JP2003087978A - Generating unit, panel board and power supply system using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply system, and its power generating unit and panel board, in which earth leakage protection can be effected surely at the time of isolated operation of a small capacity non-utility generating unit as well as interactive operation of the small capacity non-utility generating unit and a commercial system of a power company, or the like. SOLUTION: Both a function for switching the grounding state of the line at the time of interactive operation and self-supported operation, and a function capable of supplying power to both a load on the commercial system side and a load on the self-supported side at the time of interactive operation and supplying power only to the load on the self-supported side at the time of self-supported operation using a panel board having ground leakage circuit breaker is provided in a small capacity non-utility generating unit in order to deal with ground leakage protection at the time of interactive operation and self-supported operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to private power generation of a small-capacity private power generator and a commercial grid (power purchase grid) of a power company or the like.
The present invention relates to a power generation device, a distribution board, and a power supply system using the power generation device and the power distribution panel when used together with power purchase from

[0002]

2. Description of the Related Art In a house or the like, a small-capacity private power generator is provided, and a power supply system is used that supplies power to each load by using this privately-generated power and power purchase from a commercial grid together. As an energy source of this small capacity private power generator, natural energy such as sunlight and wind power is usually used. Since the supply of these natural energies is not stable, the self-generated power is used as interpolation energy for power purchase, and when the power purchase stopped, it did not bear the load independently.

For example, if a leakage accident (one-line ground fault) occurs on either side of the load, it is grounded on the commercial system side. Therefore, an earth leakage breaker provided in the main circuit of the power receiving distribution panel is installed. It operates and shuts off the power. At this time, since the small-capacity private power generator by sunlight or the like is also disconnected and stopped, only the operation of the earth leakage breaker provided in the main circuit did not cause any inconvenience.

In recent years, a small-capacity private power generator equipped with a power generator capable of stably generating and maintaining output, such as a fuel cell, has come to be used as a power supply system in combination with power purchase. In this power supply system, unlike solar power generation or wind power generation, even if the power purchase is stopped due to an accident or the like, the load within its own capacity can be stably operated.

The structure of this conventional power supply system is shown in FIG. In FIG. 6, the purchase of power from the commercial grid 11 and the privately-generated power of the power generator 27 are interconnected by the distribution board 10 and supplied to each load 12. Further, power is supplied from the power generation device 27 to the self-sustaining load 13 via the protection device 13a.

The power generation device 27 forms a power generation section for generating commercial AC power by the fuel cell 1 and the inverter 2.
The generated AC power is supplied from the interconnection operation output terminal 14 to the distribution board 10 via the interconnection switch 6, while the self-sustained operation output terminal 16 to the self-sustained load 13 via the self-sustaining load switch 6 '. We are supplying.

In the distribution board 10, power is supplied to the power purchasing system bus 21 from the commercial system 11 via the main circuit breaker 20 and the main earth leakage circuit breaker 22, and at the same time from the power generation device 27 via the branch circuit breaker 15. The privately-generated electric power is supplied, and interconnection operation is performed. Then, power is supplied to each load 12 via each of the other branch circuit breakers 15.

In this conventional power supply system, the generator 27 and the commercial system 11 are always interconnected. When the power purchase is stopped due to an accident or the like, the power generation device 27 may open the interconnection switch 6 to release the interconnection with the commercial system 11 and shift to the self-sustaining operation in which only the self-sustaining load 13 is supplied with power. it can.

[0009]

However, in this conventional power supply system, when the interconnected operation of the generator 27 and the commercial grid 11 is switched to the independent operation of the generator 27, the commercial grid 11 is grounded. Since the electric circuit during the self-sustaining operation is completely insulated from the ground because it is disconnected from the system 23, and there is no earth leakage breaker for the output during the self-sustaining operation, it is impossible to detect and protect the electric leakage.

Further, even if the power generator 27 is grounded by the AC bus 3, for example, it is necessary to match the ground system of the commercial system 11, and if a dedicated earth leakage breaker is not provided outside, the earth leakage is detected and protected. Can not. Further, when the AC bus 3 or the like is grounded, it is grounded at a plurality of points. Therefore, due to the dispersion of the grounding points, the main earth leakage breaker 22 and the newly provided earth leakage breaker at the time of the interconnection operation are connected. The detection performance may be difficult to adjust and may not be protected properly.

Therefore, the present invention ensures the protection of the leakage even when the small-capacity private power generator and the commercial system of the electric power company or the like perform the independent operation by the small-capacity private power generator. An object of the present invention is to provide a power supply system capable of performing the above, a power generation device therefor, and a distribution board.

[0012]

A power generator according to claim 1 is
Power generation units 1 and 2 that generate commercial AC power from an energy source other than electricity, an output terminal 16 for directly outputting the commercial AC power generated by this power generation unit to the outside, and a commercial power generation unit generated by the power generation unit. The output terminal 14 for outputting the AC power to the outside via the first switch 6 and the one-phase or neutral point of the output of the power generation unit are controlled so that the open / closed state is opposite to that of the first switch. And a ground terminal 7 for grounding via the second switch 8.

