JP2002315183A - Power distribution system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power distribution system for allowing only a section where a trouble occurs, and for continuously feeding power to a sound section. SOLUTION: A feeder line EW4 connected to a first feeder system (EW1, CB1, EW2, DS1, and PT1), and a feeder line EW5 connected to a second feeder system (EW1, CB1, EW3, DS2, and PT2) are connected in a closed loop to the entire bus. The entire bus is composed so that plural block buses EW1-EW4 where plural load facilities L1-L22 are connected are connected in series via circuit breakers CB2-CB6, and at the same time at least one fuse apparatus IPF1 is included. In the case of trouble such as bus short-circuiting, only the bus where the trouble occurred is separated, and power continues to be fed to other buses.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power distribution system employed in a facility such as a factory or a building, and more particularly, it is possible to continue power supply to a sound section only when a fault occurs when a fault occurs. The present invention relates to a power distribution system and an improvement thereof.

[0002]

2. Description of the Related Art As an example of a conventional power distribution system in a facility such as a factory or a building, a power distribution system of a so-called double bus system is known. An outline of the power distribution system will be described with reference to FIG. In the figure, 11A and 1
Reference numerals 1B denote buses which are substantially equivalent to each other. Power supply lines 12A and 12B connected to a power supply facility (commercial power supply) PS are connected to the buses 11A and 11B, respectively.
13B, and are connected via circuit breakers 14A and 14B. L1 to L3 are load facilities as power supply targets. A pair of distribution lines 15A, 15B for the respective load facilities L1 to L3 are connected to the buses 11A, 11B, respectively. Each of the distribution lines 15A and 15B has a disconnector 16 respectively.
A and 16B are interposed, and the load facilities L1 to L3 are merged and connected to the load facilities L1 to L3 via circuit breakers 17A, 17B and 17C. Power supply line 12A, 1
Although not shown, a disconnector is interposed between the 2B circuit breakers 14A and 14B and the buses 11A and 11B. In some cases, private power generation facilities are connected to the buses 11A and 11B.

Normally, power is supplied to each of the load facilities L1 to L3 via the bus 11B by setting the disconnector 16A to a disconnected state and connecting the disconnector 16B to a connected state. Bus 1
If a fault such as a short circuit occurs in the switch 1B, the disconnector 16
By setting B to the disconnected state, disconnecting switch 16A to the connected state, and switching to bus 11A, it is possible to quickly recover. Since the disconnectors 16A and 16B cannot be opened and closed in the energized state, the disconnectors 16A and 16B
Switching of 16B is performed by circuit breakers 14A, 14B, 17A,
It is performed after shutting off 17B and 17C.

[0004]

However, in such a conventional double bus system, when a fault occurs, one of the connected disconnectors is disconnected after the breaker is turned off and the other disconnector is disconnected. , It is necessary to switch the power supply for connection, and there is a problem that the power supply to all the load facilities is temporarily stopped due to the switching. Further, there is a possibility that both of the pair of disconnectors may be connected at the same time, which is not preferable in terms of safety, and requires a special device for preventing the simultaneous connection to avoid this. there were. Further, when one and the other of the double buses are electrically connected for some reason, there is a problem that both the pair of buses become unusable and power supply to all the load facilities is stopped.

[0005] The present invention has been made in view of such problems of the prior art, and provides a power distribution system in which when a failure occurs, only the section where the failure has occurred is taken out of service and power supply to a healthy section can be continued. The purpose is to provide.

Another object of the present invention is to further improve such a power distribution system to provide a power distribution system having excellent reliability and safety.

[0007]

According to the power distribution system of the present invention, a plurality of block buses each connected to a load facility are connected in series to each other via a circuit breaker having a synchronization function to form an entire bus. A first power supply system is connected to a block bus at one end via a circuit breaker with a synchronization function, and a second power supply system is connected to the block bus at the other end of the entire bus via a circuit breaker with a synchronization function. At least one fuse device is interposed therein.

In the wiring system according to the present invention, the block buses are connected in series via a circuit breaker with a synchronization function. The whole buses (hereinafter referred to as a single bus system or a block bus system for comparison with the conventional double bus system). In some cases.) That is, the first power supply system and the second power supply system are connected via a plurality of circuit breakers with a synchronization function. The voltage, frequency and phase are synchronized between the block bus adjacent to the bus and between the second power supply system and the block bus. Therefore, each load facility can normally receive power from both the first power supply system and the second power supply system.

