a to the single-phase loads 2 and 3 of the consumers. Also, during the interconnection operation, relays SW8a, 8b, and 8c are connected to the system 1b side, and three-phase three-wire three-phase power is supplied from the system 1b to the three-phase load 9 of the consumers. Power lines 102a, 102b, and 102c for supplying the three-phase three-wire power of the first inverter 10a are connected to the three-phase three-wire power lines 14a, 14b, and 14c connecting the system 1b and the relays SW8a, 8b, and 8c. As a result, in connection with the system 1b, three-phase three-wire power is supplied from the first power conditioner 20a to the three-phase load 9.

[0020] During independent operation, relays 7a, 7b, and 7c are connected to the output terminals 101a, 101b, and 101c of the first inverter 10a, and three-phase three-wire power is output from the independent output terminals of the first power conditioner 20a through the power lines 103a, 103b, and 103c. At this time, relay switches 8a, 8b, and 8c are switched from the system 1b side to the first power conditioner 20a side, and three-phase three-wire power is supplied from the first power conditioner 20a to the three-phase load 9 as the independent operation output.

[0021] The primary side of the transformer Tr is connected between the power line 104a and the power line 104b, which are respectively connected to the power line 103a and the power line 103b for supplying the independent operation output of the first power conditioner 20a. The secondary side of this transformer Tr is connected between the power line 105a and the power line 105c, and the power line 105b is connected to the midpoint of the secondary side of the transformer Tr. The power lines 105a, 105b, and 105c are respectively connected to the single-phase loads 2 and 3 via relay switches 6a, 6b, and 6c. By the transformer Tr, a single-phase 200V AC voltage corresponding to one phase between the power line 103a and the power line 103b among the three-phase three-wire power is converted into single-phase three-wire 100V and 200V. In this way, during independent operation, the single-phase three-wire independent operation output is supplied to the single-phase loads 2 and 3 via the relay switches 6a, 6b, and 6c switched to the first power conditioner 20a side.

[0022] In this way, in the distributed power system 1, the first power conditioner 20a can supply power to both the three-phase load 9 and the single-phase loads 2 and 3 of the customer simultaneously during independent operation.

[0023] 〔Example 1〕 Hereinafter, the distributed power system 1 according to Example 1 of the present invention will be described in more detail with reference to the drawings. However, the configurations of the devices and systems described in this example should be appropriately changed according to various conditions. That is, the scope of the present invention is not intended to be limited to the following examples.

[0024] FIG. 1 is a diagram showing a schematic configuration of a distributed power system 1 according to Embodiment 1 of the present invention. The distributed power system 1 has a first power conditioner 20a having a three-phase three-wire output connected to a storage battery 11a. The first power conditioner 20a has a first inverter 10a having three-phase three-wire output terminals 101a, 101b, and 101c. In this example, at the output terminals 101a, 101b, and 101c of the first inverter 10a, relays 5a, 5b, and 5c are connected during grid-connected operation. At this time, relays 7a, 7b, and 7c are disconnected. Relays SW8a, 8b, and 8c connected to a three-phase load 9 of a customer are connected to the grid 1b side that supplies three-phase power, and three-phase three-wire power lines 14a, 14b, and 14c connected to the three-phase load 9 via the relays SW8a, 8b, and 8c are connected to power lines 102a, 102b, and 102c that supply three-phase three-wire power of the first inverter 1 0a. Thereby, in connection with the grid 1b, three-phase three-wire power is supplied from the first power conditioner 20a to the three-phase load 9.

[0025] Also, during grid-connected operation, from the grid 1a, single-phase three-wire power is supplied via power lines 4a, 4b, and 4c to single-phase loads 2 and 3 of a customer via relays SW6a, 6b, and 6c connected to the grid 1a side.

[0026] On the other hand, during off-grid operation, at the output terminals 101a, 101b, and 101c of the first inverter 10a, relays 7a, 7b, and 7c are connected. At this time, relays 5a, 5b, and 5c are disconnected. Thereby, three-phase three-wire power is output from the off-grid output terminals of the first power conditioner 20a through power lines 103a, 103b, and 103c. At this time, relays SW8a, 8b, and 8c are switched from the grid 1b side to the first power conditioner 20a side, and three-phase three-wire power is supplied from the first power conditioner 20a to the three-phase load 9 as off-grid operation output. Here, the storage battery 11a corresponds to the first distributed power source of the present invention, and the first power conditioner 20a corresponds to the first power conversion device of the present invention. Also, the power lines 103a, 103b, and 103c correspond to the three-phase power lines of the present invention.