According to the power generator of the first aspect, during the interconnection operation in which the commercial AC power generated in the power generation units 1 and 2 is output to the outside via the first switch 6, the external commercial system 1
One grounding system 23 is used. When the first switch 6 is opened and self-sustaining operation is performed, the second switch 8 is closed and grounded. Therefore, it is possible to surely perform grounding at one place during the interconnection operation and the self-sustaining operation.

According to a second aspect of the distribution board, a main earth leakage circuit breaker 22 connected to an external power source, a first busbar 21 connected to the main earth leakage circuit breaker, and a first busbar connected to the first busbar 1 In a distribution board having one or more branch circuit breakers 15, an earth leakage circuit breaker 17 connected to another external power source, a second busbar 18 connected to the earth leakage circuit breaker, and a second busbar. It is characterized by having one or more branch circuit breakers 19 connected.

According to the distribution board of the second aspect, since the earth leakage breaker 17 of the independent system is provided, the second bus bar 18 is provided.
It is possible to independently protect the electric leakage accident on the side.

A power supply system according to a third aspect of the present invention is a power generation section 1 for generating commercial AC power from an energy source other than electricity.
2, an output terminal 16 for self-sustained operation for directly outputting the commercial AC power generated by the power generation unit to the outside, and the commercial AC power generated by the power generation unit to the outside via the first switch 6. And the second switch 8 for controlling the one-phase or neutral point of the output of the power generation unit so that the open / closed state is opposite to that of the first switch.
Generator 9 having a grounding terminal 7 which is grounded via a mains earth leakage breaker 22 connected to an external commercial system
And a first bus bar 21 connected to the main earth leakage breaker,
One or more branch circuit breakers 15 connected to this first busbar
And further, the self-sustained operation output terminal 1 of the power generator.
A distribution board having an independent earth leakage circuit breaker 17 connected to 6, a second busbar 18 connected to this independent earth leakage breaker, and one or more branch circuit breakers 19 connected to this second busbar 1
0, and one branch circuit breaker 15 connected to the first busbar is connected to the output terminal 14 for the interconnection operation of the power generator.
The first switch is closed and the second switch is opened during the interconnected operation of the commercial system and the power generation device, and the first switch is opened during the self-sustained operation of the power generation device. Further, the second switch is closed.

According to the power supply system of the third aspect, the interconnecting operation of the power generator 9 and the commercial grid 11 and the self-sustaining operation of the power generator are possible, and the grounding is performed at one place during any operation. Secured. Therefore, during interconnected operation, if leakage occurs on the load side, a fault current will flow to the main earth leakage circuit breaker of the distribution panel due to the grounding system of the commercial system to provide leakage protection. When it happens,
Due to the grounding system of the power generator, a fault current flows to the self-sustaining earth leakage circuit breaker of the distribution board to protect the earth leakage.

The distribution board according to claim 4 is the distribution board according to claim 2, characterized in that a bus bar breaker 24 for connecting the first bus bar 21 and the second bus bar 18 is provided. To do.

According to the distribution board of the present invention, when the other power source such as the external power generator is stopped for maintenance or the like, the busbar connecting circuit breaker is closed to connect to the second busbar. Electric power can be continuously supplied to a self-sustaining load or the like via the branched circuit breaker.

A power supply system according to a fifth aspect of the present invention is a power generation section 1 for generating commercial AC power from an energy source other than electricity.
2, an output terminal 16 for self-sustained operation for directly outputting the commercial AC power generated by the power generation unit to the outside, and the commercial AC power generated by the power generation unit to the outside via the first switch 6. And the second switch 8 for controlling the one-phase or neutral point of the output of the power generation unit so that the open / closed state is opposite to that of the first switch.
Generator 9 having a grounding terminal 7 which is grounded via a mains earth leakage breaker 22 connected to an external commercial system
A busbar 21 connected to the main earth leakage circuit breaker; a first distribution board 10B having one or more branch circuit breakers 15 connected to the busbar; and the self-sustained operation output terminal 16 of the power generator. A self-sustaining earth leakage circuit breaker 17 connected to, a bus bar 18 connected to the self-sustaining earth leakage circuit breaker, and a second distribution board 25 having one or more branch circuit breakers 19 connected to the bus bar, 1 connected to the bus bar of the first distribution board
One branch circuit breaker 15 is connected to the output terminal 14 for interconnection operation of the power generator, and the first switch is closed and the second switch is turned on during interconnection operation of the commercial system and the power generator. It is characterized in that the first switch is opened and the second switch is closed during the self-sustained operation of the power generator.

According to the power supply system of the fifth aspect, the same effect as that of the power supply system of the third aspect can be obtained, and the first distribution board 10B and the second distribution board 25 are provided.
Since there is only one earth leakage circuit breaker, a normal household distribution board can be used, and the power supply system can be constructed at low cost.