When a fault such as a short circuit occurs in a part of each block bus, only the block bus is separated by shutting off circuit breakers with synchronization functions at both ends of the block bus where the fault has occurred. At this time,
Power supply to the other block buses can be continued from either the first power supply system or the second power supply system. Therefore,
The power supply can be restored without stopping power supply at the time of occurrence of a failure or with a short-time power failure.

Further, since the power distribution system of the present invention is a single bus system, one of the double buses is connected to the other and causes a short circuit accident in accordance with a switching error of the disconnector as in the conventional double bus system. Problem is solved.

Further, at least one fuse device is interposed in the entire bus, so that the first power supply system and the second power supply system can be quickly separated in the event of a fault such as a short circuit accident, thereby providing high safety. Can be realized. As a fuse device, a current limiting fuse smaller than the rated current and a contact opening device that opens contacts using the explosive force of a small amount of explosive are connected in parallel, and an increase in current due to a short circuit accident is detected, and the explosive is charged. In this case, the contact can be opened by igniting the current, and the entire current can be commutated to the current limiting fuses provided in parallel and cut off. Since the contacts are opened using the explosive power of gunpowder, instantaneous operation is possible,
Safety can be improved.

In the present invention, although not particularly limited, the circuit breaker with the synchronization function can also have a function as a disconnecting switch. By using a single device having a synchronization function, a cutoff function, and a disconnection function, the configuration of the power distribution system can be simplified. In addition, an arrester (lightning arrester) may be interposed on each of the block buses in case of a lightning strike or the like.

Further, a first generator can be connected to one of the block buses, and a second generator can be connected to a block bus different from the block bus to which the first generator is connected. If multiple generators are connected to the same block bus, if a failure occurs in the block bus, all the generators cannot be used, but by connecting the generators to different block buses in this way, Even if a failure occurs in one of the block buses, power can be supplied by the generator connected to the other block bus, and reliability and safety can be improved.

Further, a part or the whole of the block bus may be supported via a supporting member having an insulating supporting portion made of resin (epoxy resin, polyester resin, etc.). The bus bar is usually supported via an insulator made of porcelain, glass, or the like. However, the insulation performance can be improved as compared with ordinary insulators, and the bus bar is lightweight and easy to handle during installation.

Further, a distribution line for a specific load facility connected to one of the block buses, and another specific load facility connected to a block bus different from the block bus to which the specific load facility is connected Can be connected by a bypass line having a circuit breaker or disconnector. If a failure occurs in a block bus to which an important load facility (for example, a control room or a pump, etc .; the same applies hereinafter) is connected, power supply to the important load facility becomes impossible if the block bus is separated. By providing such a bypass line, power supply to the important load equipment can be performed from another block bus, and reliability and safety can be improved.

In addition, a connection line from a generator can be connected to a distribution line for a specific load facility connected to one of the block buses. When a failure occurs, power can be supplied from the generator to the important load equipment via the connection line, and the reliability and safety can be improved.

In addition, priorities are assigned to the load equipment in advance, and when a failure occurs in a part of the system, power is supplied to the load equipment having a lower priority according to the degree of the failure. Can be stopped. There are various types of load equipment, such as important load equipment, less important load equipment, and load equipment that can be safely shut down.However, it is possible to supply power to all load equipment due to some kind of failure. When it is not possible, power supply to more important load equipment can be continued, and the propagation of a failure can be suppressed to a minimum.

Furthermore, a part of the block bus bar to which the load equipment is connected can be housed in independent block housings. When a plurality of block buses are housed in a single housing, the probability of occurrence of a fault such as a short circuit between the block buses increases. Such a probability can be reduced.

Further, the block housing can be installed in a building. When installed outdoors, corrosion progresses due to wind and rain, etc., which shortens the life of the block housing and busbars and increases the probability of failure. The service life can be extended, and the probability of occurrence of a failure can be reduced.

