Power Conditioner System

Abstract

To provide a power conditioner system capable of distinguishing and measuring power supplied from a photovoltaic power generation device and power supplied from a charging / discharging device even when power is supplied to a power line from a power conditioner to which the photovoltaic power generation device and the charging / discharging device are connected.SOLUTION: A power conditioner system is provided with a connection point to a power system 1 on the upstream side of a power line 2, a first power meter 3, a first connection point P1, a second power meter 4, and a second connection point P2 are arranged in this order along the power line 2 toward the downstream side from the connection point to the power system 1, and a connection switching device SW that switches, to either one of the first connection point P1 and the second connection points P2, the connection point of the power conditioner circuit unit 11 to the power line 2 according to the state of supply of the discharged power of a charge / discharge device 7 from the charge / discharge device 7 to the power line 2 via the power conditioner circuit unit 11.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a power conditioner system including a power conditioner circuit unit to which a solar power generation device and a charge / discharge device are connected and a power conditioner control unit that controls the operation of the power conditioner circuit unit, the power conditioner circuit unit being connected to a power line that is linked to a power grid. [Background technology]

[0002] When multiple power supply devices are connected to a power line connected to a power grid, power may flow back from both of the multiple power supply devices to the power grid at the same time. In such a case, multiple power meters are used to identify the reverse flow power of each of the multiple power supply devices. For example, Patent Document 1 (JP 2020-137209 A) describes a distributed power system that aims to accurately know the power flowing back from each of multiple power generation devices to the power grid by using multiple power meters installed on a power line connected to the power grid. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-137209 A Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 describes not only a configuration in which a plurality of power supply devices are connected to a power line connected to a power system, but also a configuration in which a plurality of power supply devices are connected to a power line connected to the power system by one power conditioner. Specifically, Patent Document 1 describes a configuration in which a power conditioner to which a photovoltaic power generation device and a charging / discharging device are connected is connected to a power line connected to the power system. In such a configuration, there is a problem that there is no place to install a power meter (i.e., a differential meter) for knowing the power flowing backward from each of the photovoltaic power generation device and the charging / discharging device connected to the power conditioner to the power system, that is, the power supplied from the photovoltaic power generation device and the power supplied from the charging / discharging device cannot be measured by distinguishing them with the power meter. Therefore, there is a restriction that, for example, the power supplied from the photovoltaic power generation device can be made to flow backward to the power system, but the power supplied from the charging / discharging device cannot be made to flow backward to the power system.

[0005] The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for supplying power to a power line from a power conditioner to which a solar power generation device and a charge / discharge device are connected. Reverse power flow when power is supplied only from Power and charging / discharging devices Reverse power flow when power is supplied only from The object of the present invention is to provide a power conditioner system capable of measuring separately from power. [Means for solving the problem]

[0006] A characteristic configuration of the power conditioner system according to the present invention for achieving the above object is a power conditioner system including a power conditioner circuit unit to which a photovoltaic power generation device and a charge / discharge device are connected and a power conditioner control unit to control the operation of the power conditioner circuit unit, the power conditioner circuit unit being connected to a power line that is linked to a power grid, a connection point to the power grid is provided on the upstream side of the power line, and a first power meter, a first connection point, a second power meter, and a second connection point are provided in that order on the power line from the connection point to the power grid toward the downstream side; a connection switching device that switches a connection point of the power conditioner circuit unit to the power line between the first connection point and the second connection point according to a supply state of discharge power of the charging / discharging device from the charging / discharging device to the power line via the power conditioner circuit unit; 、 The connection switching device is configured to connect the power conditioner circuit unit to the first connection point when power supplied only from the solar power generation device is to be reverse-flowed from the power conditioner circuit unit to the power grid, and to connect the power conditioner circuit unit to the second connection point when power supplied only from the charging / discharging device is to be reverse-flowed from the power conditioner circuit unit to the power grid. It's at the point.