According to another aspect of the power generator of the present invention, the commercial AC power generated by the power generation units 1 and 2 for generating commercial AC power from an energy source other than electricity and the commercial AC power generated by the power generation unit are output to the outside through the first switch 6. An output terminal 14 for outputting and one phase or a neutral point of the output of the power generation unit are grounded via a second switch 8 which is controlled so that the open / closed state is opposite to that of the first switch. The ground terminal 7, the main earth leakage breaker 17 that receives the commercial AC power generated in this power generation unit, the bus bar 18 connected to this main earth leakage breaker, and one or more branch circuit breakers 19 connected to this bus bar. It has the distribution board 25 for the self-supporting load which it has.

According to the power generator of the present invention, since the self-supporting load distribution board 25 is provided in advance inside the power generation apparatus, the existing distribution board is modified or a new distribution board is installed when the power generation apparatus is introduced. There is no need to prepare.

According to a seventh aspect of the power generator, the power generating units 1 and 2 for generating commercial AC power from an energy source other than electricity, and the commercial AC power generated by this power generating unit to the outside via the first switch 6. An output terminal 14 for outputting and one phase or a neutral point of the output of the power generation unit are grounded via a second switch 8 which is controlled so that the open / closed state is opposite to that of the first switch. A ground terminal 7 and an output terminal 16 for outputting the commercial AC power generated by the power generation unit to the outside via a third switch 6A controlled so that the open / closed state is opposite to that of the first switch. It is characterized by having.

According to the power generator of the present invention, the grounding system 23 of the external commercial system 11 is operated during the interconnection operation in which the commercial AC power generated in the power generation section is output to the outside through the first switch 6. Used. When the first switch 6 is opened to perform the self-sustaining operation, the third switch 6A is closed to supply power to the self-sustaining load, and the second switch is closed and grounded. Therefore, it is possible to surely perform grounding at one place during both the interconnection operation and the self-sustaining operation.

The power supply system according to claim 8 is a power generation section 1 for generating commercial AC power from an energy source other than electricity.
2, a connection operation output terminal 14 for outputting the commercial AC power generated by the power generation unit to the outside through the first switch 6, and a one-phase or neutral point of the output of the power generation unit, A grounding terminal 7 for grounding via a second switch 8 which is controlled so that the open / closed state is opposite to that of the first switch;
It has a self-sustained operation output terminal 16 for outputting the commercial AC power generated by the power generation unit to the outside through the third switch 6A controlled so that the open / closed state is opposite to that of the first switch. A power generation device 9, a main earth leakage circuit breaker 22 connected to an external commercial system, a bus bar 21 connected to the main earth leakage circuit breaker, and one or more branch circuit breakers 15 connected to the bus bar. 1 distribution board 10B, the self-sustaining earth leakage breaker 17 connected to the self-sustained operation output terminal 16 of the power generator, the busbar 18 connected to the self-sustaining earth leakage breaker, and the busbar The second distribution board 25 having one or more branch circuit breakers 19 and the power supply to the self-sustaining load are supplied from one branch circuit breaker 15 connected to the bus bar of the first distribution board, or One branch break connected to the bus of the two-part switchboard And a switching device 28 for switching whether to perform the 19, which is connected to the bus of the first distribution board 1
One branch circuit breaker 15 is connected to the output terminal 14 for interconnection operation of the power generation device, and the first switch 6 is closed and the second switch is operated during interconnection operation of the commercial system and the power generation device. The third switch is opened, and the first switch 6 is opened and the second switch and the third switch are closed during the self-sustained operation of the power generator.

According to the power supply system of the eighth aspect, the same effect as that of the power supply system of the fifth aspect can be obtained, and the power supply to the self-sustaining load is switched by the switching device 28.
Thus, the operation can be performed from the branch circuit breaker 15 of the first distribution board during the interconnection operation, and can be performed from the branch circuit breaker 19 of the second distribution board during the independent operation.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be sequentially described below with reference to the drawings.

FIG. 1 is a configuration diagram of a small-capacity private power generator, a distribution board, and a power supply system using them according to a first embodiment of the present invention (corresponding to claims 1 to 3).

In FIG. 1, a small capacity private power generator 9
The power generation unit is configured by connecting the output unit of the DC power generation device 1 such as a fuel cell that generates power with an energy source other than electricity and the input unit of the DC-AC converter (inverter) 2. The AC bus 3 on the output side of the inverter 2 is branched into an output bus 4 for interconnection operation and an output bus 5 for independent operation. The self-sustained operation output bus 5 is directly connected to the self-sustained operation output terminal 16 for directly outputting the commercial AC power generated by the power generation unit to the outside. On the other hand, between the AC bus 3 and the output bus 4 for interconnection operation, the interconnection switch 6 which is the first switch that is closed during interconnection operation and opened during independent operation is provided. It is connected to the interconnection operation output terminal 14 for outputting the generated commercial AC power to the outside.

A ground terminal 7 connected to one phase of the inverter 2 and the AC bus 3 (neutral point is sufficient in the case of three phases).
A grounding switch 8, which is a second switch that forms a grounding circuit during self-sustaining operation, is provided between the two. Interconnection switch 6
And the ground switch 8 are closed / opened in the opposite states.