[0020]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a system diagram showing an overall configuration of a power distribution system according to an embodiment of the present invention. A power supply line EW1 for supplying three-phase alternating current drawn from a power company as a commercial power supply into a factory facility is branched into two via a circuit breaker CB1, and one of the branched power supply line EW2 and the other power supply line E2.
W3 is connected to the primary side of the first transformer PT1 and the second transformer PT2 via disconnectors DS1 and DS2, respectively.

The secondary side of the No. 1 transformer PT1 is a feeder line EW.
4. A plurality of block buses (A bus BW1, B bus BW2, C bus BW3, and D bus B via the circuit breaker CB2.
W4) is connected in series to the A
Connected to bus BW1. The secondary side of the No. 2 transformer PT2 is connected to the entire bus D via the feeder EW5 and the circuit breaker CB6.
Connected to bus BW4. A bus BW1 and B bus B
W2, B bus BW2 and C bus BW3, C bus BW3 and D
Circuit breakers CB3, CB4,
CB5 is interposed. Each bus BW1 to BW4 is 2
3 enough to pass a large current of about 000A to 3000A
It is composed of a metal conductor formed in a plate shape of a book.

Each of the buses BW1 to BW4 is provided with an overcurrent protection relay OER1 to OER4 provided with an ammeter A via a current transformer (CT) (an overcurrent protection relay provided on the B bus). OER2 is not shown),
The overcurrent protection relays OER <b> 1 to OER <b> 4 are predetermined current values set in advance due to a failure such as a bus short circuit accident (current values that are estimated to have an accident with respect to a normal current value. When the above current is measured, the buses BW1 to BW1 provided with the overcurrent protection relays OER1 to OER4 are set.
Circuit breakers CB2 and CB3, CB3 and CB at both ends of W4
4. A trip signal for switching from a connected (closed) state to a disconnected (open) state is output to CB4 and CB5 and CB5 and CB6. Each breaker CB2-CB6
Receives the trip signal and switches from the connected state to the disconnected state. If a bus short-circuit accident occurs, all overcurrent protection relays OER1 to OER1
Although an abnormality is detected by the ER4, in the present embodiment, the circuit breaker closer to the fault occurrence point is cut off by providing the protection coordination circuit. As a result, only a section where a failure has occurred can be quickly separated from the system, and power can be continuously supplied to a healthy section where no failure has occurred.

A fuse device IPF1 is interposed between the B bus BW2 and the C bus BW3 and closer to the C bus BW3 than the circuit breaker CB4. The position where the fuse device IPF1 is provided is not limited to the above-described position, but may be between the A bus BW1 and the B bus BW2, between the C bus BW3 and the D bus BW4, or at any other position in the entire bus, or the power supply line. EW4 and EW5 may be provided. Further, the number of fuse devices is not limited to one as described above, and may be plural. In this case, the fuse devices can be disposed at two or more of the above-described positions.

Arresters (lightning arresters) SA1 to SA4 are connected to the buses BW1 to BW4, respectively. The arresters SA1 to SA4 are connected to each bus BW1
When an abnormal high voltage is generated in the BW4, it is discharged to the ground to automatically maintain a normal state, and the buses BW1 to BW1
This is a device that prevents damage to devices in the circuit including W4.
Further, each of the buses BW1 to BW4 has a grounding instrument transformer GT.
P1 to GTP4 are connected. The grounding meter transformers GTP1 to GTP4 measure the voltage values of the corresponding buses BW1 to BW4. When a grounding accident occurs, any one of three phases (R phase, S phase, T phase) It detects whether the phase is grounded and outputs the signal to a ground protection relay (not shown) provided in each of the buses BW1 to BW4. The ground protection relay takes in signals from the grounding meter transformers GTP1 to GTP4, and outputs a ground overvoltage and three-phase (R-phase, S-phase).
Phase and T phase) are detected and determined, and when it is determined that a grounding accident has occurred, the corresponding breakers CB2 to CB6 are disconnected from the connected (closed) state. A signal for switching to the (open circuit) state is output. The circuit breakers CB2 to CB6 receive this signal and switch from the connected state to the disconnected state. In the case where a bus grounding accident occurs, an abnormality will be detected by all grounding protection relays.
The provision of the protection coordination circuit to cut off the circuit breaker closer to the fault occurrence point is the same as in the case of the overcurrent protection relays OER1 to OER4 described above.