[0027] The primary side of a transformer Tr is connected between a power line 104a and a power line 104b which are respectively connected to a power line 103a and a power line 103b that supply the self - operating output of the first power conditioner 20a. The secondary side of this transformer Tr is connected between a power line 105a and a power line 105c, and a power line 105b is connected to the mid - point of the secondary side of the transformer Tr. The power lines 105a, 105b, and 105c are respectively connected to relays SW6a, 6b, and 6c. Thus, among the three - phase three - wire power output from the first power conditioner 20a through the power lines 103a, 103b, and 103c, a single - phase 200V AC voltage for one phase between the power line 103a and the power line 103b is converted by the transformer Tr into single - phase three - wire power with an AC voltage of 100V between the power line 105a and the power line 105b, an AC voltage of 100V between the power line 105b and the power line 105c, and an AC voltage of 200V between the power line 105a and the power line 105c. In this way, the single - phase three - wire AC power generated via the transformer Tr is supplied as the self - operating output of the first power conditioner 20a to the single - phase loads 2 and 3 through the relays SW6a, 6b, and 6c switched to the first power conditioner 20a side. Here, the transformer Tr corresponds to the single - phase power supply unit of the present invention. Also, the power lines 103a and 103b correspond to any two lines of the three - phase power lines of the present invention, and the power lines 105a, 105b, and 105c correspond to the single - phase power lines of the present invention.

[0028] In this distributed power system 1, during self - operation, since the first power conditioner 20a connected to the storage battery 11a can output power in a three - phase three - wire system and a single - phase three - wire system, it is possible to supply power to both the three - phase load 9 of the consumer and the single - phase loads 2 and 3 simultaneously.

[0029] In the above-described distributed power supply system 1, between the power lines 103a and 103b that supply the self-operating output from the first power conditioner 20a, by connecting the primary side of the transformer Tr via the power lines 104a and 104b, the power of one phase among the three-phase power is converted into single-phase three-wire power. However, the primary side of the transformer Tr may be connected between any two of the power lines 103a, 103b, and 103c.

[0030] [Embodiment 2] Hereinafter, the distributed power supply system 21 according to Embodiment 2 of the present invention will be described in more detail with reference to the drawings.

[0031] FIG. 2 is a diagram showing a schematic configuration of a distributed power supply system 21 according to Embodiment 2 of the present invention. For the configurations common to those in Embodiment 1, the same reference numerals are used and detailed descriptions are omitted. In the distributed power supply system 21 according to Embodiment 2, similar to Embodiment 1, a first power conditioner 20a having a three-phase three-wire system-connected output is connected to the system 1b and supplies three-phase power to the three-phase load 9 of the consumer. Also, in the distributed power supply system 21, during self-operation, similar to Embodiment 1, the first power conditioner 20a supplies three-phase three-wire AC power to the three-phase load 9. Also, in the distributed power supply system 21, similar to Embodiment 1, single-phase three-wire AC power is supplied from the system 1a to the single-phase loads 2 and 3 of the consumer.

[0032] The distributed power supply system 21 has a second power conditioner 20b including a second inverter 10b connected to the storage battery 11b and having a single-phase three-wire output. At the output terminals 101d, 101e, 101f of the second inverter 10b, the relays 5d, 5e, 5f are connected during the interconnected operation. At this time, the relays 7d, 7e, 7f are disconnected. The power lines 102d, 102e, 102f connected to the output terminals 101d, 101e, 101f of the second inverter 10b via the relays 5d, 5e, 5f are connected to the power lines 4a, 4b, 4c, and single-phase three-wire power connected to the system 1a is supplied to the single-phase loads 2 and 3.