The distribution board 10 is connected to a power purchasing system bus 21, which is a first bus, via a main circuit breaker 20 and a main earth leakage circuit breaker 22 which are connected to an external commercial system 11. One or more branch circuit breakers 15 are connected to the power purchase bus 21. The output terminal 14 for interconnection operation of the power generator 9 is connected to one of the branch circuit breakers 15 so that the commercial grid 11 and the power generator 9 are interconnected.

Furthermore, the self-sustained operation output terminal 16 of the power generator 9 is connected to the self-sustained system busbar 18 which is the second busbar via the self-sustained system earth leakage breaker 17. 1 for this independent bus 18
Two or more branch circuit breakers 19 are connected, and a predetermined independent load 1
Powered to 3.

The interconnection switch 6 is closed and the grounding switch 8 is opened during the interconnection operation between the commercial system 11 and the power generator 9, while the interconnection switch 6 is opened during the independent operation of the power generator 9. And the ground switch 8 is closed.

Next, the operation of the power supply system according to the present invention will be described. Normally, during the interconnection operation with the commercial system 11, the DC power generated by the DC power generation device 1 such as a fuel cell is converted into AC power by the inverter 2 and the interconnection operation output terminal 14 and the self-sustained operation output terminal 16 are converted. Is output to.
At this time, the inverter 2 is operating in synchronization with the voltage, frequency and phase of the power purchase system 11, that is, the interconnecting operation.

The power output to the interconnection operation output terminal 14 is guided to the branch circuit breaker 15 of the distribution board 10 and the power purchasing system bus bar 21.
Is supplied to the load 12 of the house connected to the. During the interconnection operation, the load 12 and the self-sustaining load 13 are supplied with power from the small-capacity private power generator 9, but the load 12 and the self-sustaining load 13 are supplied.
If the output power of the small-capacity private power generator is smaller than the power required by, the commercial system 11 supplies power to the load 12 and the self-sustaining load 13. However, in general, independent load 1
3 is connected to a load that can be covered by the small-capacity private power generator 9, so that power is not normally supplied from the commercial grid 11 to the self-sustaining load 13.

When an abnormality or the like of the commercial system 11 occurs, the interconnected operation is shifted to the independent operation in which electric power is supplied only to the independent load 13. The electric power output to the self-sustained operation output terminal 16 during the self-sustained operation is guided to the self-sustained system earth leakage breaker 17 of the distribution board 10 and supplied to the self-sustained load 13 of the house.

The operation when a ground fault occurs during interconnected operation and self-sustaining operation will be described below. [Ground Fault Case 1 During Interconnection Operation] When a ground fault occurs on the commercial system side of the main earth leakage breaker 22 of the distribution board 10 during interconnection operation, the distribution panel 10 is a problem on the commercial system side. The main earth leakage circuit breaker 22 does not operate and is protected on the commercial system side.

[Ground Fault Case 2 During Interconnection Operation] When a ground fault occurs on the downstream side of the main earth leakage breaker 22 of the distribution board 10 during the interconnection operation, for example, the load 12 is as follows. The electric circuit is grounded by the grounding system 23 of the commercial system 11. In this state, when an electric leakage occurs on the load 12 side, a fault current flows into the grounding system 23 of the commercial system 11 and flows into the main earth leakage breaker 22 of the distribution board 10, and the main earth leakage breaker 22 is cut off to provide protection. It works and is disconnected from the commercial system 11.

In the power generator 9, the disconnection of the main earth leakage breaker 22 is detected by detecting means such as the operation of the auxiliary contact or the increase in the current of the interconnection output bus bar 4, and the interconnection switch 6 is opened. To do. Immediately after that, the ground switch 8 is closed, and one phase of the AC bus bar 3 is grounded via the ground terminal 7. As a result, the interconnection operation is canceled, the operation is switched to the self-sustaining operation, and the self-generated power is continuously supplied from the power generation device 9 to the self-sustaining load 13.

[Ground Fault Case 3 During Interconnection Operation] When an earth fault occurs in the self-sustaining load 13 connected through the branch breaker 19 of the self-sustaining bus bar 18 of the distribution board 10 during the interconnection operation, It is as follows. During interconnection operation with the commercial system 11,
When a leakage occurs on the side of the self-sustaining load 13, the leakage current flows through both the main earth leakage breaker 22 and the self-sustaining earth leakage breaker 17, so that either the mains earth leakage breaker 22 or the self-sustaining earth leakage breaker 17 is activated. It works and protects.

If the main earth leakage breaker 22 operates quickly, the interconnection switch 6 is also opened, but since the earth leakage of the self-sustaining load 13 continues after that, the self-sustaining earth leakage breaker 17 on the self-sustaining side continues. Protects.

On the other hand, when the self-sustaining earth leakage breaker 17 operates quickly, it is disconnected from the self-sustained operation output terminal 16 so that the earth leakage current disappears. Therefore, after that, the interconnection operation with the commercial system 11 is continued.

