Power supply system

Abstract

We provide a power supply system that separates power sources according to the load. [Solution] The power supply system of the present invention comprises: a grid-side power processing device having a grid-side output unit that converts power supplied from the power grid and outputs the converted power from the grid-side output unit; a distributed power processing device having at least a first distributed-side output unit and a second distributed-side output unit that converts power supplied from distributed power sources and outputs the converted power from the first distributed-side output unit and the second distributed-side output unit; a grid-side power line electrically connected to the grid-side output unit; a first distributed-side power line electrically connected to the first distributed-side output unit and the grid-side power line, and connecting the grid-side power processing device and the distributed-side power processing device; a load-side power line electrically connected to a first load, the grid-side power line and the first distributed-side power line; and a second distributed-side power line electrically connected to a second load and a second distributed-side output unit.

Description

[Technical Field]

[0001] This invention relates to a power supply system. [Background technology]

[0002] In recent years, the introduction of power supply systems, including solar power generation systems, has been progressing. A power supply system, for example, connects the power grid provided by a power company with a solar power generation system via power lines and supplies power to the customer's load through these power lines (see, for example, Patent Document 1). The power supplied to the customer's load is prioritized from the power generated by the solar power generation system. If the power supplied to the load is insufficient, the power grid will supply the remaining power to the load. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2019-126110 [Overview of the project] [Problems that the invention aims to solve]

[0004] Incidentally, loads include types that require a stable power supply and types that do not have strict requirements for a stable power supply. In the power supply system described in Patent Document 1, even if there are multiple loads of different types, all loads are connected to a common power supply line to the solar power generation system and the power grid, and are configured to receive the same power supply from the solar power generation system and the power grid. For this reason, the power supply system described in Patent Document 1 cannot change the power supply method according to the type of load.

[0005] In view of these circumstances, the present invention aims to provide a power supply system that differentiates the power supply mode according to the load. [Means for solving the problem]

[0006] The power supply system of the present invention is characterized by comprising: a grid-side power processing device having a grid-side output unit that converts power supplied from a power grid and outputs the converted power from the grid-side output unit; a distributed power processing device having at least a first distributed-side output unit and a second distributed-side output unit that converts power supplied from distributed power sources and outputs the converted power from the first distributed-side output unit and the second distributed-side output unit; a grid-side power line electrically connected to the grid-side output unit; a first distributed-side power line electrically connected to the first distributed-side output unit and the grid-side power line, and connecting the grid-side power processing device and the distributed-side power processing device; a first load, a load-side power line electrically connected to the grid-side power line and the first distributed-side power line; and a second distributed-side power line electrically connected to the second load and the second distributed-side output unit.

[0007] In the power supply system of the present invention, the distributed power source is a DC power source, and the distributed power processing device is characterized by having a first output unit and a second output unit, a power conditioner that converts the DC power output by the distributed power source into AC power and outputs the AC power from the first output unit and the second output unit, a first transformer that has the first distributed output unit and transforms the voltage of the AC power output from the first output unit into a voltage that can be linked to the grid with the power output from the grid output unit and outputs it from the first distributed output unit, and a second transformer that has the second distributed output unit and transforms the voltage of the AC power output from the second output unit into a voltage to be supplied to the second load.

[0008] In the power supply system of the present invention, when the distributed power processing device defines the path through which it supplies power to the first load via the first distributed power line and the load-side power line as the first power supply path, and the distributed power processing device defines the path through which it supplies power to the second load via the second distributed power line as the second power supply path, the distributed power processing device includes: a first switch provided in the third power supply path that electrically connects the first output unit and the first power supply path, which opens or closes the third power supply path when turned on or off; a second switch provided in the fourth power supply path that electrically connects the second output unit and the second power supply path, which opens or closes the fourth power supply path when turned on or off; and the third power supply path on the first power supply path side of the first switch, and the fourth power supply path on the second power supply path side of the second switch, which electrically connects the third power supply path on the first power supply path side of the first switch. The system includes a third switch provided in a fifth power supply path to which the system is connected, which opens or closes the fifth power supply path by being turned on or off, and an operating unit that switches between a first state in which the first and second switches are on and the third switch is off, and a second state in which the first and second switches are off and the third switch is on, wherein in the first state, the third and fourth power supply paths are open and the fifth power supply path is closed, in the second state, the third and fourth power supply paths are closed and the fifth power supply path is open, and a sixth power supply path is open which includes the fifth power supply path and electrically connects the grid-side power processing device and the second power supply path, and in the second state, the grid-side power processing device supplies power to the second load through the sixth power supply path and the second power supply path.

[0009] In the power supply system of the present invention, the distributed power processing device is electrically connected to the second output unit and has a branch power line having a plurality of branch destinations, the second transformer is electrically connected to one of the branch destinations of the branch power line, and each of the other branch destinations of the branch power line has a corresponding transformer electrically connected.

[0010] In the power supply system of the present invention, the second transformer outputs three-phase AC power, and one of the other branch destinations of the branch power line is electrically connected to a transformer having two output sections, which outputs three-phase AC power as single-phase AC power from the two output sections.

[0011] In the power supply system of the present invention, the first transformer is characterized by being an isolation transformer.

[0012] In the power supply system of the present invention, the system includes an abnormality detection unit for detecting abnormalities in the power system, and a control unit that controls the on / off status of the output in the first distributed-side output unit and the second distributed-side output unit according to the detection result of the abnormality detection unit, wherein the distributed-side power processing unit defines the path through which it supplies power to the first load via the first distributed-side power line and the load-side power line as the first power supply path, and the distributed-side power processing unit defines the path through which it supplies power to the second load via the second distributed-side power line as the second power supply path, the control unit controls the on / off status of the output in the first distributed-side output unit in a normal state in which no abnormality in the power system is detected by the abnormality detection unit. The output of the power unit and the second distributed output unit is turned on to supply power to the first load through the first power supply path and to the second load through the second power supply path by the distributed power processing device. In the event of an abnormal state in which an abnormality in the power system is detected by the abnormality detection unit, the output of the first distributed output unit is turned off to stop the supply of power to the first load through the first power supply path by the distributed power processing device, while the output of the second distributed output unit is turned on to supply power to the second load through the second power supply path by the distributed power processing device.

[0013] In the power supply system of the present invention, the control unit, after detecting an abnormality in the power system by the abnormality detection unit, temporarily turns off the output of the second distributed output unit to stop the supply of power to the second load through the second power supply path by the distributed power processing unit, and then turns on the output of the second distributed output unit at a predetermined timing to supply power to the second load through the second power supply path by the distributed power processing unit. [Effects of the Invention]

[0014] According to the power supply system of the present invention, the mode of power supply can be divided according to the load. [Brief explanation of the drawing]

[0015] [Figure 1] This figure shows the configuration of a power supply system in an embodiment of the present invention. [Figure 2] (A) is a diagram showing the configuration of the power conditioner of the power supply system in an embodiment of the present invention. (B) is a diagram showing a modified configuration of the power conditioner of the power supply system in an embodiment of the present invention. [Figure 3] (A) is a cross-sectional view of a compound-wound transformer included in a power supply system according to an embodiment of the present invention. (B) is a cross-sectional view of (A) taken along the FF arrow. [Figure 4] (A) is a diagram showing the configuration of the power supply system's connection switching unit in an embodiment of the present invention when it is in the connected state (first state). (B) is a diagram showing the configuration of the power supply system's connection switching unit in an embodiment of the present invention when it is in the disconnected state (second state). [Figure 5] This figure shows the configuration of a circuit breaker in a power supply system according to an embodiment of the present invention. [Figure 6] This figure shows the power flow during the normal operating mode of the power supply system in an embodiment of the present invention. [Figure 7]It is a diagram showing the flow of power in the independent operation mode of the power supply system according to an embodiment of the present invention. [Figure 8] It is a diagram showing the flow of power when the connection switching unit of the power supply system according to an embodiment of the present invention is in a disconnected state (second state). [Figure 9] It is a diagram showing the configuration of a modified example of the power supply system according to an embodiment of the present invention.