[0033] Also, at the output terminals 101d, 101e, and 101f of the second inverter 10b, relays 7d, 7e, and 7f are connected during independent operation. At this time, relays 5d, 5e, and 5f are disconnected. As a result, single-phase three-wire power is output from the independent output terminals of the second power conditioner 20b through power lines 103d, 103e, and 103f. At this time, relay switches 6a, 6b, and 6c are switched from the system 1a side to the second power conditioner 20b side, and single-phase three-wire power is supplied as independent operation output from the second power conditioner 20b to the single-phase loads 2 and 3. Here, the storage battery 11b corresponds to the second distributed power source of the present invention, and the second power conditioner 20b corresponds to the second power conversion device that constitutes the single-phase power supply unit of the present invention. Also, the power lines 103d, 103e, and 103f correspond to the single-phase power lines of the present invention. Among these, the power lines 103d and 103f are voltage lines, and the power line 103e is a neutral line. Also, the power lines 103d and 103f connected to the independent operation output terminals of the second power conditioner 20b are respectively connected by connection lines 104d and 104f to the power lines 103a and 103b connected to the independent operation output terminals of the first power conditioner 20a. Here, the power lines 103a, 103b, and 103c correspond to the three-phase power lines of the present invention, and the power lines 103a and 103b correspond to any two lines of the three-phase power lines of the present invention. Also, the power lines 103d and 103f correspond to the two voltage lines of the present invention.

[0034] In this way, by connecting the power line connected to the isolated operation output terminal of the first power conditioner 20a and the power line connected to the isolated operation output terminal of the second power conditioner 20b, it is possible to supply power output from one power conditioner to the other power conditioner. As described above, when the storage battery 11a and the storage battery 11b are connected to the first power conditioner 20a and the second power conditioner 20b, respectively, it is possible to supply power from both the storage battery 11a and the storage battery 11b. During isolated operation, when the two power conditioners have only single-phase and only three-phase outputs, respectively, they can only supply power to either the single-phase load or the three-phase load. However, by connecting two power conditioners, the first power conditioner 20a and the second power conditioner 20b, the power of the storage batteries 11a and 11b can be shared between the first power conditioner 20a and the second power conditioner 20b, so that the storage batteries 11a and 11b can be used equally. Here, the first power conditioner 20a and the second power conditioner 20b are connected to the storage battery 11a and the storage battery 11b, respectively. A distributed power source having a power generation function, such as a PV panel 11c described below, may be connected to each of the first power conditioner 20a and the second power conditioner 20b. In this case, the distributed power source having a power generation function connected to the first power conditioner 20a corresponds to the first distributed power source of the present invention, and the distributed power source having a power generation function connected to the second power conditioner 20b corresponds to the second distributed power source of the present invention.

[0035] Example 3 Third Embodiment A distributed power system 31 according to a third embodiment of the present invention will be described in more detail below with reference to the drawings.

[0036] Third Embodiment FIG. 3 is a diagram showing a schematic configuration of a distributed power system 31 according to a third embodiment of the present invention. Configurations common to the first and second embodiments are given the same reference numerals and detailed descriptions thereof will be omitted.

[0037] The distributed power system 31 includes a third power conditioner 20c having a single-phase three-wire output connected to the PV panel 11c, and a fourth power conditioner 20d connected to the storage battery 11d and having a single-phase three-wire grid-connected output and a three-phase three-wire self-sustaining operation output. Here, the PV panel 11c corresponds to the third distributed power source having the power generation function of the present invention, and the third power conditioner 20c corresponds to the second power conversion device constituting the single-phase power supply unit of the present invention. Also, the storage battery 11d corresponds to the first distributed power source of the present invention, and the fourth power conditioner 20d corresponds to the first power conversion device of the present invention.

[0038] The third power conditioner 20c has a third inverter 10c having single-phase three-wire output terminals 101g, 101h, 101i. At the output terminals 101g, 101h, 101i of the third inverter 10c, relays 5g, 5h, 5i are connected during grid-connected operation. At this time, relays 7g, 7h, 7i are disconnected. Relays SW6a, 6b, 6c connected to the single-phase loads 2, 3 of the consumer are connected to the grid 1a side that supplies single-phase power, and power lines 102g, 102h, 102i that supply the single-phase three-wire power of the third inverter 10c are connected to the single-phase three-wire power lines 4a, 4b, 4c that are connected from the grid 1a to the single-phase loads 2, 3 via the relays SW6a, 6b, 6c.