Further, each of the buses BW1 to BW4 has a distribution line EW6 for a plurality of load facilities L1 to L15.
To EW20 are respectively connected. Each distribution line EW6
In the vicinity of corresponding bus lines BW1 to BW4 of EW20,
Circuit breakers CB7 to CB21 are interposed respectively. Overcurrent protection including a power meter W, an integrated power meter WH, and an ammeter A in the vicinity of the load facilities L1 to L15 of the circuit breakers CB7 to CB21 of the distribution lines EW6 to EW20, respectively, via current transformers. Relays OER6 to OER20 are provided. The functions of these overcurrent protection relays OER6 to OER20 are the same as those of the overcurrent protection relays OER1 to OER4 described above.
Is the same as

Further, the load facilities L1 to L1 of the overcurrent protection relays OER6 to OER20 of the respective distribution lines EW6 to EW20.
The ground protection relays EER1 to EER15 are located near the fifth side.
Is provided. These earth protection relays EER1
The EER15 is connected to the above-mentioned grounding instrument transformers GTP1 to GTP.
4 to capture ground overvoltage and three phases (R phase,
(S phase, T phase) is detected and determined, and when it is determined that a ground accident has occurred, the corresponding circuit breakers CB7 to CB21 are connected to (closed from) a circuit breaker. A signal for switching to a disconnection (open circuit) state is output. The circuit breakers CB7 to CB21 receive this signal and switch from the connected state to the disconnected state. In FIG. 1, the overcurrent protection relays OER6 to OER20 and the earth protection relays EER1 to EER15 for the distribution lines EW6 to EW20 are representatively shown only for the distribution line EW6 and the distribution line EW13. The components are not shown.

The first generator P is connected to the A bus BW1 and the C bus BW3 via feed lines EW21 and EW22, respectively.
The G1 and PG2 generators are connected. Feed line EW
21 and EW22, the breakers CB2
2 and CB23, CB24 and CB25 are interposed, and the generators PG1, PG2 of the circuit breakers CB22, CB24
Near the side, the overcurrent protection relays OER21, OER2
2 and ground protection relays EER16 and EER17. These overcurrent protection relays OER21, OE
R22 is the overcurrent protection relay OER1 to OER described above.
20 and ground protection relays EER16, EER
Reference numeral 17 denotes the above-described ground protection relays EER1 to EER15.
Is the same as

A distribution line EW23 for the load equipment L16 is connected near the A bus BW1 side of the circuit breaker CB23 of the power supply line EW21, and near a C bus BW3 side of the circuit breaker CB25 of the power supply line EW22. Is the load equipment L1
7 is connected via a fuse device IPF2. Further, a distribution line EW25 is connected to the power supply line EW22 via a fuse device IPF3.
B26 and CB27 are connected to load equipment L18 and L19. An integrating wattmeter WH is connected to the distribution line EW25 via a current transformer. The fuse device I
The PF2 and IPF3 are the same as the above-described fuse device IPF1, and will be described later in detail.

Distributors EW8 include disconnectors DS3 to DS5.
And a circuit breaker CB28, and a branch distribution line EW26 is connected between the disconnector DS3 and the disconnector DS4. The branch distribution line EW26 is connected to the load facility L20 via the disconnector DS6 and the transformer PT3. Disconnectors DS7 and DS8 and a circuit breaker CB29 are interposed in the distribution line EW17.
In the vicinity of the circuit breaker CB29, a branch distribution line EW27 is connected. The branch distribution line EW27 is connected to the load equipment L21 via the disconnector DS9 and the transformer PT4. Another branch distribution line EW28 is connected to the branch distribution line EW27, and the branch distribution line EW28 is connected to the disconnector DS10.
Is connected to the load equipment L22 via the. In this embodiment, the load equipment L3 and the load equipment L12 are motors for driving a pump, and are more important equipment than other load equipment.

Disconnector DS4 and disconnector D of distribution line EW8
Between S5 and between the disconnector DS7 and the disconnector DS8 of the distribution line EW17 are connected to each other by a bypass line EW29 in which a pair of disconnectors DS11 and DS12 are interposed.