[0008] The connection switching device ,before The power conditioner circuit unit can be configured to be connected to the first connection point when, even if the power conditioner circuit unit is outputting discharge power of the charging / discharging device to the power line, no reverse flow of power is occurring from the power line to the power system.

[0009] According to the above characteristic configuration, when the connection switching device connects the power conditioner to the first connection point, i.e., when the connection switching device connects the power conditioner to the power line between the first power meter and the second power meter, the power flowing back from the power conditioner to the power grid is measured by the first power meter but not by the second power meter. Also, when the connection switching device connects the power conditioner to the second connection point, i.e., when the connection switching device connects the power conditioner to the power line downstream of the second power meter, the power flowing back from the power conditioner to the power grid can be measured by the second power meter. In this way, a configuration is adopted in which the connection switching device switches the connection point of the power conditioner circuit unit to the power line to either the first connection point or the second connection point. The connection switching device is configured to connect the power conditioner circuit unit to the first connection point when power supplied only from the solar power generation device is to be reversed from the power conditioner circuit unit to the power grid, and to connect the power conditioner circuit unit to the second connection point when power supplied only from the charging / discharging device is to be reversed from the power conditioner circuit unit to the power grid. Therefore, even when power is supplied to the power line from a power conditioner to which the solar power generation device and the charge / discharge device are connected, the solar power generation device Reverse power flow when power is supplied only from Power and charging / discharging devices Reverse power flow when power is supplied only from It is possible to provide a power conditioner system that can measure separately from power.

[0010] Another characteristic configuration of the power conditioner system of the present invention is that the connection switching device connects the power conditioner circuit unit to the second connection point when the power conditioner circuit unit charges the charging / discharging device with power greater than the power generated by the solar power generation device, and connects the power conditioner circuit unit to the first connection point when the power conditioner circuit unit charges the charging / discharging device with power equal to or less than the power generated by the solar power generation device.

[0011] According to the above characteristic configuration, when the power charged by the charging / discharging device includes only power originating from the solar power generation device, the power conditioner circuit unit can be connected to the first connection point, and when the power charged by the charging / discharging device includes power other than power originating from the solar power generation device, the power conditioner circuit unit can be connected to the second connection point.

[0012] Another characteristic configuration of the power conditioner system according to the present invention is that, in a normal state in which power is normally supplied from the power system to the power line, the power conditioner connects the power conditioner circuit unit to an interconnection line that is connected to the first connection point or the second connection point while being electrically connected to the power system, and, in an abnormal state in which power is not normally supplied from the power system to the power line, the power conditioner connects the power conditioner circuit unit to an independent connection line that is connected to a third connection point midway on the power line, downstream of the second connection point, while not being electrically connected to the power system, and the connection switching device switches the connection point of the interconnection line to the power line to either the first connection point or the second connection point.

[0013] According to the above characteristic configuration, the connection switching device can connect the power conditioner circuit unit to the grid connection line connected to the first connection point or the second connection point of the power line while the power conditioner circuit unit is electrically connected to the power grid. As a result, power can be reversed from the power conditioner circuit unit to the power grid via the first connection point or the second connection point to which the grid connection line is connected. In addition, the connection switching device can connect the power conditioner circuit unit to the independent connection line connected to the third connection point of the power line while the power conditioner circuit unit is not electrically connected to the power grid. As a result, power can be supplied from the power conditioner circuit unit to the third connection point of the power line via the independent connection line.

[0014] Another characteristic configuration of the power conditioner system according to the present invention is that, in a normal state in which power is being supplied normally from the power system to the power line, the connection switching device connects the power conditioner circuit unit, while electrically connected to the power system, to either an interconnection line connected to the first connection point of the power line or an independent connection line connected to the second connection point of the power line, and, in an abnormal state in which power is not being supplied normally from the power system to the power line, the connection switching device connects the power conditioner circuit unit to the independent connection line connected to the second connection point of the power line, while not electrically connected to the power system.

