Multi-stage current-limiting protection method and configuration system for main line of power distribution network

Abstract

According to the multi-stage current-limiting protection method and configuration system for the main line of the power distribution network, a bus current limiter is arranged between a bus circuit breaker of a main transformer and a bus correspondingly connected with the bus circuit breaker, the main line is divided into N sections of main lines, and a main line current limiter and a main line circuit breaker are sequentially arranged on each main line. The circuit breakers and the quick circuit breakers are in a closed state, and when a short-circuit fault occurs in a line, the current limiter and the circuit breakers adopt sectional protection according to fault parts: the controller triggers the circuit breakers and the quick circuit breakers of the current limiter, and sends the short-circuit fault and address information to a superior controller; and the functions of fault line current-limiting protection and feed automation are realized. According to the method, the protection judgment logic is simple, and fault current-limiting isolation and power supply recovery can be performed more quickly.

Description

technical field [0001] The invention belongs to the technical field of power grid protection, and in particular relates to a multi-level current limiting protection method and a configuration system for a main line of a distribution network. Background technique [0002] With the rapid development of the national economy, the society's demand for electricity continues to increase, which drives the continuous development of the power system. The capacity of single machines and power plants, the capacity of substations, and the load of cities and industrial centers continue to increase, which makes the interconnection of power systems , the level of short-circuit current in the power grid at all levels is increasing continuously, and the destructiveness of short-circuit faults to the power system and its connected electrical equipment is also increasing. Moreover, while the demand for electric energy is increasing day by day, people also put forward higher requirements for pow...

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Problems solved by technology

[0004] At present, due to the short power supply radius of the urban distribution network, the short-circuit current along the line has little difference, it is difficult to use the traditional differential protection to achieve satisfactory selectivity, resulting in an increase in the delay time of substation outlet protection

The disadvantages of this protection method appear with the increase of the short-circuit current level of the urban distribution network, that is, before the circuit breaker can effectively block the fault, the large short-circuit current is likely to cause a sag in the bus voltage and affect the load of the non-faulted line; at the same time, the short-circuit current It will impact the equipment in the station and affect the safety of the equipment

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