JP4619220B2 - Power supply system - Google Patents

Description

  The present invention relates to a power supply system. Specifically, in large-scale factories that operate using electric power from private power generation facilities and power from commercial power sources, important loads that are operated with strict control of fluctuations in the power supply voltage, and other general loads In the case of having both loads, the power from the private power generation equipment from the side that drives the important load is also given to the general load from the side that drives the important load even in the event of an abnormal situation such as the occurrence of lightning. It can be reduced.

  Semiconductor factories belong to the category of special high-voltage customers (large-scale factories). This semiconductor factory, etc. has a private power generation facility on the factory premises as a measure against instantaneous voltage drop or stoppage of power transmission due to lightning.

This in-house power generation facility usually uses a distributed power source such as a gas turbine (GT) or a steam turbine (ST), and the in-house power generation facility has a load (for which voltage fluctuation must be strictly managed even in the same factory ( It is provided to drive the critical load).
For example, various semiconductor manufacturing apparatuses are installed in a clean room. An exposure apparatus, a drawing apparatus, an etching apparatus, an ion implantation apparatus, and the like. Such a semiconductor manufacturing apparatus is positioned as an important load in a factory, and is handled separately from general loads such as cooler equipment in the factory.

  For such important loads, power is generated from the private power generation equipment so that the drive voltage does not become low even instantaneously due to external factors such as switching of the transmission system (commercial power source) or generation of surge voltage due to lightning. Is always supplied. A part of the electric power from this private power generation facility is also supplied for the general load, but the shortage is covered by commercial power from the power company. The power transmission system from the private power generation facility (on-site power transmission system) and the power transmission system from the power company (commercial power transmission system) are interconnected, and a high-speed circuit breaker is placed between them. When there is an influence by the power transmission system, this high-speed circuit breaker is operated to divide the commercial power transmission system and the on-site power transmission system so that the influence on the important load can be avoided.

  Note that Patent Documents 1 to 6 are known as power supply systems using a distributed power source and a commercial power source. Patent Document 1 discloses a technique in which the power consumption of a load system does not exceed the power supply from a distributed power source. Patent Document 2 relates to a technology including a power storage device in order to continuously supply power from a distributed power source without interrupting power supply to a private load.

  Patent Document 3 discloses a high-speed current limiting circuit breaker that shuts off at high speed without waiting for the zero point of the accident power when a large-current accident occurs on the load side. Patent Document 4 discloses a distributed power supply system that can easily detect an abnormality in a distributed power supply that is connected to a power distribution system. That is, this patent document 4 is a monitoring system for detecting an abnormality. Patent Document 5 discloses a technique for quickly and reliably detecting that a distributed power source is in a single operation state for any load condition when the system is shut off. Patent Document 6 discloses a technique related to effective use of private power generation equipment. Therefore, Patent Document 6 is a low-cost power supply technology.

Japanese Patent Laid-Open No. 2004-266962 JP 2002-347625 A JP 2003-132768 A JP 11-89093 A JP 2001-268802 A JP 2004-32983 A

  By the way, when considering such a power receiving system, when there is a concern about the effect of the surge voltage and the surge voltage, or when the power transmission system is momentarily interrupted, the high-speed circuit breaker is activated and the two power transmission systems are operated. That is, the influence on the important load (voltage fluctuation) is avoided by disconnecting the interconnection bus connecting the commercial power transmission system and the on-site power transmission system.

  Even if the interconnected bus is disconnected from the power transmission system by a high-speed circuit breaker, the power is still supplied from the private power generation facility (co-generator) to the critical load, so voltage fluctuations can be avoided and normal operation continues. can do. This ensures protection against important loads.

  However, on the other hand, along with the disconnection of the electric circuit from the interconnection bus, the power supply to the general load is insufficient or completely zero, and the general load cannot be operated normally. Even in such a case, it is desirable to perform control so as to avoid the influence on the general load as much as possible.

  Therefore, the present invention solves such a conventional problem, and in particular, an electric power supply system that can supply electric power that can operate a general load even when an electric circuit from an interconnection bus is disconnected. It is what we propose.