Mode for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The accompanying drawings show an example of embodiments for carrying out the invention, and in the figures, portions denoted by the same reference numerals represent the same components.

[0017] The power supply system 1 according to an embodiment of the present invention supplies power supplied from the power grid G and the distributed power source D to a load. The power supply system 1 according to the present embodiment includes, for example, a grid-side power processing device 2 electrically connected to the power grid G, a distributed-side power processing device 3 electrically connected to the distributed power source D, a control unit 4, grid-side power lines 5A and 5B electrically connected to the grid-side power processing device 2, distributed-side power lines 6A to 6D electrically connected to the distributed-side power processing device 3, load-side power lines 7A and 7B, an abnormality detection unit 8, and a disconnection unit 9.

[0018] The power grid G is a system integrating power generation, transformation, transmission, and distribution that supplies power to the grid-side power processing device 2 using a grid power source as an alternating-current power source, and is provided by, for example, an electric power company.

[0019] <Grid-side power processing device> Referring to FIG. 1, the grid-side power processing device 2 will be described below. The grid-side power processing device 2 receives power supplied from the power grid G, converts the received power, and outputs the converted power. The grid-side power processing device 2 is configured as, for example, a cubicle. The grid-side power processing device 2 includes a power conversion unit 20 having grid-side output units 200A and 200B, and an instrument transformer 22.

[0020] The power conversion unit 20 converts the power supplied from the power grid G ​​into power usable at the first load 11A and outputs it from the grid-side output units 200A and 200B. In this embodiment, the grid-side output units 200A and 200B are configured as output units of the power conversion unit 20.

[0021] The power conversion unit 20 includes, for example, a power transformer 20A and a lighting transformer 20B. The power transformer 20A is electrically connected to the grid-side power line 5A. The power transformer 20A is composed of, for example, a three-phase transformer that outputs three-phase AC power. The lighting transformer 20B is electrically connected to the grid-side power line 5B. The lighting transformer 20B is composed of, for example, a single-phase transformer that outputs single-phase AC power. The power transformer 20A and the lighting transformer 20B transform the power supplied from the power grid G ​​to a predetermined set voltage. In this embodiment, the high-voltage (6600V) power supplied from the power company is transformed to a voltage usable by the first load 11A (for example, 210V for the power transformer 20A, and 105V or 210V for the lighting transformer 20B). In other words, in this embodiment, the grid-side power processing device 2 transforms (reduces) the voltage of the power supplied from the power grid G ​​to the set voltage and outputs it.

[0022] In this embodiment, the first load 11A includes a first device 11A1 that operates on three-phase AC power and a second device 11A2 that operates on single-phase AC power, but is not limited to this; it is sufficient if at least one of them is included.

[0023] The power transformer 20A is electrically connected to the power distribution panel 10A via the grid-side power line 5A and the load-side power line 7A, and outputs transformed three-phase AC power to the power distribution panel 10A. The first device 11A1, which operates on the transformed three-phase AC power, is connected to the power distribution panel 10A.

[0024] The lighting transformer 20B is electrically connected to the lighting distribution panel 10B via the grid-side power line 5B and the load-side power line 7B, and outputs transformed single-phase AC power to the lighting distribution panel 10B. A second device 11A2, which operates on the transformed single-phase AC power, is connected to the lighting distribution panel 10B. The lighting transformer 20B also functions as a power source for various parts of the power supply system 1 (for example, the control unit 4).

[0025] Furthermore, the power distribution panel 10A and the lighting distribution panel 10B may be collectively referred to as the first distribution panel.

[0026] The above example illustrates a case where the power conversion unit 20 includes a power transformer 20A and a lighting transformer 20B, but it is not limited to this; it is sufficient to include at least one transformer as needed.

[0027] The instrument transformer 22 is a device that converts (transforms) the high voltage and large current of power supplied from the power system G into low voltage and small current for measurement. The measurement results from the instrument transformer 22 are sent to the control unit 4. The control unit 4 has a reverse power relay (RPR: not shown). For example, if a reverse current is detected in the instrument transformer 22, the reverse power relay sends a signal to the power conditioner (PCS) 30, for example, to stop operation.

[0028] <Distributed power supply> Referring to Figure 1, the distributed power source D will be described below. The distributed power source D is a power source separate from the grid power source of the power system G used in the power supply system 1, and is composed of power generation equipment.

[0029] In this embodiment, the distributed power source D includes, for example, a solar cell D1 that generates electricity from sunlight and a storage battery D2, and is a DC power source. The solar cell D1 is composed of, for example, a photovoltaic panel. The storage battery D2 includes, but is not limited to, at least one of, a lead-acid battery, a nickel-cadmium battery, a nickel-metal hydride battery, a lithium-ion battery, etc., and may be composed of other batteries.

[0030] Furthermore, the distributed power source D may include, in place of or in addition to, solar cells D1, other renewable energy sources such as wind, geothermal, and hydroelectric power that can generate electricity.

[0031] <Distributed power processing device> Referring to Figures 1 to 3, the distributed power processing device 3 will be described below. The distributed power processing device 3 is electrically connected to the distributed power supply D and has a first distributed output unit 30A, a second distributed output unit 30B, a third distributed output unit 30C, and a fourth distributed output unit 30D. The distributed power processing device 3 converts the power supplied from the distributed power supply D and outputs the converted power from the first distributed output unit 30A, the second distributed output unit 30B, the third distributed output unit 30C, and the fourth distributed output unit 30D.

[0032] The distributed power processing device 3 includes, for example, a power conditioner (PCS) 30, a first transformer 31, a second transformer 32, a third transformer 33, and a connection switching unit 34. The power conditioner (PCS) 30, the first transformer 31, the second transformer 32, and the third transformer 33 can be considered to constitute a power conversion unit that converts the power supplied from the distributed power source D into power usable by the first load 11A to the fourth load 11D and outputs it from the first distributed output unit 30A, the second distributed output unit 30B, the third distributed output unit 30C, and the fourth distributed output unit 30D. To distinguish it from the power conversion unit 20 of the grid-side power processing device 2, the power conversion unit 20 of the grid-side power processing device 2 may be called the first power conversion unit 20, and the power conversion unit of the distributed power processing device 3 may be called the second power conversion unit.

[0033] <Power Conditioner> The power conditioner 30 converts the DC power supplied from the distributed power source D into AC power and outputs it. The power conditioner 30 also has at least two outputs, one of which is the first output unit 301 and the other is the second output unit 302.

[0034] The first output unit 301 is electrically connected to a power line 36A, which forms the power supply path (third power supply path) to the first distributed output unit 30A. A connection switching unit 34 is interposed in the middle of the power line 36A, and the first transformer 31 is located at the end (termination) of the power line 36A. The connection switching unit 34 and the first transformer 31 are electrically connected to the power line 36A. The output of the first transformer 31 corresponds to the first distributed output unit 30A, and the distributed power line 6A is electrically connected to it.