From this fact, whichever of the main earth leakage breaker 22 and the self-standing earth leakage breaker 17 operates, the earth leakage protection is surely performed. However, when the main earth leakage breaker 22 operates first, the interconnection operation is stopped, and the self-sustaining operation is subsequently stopped, so that power supply to all loads is stopped. In order to avoid stopping the power supply to all the loads, it is desirable to set the detection time period t1 of the main earth leakage circuit breaker 22 longer than the detection time period t2 of the self-sustaining system earth leakage circuit breaker 17 (t1> t2).

[Ground fault case 1 during self-sustaining operation] When an earth leakage occurs in the self-sustaining load 13 during self-sustaining operation, a short-circuit current flows through the ground terminal 7 of the small-capacity private power generator 9 and is connected to the self-sustaining output terminal 16. A fault current flows through the self-sustaining earth leakage circuit breaker 17 and the self-sustaining earth leakage circuit breaker 17 operates and is protected.

According to the present embodiment, the distribution board 10 is provided with the self-supporting earth leakage circuit breaker 17 on the self-supporting system busbar 18 independent of the power purchasing system busbar 21 so that the gridboard 10 is connected to the commercial system 11. When the earth system 23 of the commercial system 11 protects the earth leakage, and when the electric power purchase system is in an abnormal state or the like, the earth system 7 of the small-capacity private power generator 9 can protect the earth leakage.

According to the first embodiment, during the interconnection operation in which the commercial AC power generated by the power generation units 1 and 2 is output to the outside through the interconnection switch 6, the ground system of the external commercial system is used. 23 is used. When the interconnection switch 6 is opened to perform the self-sustaining operation, the ground switch 8 is closed and grounded. Therefore, it is possible to surely perform grounding at one place during both the interconnection operation and the self-sustaining operation. Further, by providing the self-sustaining earth leakage breaker 17 on the distribution board, it is possible to independently protect the earth leakage accident on the self-sustaining bus bar 18 side.

As a power supply system, it is possible to operate the generator 9 and the commercial system 11 in an interconnected manner and to operate the generator 9 independently. In addition, grounding is secured at one place during any operation. Therefore, during interconnection operation, load 1
When a leakage occurs on the second side, a fault current flows to the main earth leakage breaker 22 of the distribution board 10 by the grounding system 23 of the commercial system 11 to perform leakage protection. Further, if a leakage occurs on the load 13 side during the self-sustaining operation, a fault current flows to the self-sustaining earth leakage circuit breaker 17 of the distribution board 10 by the grounding systems 7 and 8 of the power generator 9 to protect the earth leakage.

FIG. 2 shows a second embodiment of the present invention (corresponding to claim 4), a small-capacity private power generator, a distribution board,
It is a block diagram of a power supply system using them and.

In FIG. 2, the difference from the first embodiment of FIG. 1 is that the power generating system is always open between the power purchasing system bus 21 and the self-supporting system bus 18 in the distribution board 10A. 9 has a structure in which a busbar connecting circuit breaker 24 that is closed at the time of maintenance or the like is inserted. Since other points are the same as those in FIG. 1, only different points will be described.

When the small-capacity private power generator 9 is operating in connection with the commercial grid 11, the maintenance busbar communication circuit breaker 24 is left open so that the load 12 and the self-sustaining grid are independent of each other, as in the case of FIG. Electric power is supplied to each of the loads 13.

When the small-capacity private power generator 9 is operating independently, the maintenance busbar communication circuit breaker 24 is left open, so that the self-sustaining load 13 is the same as in the case of FIG.
Is supplying power to.

When the small-capacity private power generator 9 operating in the interconnected or self-sustaining operation is stopped and maintenance / inspection is performed, the branch circuit breaker 15 and the self-sustaining earth leakage interrupt of the distribution board 10A are connected. The vessel 17 will be shut off.

At this time, power is supplied from the commercial grid 11 to the self-sustaining load 13 by closing the maintenance busbar breaker 24.

According to the second embodiment, the distribution board 1
By providing the maintenance busbar communication circuit breaker 24 between the power purchase system busbar 21 of 0 A and the independent busbar 18 which is independent, the self-supporting load 13 is maintained even when the small capacity private power generator 9 is stopped.
It is possible to continuously supply power to.

FIG. 3 shows a third embodiment of the present invention (corresponding to claim 5), a small-capacity private power generator, a distribution board,
It is a block diagram of a power supply system using them and.

In FIG. 3, the difference from the first embodiment of FIG. 1 is that two distribution boards 10B and 25 are provided. Since other points are the same as those in FIG. 1, only different points will be described.

The first distribution board 10B is an external commercial system 1
The main circuit breaker 20 and the main earth leakage circuit breaker 22 connected to 1 are connected to the power purchasing system bus 21 which is the first bus. One or more branch circuit breakers 15 are connected to the power purchase bus 21. The output terminal 14 for interconnection operation of the power generator 14 is connected to one of the branch circuit breakers 15, and the commercial grid 11 and the power generator 9 are interconnected.