In FIG. 1, devices and circuits in a region indicated by a two-dot line constitute a switchboard PS, and the switchboard PS is installed in a building to protect it from wind and rain. In the present embodiment, as shown in FIG. 2, the switchboard PS includes four block switchboards (A bus switchboard, B bus switchboard, C bus switchboard, and D bus switchboard) respectively corresponding to the buses BW1 to BW4. It is configured.

The corresponding buses BW1 to BW4 and the corresponding circuit breakers CB2 to CB20 and other circuits (overcurrent protection relays OER1 to OER22, ground protection relays EER1 to EER1)
The respective block switchboards including the EER 17 and the fuse devices IPF1 to IPF3 are housed in metal housings (block housings) PS1 to PS4 which are configured independently of each other. Between the block housings PS1 and PS2, between the block housings PS2 and PS3, and the block housing PS3
And PS4, bus ducts BD1 to BD3, respectively.
Is interposed. Each of the bus ducts BD1 to BD3 is configured by housing a conductor (copper) for connecting the buses BW1 to BW4 in each of the block housings PS1 to PS3 in a metal box. Is not going to happen. In this embodiment, each of the block housings PS1 to PS4 is a metal clad type,
That is, a high protection class is adopted in which each part such as the bus bar and the circuit breaker is separated by a partition plate made of metal or the like. However, the partition plate may be omitted or a cubicle-type partition plate having a low protection grade may be used.

Although the buses BW1 to BW4 and the wiring constituting the other circuits are not shown,
In S1-PS4, it is supported via a support member (resin insulator) having an insulating support portion made of epoxy resin. The bus bars and the like are usually supported by using an insulator using porcelain as an insulator. In the present embodiment, the bus is supported by a resin insulator. Resin insulators can be manufactured with higher weather resistance, insulation performance, tracking resistance, mechanical strength, etc. than ordinary insulators, and by supporting buses etc. with such resin insulators In addition, the reliability and safety of the power distribution system can be improved, and the power distribution system is lightweight and easy to handle during installation and maintenance. As the resin insulator, a material using a polyester resin or the like other than a material using an epoxy resin can be used.

Circuit breakers CB1 and CB2 used in this embodiment
As 9, one in which a spring is energized by an electromagnet or an electric motor, and the spring is opened to be closed or closed (connected) can be adopted. The blocking medium may be any of air, gas, oil, and vacuum, but is preferably a vacuum or an inert gas because of its excellent insulation reliability. In the present embodiment, an apparatus using SF ₆ gas, which is an inert gas, is employed.
SF ₆ is particularly excellent because the electrical negativeness (degree of attracting electricity) of fluorine atoms is remarkably higher than that of air and the like, and negative ions are easily formed, so that a stable dielectric strength can be realized. is there.

In this embodiment, the circuit breaker CB
Circuit breakers CB1 to CB6 and CB22 among 1 to CB29.
CB25 is a circuit breaker with a synchronization function having a synchronization function. This synchronizing function adjusts the frequency, voltage, and phase between the two terminals of the circuit breaker or between predetermined detection positions so that they substantially match when the frequency is different, and turns on the circuit breaker at the time of the match. Function.

More specifically, the synchronization function detects the frequency, voltage, and phase of each of a pair of lines (bus or distribution line) connected to the input / output terminals of the circuit breaker with the synchronization function, and one of them detects one. A power converter that adjusts and converts the target so that it substantially matches the other or a target value that substantially matches both, and when the frequency, the voltage, and the phase substantially match, the circuit breaker is turned on. This is realized by a synchronous input device for inputting. Regarding the circuit breakers CB23 and CB25 provided near the generators PG1 and PG2, the frequency, voltage and phase of the lines (distribution lines) EW21 and EW22 connected to the terminals on the opposite side to the generators PG1 and PG2 are determined. This is realized by a synchronous closing device that detects and controls the generators PG1 and PG2 so as to substantially match them, and closes the circuit breaker at the time of matching. In addition, any or all of the remaining circuit breakers CB7 to CB21 and CB26 to CB29 may be configured as the circuit breakers with the synchronization function as described above.