[0015] According to the above characteristic configuration, the connection switching device can connect the power conditioner circuit unit to the grid connection line connected to the first connection point of the power line and the independent connection line connected to the second connection point of the power line while the power conditioner circuit unit is electrically connected to the power grid. As a result, power can be reversed from the power conditioner circuit unit to the power grid via the grid connection line or the independent connection line. In addition, the connection switching device can connect the power conditioner circuit unit to the independent connection line connected to the second connection point of the power line while the power conditioner circuit unit is not electrically connected to the power grid. As a result, power can be supplied from the power conditioner circuit unit to the second connection point of the power line via the independent connection line. [Brief description of the drawings]

[0016] [Figure 1] 1 is a diagram showing a configuration of a power supply system in which a power conditioner system according to a first embodiment is provided. [Diagram 2] 1 is a diagram showing a configuration of a power supply system in which a power conditioner system according to a first embodiment is provided. [Diagram 3] 1 is a diagram showing a configuration of a power supply system in which a power conditioner system according to a first embodiment is provided. [Figure 4] FIG. 11 is a diagram showing a configuration of a power supply system in which a power conditioner system according to a third embodiment is provided. [Diagram 5] FIG. 11 is a diagram showing a configuration of a power supply system in which a power conditioner system according to a third embodiment is provided. [Figure 6] FIG. 11 is a diagram showing a configuration of a power supply system in which a power conditioner system according to a third embodiment is provided. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] First Embodiment Hereinafter, a power supply system provided with a power conditioner system according to a first embodiment of the present invention will be described with reference to the drawings. Figures 1 to 3 are diagrams showing the configuration of a power supply system provided with a power conditioner system according to a first embodiment. In Figures 1 to 3, locations where power is supplied are indicated by bold lines.

[0018] As shown in the figure, the power conditioner system includes a power conditioner 10 and a connection switching device SW. The power conditioner 10 includes a power conditioner circuit unit 11 to which a solar power generation device 8 and a charge / discharge device 7 are connected, and a power conditioner control unit 12 to control the operation of the power conditioner circuit unit 11. The power conditioner circuit unit 11 is connected to a power line 2 that is linked to a power system 1. The power conditioner circuit unit 11 has electric circuits such as a DC / DC conversion circuit and a DC / AC conversion circuit that are configured using semiconductor switching elements and the like. The solar power generation device 8 is a device that receives sunlight and generates power, and is connected to the power conditioner circuit unit 11. The charge / discharge device 7 is a device that can discharge power stored in a charge / discharge unit such as a storage battery and charge power to the charge / discharge unit, and is connected to the power conditioner circuit unit 11.

[0019] A connection point to the power grid 1 is provided on the upstream side of the power line 2, and a first power meter 3, a first connection point P1, a second power meter 4, a second connection point P2, a third connection point P3, and a fourth connection point P4 are provided in that order along the power line 2 from the connection point to the power grid 1 toward the downstream side.

[0020] The power conditioner 10 controls the operation of outputting the power generated by the solar power generation device 8 to the power line 2, and the operation of charging and discharging the charge / discharge device 7. The power conditioner 10 can control the power generated by the solar power generation device 8 by, for example, maximum power tracking control, and supply the generated power to the power line 2. In addition, the power conditioner 10 may charge the charge / discharge device 7 with a part or all of the power generated by the solar power generation device 8. The power conditioner 10 can also charge the charge / discharge device 7 with power received from the power line 2.

[0021] A fuel cell device 6 and a power load device 5 are connected to the fourth connection point P4. The fuel cell device 6 has a fuel cell section, such as a solid oxide fuel cell (SOFC) or a polymer electrolyte fuel cell (PEFC), and a fuel cell control section that controls the operation of the fuel cell section. The fuel cell device 6 also has a power conversion section that converts the power generated in the fuel cell section into power of a desired voltage, frequency, and phase, and outputs it to the fourth connection point P4 of the power line 2. The fuel cell device 6 may also include a fuel reformer that generates hydrogen or the like as a fuel gas to be supplied to the fuel cell section through a reforming process.