Second distribution board, ie, distribution board 25 for self-sustaining load
Is connected to the self-sustaining system busbar 18 which is the second busbar via the self-sustaining circuit breaker 26 and the self-sustaining system earth leakage circuit breaker 17 connected to the self-sustaining operation output terminal 16 of the power generator 9. One or more branch circuit breakers 19 are connected to the self-sustaining system bus 18 to supply power to a predetermined self-sustaining load 13.

The first distribution board 10B and the second distribution board 25 have different names such as circuit breakers and bus bars.
A completely similar distribution board can be used as the configuration. Therefore, the distribution board generally used in a house or the like can be used as it is as the distribution board 25 for the self-sustaining load.

Next, the operation of this embodiment will be described. During the interconnection operation with the commercial grid 11, power is supplied from the small-capacity private power generator 9 to the load 12 connected to the power purchase bus 21 via the branch circuit breaker 15 connected to the grid-side output terminal 14. And power supply to the self-sustaining load 13 connected to the branch circuit breaker 19 of the self-sustaining system bus 18 via the self-sustaining circuit breaker 26 connected to the self-sustaining operation output terminal 16 and the self-sustaining system earth leakage circuit breaker 17. Done.

During the interconnected operation of the small capacity private power generator 9,
Even if leakage occurs in the load 12 or the self-sustaining load 13, the grounding system 2 of the commercial system 11 is used as in the first embodiment of FIG.
A fault current flows through the circuit 3 and can be protected by the main earth leakage breaker 22 or the self-sustaining earth leakage breaker 17.

During independent operation of the small-capacity private power generator 9,
Even if a leakage occurs in the self-sustaining load 13, a fault current similarly flows to the grounding systems 7 and 8 of the small-capacity private power generator 9 and can be protected by the self-sustaining earth leakage breaker 17.

According to the third embodiment, the existing distribution board 10B and the distribution board 25 for the self-sustaining load are constituted by the distribution board generally used in a house, etc. Since it becomes possible to have the same function as the above-mentioned form, the installation area is large, but an inexpensive distribution board can be used.

FIG. 4 shows a fourth embodiment of the present invention (corresponding to claim 6), a small-capacity private power generator, a distribution board,
It is a block diagram of a power supply system using them and.

In FIG. 4, the difference from the third embodiment of FIG. 3 is that the second one of the two distribution boards 10B and 25 is
This is the point that the distribution board, namely, the distribution board 25 for self-supporting load is provided inside the power generation device 9A. Since other points are the same as those in FIG. 3 (or FIG. 1), only different points will be described.

A second distribution board, that is, an independent load distribution board 25 is provided in advance inside the power generator 9A. This self-sustaining load distribution board 25 is connected to the self-sustaining circuit breaker 26 and the self-sustaining system earth leakage circuit breaker 17 which are connected to the self-sustaining operation output terminal 16, and then the second
It is connected to the self-sustaining system busbar 18 which is a busbar. One or more branch circuit breakers 19 are connected to the self-sustaining system bus 18, and power is supplied to a predetermined self-sustaining load 13 from its output terminal. As the distribution board 25 for the self-sustaining load, a distribution board generally used in a house or the like can be used as it is, like the first distribution board.

Next, the operation of this embodiment will be described. During the interconnection operation with the commercial grid 11, from the small-capacity private power generator 9A to the load 12 connected to the power purchase bus 21 via the branch circuit breaker 15 connected to the interconnection connection output terminal 14. Power supply and self-sustained operation output terminal 1
The self-sustaining load 13 connected to the branch circuit breaker 19 of the self-sustaining system busbar 18 via the self-sustaining circuit breaker 26 connected to
Power is supplied to.

During the interconnected operation of the small-capacity private power generator 9A, even if the load 12 or the self-sustaining load 13 leaks, the ground system 23 of the commercial system 11 fails as in the first embodiment shown in FIG. A current flows and can be protected by the main earth leakage breaker 22 or the self-supporting earth leakage breaker 17. During the self-sustained operation of the small-capacity private power generator 9A, the grounding systems 7 and 8 of the small-capacity private power generator 9A are similarly provided even if a leakage occurs in the self-supporting load 13.
A fault current flows to the self-sustaining system and protection can be provided by the earth leakage breaker 17.

According to the fourth embodiment, it is possible to omit the independent installation of the stand-alone load distribution board 25, so that the installation cost for introducing the small capacity private power generator 9A can be reduced. it can.

FIG. 5 is a configuration diagram of a small-capacity private power generator, a distribution board, and a power supply system using them in a fifth embodiment of the present invention (corresponding to claims 7 and 8).

In FIG. 5, a small capacity private power generator 9B
Is a third switch, which is a third switch controlled between the AC bus 3 and the output bus 5 for self-sustained operation so that the open / close state is reversed between the AC bus 3 and the self-sustained operation output bus 5 in the small capacity private power generator 9 of FIG. A switch 6A is provided. Therefore, the electric power is supplied from the self-sustained operation output terminal 16 only when the electric power is not supplied from the interconnection operation output terminal 14.

The distribution board 10B and the self-supporting load distribution board 25 are the same as those in the third embodiment of FIG.