Although not particularly limited, the circuit breakers CB1 to CB29 of the present embodiment also have a function as a disconnecting switch. That is, the circuit breakers CB1 to CB29 are configured as a single unit, and the circuit breaker unit is configured to be able to be pulled out from a main unit connected to a line (bus, power supply line, or distribution line). . The main unit is provided with a pair of connection terminals for each of the three divided lines, and the breaker unit is provided with corresponding connection terminals, respectively. By pulling out the breaker unit, the connection between the opposing connection terminals is released and the line is disconnected.On the other hand, by pushing the breaker unit into the main unit, the circuit breaker unit is electrically disconnected between the separated lines. It is in a state of being interposed. In this state, when the circuit breakers CB1 to CB29 are closed, the disconnection between the lines is released. The attachment / detachment of the breaker unit to / from the main unit is performed by the corresponding breaker CB1.
Needless to say, CB29 is performed in a disconnected state.

Fuse device IPF1 used in this embodiment
To IPF3, a normally-closed contact is provided with a current-limiting fuse having a rated current of one tenth or less of the rated current of the device in parallel, detecting an increase in current due to a short circuit accident or the like, and opening the contact; A device is used in which all current is diverted to a current limiting fuse provided in parallel, and the current limiting fuse is cut off by blowing. Since the contact must be opened quickly, a method using an electromagnet or a spring is not used, but a very small amount of explosive power is used, and a detection device using a current transformer and a semiconductor element is used for ignition. Used. This fuse device has the advantages that it does not require a separate power supply, can operate instantaneously, can be handled exactly the same as a conventional fuse, and can significantly reduce manufacturing costs.

During normal operation, however, the circuit breakers CB1 to CB6 with the synchronization function and the disconnectors DS1 and DS2 are in a connected state, and the circuit breakers CB7 to CB29 and the disconnectors DS3 to DS3 to the respective load facilities L1 to L21 are connected. When the DS 10 is appropriately connected, the corresponding load equipment L
Power is supplied to 1 to L22. At this time, the first power supply system (EW1, CB1, EW2, DS1, PT1)
Feeder EW4 connected to the second feeder (EW1, CB
1, EW3, DS2, PT2)
5 and each bus bar BW connecting them in an open loop
1 to BW4 are in a state where their respective frequencies, voltages and phases are practically matched, that is, synchronized, by the synchronization function of the circuit breakers with synchronization function CB2 to CB6 at the respective connection portions. Also, a generator P as a third power supply system
G1, when performing power supply by the generator PG4 as the fourth power supply system, the circuit breakers CB22 to CB2 with a synchronization function are provided.
5 are similarly synchronized by the synchronization function.

In this state, if a fault such as a short circuit accident or a ground accident occurs in any of the buses BW1 to BW4,
The fact is detected by the overcurrent protection relays OER1 to OER4, the grounding meter transformers GTP1 to GTP4 and the grounding protection relays for the buses BW1 to BW4, and through a control device for controlling and managing the entire system, Circuit breakers CB4 and CB5 provided at both ends of the faulty bus (for example, BW3) are operated to cut off the buses BW2 and BW4 connected to the bus BW3. As a result, the bus BW3 where the fault has occurred
Only the state is separated from the power distribution system. At this time, power is continuously supplied from the first power supply system to the buses BW1 and BW2 where no fault has occurred, and power is continuously supplied from the second power supply system to the bus BW4. ~ L7, L13 ~ L16, L20
Etc. can continue the normal operation.

With regard to the restoration of the faulty bus BW3, the circuit breaker unit is pulled out of the main unit to completely operate the disconnectors provided as additional functions to the circuit breakers CB4 and CB5 at both ends of the bus BW3. After the disconnection, the work is performed. When the restoration work is completed, the circuit breaker C is synchronized with the adjacent buses BW2 and BW4 by the synchronization function of the circuit breakers CB4 and CB5.
By turning on B4 and CB5, it is possible to return to the normal operation state.

In the present embodiment, when a failure such as a bus short-circuit accident occurs, power supply to important load equipment (for example, motors L3 and L12 for driving pumps) and a control room in a factory facility is stopped. Various safety circuits are provided so that there is no safety circuit. These are outlined below.