[0039] On the other hand, the fourth power conditioner 20d has a fourth inverter 10d having three-wire output terminals 101j, 101k, 101p. At the output terminals 101j, 101k, 101p of the fourth inverter 10d, relays 5j, 5k, 5p are connected during grid-connected operation. At this time, relays 7j, 7k, 7p are disconnected. During grid-connected operation, single-phase three-wire power is output from the output terminals 101j, 101k, 101p of the fourth inverter 10d. Power lines 102j, 102k, 102p connected to the output terminals 101j, 101k, 101p via the relays 5j, 5k, 5p are connected to the power lines 102g, 102h, 102i, and are connected to the power lines 4a, 4b, 4c via the power lines 102g, 102h, 102i.

[0040] In this way, during the interconnection operation, the single-phase three-wire power output from the third power conditioner 20c and the fourth power conditioner 20d is supplied to the single-phase loads 2 and 3 via the relays SW6a, 6b, and 6c. Also, during the interconnection operation, the relays SW8a, 8b, and 8c connected to the three-phase load 9 of the customer are connected to the system 1b side that supplies three-phase power, and three-phase power is supplied from the system 1b to the three-phase load 9 through the three-phase three-wire power lines 14a, 14b, and 14c connected to the three-phase load 9 via the relays SW8a, 8b, and 8c.

[0041] At the output terminals 101g, 101h, and 101i of the third inverter 10c, during the independent operation, the relays 7g, 7h, and 7i are connected. At this time, the relays 5g, 5h, and 5i are disconnected. The power lines 103g, 103h, and 103i connected to the output terminals 101g, 101h, and 101i of the third inverter 10c are connected to the relays SW6a, 6b, and 6c via the relays 7g, 7h, and 7i. During the independent operation, the relays SW6a, 6b, and 6c are switched from the system 1a side to the third power conditioner 20c side. In this way, the single-phase three-wire independent operation output is supplied to the single-phase loads 2 and 3 through the power lines 103g, 103h, and 103i connected to the independent operation output terminals of the third power conditioner 20c. Here, the power lines 103g, 103h, and 103i correspond to the single-phase power lines of the present invention. Among them, the power lines 103g and 103i are voltage lines, and the power line 103h is a neutral line.

[0042] At the output terminals 101j, 101k, and 101p of the fourth inverter 10d, during independent operation, the relays 7j, 7k, and 7p are connected. At this time, the relays 5j, 5k, and 5p are disconnected. During independent operation, three-phase three-wire power is output from the output terminals 101j, 101k, and 101p of the fourth inverter through the power lines 103j, 103k, and 103p. The power lines 103j, 103k, and 103p connected to the output terminals 101j, 101k, and 101p are connected to the relay SW8a, 8b, and 8c via the relays 7j, 7k, and 7p. During independent operation, the relay SW8a, 8b, and 8c are switched from the system 1b side to the fourth power conditioner 20d side, and three-phase three-wire power is supplied from the fourth power conditioner 20d to the three-phase load 9 as the independent operation output. Here, the power lines 103j, 103k, and 103p correspond to the three-phase power lines of the present invention. Also, the power line 103j and the power line 103p connected to the independent operation output terminal of the fourth power conditioner 20d are respectively connected to the power line 103g and the power line 103i connected to the independent operation output terminal of the third power conditioner 20c by the connection line 104g and the connection line 104i. Here, the power lines 103g and 103i correspond to two voltage lines of the single-phase power lines of the present invention. Also, the power lines 103j and 103p correspond to any two lines of the three-phase power lines of the present invention.

[0043] In this way, during independent operation, the third power conditioner 20c can output single-phase three-wire AC 100V, and the fourth power conditioner 20d can output three-phase three-wire AC 200V. Also, by connecting the power line connected to the independent operation output terminal of the third power conditioner 20c connected to the PV panel 11c and the power line connected to the independent operation output terminal of the fourth power conditioner 20d connected to the storage battery 11d, when the power generated by the PV panel 11c is surplus for the independent operation load (here, the single-phase loads 2 and 3), it can also be charged to the storage battery 11d connected to the fourth power conditioner 20d, and the independent operation output to the single-phase loads 2 and 3 and the three-phase load 9 is also possible.