[0035] The second output unit 302 is electrically connected to a power line 36B that forms the power supply path (fourth power supply path) from the second distributed output unit 30B to the fourth distributed output unit 30D. The power line 36B branches into two along its course. A connection switching unit 34 is interposed in the power line 36B just before it branches and is electrically connected to the power line 36B. The second transformer 32 is electrically connected to the end (termination) of one of the branched power lines 36B1. The output of the second transformer 32 corresponds to the second distributed output unit 30B, and the distributed power line 6B is electrically connected to it.

[0036] A third transformer 33 is connected to the end (termination) of the other branch of power line 36B2. The third transformer 33 has two outputs; one output corresponds to the third distributed output section 30C, and the other output corresponds to the fourth distributed output section 30D. One output of the third transformer 33 is electrically connected to the distributed power line 6C, and the other output is electrically connected to the distributed power line 6D.

[0037] Power line 36B may be branched into three or more lines along its course. In this case, a transformer will be connected to the end (termination) of each branch.

[0038] When the distributed power source D includes a solar cell D1 and a storage battery D2, the power conditioner 30 includes, for example, a first DC / DC converter 303, a second DC / DC converter 304, an inverter 305, a branch output unit 306, a first circuit breaker 307, a second circuit breaker 308, and a power conditioner (PCS) control unit 309 that controls each of the above units, as shown in Figure 2(A). The PCS control unit 309 may also be simply called the control unit 309.

[0039] The first DC / DC converter 303 transforms the DC power output from the solar cell D1 into a voltage suitable for input to the inverter 305. The first DC / DC converter 303 also has a function to prevent reverse power flow to the solar cell D1.

[0040] The second DC / DC converter 304 has the function of transforming the output of the battery D2 to a voltage suitable for input to the inverter 305, and the function of transforming the output from the inverter 305 to the second DC / DC converter 304 to power suitable for charging the battery D2, in response to the charging and discharging of the battery D2.

[0041] The inverter 305 converts the DC power transformed by the first DC / DC converter 303 or the second DC / DC converter 304 into AC power and outputs it. The inverter 305 also converts the AC power supplied from the power system G through the system-side power processing unit 2 (power conversion unit 20) into DC power and outputs it to the second DC / DC converter 304. The DC power output to the second DC / DC converter 304 is transformed by the second DC / DC converter 304 and output to the storage battery D2, which is then charged.

[0042] In this embodiment, the inverter 305 is, for example, a three-phase inverter that outputs three-phase AC power, but it is not limited to this.

[0043] The branch output section 306 is electrically connected to the output section of the inverter 305, and the output is split into two. The branch output section 306 splits the AC power output from the inverter 305 into two. The output of one of the branched parts, the first branched power line 306A, corresponds to the first output section 301, and the output of the other branched part, the second branched power line 306B, corresponds to the second output section 302.

[0044] Furthermore, a first circuit breaker 307 is provided on the first branch power line 306A. A second circuit breaker 308 is provided on the second branch power line 306B. The first circuit breaker 307 interrupts or uninterrupts the power supply path consisting of the first branch power line 306A in response to instructions from the PCS control unit 309. As a result, when the corresponding power supply path is interrupted by the first circuit breaker 307, the output from the first output unit 301 stops, and when the interruption of the corresponding power supply path by the first circuit breaker 307 is released, the output from the first output unit 301 resumes.

[0045] The second circuit breaker 308 interrupts or uninterrupts the power supply path consisting of the second branch power line 306B in response to instructions from the PCS control unit 309. As a result, when the corresponding power supply path is interrupted by the second circuit breaker 308, the output from the second output unit 302 stops, and when the interruption of the corresponding power supply path by the second circuit breaker 308 is released, the output from the second output unit 302 resumes.

[0046] The power conditioner 30 described above is configured as a so-called hybrid power conditioner, which is shared by both the solar cell D1 and the storage battery D2.

[0047] Alternatively, unlike the above, for example, as shown in Figure 2(B), a solar cell power conditioner (solar cell PCS) 37 may be used for the solar cell D1, and a separate battery power conditioner (battery PCS) 38 may be used for the battery D2. The solar cell power conditioner 37 has the function of converting the DC power supplied from the solar cell D1 into AC power and outputting it, while also preventing the reverse flow of power to the solar cell D1. The battery power conditioner 38 has the function of converting the DC power supplied from the battery D2 into AC power and outputting it, while also converting the AC power supplied from the power grid G ​​through the power conversion unit 20 or the AC power supplied from the solar cell power conditioner 37 into DC power and outputting it to the battery D2 to charge the battery D2.

[0048] The PCS control unit 309 controls the operation of the first DC / DC converter 303, the second DC / DC converter 304, the inverter 305, the first circuit breaker 307, and the second circuit breaker 308. The control of opening and closing the power supply path by the first circuit breaker 307 and the second circuit breaker 308 is preferably triggered by an abnormality detection signal and a normal detection signal (abnormality release detection signal), which will be described later. The operation of the inverter 305 is also triggered by an abnormality detection signal and a normal detection signal (abnormality release detection signal), which will be described later.

[0049] Furthermore, if the distributed power source D includes a solar cell D1 and a storage battery D2, it is preferable to separately provide a power generation measurement unit (not shown) for measuring the amount of power generated by the solar cell D1 and a storage amount measurement unit (not shown) for measuring the amount of energy stored in the storage battery D2, and to control the operation of the power conditioner 30 based on the results of these measurements.

[0050] There are various control modes for the power conditioner 30. For example, if the measurement result from the power generation measurement unit (power generation amount of solar cell D1) is above a threshold, the power conditioner 30 may prioritize converting the power generated by solar cell D1 to power stored in battery D2 and outputting it. If surplus power is detected in the measurement result from the power generation measurement unit (power generated by solar cell D1), the power conditioner 30 may use the surplus power to charge battery D2. Also, if the measurement result from the power generation measurement unit (power generation amount of solar cell D1) is below a threshold, the power conditioner 30 may prioritize converting the power stored in battery D2 to power generated by solar cell D1 and outputting it. The above control modes for the power conditioner 30 are just examples, and other control modes are also included within the scope of the present invention.

[0051] <First Transformer> The first transformer 31 will be described with reference to Figures 1 and 3. As shown in Figure 1, the first transformer 31 is electrically connected to power line 36A at its end (termination). The first transformer 31 transforms (for example, reduces) the voltage of the AC power output from the first output section 301 of the power conditioner 30 to a set voltage and outputs it. The output portion of the first transformer 31 corresponds to the first distributed side output section 30A and is connected to the distributed side power line 6A. The set voltage for this transformation is compatible with the AC power converted by the grid-side power processing device 2 (power conversion section 20) and can be connected to the grid. In this embodiment, since three-phase AC power is output from the power conditioner 30, the first transformer 31 is composed of a three-phase transformer. As a result, three-phase AC power is output from the first transformer 31.

[0052] Furthermore, in order to prevent unnecessary operation of the ground fault alarm and other devices in the grid-side power processing device 2, it is preferable that leakage current generated in the power conditioner 30 and flowing into the grid-side power processing device 2 is interrupted. It is also preferable to interrupt lightning surges so that lightning surges entering from the power grid G ​​side do not flow into the power conditioner 30 and the distributed power supply D. To achieve the above, it is preferable that the first transformer 31 be an isolation transformer. And, in this embodiment, it is preferable that the isolation transformer be a compound-winding transformer rather than a single-winding transformer.