[0022] The fuel cell device 6 can perform load following operation, constant output operation, and the like. For example, when performing load following operation, the fuel cell device 6 adjusts the output power to the power line 2 so that the power measured by the power measuring unit 18 becomes zero. When performing constant output operation, the fuel cell device 6 supplies a predetermined output power to the power line 2. When the fuel cell device 6 performs constant output operation, if the power supplied from the fuel cell device 6 to the fourth connection point P4 of the power line 2 is greater than the power consumption of the power load device 5, the surplus power is supplied from the fourth connection point P4 toward the upstream changeover switch 17. On the other hand, if the power supplied from the fuel cell device 6 to the fourth connection point P4 of the power line 2 is less than the power consumption of the power load device 5, the shortage power is supplied from the changeover switch 17 toward the fourth connection point P4.

[0023] In addition, the power conditioner 10 includes a changeover switch 14. The changeover switch 14 switches the power conditioner 10 to be connected to either the changeover unit 20 or a changeover switch 17 provided at the third connection point P3 of the power line 2. Specifically, a contact a of the changeover switch 14 is connected to the power conditioner circuit unit 11, a contact b of the changeover switch 14 is connected to a contact a of the changeover switch 21 of the changeover unit 20 via the grid connection line 15, and a contact c of the changeover switch 14 is connected to a contact b of the changeover switch 17 provided at the third connection point P3 of the power line 2 via the independent connection line 16.

[0024] The changeover unit 20 includes a changeover switch 21 and a drive circuit 22 that controls the operation of the changeover switch 21. A contact a of the changeover switch 21 is connected to a contact b of the changeover switch 14 of the power conditioner 10 via the grid connection line 15, the contact b of the changeover switch 21 is connected to a first connection point P1 of the power line 2, and a contact c of the changeover switch 21 is connected to a second connection point P2 of the power line 2. The drive circuit 22 controls the operation of the changeover switch 21 in response to an instruction from the power conditioner control unit 12.

[0025] When the voltage measured by the voltage measuring unit 23 is equal to or higher than a predetermined lower limit voltage, the power conditioner control unit 12 determines that the power supply from the power system 1 to the power line 2 is normal, and connects the power conditioner circuit unit 11 to the grid connection line 15 by switching the changeover switch 14 to a state in which the contacts a and b are connected, as shown in Figures 1 and 2. In addition, in the normal state, the power conditioner control unit 12 switches the changeover switch 17 to a state in which the contacts a and c are connected.

[0026] Furthermore, when the voltage measured by voltage measuring unit 23 is lower than the lower limit voltage, power conditioner control unit 12 determines that an abnormal state exists in which power supply from power system 1 to power line 2 is not being performed normally, and connects power conditioner circuit unit 11 to independent connection line 16 by switching changeover switch 14 to a state in which contact a and contact c are connected, as shown in Fig. 3. In addition, in the case of an abnormal state, power conditioner control unit 12 switches changeover switch 17 to a state in which contact a and contact b are connected.

[0027] In this way, in the power conditioner 10, in a normal state in which power is being supplied normally from the power system 1 to the power line 2, the power conditioner circuit unit 11 is connected to the interconnection line 15 that is connected to the first connection point P1 or the second connection point P2 while being electrically connected to the power system 1, and in an abnormal state in which power is not being supplied normally from the power system 1 to the power line 2, the power conditioner circuit unit 11 is connected to the independent connection line 16 that is connected to the third connection point P3 midway along the power line 2, downstream of the second connection point P2, while not being electrically connected to the power system 1, and the connection switching device SW is configured to switch the connection point of the interconnection line 15 to the power line 2 to either the first connection point P1 or the second connection point P2.