In order to solve the above-described problem, in the power supply system according to the present invention as set forth in claim 1, an interconnection bus connecting the transmission system from the commercial power source and the transmission system provided in the premises, A first circuit breaker connected to the system bus, a general load connected to the local bus on the commercial power transmission system side than the first circuit breaker, and the above-mentioned on the local power transmission system side than the first circuit breaker An important load with stricter voltage management than the general load connected to the interconnection bus, a private power generation facility provided on the premises, a private power generation facility for a standby power supply, and a private load for the general load and the standby power supply A power supply path provided between the power generation facility and supplying the power of the standby power source to the general load; and a second circuit breaker connected to the power supply path and adjusted so as to slow down operation sensitivity. during operation of the first circuit breaker, from top Symbol backup power Power characterized in that it is supplied to the common load via the feed line and the second circuit breaker.

  In this invention, the interconnection bus which connects a commercial power transmission system and a campus power transmission system is provided. A circuit breaker that can be disconnected at high speed is connected to the interconnection bus. A general load is connected to the commercial power transmission system side of the circuit breaker, and an important load is connected to the interconnection bus on the premises power transmission system side of the circuit breaker.

  The important load refers to a load whose power supply voltage is more strictly managed than a general load. When the large-scale factory is a semiconductor factory, a semiconductor connection device or the like becomes an important load, and other cooler facilities or the like are classified as general loads.

  Important loads are covered by power from private power generation facilities using distributed power sources. A part of this electric power is also supplied to the general load via the interconnection bus. The important load has a bank configuration in order to realize stable operation, and the important load is constituted by a plurality of banks.

  Each bank is equipped with private power generation facilities. In-house power generation equipment uses gas turbines or steam turbines. A reserve power supply is provided in the private power generation facility for operating the lightest load in the bank. In addition to generating power when checking other private power generation facilities, the standby power supply can also be used from the stage before lightning arrives, even if lightning occurs and the effect of the surge voltage is predicted. Predicting the arrival will start power generation. In the present invention, a power supply path for supplying power from the standby power supply to the general load is provided.

  If lightning occurs and the interconnection bus is cut by the operation of the circuit breaker, and the power from the private power generation facility is supplied only to the critical load, the power supply from the commercial power transmission system to the general load is not Blocked.

  However, even in that case, since the power supply path is provided, the power from the standby power supply is supplied to the general load through this power supply path. Can cover part of it. In some cases, the entire power can be covered by the power from this standby power supply. Therefore, even when lightning occurs and power supply from the commercial power transmission system is interrupted, the influence on the general load can be reduced.

  Since the standby power source is diverted from the standby power source used when inspecting the private power generation facility, the power generation facility can be shared.

  In the present invention, when an important load is driven by electric power from a premises transmission system, and a general load is driven by a part of the electric power and electric power from the commercial transmission system, power supply from the commercial transmission system is performed. Even in the event of a break, the general load can be driven.

  According to this, when the power supply from the commercial power transmission system is interrupted in this way, the influence on the important load can be surely avoided and the influence on the general load can be reduced.

  In the event of an emergency, power supply to such a general load is performed using a standby power source, and this standby power source can be shared by using the standby power source used when inspecting private power generation facilities. Has characteristics.

  Next, a preferred embodiment of the power supply system according to the present invention will be described in detail with reference to the drawings.

  This embodiment is intended for special high voltage customers such as semiconductor factories equipped with private power generation facilities as described above. This special high-pressure customer is just an example listing.

  As a private power generation facility, a distributed power source such as a gas turbine (GT) or a steam turbine (ST) is usually used, and the private power generation facility is used for a semiconductor manufacturing apparatus positioned as an important load. The gas turbine and the steam turbine may or may not be the same scale. For example, when the power generation amount of the gas turbine is 7000 kW / 1 unit, for example, the power generation amount of the steam turbine is different, for example, 4000 kW / unit, and the power generation amount is different, for example, 4000 kW / unit. Can do.

  The important load is composed of a plurality of banks in order to ensure the reliability of power supply, and each bank is equipped with a private power generation facility.

  Therefore, for example, the power supply system (on-site power distribution system) 10 in such a factory is often configured as shown in FIG. In this embodiment, the important load is covered by the power generated by the private power generation facility, and a part of the power is sent to the general load. The general load is covered by a part of the power generated by this private power generation facility and the shortage by the power from the commercial power source. For this reason, the factory is provided with a connected bus for connecting power from the power company (power from the commercial power transmission system) and power from the private power generation facility (power from the on-site power transmission system).