[0053] The double-wound transformer in this embodiment, as shown in Figure 3(A), has a core member 310, an inner winding 311, an outer winding 312, and first to third insulating layers 313 to 315. The core member 310 includes, for example, a metal iron core. The inner winding 311 and the outer winding 312 are made of conductors. The first to third insulating layers 313 to 315 are made of insulating materials having insulating properties.

[0054] As shown in Figure 3(A), the double-wound transformer is constructed by stacking multiple annular layers (cylindrical layers) that surround the core member 310 when viewed from the axial direction of the core member 310, in a direction perpendicular to the central axis 310A of the core member 310. The multiple layers are stacked in the following order from the side closest to the core member 310: first insulating layer 313, inner winding 311, second insulating layer 314, outer winding 312, and third insulating layer 315.

[0055] Specifically, the first insulating layer 313 is provided so as to surround the core member 310 in the circumferential direction around the central axis 310A of the core member 310. The inner winding 311 is wound around the outer surface of the first insulating layer 313 so as to surround the first insulating layer 313 in the circumferential direction around the central axis of the first insulating layer 313 (core member 310). The second insulating layer 314 is provided so as to surround the inner winding 311 in the circumferential direction around the central axis of the inner winding 311 (core member 310). The outer winding 312 is wound around the outer surface of the second insulating layer 314 so as to surround the second insulating layer 314 in the circumferential direction around the central axis of the second insulating layer 314 (core member 310). The third insulating layer 315 is provided so as to surround the outer winding 312 (core member 310) in the circumferential direction around its central axis.

[0056] The core member 310 and the inner winding 311 are insulated by the first insulating layer 313. The inner winding 311 and the outer winding 312 are insulated by the second insulating layer 314. The outer winding 312 is insulated by the third insulating layer 315 from components outside the third insulating layer 315 (not shown). In order to prevent contact between the inner winding 311 and the outer winding 312, a contact prevention plate (not shown) may be provided between them. The contact prevention plate is expected to be made of, for example, a metal plate, but is not limited to this, and may be a plate of other materials. As long as the core member 310, inner winding 311, and outer winding 312 are insulated from each other as described above, the first insulating layer 313 to the third insulating layer 315 may have any shape or configuration.

[0057] Furthermore, it is preferable that the creepage distance L1 and / or clearance distance L2 between the inner winding 311 and the outer winding 312 be 6 mm or more. As shown by the dotted line in Figure 3(B), the creepage distance L1 refers to the distance along the path on the surface of the second insulating layer 314 from the first position 316 where the first winding portion 311A ​​at one end of the inner winding 311 (core member 310) in the axial direction contacts the second insulating layer 314, through the axial end 314A of the second insulating layer 314 on the same side as the first winding portion 311A, to the second position 317 where the first winding portion 312A at the axial end of the outer winding 312 on the same side as the first winding portion 311A ​​contacts the second insulating layer 314. The first position 316 refers to the end of the contact area where the first winding portion 311A ​​and the second insulating layer 314 are in contact, and which is closest to the end 314A of the second insulating layer 314 in the axial direction of the inner winding body 311 (core member 310). The second position 317 refers to the end of the contact area where the first winding portion 312A and the second insulating layer 314 are in contact, and which is closest to the end 314A of the second insulating layer 314 in the axial direction of the outer winding body 312 (core member 310). As shown by the dashed line in Figure 3(B), the spatial distance L2 refers to the shortest distance from the end 311B of the inner winding 311 (single turn portion 311A) that is closest to the end 314A of the second insulating layer 314 in the axial direction of the inner winding 311 (core member 310), via the end 314A of the second insulating layer 314, to the end 312B of the outer winding 312 (single turn portion 312A) that is closest to the end 314A of the second insulating layer 314 in the axial direction of the outer winding 312 (core member 310).

[0058] Furthermore, it is preferable that the creepage distance and / or clearance distance between the core member 310 and the inner winding 311 be 3 mm or more. The creepage distance and clearance distance between the core member 310 and the inner winding 311 are determined in the same manner as the creepage distance L1 and clearance distance L2, respectively.

[0059] Furthermore, in order to provide a high insulation effect against high-frequency AC power and enable it to withstand high voltages, it is preferable to design the transformer so that the stray capacitance between the inner winding 311 and the outer winding 312 is minimized. When the attenuation rate P of the lightning surge of the double-wound transformer is defined as P = 20log(secondary output surge voltage / primary output surge voltage) (dB), -30(dB)≧P is preferable, -40(dB)≧P is more preferable, and -50(dB)≧P is even more preferable.

[0060] <Second Trans> The second transformer 32 will be described with reference to Figure 1. As shown in Figure 1, the second transformer 32 is electrically connected to the power line 36B1 at its end (termination). The second transformer 32 transforms (for example, reduces) the voltage of the AC power output from the second output section 302 of the power conditioner 30 to a set voltage and outputs it. The output portion of the second transformer 32 corresponds to the second distributed side output section 30B and is connected to the distributed side power line 6B. The set voltage for this transformation is transformed to a voltage usable by the second load 11B (for example, 210V). In this embodiment, since three-phase AC power is output from the power conditioner 30, the second transformer 32 is composed of a three-phase transformer. As a result, three-phase AC power is output from the second transformer 32.

[0061] <Third Trans> The third transformer 33 will be described with reference to Figure 1. As shown in Figure 1, the third transformer 33 has an input section 33A and two output sections 33B and 33C. The input section 33A of the third transformer 33 is electrically connected to the power line 36B2 at its end (termination). The output section 33B of the third transformer 33 corresponds to the third distributed side output section 30C, to which the distributed side power line 6C is electrically connected. The output section 33C of the third transformer 33 corresponds to the fourth distributed side output section 30D, to which the distributed side power line 6D is electrically connected. The third transformer 33 transforms the voltage of the three-phase AC power to a set voltage (for example, by reducing the voltage) and outputs it in the form of two sets of single-phase AC power. The set voltage for this transformation is the voltage usable by the second load 11B (for example, 105V). One of the single-phase AC powers is output from output section 33B, and the other single-phase AC power is output from output section 33C. The third transformer 33 is, for example, composed of a Scott-connected transformer.

[0062] <Connection switching section> The connection switching unit 34 will be described with reference to Figures 1 and 4. The connection switching unit 34 connects or disconnects the power conditioner 30 to the main system and the auxiliary system. In this embodiment, the connection switching unit 34 has a first switch 340, a second switch 341, and a third switch 342.

[0063] The main system refers to the system consisting of equipment including load-side power lines 7A and 7B, power-side distribution panel 10A, and lighting-side distribution panel 10B. The auxiliary system refers to the system consisting of equipment including distributed-side power lines 6B to 6D and second to fourth distribution panels 10C to 10E. The main system supplies power to the first load 11A. The auxiliary system supplies power to the second to fourth loads 11B to 11D. The main system may be interpreted as the GRID system as appropriate. The auxiliary system may be interpreted as the EPS system as appropriate.

[0064] Here, with the first switch 340 as the reference, a portion of the power line 36A on the first output unit 301 side is defined as the first power line segment, and a portion of the power line 36A on the opposite side of the first power line segment (the first distributed output unit 30A side) is defined as the second power line segment. Similarly, with the second switch 341 as the reference, a portion of the power line 36B on the second output unit 302 side is defined as the third power line segment, and a portion of the power line 36B on the opposite side of the third power line segment (the second distributed output unit 30B to the fourth distributed output unit 30D side) is defined as the fourth power line segment.