[0044] Here, although the storage battery 11d is connected to the fourth power conditioner 20d, it may be a storage battery for an EV. Also, two of the three power lines 103j, 103k, and 103p of the three-phase three-wire power lines of the fourth power conditioner 20d, i.e., the power lines 103j and 103p, are connected to the single-phase three-wire power lines 103g and 103i of the third power conditioner 20c, but any other two lines may be connected. Here, the third power conditioner 20c connected to the PV panel 11c has a single-phase three-wire grid-connected output and an independent operation output, and the fourth power conditioner 20d connected to the storage battery 11d has a single-phase three-wire grid-connected output and a three-phase three-wire independent operation output. Although the distributed power system 31 has been described, the configuration of the distributed power system is not limited to this. The third power conditioner 20c connected to either the storage battery 11d or the PV panel 11c has a single-phase three-wire grid-connected output and an independent operation output, and the fourth power conditioner 20d connected to the other of the storage battery 11d and the PV panel 11c can have a single-phase three-wire grid-connected output and a three-phase three-wire independent operation output. That is, the storage battery 11d is connected to the third power conditioner 20c, and the third power conditioner 20c converts the output of the storage battery 11d into a single-phase three-wire grid-connected output and an independent operation output, the PV panel 11c is connected to the fourth power conditioner 20d, and the fourth power conditioner 20d converts the power generated by the PV panel 11c into a single-phase three-wire grid-connected output and a three-phase three-wire independent operation output. In this case, the PV panel 11c corresponds to the third distributed power source and the first distributed power source of the present invention.

[0045] <Appendix 1> A distributed power system including distributed power sources (11a, 11b, 11c, 11d) that supply power during independent operation to single-phase loads (2, 3) and three-phase loads (9) receiving power supply from a commercial power system (1a, 1b), During autonomous operation, a first power conversion device (20a, 20d) that converts the power output from the first distributed power sources (11a, 11d) into three-phase power and supplies it to the three-phase load (9); During autonomous operation, a single-phase power supply unit (Tr, 20b, 20c) that supplies single-phase power to the single-phase loads (2, 3); A distributed power supply system, characterized by comprising the above.

Explanation of symbols

[0046] 1, 21, 31: Distributed power supply system 1a, 1b: Commercial power system 2, 3: Single-phase load 9: Three-phase load 11a, 11b, 11d: Storage battery 11c: PV panel 20a: First power conditioner 20b: Second power conditioner 20c: Third power conditioner 20d: Fourth power conditioner Tr: Transformer

Claims

1. A distributed power source system including a single-phase load and a three-phase load that receive power supply from a commercial power system, and a distributed power source that supplies power during self-operation, comprising: a first power conversion device that, during self-operation, converts the power output from a storage battery as the first distributed power source into three-phase power and supplies the three-phase power to the three-phase load; a second power conversion device that, during self-operation, converts the power output from a storage battery as the second distributed power source into single-phase three-wire single-phase power and supplies the single-phase power to the single-phase load; A distributed power source system, characterized in that, during self-operation, any two of the three wires of the three-phase power line that supplies the three-phase power from the first power conversion device to the three-phase load in a three-phase three-wire manner are respectively connected to two voltage lines of the single-phase power line that supplies the single-phase power from the second power conversion device to the single-phase load in a single-phase three-wire manner.

2. A distributed power source system including a single-phase load and a three-phase load that receive power supply from a commercial power system, and a distributed power source that supplies power during self-operation, comprising: a first power conversion device that, during self-operation, converts the power output from a first distributed power source into three-phase power and supplies the three-phase power to the three-phase load; a second power conversion device that, during self-operation, converts the power output from a second distributed power source into single-phase three-wire single-phase power and supplies the single-phase power to the single-phase load; wherein either one of a storage battery and a third distributed power source having a power generation function is provided as the first distributed power source; wherein the other of the storage battery and the third distributed power source is provided as the second distributed power source; A distributed power source system, characterized in that, during self-operation, any two of the three wires of the three-phase power line that supplies the three-phase power from the first power conversion device to the three-phase load in a three-phase three-wire manner are respectively connected to two voltage lines of the single-phase power line that supplies the single-phase power from the second power conversion device to the single-phase load in a single-phase three-wire manner.

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