  I will explain from the important load side. The example of FIG. 1 shows a case where the important load has a three-bank configuration of A to C, in which only the B bank has a smaller scale of the important load 14B than the important loads 14A and 14C in the A bank and the C bank. .

  Therefore, in this example, three private power generation facilities (distributed power sources) 12A and 12C are provided for A bank and C bank. In the figure, two of them are generators using a gas turbine (GT) and the remaining one is a generator using a steam turbine (ST). On the other hand, the private power generation facility 12B related to the important load of the B bank is covered by only one generator using a gas turbine. Waste heat from the boiler B of each gas turbine is reused as a heat source for the steam turbine and steam for the factory.

  Private power generation facility 12A is connected to bank A by interconnection bus 17A connected thereto. Similarly, private power generation facility 12C is connected to bank C by interconnection bus 17C connected thereto. The remaining private power generation facilities 12B are connected to the B bank via the interconnection bus 17B.

  The private power generation facilities 12A and 12C are interconnected by the local bus 16, respectively, and a pair of disconnectors 18A and 18C used when checking the private power generation facilities 12A and 12C are disposed therebetween. One disconnector 18A is for the A bank and is connected to the local bus 16A. The other disconnector 18C is for the C bank and is connected to the local bus 16C.

  Further, a local bus 16B between the pair of disconnectors 18A and 18C is connected to the interconnection bus 17B via the disconnector 18B. Therefore, this disconnector 18B is for the B bank.

  In the present invention, in addition to these configurations, a standby power source 40, that is, a private power generation facility 40 for the standby power source is further installed on the local bus 16B. As will be described later, the private power generation facility 40 is used as a substitute for the private power generation facility under inspection when another private power generation facility is inspected. Therefore, it is stopped at the steady state.

  This inspection work is performed by stopping the private power generation facilities one by one at a rate of about once a year. For example, when checking the steam turbine generator of the private power generation facility 12A, instead of stopping the steam turbine generator, the private power generation facility 40 for standby power is put into an operating state, and the disconnector 18A is manually or automatically operated. Close with. If it does so, electric power can be supplied to A bank by a total of 3 machines including the private power generation equipment 40. FIG. When the inspection is finished, the inspected steam turbine generator is started, the disconnector 18A is controlled to be opened, and the private power generation facility 40 is stopped.

  Further, at the time of inspection of the private power generation facility 12B, the private power generation facility 40 for standby power is operated instead of stopping the private power generation facility 12B, and the disconnector 18B is closed, so that private power generation is performed instead of the private power generation facility 12B. Electric power can be supplied from the facility 40 to the B bank. When the inspection is completed, the disconnector 18B is controlled to the open state.

  The same applies to the disconnector 18C, and when inspecting one generator constituting the private power generation facility 12C, if the private power generation facility 40 for standby power supply is activated and the disconnector 18C is closed, the private power generation facility 40 is The necessary power can be supplied to the A bank with the added power. When the inspection is completed, the disconnector 18C is controlled to the open state.

  In this example, a gas turbine having the same scale as the gas turbine provided in the A bank or the C bank is used as the private power generation facility 40 for the standby power source. Therefore, the waste heat of the boiler B is used as a heat source for other steam turbines.

  In the present invention, a power supply path 42 is further provided between the local bus 16B and the internal low-voltage bus (described later) 28. A circuit breaker 44 is attached to the power supply path 42.

  Next, the commercial power transmission system will be described. The power receiving end of the transmission line 20 is connected to a local high voltage bus (for example, 110 kV) 24 via a power supply / demand instrument transformer (VCT) 22, and the local bus 24 is further connected to a plurality of local transformers ( It is connected to a local low-voltage bus (for example, 6600 V) 28 through a No. 1 transformer to an No. n transformer) 26.

  A plurality of general loads 30 are connected to the local low-voltage bus 28, and the internal low-voltage bus 28 connecting between the transformers 26 and 26 is provided with a breaker (CB) 32 for bus interconnection. In such a case, the electric circuit can be disconnected. As described above, the general load refers to equipment in the factory that is less affected even when lightning occurs.