[0065] The first switch 340 is interposed in the middle of power line 36A (third power supply path) and is electrically connected to power line 36A. By being turned on or off, the first switch 340 connects or disconnects the first power line segment and the second power line segment, thereby opening or shutting off power line 36A (third power supply path).

[0066] The second switch 341 is interposed in the middle of power line 36B (the fourth power supply route) just before it branches off, and is electrically connected to power line 36B. By turning on or off, the second switch 341 connects or disconnects the third power line segment and the fourth power line segment, thereby opening or shutting off power line 36B (the fourth power supply route).

[0067] The third switch 342 is interposed in the fifth power supply path 36C, which is electrically connected to both the second and fourth power line segments, and is electrically connected to the fifth power supply path 36C. The third switch 342 connects or disconnects the fifth power supply path 36C by turning on or off, thereby opening or interrupting the fifth power supply path 36C. The fifth power supply path 36C may consist of power lines or other configurations.

[0068] As shown in Figure 4(A), when the power conditioner 30 is connected to the main and auxiliary systems, the first switch 340 and the second switch 341 are ON (closed), and the third switch 342 is OFF (open). This state of the connection switching unit 34 is simply called the connected state (first state). As shown in Figure 4(B), when the power conditioner 30 is disconnected from the main and auxiliary systems, the first switch 340 and the second switch 341 are OFF (open), and the third switch 342 is ON (closed). This state of the connection switching unit 34 is simply called the disconnected state (second state).

[0069] Switching between the connected and disconnected states of the connection switching unit 34 is performed by an operation unit (not shown). The connected and disconnected states of the connection switching unit 34 are switched by an operation on the operation unit. For example, the operation unit includes a mechanism in which, in conjunction with the first operation, the first switch 340 and the second switch 341 are simultaneously turned on (closed), and the third switch 342 is turned off (open), and in conjunction with the second operation, the first switch 340 and the second switch 341 are simultaneously turned off (open), and the third switch 342 is turned on (closed). The operation unit is composed of, for example, a lever, a knob, a touch panel, etc. The connection switching unit 34 is assumed to be composed of, for example, a cam switch, but is not limited to this, and may be composed of other devices.

[0070] Normally, the connection switching unit 34 is kept in the connected state. When performing maintenance on the power conditioner 30, the connection switching unit 34 is set to the disconnected state. In the disconnected state, the power conditioner 30 is disconnected from the main and auxiliary systems, thus eliminating the risk of electric shock to workers during maintenance work.

[0071] <Grid-side power lines> The grid-side power lines 5A and 5B will be described with reference to Figure 1. Each of the grid-side power lines 5A and 5B is electrically connected to the grid-side output sections 200A and 200B of the power conversion unit 20 (grid-side power processing device 2), respectively. In this embodiment, each of the grid-side power lines 5A and 5B is composed of, for example, a power cable capable of transmitting power. The grid-side power line 5A is electrically connected to the grid-side output section 200A of the power transformer 20A. The grid-side power line 5B is electrically connected to the grid-side output section 200B of the lighting transformer 20B.

[0072] In the power supply system 1 of this embodiment, the grid-side power processing device 2 (power conversion unit 20) is electrically connected to the main grid through grid-side power lines 5A and 5B. Therefore, the grid-side power processing device 2 can supply power to the main grid. Furthermore, the grid-side power processing device 2 is electrically connected to the auxiliary grid through grid-side power line 5A and distributed power line 6A. Therefore, the grid-side power processing device 2 can also supply power to the auxiliary grid.

[0073] <Distributed power line> The distributed power lines 6A to 6D will be described with reference to Figure 1. The distributed power lines 6A to 6D are electrically connected to the distributed power processing device 3. In this invention, the distributed power line 6A may be referred to as the first distributed power line 6A, the distributed power line 6B as the second distributed power line 6B, the distributed power line 6C as the third distributed power line 6C, and the distributed power line 6D as the fourth distributed power line 6D, as appropriate.

[0074] In this embodiment, the distributed power line 6A is electrically connected to the first distributed output unit 30A and the grid-side power line 5A. The grid-side power line 5A and the distributed power line 6A are electrically connected at the power line connection unit 12. The power line connection unit 12 can be any type of power line connection unit 12, as long as it is capable of electrically connecting the grid-side power line 5A, the distributed power line 6A, and the load-side power line 7A.

[0075] The distributed power line 6B is electrically connected to the second distributed output unit 30B and the second distribution board 10C, electrically connecting the second distributed output unit 30B and the second distribution board 10C. The second load 11B, which operates on three-phase AC power, is electrically connected to the second distribution board 10C.

[0076] The distributed power line 6C is electrically connected to the third distributed output unit 30C and the third distribution board 10D, electrically connecting the third distributed output unit 30C and the third distribution board 10D. The third load 11C, which operates on single-phase AC power, is electrically connected to the third distribution board 10D.

[0077] The distributed power line 6D is electrically connected to the fourth distributed output unit 30D and the fourth distribution panel 10E, electrically connecting the fourth distributed output unit 30D and the fourth distribution panel 10E. The fourth load 11D, which operates on single-phase AC power, is electrically connected to the fourth distribution panel 10E.

[0078] In the power supply system 1 of this embodiment, the distributed power processing unit 3 is electrically connected to the main power system through the distributed power line 6A. Therefore, the distributed power processing unit 3 can supply power to the main power system. Furthermore, the distributed power processing unit 3 is electrically connected to the auxiliary power system through the distributed power lines 6B to 6D. Therefore, the distributed power processing unit 3 can also supply power to the auxiliary power system.

[0079] <Load-side power line> The load-side power lines 7A and 7B will be described with reference to Figure 1. The load-side power line 7A is electrically connected to the grid-side power line 5A, the distributed-side power line 6A, and the power-side distribution board 10A, and electrically connects the grid-side power processing device 2 and the distributed-side power processing device 3 to the power-side distribution board 10A. In this embodiment, the load-side power line 7A is electrically connected to the grid-side power line 5A and the distributed-side power line 6A at the power line connection section 12. The first equipment 11A1, which is included in the first load 11A and operates on three-phase AC power, is electrically connected to the power-side distribution board 10A.

[0080] The load-side power line 7B is electrically connected to the grid-side power line 5B and the lighting-side distribution panel 10B, and the grid-side power processing unit 2 is electrically connected to the lighting-side distribution panel 10B. The second device 11A2, which is part of the first load 11A and operates on three-phase AC power, is electrically connected to the lighting-side distribution panel 10B.

[0081] <Anomaly Detection Unit> The abnormality detection unit 8 will be described with reference to Figure 1. The abnormality detection unit 8 detects abnormalities in the power system G. Examples of abnormalities in the power system G include, but are not limited to, a power outage in the power system G, the supply of power with reversed phase, and the supply of power with phase loss. If the abnormality in the power system G is a power outage, the abnormality detection unit 8 is expected to be configured to include, for example, a voltage detection unit that detects when the voltage of the power supplied from the power system G to the system-side power processing device 2 falls below a threshold.

[0082] Furthermore, to avoid including short-term detection of a threshold below a certain level, such as when the power system G experiences a momentary power outage, the abnormality detection unit 8 may be configured to detect a power outage only when the voltage detection unit continuously detects a threshold below a certain level for a set period of time.