In this embodiment, the method of supplying power to the self-sustaining load 13 is different from that of the other embodiments.
The power supply to the self-sustaining load 13 is performed from one branch circuit breaker 15 connected to the bus bar of the distribution board 10B, or one branch circuit breaker connected to the self-supporting bus bar 18 of the distribution board 25 for the self-sustaining load. It is configured to be performed via the power supply switching device 28 that switches whether to perform from 19. The power supply switching device 28 is normally connected to the power purchasing system bus bar 21 side and has a function of switching the power supply to the self-supporting system bus line 18 when the voltage on the power purchasing system bus bar 21 side disappears. This power supply switching device 28 may be provided on the self-sustained load 13 side, or may be provided on the load side of one branch circuit breaker 15 of the distribution board 10B.

In the power supply system of FIG. 5, during the interconnection operation, power is supplied from the commercial system 11 to the self-sustained load 13 via the power purchasing system bus 21 and the branch circuit breaker 15 and the power source changeover switch 28. To do.

When the commercial system 11 shifts to the self-sustaining operation due to an abnormality or the like, in the power generator 9B, the interconnection switch 6 is opened in response to the opening of the main earth leakage breaker 22 or the main breaker 20. Immediately after that, the grounding switch 8 is closed to ground one phase of the AC bus 3 via the grounding terminal 7, the self-sustaining switch 6A is closed, and power is supplied to the self-sustained operation output terminal 16. As a result, the self-generated power of the power generation device 9B is generated by the branch circuit breaker 1 of the distribution board 25 for the self-sustaining load.
The power is supplied to the power switch 28 via the switch 9. However, at this time, the power switch 28 has already been switched to the branch breaker 19 side of the self-sustaining load distribution panel 25. In this way, the interconnection operation is canceled, the operation is switched to the self-sustaining operation, and the self-generated power is supplied from the power generation device 9 to the self-sustaining load 13.

According to this embodiment, the power generator 9 is normally operated.
When the grid B and the commercial grid 11 are interconnected, power is supplied from the power purchase bus 21 of the distribution board 10B to the general load 12 and the self-supporting load 13, and when a grid abnormality or the like occurs, small-capacity private power generation The power source changeover switch 28 can be switched to the device 9B side to continue the operation of the self-sustaining load 13. Even in this case, unlike the conventional small-capacity private power generator, grounding is secured at one place during any operation, so that leakage protection can be reliably performed.

[0078]

According to the present invention, a small-capacity private power generator is provided with a function of switching the grounding state of the electric circuit between the interconnected operation and the self-sustained operation, and a distribution board having an earth leakage breaker is used. Power is supplied to both the commercial system load and the self-sustaining load during grid-connected operation, and it has the function of supplying power only to the self-supporting load during self-sustaining operation. It is possible to deal with leakage protection.

[Brief description of drawings]

FIG. 1 is a power generation device according to a first embodiment of the present invention,
The block diagram of a distribution board and a power supply system.

FIG. 2 is a power generation device according to a second embodiment of the present invention,
The block diagram of a distribution board and a power supply system.

FIG. 3 is a power generation device according to a third embodiment of the present invention,
The block diagram of a distribution board and a power supply system.

FIG. 4 is a power generation device according to a fourth embodiment of the present invention,
The block diagram of a distribution board and a power supply system.

FIG. 5 is a power generation device according to a fifth embodiment of the present invention,
The block diagram of a distribution board and a power supply system.

FIG. 6 is a configuration diagram of a conventional power generator, distribution board, and power supply system.

[Explanation of symbols]

1 DC power generator (fuel cell) 2 inverter 3 AC bus 4 Output bus for interconnection 5 Independent operation output bus 6 interconnection switch 6A independent switch 7 Ground terminal 8 ground switch 9, 9A, 9B Small capacity private power generator 10, 10A, 10B distribution board 11 Commercial system (power purchase system) 12 load 13 Independent load 14 Output terminal for interconnection operation 15 Branch circuit breaker 16 Independent operation output terminal 17 Self-supporting earth leakage circuit breaker 18 Independent Bus 19 Branch circuit breaker 20 Main circuit breaker 21 Power purchase bus 22 Main leakage circuit breaker 23 Grounding system 24 Busbar breaker 25 Independent load distribution board 26 Independent circuit breaker 27 Small capacity private power generator 28 Power switch

Claims (8)