  A watt hour meter (WH) 36 is connected to a power transmission point from the private power generation facilities 12A to 12C, and the high speed circuit breaker 34 ( 34A to 34C) to the local low-pressure bus 28. As for the electric power from the private power generation facilities 12 </ b> A to 12 </ b> C, a surplus portion of the electric power supplied to the A bank to the C bank is supplied to each general load 30 via the local low-voltage bus 28. Therefore, the general load 30 covers an amount of power that is insufficient with the power from the private power generation facilities 12A to 12C from the power company.

  As the high-speed circuit breaker 34, a vacuum circuit breaker (VCB) or the like is used, so that the interconnection buses 17A to 17C are opened, for example, within 18.6 msec after detecting that the system voltage has dropped. The operation timing of the high-speed circuit breaker 34 is set, and the operation is performed so that the important load is instantaneously disconnected from the commercial power transmission system.

  In the present invention, a standby power supply facility (in-house power generation facility) 40 used for inspection is further provided. The in-house power generation facility 40 is connected to the on-site bus 16B for the B bank, and the on-site bus 16B and the on-site low voltage are connected. A power supply line 42 is connected to the bus 28. The power supply line 42 is connected to a circuit breaker 44 that is adjusted so that its operation sensitivity is slowed to the extent that the private power generation facility 40 for the standby power supply is not damaged by the overcurrent.

  In the present invention, this private power generation facility 40 for standby power supply is also used as a standby power supply for the general load 30 when lightning occurs. A lightning approach detection system (not shown) sets the start timing of the private power generation facility 40 so as to start pre-operation when lightning approaches a specified distance, for example, within 200 km. A predetermined operating power is supplied to the general load 30 via the. Since the plurality of circuit breakers 32 connected to the local low-voltage bus 28 are all set to have lower operation sensitivity than the high-speed circuit breaker 34, the power supply from the private power generation facility 40 for the standby power supply The operation stop of the general load 30 can be prevented. Even if lightning occurs due to this power supply, the voltage shock on the general load 30 side is alleviated.

  In this way, in the present invention, the standby power source private power generation facility 40 used for checking the private power generation facilities 12A to 12C is used as a standby power source for the general load 30 at the time of lightning.

  In the above-described embodiment, the case where the size of the B bank is smaller than the other banks has been described. However, the same size may be used, and the present invention can be applied even when the sizes of the banks are all different. The type and the number of installed generators used as private power generation facilities are not limited to the embodiment.

  For example, in addition to the gas turbine generator and steam turbine generator described above, a gas engine generator, a diesel engine generator, and the like are conceivable, and electric power such as a fuel cell or a storage battery is used as private power generation instead of the generator. You can also.

  The present invention can be applied to a power receiving system of a large-scale factory that is a special high voltage consumer who operates a commercial power transmission system and a premises power transmission system in an interconnected manner.

It is a power receiving system diagram showing an example of a power supply system according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Power supply system 12A-12C ... Private power generation facility 16, 16A ... On-site bus 17A-17C ... Interconnection bus 24 ... On-site high voltage bus 26 ... Power receiving transformer 28- ..Local low-voltage bus 34 ... High-speed circuit breaker 32 ... Bus link breaker 42 ... Power supply line 40 ... Private power generation equipment 18A-18C for standby power supply ... Disconnector

Claims (3)

An interconnecting bus connecting the power transmission system from the commercial power source and the power transmission system provided on the premises;
A first circuit breaker connected to the interconnection bus;
A general load connected to the premises bus on the commercial power transmission system side of the first circuit breaker;
An important load whose voltage management is stricter than the general load connected to the interconnection bus on the premises transmission system side from the first circuit breaker,
In-house power generation equipment provided on the premises,
In-house power generation equipment for standby power,
A power supply path provided between the general load and the private power generation facility for the standby power source, and supplying the power of the standby power source to the general load ;
A second circuit breaker connected to the power supply path and adjusted to slow down the operation sensitivity ;
The operation of the first circuit breaker, power supply system, characterized in that the power from above Symbol standby power is supplied to the common load via the feed line and the second circuit breaker. The critical load is distributed across multiple banks,
The private power generation facility is provided for the bank,
The power supply system according to claim 1, wherein the private power generation facility for the standby power supply is connected to the lightest private load power generation facility. The power supply system according to claim 1, wherein the standby power supply is used when an in-house power generation facility provided in the premises is inspected and when lightning occurs.

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