[0083] When the abnormality detection unit 8 detects an abnormality in the power system G, it sends an abnormality detection signal to the power conditioner 30 (PCS control unit 309) and the circuit breaker 9. Furthermore, when the abnormality in the power system G is cleared or normal is detected, the abnormality detection unit 8 sends an abnormality clearing signal or a normal detection signal to the power conditioner 30 (PCS control unit 309) and the circuit breaker 9.

[0084] <Blocking section> The circuit breaker 9 will be described below with reference to Figures 1 and 5. As shown in Figure 1, the circuit breaker 9 is interposed in the middle of the distributed power line 6A and is electrically connected to the distributed power line 6A. The circuit breaker 9 then interrupts or opens the power supply path between the first output unit 301 of the power conditioner 30 and the power line connection unit 12 according to the detection result of the abnormality detection unit 8. As shown in Figure 5, the circuit breaker 9 has, for example, a switch unit 90 and an on / off unit 92. In this embodiment, the circuit breaker 9 may be omitted.

[0085] The switch unit 90 is interposed in the middle of the power supply path. The power supply path is interrupted or opened by opening or closing the switch unit 90.

[0086] The switching unit 92 receives an abnormality detection signal and opens the switch unit 350. The switching unit 92 also receives an abnormality release signal or a normal detection signal and closes the switch unit 90. The switching unit 92 may be configured, for example, by an undervoltage trip device (UVT).

[0087] <Department Head> The control unit 4 controls each part of the power supply system 1. As described above, the control unit 4 has a reverse power relay (RPR), and for example, when a reverse current is detected in the instrument transformer 22, the reverse power relay sends a signal to the power conditioner (PCS) 30 to stop operation.

[0088] <Operation of the power supply system under normal conditions> Referring to Figure 6, the operation of the power supply system 1 under normal conditions will be described below. Under normal conditions, power supplied from the power grid G ​​undergoes predetermined power conversion processing in the grid-side power processing device 2 (power conversion unit 20), and is supplied to the power-side distribution board 10A and the lighting-side distribution board 10B through a power supply path consisting of grid-side power lines 5A, 5B and load-side power lines 7A, 7B. Power is then supplied to the first loads 11A (for example, the first equipment 11A1 and the second equipment 11A2) connected to the power-side distribution board 10A and the lighting-side distribution board 10B, respectively. In other words, the power supplied from the power grid G ​​is output to the main grid via the grid-side power processing device 2. Note that the power supplied from the power grid G ​​may also be configured to be supplied to the storage battery D2 for charging, for example, at night.

[0089] On the other hand, under normal conditions, the connection switching unit 34 of the distributed power processing unit 3 enters a grid-connected state in which the power conditioner 30 is connected to the main system and the auxiliary system. In the grid-connected state, in the system including the distributed power source D and the distributed power processing unit 3 (hereinafter referred to as the power generation system), the output of the first distributed output unit 30A is turned on, and AC power is supplied from the first distributed output unit 30A (power generation system) to the main system (GRID system) through the power supply path (hereinafter referred to as the first power supply path) consisting of the distributed power line 6A and the load power line 7A. In addition, in the power generation system, the outputs of the second to fourth distributed output units 30B and 30D are each turned on, and AC power is supplied from the second to fourth distributed output units 30B and 30D (power generation system) to the auxiliary system (EPS system) through the power supply paths (hereinafter referred to as the second to fourth power supply paths) consisting of the distributed power lines 6B to 6D, respectively. In other words, under normal conditions, the power output from the power generation system is supplied to both the main and auxiliary systems. The power generation system may also be configured such that the power generated by the solar cell D1 is supplied to the battery D2 for charging.

[0090] Furthermore, the power output from the power generation system is distributed according to the power required by each of the first load 11A to the fourth load 11D, and supplied to the main system and the auxiliary system. In a first power state where the total power required by the first load 11A to the fourth load 11D can be covered by the distributed power source D, power from the power generation system is preferentially supplied to the first load 11A. That is, let the power consumed by each of the first load 11A to the fourth load 11D be E A ~E D and the power supplied from the power generation system be E3. In the first power state, E3≧(E A +E B +E C +E D ), and all of the first load 11A to the fourth load 11D operate only with the power supplied from the power generation system. At this time, the grid-side power processing apparatus 2 does not supply power to the main system.

[0091] On the other hand, in a second power state where the total power required by the first load 11A to the fourth load 11D cannot be covered by the power generation system, the power shortage is supplied from the grid-side power processing apparatus 2 to the first load 11A (main system). That is, in the second power state, E3<(E A +E B +E C +E D ), the second load 11B to the fourth load 11D operate with the power supplied from the power generation system, and the first load 11A operates with the power supplied from the power generation system and the grid-side power processing apparatus 2 (power grid G).

[0092] Hereinafter, the operating state of the power supply system 1 in <Operation of Power Supply System in Normal Condition> is referred to as "normal operation mode". In the normal operation mode, the power generation system is grid-connected to the grid-side power processing apparatus 2 (power grid G) to supply power to the main system in a parallel state, and also supplies power to the auxiliary system, so the normal operation mode may be read as grid-connected operation mode.

[0093] <Operation of Power Supply System in Abnormal Condition> Referring to Figure 7, the operation of the power supply system 1 in the event of an abnormality will be described below. When an abnormality occurs in the power grid G, the abnormality detection unit 8 detects the abnormality. At this time, an abnormality detection signal is sent from the abnormality detection unit 8 to the power conditioner 30.

[0094] The power conditioner 30, upon receiving an abnormality detection signal, stops the normal operation mode and switches to the independent operation mode after the first switching time has elapsed. In other words, the power conditioner 30 stops the normal operation mode upon receiving an abnormality detection signal and then switches to the independent operation mode at a predetermined timing. The first switching time refers to the time it takes to switch from the normal operation mode to the independent operation mode and can be set in advance. The first switching time is preferably in the range of 5 to 100 (ms), more preferably in the range of 8 to 80 (ms), and even more preferably in the range of 10 to 60 (ms).

[0095] Specifically, upon receiving an abnormality detection signal, the power conditioner 30 stops the normal operation mode and temporarily turns off the outputs from the first output unit 301 and the second output unit 302 (first distributed output unit 30A, second distributed output unit 30B, third distributed output unit 30C, and fourth distributed output unit 30D). More specifically, upon receiving the abnormality detection signal, the PCS control unit 309 sends a normal operation stop signal to the first circuit breaker 307 and the second circuit breaker 308 (see Figure 2). The normal operation stop signal includes a tripping signal for the first circuit breaker 307 and the second circuit breaker 308. Upon receiving the tripping signal of the normal operation stop signal, the first circuit breaker 307 and the second circuit breaker 308 enter a tripped state, and the outputs from the first output unit 301 and the second output unit 302 (first distributed output unit 30A, second distributed output unit 30B, third distributed output unit 30C, and fourth distributed output unit 30D) are turned off. As a result, the power supply from the power generation system to the main and auxiliary systems via the first to fourth power supply paths is temporarily stopped. The turning off of the outputs from both the first output unit 301 and the second output unit 302 may be done by the inverter 305, which has received a normal operation stop signal from the PCS control unit 309, operating or stopping its output.

[0096] Furthermore, in order to ensure that the power supply to the main system and the power generation system is stopped, the interruption unit 9 receives an abnormality detection signal and interrupts the power supply path between the first output unit 301 and the power line connection unit 12. However, since the power supply path between the first output unit 301 and the power line connection unit 12 can be interrupted by the output stop operation of the first output unit 301 of the power conditioner 30, the interruption unit 9 may be omitted.