[0028] The changeover switch 21 of the changeover unit 20 and the changeover switch 14 of the power conditioner 10 realize a connection switching device SW of the present invention. The connection switching device SW switches the connection point of the power conditioner circuit unit 11 to the power line 2 to either the first connection point P1 or the second connection point P2 depending on the supply state of discharged power of the charge / discharge device 7 from the charge / discharge device 7 to the power line 2 via the power conditioner circuit unit 11. FIG. 1 shows a state in which the connection point of the power conditioner circuit unit 11 to the power line 2 is switched to the first connection point P1. FIG. 2 shows a state in which the connection point of the power conditioner circuit unit 11 to the power line 2 is switched to the second connection point P2. The operation of the connection switching device SW is controlled by the power conditioner control unit 12.

[0029] [When discharging (normal state)] In a normal state, when the power conditioner circuit unit 11 outputs the discharge power of the charge / discharge device 7 to the power line 2, the connection switching device SW connects the power conditioner circuit unit 11 to the second connection point P2. Specifically, information on the charge / discharge power to the charge / discharge device 7, which can be measured by the power measurement unit 19, is transmitted to the power conditioner control unit 12. Then, in a normal state, when the sign of the discharge power of the charge / discharge device 7 is plus, the power conditioner control unit 12 switches the changeover switch 14 as the connection switching device SW to a state in which the contacts a and b are connected, and the changeover switch 21 as the connection switching device SW to a state in which the contacts a and c are connected, as shown in FIG.

[0030] [When charging (normal state)] In a normal state, when the power conditioner circuit unit 11 charges the charging / discharging device 7 with power greater than the power generated by the solar power generation device 8, the connection switching device SW connects the power conditioner circuit unit 11 to the second connection point P2, and when the power conditioner circuit unit 11 charges the charging / discharging device 7 with power less than the power generated by the solar power generation device 8, the connection switching device SW connects the power conditioner circuit unit 11 to the first connection point P1.

[0031] Specifically, the power conditioner control unit 12 is transmitted information on the charging / discharging power to the charge / discharge device 7, which can be measured by the power measurement unit 19, and information on the power generated by the photovoltaic power generation device 8, which can be measured by the power measurement unit 24. In the normal state, when the charging power of the charge / discharge device 7 is greater than the power generated by the photovoltaic power generation device 8, the power conditioner control unit 12 switches the changeover switch 14 as the connection switching device SW to a state in which the contacts a and b are connected, as shown in FIG. 2, and the changeover switch 21 as the connection switching device SW to a state in which the contacts a and c are connected, as shown in FIG. 1, when the charging power of the charge / discharge device 7 is equal to or less than the power generated by the photovoltaic power generation device 8.

[0032] As described above, when the connection switching device SW connects the power conditioner 10 to the first connection point P1, i.e., when the connection switching device SW connects the power conditioner 10 to the power line 2 between the first power meter 3 and the second power meter 4, the power flowing back from the power conditioner 10 to the power grid 1 is measured by the first power meter 3 but not by the second power meter 4. Also, when the connection switching device SW connects the power conditioner 10 to the second connection point P2, i.e., when the connection switching device SW connects the power conditioner 10 to the power line 2 downstream of the second power meter 4, the power flowing back from the power conditioner 10 to the power grid 1 can be measured by the second power meter 4. In this way, by adopting a configuration in which the connection switching device SW switches the connection point of the power conditioner circuit section 11 to the power line 2 to either the first connection point P1 or the second connection point P2, it is possible to perform switching such as connecting the power conditioner 10 to the first connection point P1 when power from the solar power generation device 8 is to be reverse-flowed to the power grid 1, and connecting the power conditioner 10 to the second connection point P2 when power from the charging / discharging device 7 is to be reverse-flowed to the power grid 1.

[0033] <Second embodiment> The power conditioner system of the second embodiment differs from the above-mentioned embodiment in the operation during discharging of the charge / discharge device 7. The power conditioner system of the second embodiment will be described below, but a description of the same configuration as the above-mentioned embodiment will be omitted.