[Claims] 1. A power generation unit for generating commercial AC power from an energy source other than electricity, an output terminal for directly outputting the commercial AC power generated by this power generation unit to the outside, and a power generation unit generated by the power generation unit. An output terminal for outputting commercial AC power to the outside through the first switch and a one-phase or neutral point of the output of the power generation unit are controlled so that the open / close state is opposite to that of the first switch. And a grounding terminal for grounding via the second switch. 2. A main circuit earth leakage circuit breaker connected to an external power source, a first busbar connected to the main circuit earth leakage circuit breaker, and one or more branch circuit breakers connected to the first busbar. The switchboard further includes an earth leakage circuit breaker connected to another external power source, a second busbar connected to the earth leakage circuit breaker, and one or more branch circuit breakers connected to the second busbar. A distribution board characterized by that. 3. A power generation unit for generating commercial AC power from an energy source other than electricity, an output terminal for self-sustaining operation for directly outputting the commercial AC power generated by this power generation unit to the outside, and the power generation unit. The output terminal for interconnection operation for outputting the generated commercial AC power to the outside through the first switch, and the one-phase or neutral point of the output of the power generation unit are referred to as the first
A power generator having a switch and a ground terminal that is grounded via a second switch whose open / closed state is reversed, a main earth leakage circuit breaker connected to an external commercial system, and this main earth leakage interruption A first busbar connected to the power generator, one or more branch circuit breakers connected to the first busbar, and a self-sustaining earth leakage circuit breaker connected to the self-sustained operation output terminal of the power generator, A second busbar connected to the self-sustaining earth leakage circuit breaker; and a distribution board having one or more branch circuit breakers connected to the second busbar, and one connected to the first busbar. The branch circuit breaker is connected to the output terminal for interconnection operation of the power generation device, and during the interconnection operation of the commercial system and the power generation device, the first switch is closed and the second switch is opened, During the self-sustained operation of the power generator, the first switch Power supply system, characterized in that the pitch is opened and the second switch is closed. 4. The distribution board according to claim 2, further comprising a busbar connecting circuit breaker for connecting the first busbar and the second busbar. 5. A power generation section for generating commercial AC power from an energy source other than electricity, an output terminal for self-sustaining operation for directly outputting the commercial AC power generated by this power generation section to the outside, and the power generation section. The output terminal for interconnection operation for outputting the generated commercial AC power to the outside through the first switch, and the one-phase or neutral point of the output of the power generation unit are referred to as the first
A power generator having a switch and a ground terminal that is grounded via a second switch whose open / closed state is reversed, a main earth leakage circuit breaker connected to an external commercial system, and this main earth leakage interruption And a first distribution board having one or more branch circuit breakers connected to the bus, and a self-sustaining earth leakage circuit breaker connected to the self-sustained operation output terminal of the power generator. A busbar connected to the self-sustaining earth leakage circuit breaker and a second distribution board having at least one branch circuit breaker connected to the busbar, the busbar being connected to the busbar of the first distribution board. The branch operation breaker is connected to the output terminal for interconnection operation of the power generator, and the first switch is closed and the second switch is closed during interconnection operation of the commercial system and the power generator. When the power generator is operated independently, A power supply system, wherein the first switch is opened and the second switch is closed. 6. A power generation unit that generates commercial AC power from an energy source other than electricity, an output terminal for outputting the commercial AC power generated by the power generation unit to the outside via a first switch, and the power generation. A ground terminal for grounding a one-phase or neutral point of the output of the unit via a second switch which is controlled so that the open / closed state is opposite to that of the first switch, and a commercial terminal generated by this power generation unit. A main earth leakage circuit breaker for receiving alternating-current power; a busbar connected to the main earth leakage circuit breaker; and a distribution board for a self-sustaining load having one or more branch circuit breakers connected to the busbar. Generator. 7. A power generation unit for generating commercial AC power from an energy source other than electricity, an output terminal for outputting the commercial AC power generated by the power generation unit to the outside through a first switch, and the power generation. A ground terminal for grounding a one-phase or neutral point of the output of the unit via a second switch controlled so that the open / closed state is opposite to that of the first switch, and a commercial terminal generated by the power generation unit. A power generation device comprising: an output terminal for outputting AC power to the outside through the third switch controlled so that the open / closed state is opposite to that of the first switch. 8. A power generation unit for generating commercial AC power from an energy source other than electricity, and an output terminal for interconnection operation for outputting the commercial AC power generated by this power generation unit to the outside via a first switch. And a ground terminal for grounding a one-phase or neutral point of the output of the power generation unit via a second switch that is controlled so that the open / closed state is opposite to that of the first switch, and the power generation unit. A third commercial AC power that is controlled so that the open / closed state is opposite to that of the first switch.
A generator having an output terminal for self-sustained operation for outputting to the outside through a switch, a main earth leakage breaker connected to an external commercial system, a busbar connected to this main earth leakage breaker, and this busbar A first distribution board having at least one branch circuit breaker connected to the self-sustaining system; a self-sustaining earth leakage circuit breaker connected to the self-sustained operation output terminal of the power generator; and a self-sustaining system earth leakage circuit breaker. A second distribution board having a busbar and one or more branch circuit breakers connected to the busbar; and a branch cutoff connected to the busbar of the first distribution board for supplying power to an independent load. And a switching device for switching from one branch circuit breaker connected to the bus bar of the second distribution board, and one branch circuit breaker connected to the bus bar of the first distribution board. The output terminal for interconnection operation of the power generator is connected to, The first switch is closed and the second switch and the third switch are opened during the interconnected operation of the utility system and the power generator, and the first switch is opened during the independent operation of the power generator. A power supply system characterized in that the second switch and the third switch are closed.