[0097] After the first switching time has elapsed following the normal operation stop signal, the PCS control unit 309 sends an independent operation start signal to the first circuit breaker 307 and the second circuit breaker 308. The independent operation start signal includes a tripping signal for the first circuit breaker 307 and an opening signal for the second circuit breaker 308. The first circuit breaker 307 remains tripped upon receiving the tripping signal of the independent operation start signal, and the second circuit breaker 308 changes from tripped to open upon receiving the opening signal of the independent operation start signal, thus starting the independent operation mode. As a result, in independent operation mode, the outputs of the second output unit 302 (second distributed output unit 30B, third distributed output unit 30C, fourth distributed output unit 30D) are turned on, and the supply of power from the power generation system to the auxiliary system through the second to fourth power supply paths is resumed, but the output of the first output unit 301 (first distributed output unit 30A) remains off, and the supply of power from the power generation system to the main system through the first power supply path remains stopped. However, the first switching time is extremely short. Therefore, although the power generation system (power conditioner 30) temporarily stops supplying power to the auxiliary system upon receiving an abnormality detection signal from the abnormality detection unit 8, the first switching time is extremely short, so in effect, it can be considered that power supply is continuing between the power generation system and the auxiliary system.

[0098] Furthermore, it is not necessary to provide a first switching time when switching from normal operation mode to independent operation mode. In this case, the power conditioner 30 is configured to receive an abnormality detection signal and turn off only the output from the first output unit 301 (first distributed side output unit 30A), while keeping the outputs from the second output unit 302 (second distributed side output unit 30B, third distributed side output unit 30C, fourth distributed side output unit 30D) on without turning them off. Specifically, the PCS control unit 309 receives an abnormality detection signal and sends a signal to the first circuit breaker 307 and the second circuit breaker 308 that serves as both a normal operation stop signal and an independent operation start signal. This signal includes a tripping signal for the first circuit breaker 307 and an opening signal for the second circuit breaker 308. Upon receiving the tripping signal from this signal, the first circuit breaker 307 changes from an open state to a tripped state, and the output of the first output unit 301 (first distributed side output unit 30A) turns off. On the other hand, the second circuit breaker 308, which is open in normal operation mode, remains open upon receiving the open signal, and the outputs of the second output unit 302 (second distributed output unit 30B, third distributed output unit 30C, and fourth distributed output unit 30D) remain ON. In this case, the power generation system stops supplying power to the main system, but the power supply to the auxiliary system continues without interruption.

[0099] The power conditioner 30 will continue in self-sustaining operation mode until the abnormality detection unit 8 no longer detects any abnormalities.

[0100] <Operation of the power supply system when an abnormality is resolved> Referring to Figure 6, the operation of the power supply system 1 when an abnormality is resolved will be described below. When the power system G transitions from an abnormal state to a normal state (abnormality resolved state), the abnormality detection unit 8 detects the normal state (abnormality resolved state) of the power system G. At this time, a normal detection signal (abnormality resolved detection signal) is sent from the abnormality detection unit 8 to the circuit breaker 9 and the power conditioner 30.

[0101] The power conditioner 30, upon receiving a normal detection signal (abnormality release detection signal), stops the independent operation mode and switches to the normal operation mode after the second switching time has elapsed. In other words, the power conditioner 30 stops the independent operation mode upon receiving a normal detection signal (abnormality release detection signal) and then switches to the normal operation mode at a predetermined timing. The second switching time refers to the time it takes to switch from the independent operation mode to the normal operation mode and can be set in advance. The second switching time is preferably in the range of 5 to 100 (ms), more preferably in the range of 8 to 80 (ms), and even more preferably in the range of 10 to 60 (ms). The second switching time may be the same as or different from the first switching time.

[0102] Specifically, the PCS control unit 309 receives a normal detection signal (abnormality release detection signal) and sends an independent operation stop signal to the first circuit breaker 307 and the second circuit breaker 308. The independent operation stop signal consists of tripping signals to the first circuit breaker 307 and the second circuit breaker 308. The first circuit breaker 307 remains tripped upon receiving the tripping signal of the independent operation stop signal, and the second circuit breaker 308, which was in the open state in independent operation mode, changes from the open state to the tripped state upon receiving the tripping signal of the independent operation stop signal, thus stopping the independent operation mode. Then, after the second switching time has elapsed since sending the independent operation stop signal, the PCS control unit 309 sends a normal operation start signal to the first circuit breaker 307 and the second circuit breaker 308. The normal operation start signal consists of opening signals to the first circuit breaker 307 and the second circuit breaker 308. The first circuit breaker 307 and the second circuit breaker 308 both become open upon receiving the opening signal of the normal operation start signal, and the normal operation mode begins. As a result, in normal operation mode, the output of the first output unit 301 (first distribution side output unit 30A) and the outputs of the second output unit 302 (second distribution side output unit 30B, third distribution side output unit 30C, and fourth distribution side output unit 30D) are turned on.

[0103] Furthermore, it is not necessary to provide a second switching time when switching from independent operation mode to normal operation mode. In this case, the power conditioner 30 receives a normal detection signal (abnormality release detection signal) and turns on the output from the first output unit 301 (first distributed side output unit 30A), and is configured to keep the outputs from the second output unit 302 (second distributed side output unit 30B, third distributed side output unit 30C, fourth distributed side output unit 30D) on without turning them off. Specifically, the PCS control unit 309 receives a normal detection signal (abnormality release detection signal) and sends a signal to the first circuit breaker 307 and the second circuit breaker 308 that serves as both an independent operation stop signal and a normal operation start signal. This signal consists of an open signal for the first circuit breaker 307 and the second circuit breaker 308. The first circuit breaker 307 receives the open signal and changes from the tripped state to the open state, and the output of the first output unit 301 (first distributed side output unit 30A) turns on. On the other hand, in the independent operation mode, the second circuit breaker 308, which is in the open state, receives the open signal and continues to remain open, and the outputs of the second output unit 302 (second distributed output unit 30B, third distributed output unit 30C, and fourth distributed output unit 30D) remain ON. In this case, the power generation system continues to supply power to the main system while continuing to supply power to the auxiliary system without interrupting the power supply.

[0104] Furthermore, upon receiving a normal detection signal (abnormal release detection signal), the circuit breaker 9 releases the circuit breaker in the power supply path between the first output unit 301 and the power line connection unit 12, thereby opening the power supply path. Again, the circuit breaker 9 may be omitted.

[0105] As a result, the power generation system becomes capable of supplying power to the main and auxiliary systems, and the power supply system 1 continues in the normal operating mode described in <Operation of the power supply system under normal conditions> until the abnormality detection unit 8 detects the next abnormality in the power system G.

[0106] <Operation of the power supply system during maintenance> Referring to Figure 8, the operation of the power supply system 1 during maintenance is described below. During maintenance, the connection switching unit 34 (operating unit) is operated to disconnect the connection switching unit 34. In this case, the power generation system (power conditioner 30) is disconnected from the main system and the auxiliary system.

[0107] In the disconnected state, the first switch 340 and the second switch 341 are turned off, while the third switch 342 is turned on, and the fifth power supply path 36C becomes open. In this case, the sixth power supply path, which includes the fifth power supply path 36C and electrically connects the grid-side power processing device 2 to the second to fourth power supply paths, becomes open. As a result, when the connection switching unit 34 is in the disconnected state, the power generation system is disconnected from the main and auxiliary systems, so the grid-side power processing device 2 supplies power to the main and auxiliary systems. Therefore, even if the power generation system (power conditioner 30) is disconnected from the main and auxiliary systems during maintenance, power can continue to be supplied to the first load 11A to the fourth load 11D. On the other hand, once maintenance is complete, the connection switching unit 34 (operating unit) can be operated to return to the connected state.