[0034] In the present embodiment, the connection switching device SW is configured to connect the power conditioner circuit unit 11 to the second connection point P2 as shown in FIG. 2 when, in a normal state, the power conditioner circuit unit 11 outputs the discharged power of the charging / discharging device 7 to the power line 2 and a reverse flow of power from the power line 2 to the power system 1 is occurring, and to connect the power conditioner circuit unit 11 to the first connection point P1 as shown in FIG. 1 when the power conditioner circuit unit 11 outputs the discharged power of the charging / discharging device 7 to the power line 2 but a reverse flow of power from the power line 2 to the power system 1 is not occurring.

[0035] For example, the power conditioner control unit 12 can determine whether or not a reverse flow of power is occurring from the power line 2 to the power system 1 by referring to the power measured by the power measurement unit 9 provided upstream of the first connection point P1 of the power line 2. Then, the power conditioner control unit 12 can determine whether to connect the power conditioner circuit unit 11 to the first connection point P1 or the second connection point P2 based on whether or not a reverse flow of power is occurring from the power line 2 to the power system 1 and whether or not the discharge power of the charge / discharge device 7 is being output to the power line 2.

[0036] <Third embodiment> The power conditioner system of the third embodiment differs from the above-mentioned embodiments in the configuration of the connection switching device SW. The power conditioner system of the third embodiment will be described below, but the description of the same configuration as the above-mentioned embodiments will be omitted.

[0037] Figures 4 to 6 are diagrams showing the configuration of a power supply system provided with a power conditioner system according to the third embodiment. In Figures 4 to 6, the locations where power is being supplied are indicated by thick lines.

[0038] As shown in Figures 4 to 6, a connection point to the power grid 1 is provided on the upstream side of the power line 2, and a first power meter 3, a first connection point P1, a second power meter 4, a switching unit 30, a second connection point P2, and a third connection point P3 are provided in that order along the power line 2 from the connection point to the power grid 1 toward the downstream side.

[0039] The power conditioner 10 includes a changeover switch 14. The changeover switch 14 switches the power conditioner 10 to be connected to either a first connection point P1 or a second connection point P2. Specifically, a contact a of the changeover switch 14 is connected to the power conditioner circuit unit 11, a contact b of the changeover switch 14 is connected to the first connection point P1 of the power line 2 via an interconnection connection line 15, and a contact c of the changeover switch 14 is connected to the second connection point P2 of the power line 2 via an independent connection line 16.

[0040] The switching unit 30 includes a changeover switch 31 and a drive circuit 32 that controls the operation of the changeover switch 31. The changeover switch 31 is interposed in the middle of the power line 2, and when in a connected state, it brings the upstream side and downstream side of the power line 2 into conduction, and when in a non-connected state, it insulates the upstream side and downstream side of the power line 2. The drive circuit 32 controls the operation of the changeover switch 31 in response to an instruction from the power conditioner control unit 12.

[0041] When the voltage measured by the voltage measuring unit 33 is equal to or higher than a predetermined lower limit voltage, the power conditioner control unit 12 determines that the power supply from the power system 1 to the power line 2 is normal, and in the example shown in Fig. 4, the changeover switch 14 is switched to a state in which the contacts a and b are connected, thereby connecting the power conditioner circuit unit 11 to the grid-connected connection line 15 and bringing the changeover switch 31 into a connected state. When the power conditioner control unit 12 determines that the power system is normal, in the example shown in Fig. 5, the changeover switch 14 is switched to a state in which the contacts a and c are connected, thereby connecting the power conditioner circuit unit 11 to the independent connection line 16 and bringing the changeover switch 31 into a connected state.

[0042] Furthermore, when the voltage measured by the voltage measuring unit 33 is lower than the lower limit voltage, the power conditioner control unit 12 determines that an abnormal state has occurred, in which power supply from the power system 1 to the power line 2 is not being performed normally, and in the example shown in FIG. 6 , by switching the change-over switch 14 to a state in which contacts a and c are connected, the power conditioner circuit unit 11 is connected to the independent connection line 16 and the change-over switch 31 is brought into a disconnected state.

