JPS6135121A - Method of solely operating in station at external power source failure time - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to the in-house independent operation of a steam power generation plant, and particularly to a substation of a plant consisting of a plurality of steam power generation units equipped with main steam temperature drop protection devices. Regarding the in-house independent operation method used.

[Background of the invention]

We will discuss the in-house isolated operation system in the plant configuration shown in the figure. The power generated by the generator 20 is supplied to the unit auxiliary equipment via the unit breaker 22 via the unit bus bar 23, and also to the breaker 1.
1 to the grid 32, the circuit breaker 12, the substation B
Bus line 17. And, via circuit breakers 7, 8.9, substation B
Power is also supplied to other systems 33 through the bus 16. Furthermore, power is also received through circuit breakers 13 and 16 to a station bus 19 that supplies power to the common auxiliary equipment of each unit.

In such a power generation plant, if an accident occurs in the system 32, the circuit breakers 10, 11 and 12 are opened, and fuel and water supplies are rapidly reduced using only the unit auxiliary power source of the power generation unit 20. Perform independent operation of the unit within the facility. However, in developing countries where the reliability of the system is low, an accident in one system instantly spreads to the entire system, often resulting in the loss of all external power supplies connected to the plant.

In this case, all circuit breakers 1 and 2 connected to the external system
, 4, 5, 10, 11, 13, and 14 are opened, and for example, if the generator 20 is automatically selected as the unit that supplies power to the common auxiliary equipment, the generator breaker 12 remains closed. , open another generator breaker 5. By operating the circuit breaker at this substation, power is supplied from the generator 20 to the station mother 11A19 as soon as possible.
The air conditioning equipment, compressor equipment, and cooling water equipment necessary for continued operation of the unit were operated independently within the plant.

However, the selection circuit of the unit that should be selected in this operation method has the load before isolated operation in the station, or

Since the main steam temperature is not taken into account, if a unit operated at low load is selected, the station's isolated load time will be too short due to the main steam temperature 4 white limit, and all units will stop before joining the grid. However, there is a possibility that the entire station will be shut down.

[Purpose of the invention]

An object of the present invention is to provide a method for independent operation in a station when an external power supply is lost, which allows for safer independent operation in a station for a longer period of time.

[Summary of the invention]

Therefore, when selecting one of the units to be transferred to the station alone, the unit operating at a higher load is selected preferentially, and at the same time, the common power source for the station is secured through the B bus of the substation.

[Embodiments of the invention]

In the present invention, during isolated operation within a station when external power is lost, a generator that supplies power to common equipment is selected as follows.

The figure shows the power system diagram around the substation of the power station.

Breaker 1 connected to all external systems due to an accident on the grid side
, 2, 4, 5, 10, 11, and 13.14 are opened, and the load before the occurrence of the grid fault is monitored by the selection circuit 35 using the generator output converter 34.35, and the load that was being operated the most is If a power generation unit such as the generator 20 is selected, the generator breaker 12 remains closed and the other generator breaker 15 is opened. The load before this system accident,
Alternatively, by making the main steam temperature the top priority condition in the selection circuit of the power generation units that carry a common load, it is possible to ensure safe isolated operation within the station for a longer period of time.

In addition, in the figure, 3 and 6 are circuit breakers, 18 is substation C bus, and 2
1.25 is a unit transformer, 24.degree. 27 is a unit busbar, 26 is a unit breaker, 28.29 is a station connection breaker, and 30.degree. 31 is a power supply system.

〔Effect of the invention〕

According to the present invention, even if all external power is lost due to a system failure, it is possible to supply power from the selected unit to the common equipment for a long period of time, and the station can operate independently for a longer period of time. .

[Brief explanation of the drawing]

The figure is a power supply system diagram around a substation of a power plant according to the present invention. 10.13... Grid breaker, 11, 12, 14゜1
5... Generator breaker, 20.24... Generator, 2
1.25... Unit transformer, 22.26... Unit breaker, 23.27... Unit bus bar, 28
．． 29...Station communication breaker.

Claims (1)

[Claims] 1. In a steam power plant equipped with a main steam temperature low protection device that has an in-plant isolated operation function, when external power is lost, a substation is used to supply the common load power of each unit to one power generation unit. A method for independent operation in a station when external power is lost, which is characterized by adding selection conditions of a power generation unit to the operating load.