[0108] Furthermore, the above explanation is not limited to maintenance, but can also be applied when disconnecting the power generation system (power conditioner 30) from the main and auxiliary systems for other purposes.

[0109] <Variation> As shown in Figure 9, the scope of the present invention also includes a modified version in which the second transformer 32 and the third transformer 33 in the power supply system 1 of the above embodiment are replaced with a fourth transformer 39 that has a combined function of the second transformer 32 and the third transformer 33. The fourth transformer 39 is composed of, for example, a lighting and power shared transformer that transforms the input three-phase AC power and outputs both the transformed three-phase AC power and single-phase AC power. The fourth transformer 39 has second distributed output sections 30B to fourth distributed output sections 30D. Three-phase AC power is output from the second distributed output section 30B, and single-phase AC power is output from the third distributed output section 30C and the fourth distributed output section 30D. According to this modified version, the number of transformers can be reduced, which contributes to space saving and energy saving of the power supply system 1.

[0110] It should be noted that the power supply system 1 of the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the present invention. [Explanation of Symbols]

[0111] 1. Power supply system 2. Power processing unit for the 2nd system 3. Distributed power processing unit 4. Control Unit 5A grid side power line 5B Grid side power line 6A distributed side power line (first distributed side power line) 6B Distributed power line (second distributed power line) 6C Distributed side power line (third distributed side power line) 6D Distributed side power line (4th distributed side power line) 7A,7B Load side power line 8 Anomaly detection unit 9. Shut-off section 10A power side switchboard 10B Lighting side distribution panel 10C second switchboard 10D Third switchboard 10E Fourth switchboard 11A first load 11A1 First equipment 11A2 Second device 11B Second load 11C Third load 11D Fourth load 12 Power line connection 20 Power Conversion Unit (First Power Conversion Unit) 20A Power Transformer 20B Lighting Transformer 22 Instrument transformers 30 Power Conditioner 30A First distributed side output section 30B Second distribution side output section 30C Third distribution side output section 30D Fourth distribution side output section 31 First Transformer 32 Second Transformer 33 Third Transformer 34 Connection switching section 36A,36B,36B1,36B2 Power line 36C Fifth Power Supply Path 37. Solar Power Conditioner 38. Battery Power Conditioner 39 Fourth Transformer 90 Switch section 92 Opening / Closing Section 200A grid side output section 200B Grid side output section 301 First output section 302 Second Output Section 303 First DC / DC Converter 304 Second DC / DC Converter 305 Inverter 306 Branch Output Section 306A First Branch Power Line 306B Second Branch Power Line 307 First Circuit Breaker 308 Second circuit breaker 309 PCS Control Unit 310 Core component 310A center axis 311 Inner winding 312 Outer winding body 313 First insulating layer 314 Second insulating layer 315 Third insulating layer 316 First position 317 Second position 340 First Switch 341 Second switch 342 Third switch D Distributed power supply D1 solar cell D2 Battery G Power system

Claims

1. A grid-side power processing device having a grid-side output unit that converts power supplied from the power grid and outputs the converted power from the grid-side output unit, A distributed power processing device having at least a first distributed output unit and a second distributed output unit, which converts power supplied from a distributed power source and outputs the converted power from the first distributed output unit and the second distributed output unit, The grid-side power line electrically connected to the aforementioned grid-side output section, The first distributed output unit and the grid-side power line are electrically connected, and the first distributed power line connects the grid-side power processing unit and the distributed power processing unit, A first load, a load-side power line electrically connected to the grid-side power line and the first distributed-side power line, The second load and the second distributed power line electrically connected to the second distributed output section, A feature comprising: Power supply system.

2. The distributed power supply is a DC power supply, The aforementioned distributed power processing device is A power conditioner having a first output section and a second output section, which converts the DC power output by the distributed power supply into AC power and outputs the AC power from the first output section and the second output section, A first transformer having the first distributed output section, which transforms the voltage of the AC power output from the first output section into a voltage that can be connected to the grid with the power output from the grid output section and outputs it from the first distributed output section, A second transformer having the second distributed output section, which transforms the voltage of the AC power output from the second output section into a voltage supplied to the second load, A feature having The power supply system according to claim 1.

3. When the distributed power processing device defines the path through which it supplies power to the first load via the first distributed power line and the load-side power line as the first power supply path, and the distributed power processing device defines the path through which it supplies power to the second load via the second distributed power line as the second power supply path, The aforementioned distributed power processing device is A first switch is provided in the third power supply path, which electrically connects the first output unit and the first power supply path, and which opens or closes the third power supply path by being turned on or off. A second switch is provided in the fourth power supply path that electrically connects the second output unit and the second power supply path, and which opens or closes the fourth power supply path by being turned on or off. A third switch is provided in a fifth power supply path that electrically connects the third power supply path on the first power supply path side of the first power supply path to the fourth power supply path on the second power supply path side of the second power supply path to the first switch, and which opens or closes the fifth power supply path when turned on or off. An operating unit that switches between a first state in which the first and second switches are ON and the third switch is OFF, and a second state in which the first and second switches are OFF and the third switch is ON. It has, In the first state described above, the third power supply path and the fourth power supply path are open, while the fifth power supply path is shut off. In the second state, the third and fourth power supply paths are shut off, the fifth power supply path is opened, and a sixth power supply path is opened, which includes the fifth power supply path and electrically connects the grid-side power processing device and the second power supply path. In the second state, the grid-side power processing device supplies power to the second load through the sixth power supply path and the second power supply path. The power supply system according to claim 2.

4. The aforementioned distributed power processing device is The second output section has a branch power line that is electrically connected to it and has multiple branch destinations, The second transformer is electrically connected to one of the branch destinations of the aforementioned branch power line. Each of the other branch destinations of the aforementioned branch power line is electrically connected to a corresponding transformer. The power supply system according to claim 2.

5. The first transformer is characterized by being an isolation transformer. The power supply system according to claim 2.

6. An abnormality detection unit for detecting abnormalities in the power system, A control unit that controls the on or off of the output in the first distributed output unit and the second distributed output unit according to the detection result in the abnormality detection unit, Equipped with, When the distributed power processing device defines the path through which it supplies power to the first load via the first distributed power line and the load-side power line as the first power supply path, and the distributed power processing device defines the path through which it supplies power to the second load via the second distributed power line as the second power supply path, The control unit, In a normal state where no abnormality is detected in the power system by the abnormality detection unit, the outputs of the first distributed output unit and the second distributed output unit are turned on, and the distributed power processing device supplies power to the first load through the first power supply path and power to the second load through the second power supply path. In the abnormal state in which the abnormality detection unit detects an abnormality in the power system, the output of the first distributed output unit is turned off to stop the supply of power to the first load through the first power supply path by the distributed power processing unit, while the output of the second distributed output unit is turned on to supply power to the second load through the second power supply path by the distributed power processing unit. The power supply system according to claim 1 or 2.

7. The control unit, after detecting an abnormality in the power system by the abnormality detection unit, temporarily turns off the output of the second distributed output unit to stop the supply of power to the second load through the second power supply path by the distributed power processing unit, and then turns on the output of the second distributed output unit at a predetermined timing to supply power to the second load through the second power supply path by the distributed power processing unit. The power supply system according to claim 6.

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