[0043] The changeover switch 14 of the power conditioner 10 realizes the connection switching device SW of the present invention. The connection switching device SW switches the connection point of the power conditioner circuit unit 11 to the power line 2 between the first connection point P1 and the second connection point P2 depending on the supply state of the discharged power of the charge / discharge device 7 from the charge / discharge device 7 to the power line 2 via the power conditioner circuit unit 11. FIG. 4 shows a state in which the connection point of the power conditioner circuit unit 11 to the power line 2 is switched to the first connection point P1. FIG. 5 shows a state in which the connection point of the power conditioner circuit unit 11 to the power line 2 is switched to the second connection point P2. The operation of the connection switching device SW is controlled by the power conditioner control unit 12.

[0044] In other words, in a normal state in which power is being supplied normally from the power system 1 to the power line 2, the change-over switch 14 as a connection switching device SW connects the power conditioner circuit unit 11 to either the interconnection connection line 15 connected to the first connection point P1 of the power line 2 or the independent connection line 16 connected to the second connection point P2 of the power line 2, while being electrically connected to the power system 1; and in an abnormal state in which power is not being supplied normally from the power system 1 to the power line 2, the change-over switch 14 connects the power conditioner circuit unit 11 to the independent connection line 16 connected to the second connection point P2 of the power line 2, while being not electrically connected to the power system 1.

[0045] [When discharging (normal state)] The connection switching device SW connects the power conditioner circuit unit 11 to the second connection point P2 when the power conditioner circuit unit 11 outputs the discharge power of the charge / discharge device 7 to the power line 2. Specifically, information on the charge / discharge power to the charge / discharge device 7, which can be measured by the power measurement unit 19, is transmitted to the power conditioner control unit 12. Then, when the sign of the discharge power of the charge / discharge device 7 is plus, the power conditioner control unit 12 switches the changeover switch 14 serving as the connection switching device SW to a state in which contact a and contact c are connected, as shown in FIG.

[0046] [When charging (normal state)] When the power conditioner circuit unit 11 charges the charging / discharging device 7 with power greater than the power generated by the solar power generation device 8, the connection switching device SW connects the power conditioner circuit unit 11 to the second connection point P2, and when the power conditioner circuit unit 11 charges the charging / discharging device 7 with power less than the power generated by the solar power generation device 8, the connection switching device SW connects the power conditioner circuit unit 11 to the first connection point P1.

[0047] Specifically, information on the charging / discharging power to / from the charge / discharge device 7, which can be measured by the power measuring unit 19, and information on the power generated by the photovoltaic power generation device 8, which can be measured by the power measuring unit 24, are transmitted to the power conditioner control unit 12. When the charging power of the charge / discharge device 7 is greater than the power generated by the photovoltaic power generation device 8, the power conditioner control unit 12 switches the changeover switch 14, which serves as the connection switching device SW, to a state in which the contacts a and c are connected, as shown in Fig. 5. When the charging power of the charge / discharge device 7 is equal to or less than the power generated by the photovoltaic power generation device 8, the power conditioner control unit 12 switches the changeover switch 14, which serves as the connection switching device SW, to a state in which the contacts a and b are connected, as shown in Fig. 4.

[0048] <Another embodiment> <1> In the above embodiment, specific examples of the configurations of the power conditioner 10 and the power supply system have been given and explained, but these configurations can be changed as appropriate. For example, although the power supply system has been illustrated as including a fuel cell device 6, it may include other types of power generation devices.

[0049] <2> In the above embodiment, the configuration for connecting the fuel cell device 6 and the power conditioner circuit unit 11 in an abnormal state where power is not being normally supplied to the power line 2 can be modified as appropriate. For example, a separate connection line can be provided to directly connect the fuel cell device 6 to the power conditioner circuit unit 11, and the two can be electrically connected using the connection line in the abnormal state.