First, in this embodiment, the distribution line EW
8, EW17 are connected to motors L3, L12 for driving a pump as important load equipment. Here, for example, as described above, a failure occurs in the bus BW3,
When the bus BW3 is separated from the system by the circuit breakers CB4 and CB5, the power supply to the important load equipment L12 stops. However, in the present embodiment, the bypass line EW2 connecting the distribution line EW8 and the distribution line EW17.
9 when such a failure occurs, the bypass line E
By connecting the disconnectors DS11 and DS12 provided in W29, power supply to the load equipment L12 can be continued via the bus BW1, the distribution line EW8, and the bypass line EW29. Conversely, a fault occurs in the A bus EW1, and the breakers CB2 and CB3
Even when W1 is separated from the system, power can be similarly supplied to the important load equipment L3. Power can be similarly supplied to the load facilities L20 to L22.

Further, in the present embodiment, the power supply from the commercial power supply can be used as a backup when the power supply from the commercial power supply cannot be received at all or sufficiently, or even when the power supply from the commercial power supply can be used, for the purpose of cost reduction, etc. A pair of generators PG1 and PG2 are provided as a power generator. These generators PG1 and PG2 are provided with different buses BW
1 and BW3. When these generators PG1 and PG2 are connected to the same bus, when a fault occurs in the bus, both generators PG1 and PG2 are connected.
2 cannot supply power, but a different bus BW
1 and BW3, even if a fault occurs in one bus, power supply can be continued via the other bus, which is advantageous in safety measures.

Further, in this embodiment, important load equipment such as a control room (for example, in FIG. 1, load equipment L16
To L19), power can be supplied directly from the generators PG1 and PG2 without passing through the buses BW1 to BW4.
Even when power cannot be supplied via the buses EW1 to EW4 at all, power supply can be continued from the generator PG1 or PG2, which is advantageous in safety measures.

In the present embodiment, each of the load facilities L1 to L22 is provided with consideration of the importance of the equipment.
Priority is given. For example, important load equipment (motors L3 and L12 for driving the pump, or the control room L
16 to L19), a high priority is assigned to the other load equipment, and a low priority is assigned to the remaining load equipment. The power supply capability of the commercial power supply or the generators PG1 and PG2 due to a failure or other reasons. Then, when the power consumption of the entire system cannot be covered, the power supply to the low-priority load equipment is stopped. Thus, power supply to more important load equipment can be continued. In addition,
Priorities may be assigned to the load facilities L1 to L22 in more detail, and the power supply may be stopped in order from the lowest priority according to the power supply capacity.

The embodiments described above are described for facilitating the understanding of the present invention, and are not described for limiting the present invention. Therefore,
Each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

[0049]

As described above, according to the present invention,
There is an effect that a power distribution system is provided in which only a section where a failure has occurred at the time of a failure is set as a power failure and power supply to a healthy section can be continued. In addition, there is an effect that a power distribution system excellent in reliability and safety is provided.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an overall configuration of a power distribution system according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a schematic configuration of a switchboard of the power distribution system according to the embodiment of the present invention.

FIG. 3 is a diagram schematically illustrating a conventional power distribution system.

[Explanation of symbols]

BW1 to BW4 ... bus (block bus) EW1 to EW5, EW21, EW22 ... power supply line EW6 to EW20, EW23 to EW28 ... distribution line EW29 ... bypass line L1 to L22 ... load equipment CB1 to CB6, CB22 to CB25 ... with synchronization function Circuit breakers CB7 to CB20, CB26 to CB29 ... Circuit breakers DS1 to DS12 ... Disconnectors PT1 to PT4 ... Transformers IPF1 to IPF3 ... Fuse devices (current limiting fuses) SA1 to SA4 ... Arresters (arresters) GTP1 to GTP4 ... OER1 to OER20: Overcurrent protection relay EER1 to EER15: Ground protection relay

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 5G066 HA24 HA30 HB11

Claims (3)

[Claims] A plurality of block buses to which load equipment is connected are connected in series with each other via a circuit breaker with a synchronization function to form an entire bus, and a block breaker with a synchronization function is connected to a block bus at one end of the whole bus. A first power supply system is connected via a power supply, a second power supply system is connected to a block bus at the other end of the overall bus via a circuit breaker with a synchronization function, and at least one fuse device is interposed in the overall bus. A power distribution system, characterized in that: 2. The power distribution system according to claim 1, wherein the circuit breaker with a synchronization function also has a function as a disconnector. 3. The power distribution system according to claim 1, wherein an arrester is interposed in each of the block buses.