[0050] <3> The configurations disclosed in the above embodiments (including other embodiments, the same applies below) can be applied in combination with configurations disclosed in other embodiments, provided that no contradiction arises. Furthermore, the embodiments disclosed in this specification are illustrative, and the embodiments of the present invention are not limited thereto, and can be appropriately modified within the scope that does not deviate from the purpose of the present invention. [Industrial Applicability]

[0051] The present invention can be used in a power conditioner system that can distinguish and measure the power supplied from a solar power generation device and the power supplied from a charging / discharging device, even when power is supplied to a power line from a power conditioner to which a solar power generation device and a charging / discharging device are connected. [Explanation of symbols]

[0052] 1 Power system 2. Power Lines 3. First power meter 4. Second Power Meter 7 Charging / discharging device 8. Solar power generation equipment 10 Power conditioner 11 Power conditioner circuit section 12 Power conditioner control section 15 Interconnection line 16 Self-supporting connection line P1 First connection point P2 Second connection point P3 3rd connection point SW connection switching device

Claims

1. A power conditioner system including a power conditioner circuit unit to which a photovoltaic power generation device and a charge / discharge device are connected and a power conditioner control unit to control the operation of the power conditioner circuit unit, the power conditioner circuit unit being connected to a power line that is connected to a power grid, a connection point to the power grid is provided on an upstream side of the power line, and a first power meter, a first connection point, a second power meter, and a second connection point are provided in that order on the power line from the connection point to the power grid toward a downstream side; a connection switching device that switches a connection point of the power conditioner circuit unit to the power line between the first connection point and the second connection point depending on a supply state of discharge power of the charging / discharging device from the charging / discharging device to the power line via the power conditioner circuit unit, The connection switching device is configured to connect the power conditioner circuit unit to the first connection point when power supplied only from the solar power generation device is to be reversed from the power conditioner circuit unit to the power grid, and to connect the power conditioner circuit unit to the second connection point when power supplied only from the charging / discharging device is to be reversed from the power conditioner circuit unit to the power grid.

2. 2. The power conditioner system according to claim 1, wherein the connection switching device is configured to connect the power conditioner circuit unit to the first connection point when a reverse flow of power from the power line to the power grid is not occurring even if the power conditioner circuit unit is outputting discharge power of the charging / discharging device to the power line.

3. the connection switching device connects the power conditioner circuit unit to the second connection point when the power conditioner circuit unit charges the charging / discharging device with power greater than the power generated by the solar power generation device, 3. The power conditioner system according to claim 1, wherein the power conditioner circuit unit connects the power conditioner circuit unit to the first connection point when charging the charging / discharging device with power equal to or less than the power generated by the solar power generation device.

4. In a normal state in which power is normally supplied from the power system to the power line, the power conditioner connects the power conditioner circuit unit to an interconnection connection line connected to the first connection point or the second connection point while being electrically connected to the power system, and in an abnormal state in which power is not normally supplied from the power system to the power line, the power conditioner connects the power conditioner circuit unit to an independent connection line connected to a third connection point midway on the power line and downstream of the second connection point while not being electrically connected to the power system; The power conditioner system according to any one of claims 1 to 3, wherein the connection switching device switches a connection point of the interconnection line to the power line to either the first connection point or the second connection point.

5. The connection switching device includes: In a normal state in which power is normally supplied from the power system to the power line, the power conditioner circuit unit is electrically connected to the power system and is connected to either one of an interconnection line connected to the first connection point of the power line and an independent connection line connected to the second connection point of the power line, The power conditioner system according to any one of claims 1 to 3, wherein in the event of an abnormal state in which power supply from the power system to the power line is not being performed normally, the power conditioner circuit unit is connected to an independent connection line connected to the second connection point of the power line while not being electrically connected to the power system.

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