Method for realizing distribution firewall

Abstract

The invention belongs to the technical field of the electrical distribution equipment, which relates to a method for realizing a distribution firewall. A monostable permanent-magnet vacuum circuit breaker, a relay protection device and a permanent-magnet controller are combined into an integral firewall controller; the monostable permanent-magnet vacuum circuit breaker is matched with the gapless outlet of the relay protection type permanent-magnet controller and is electrically communicated and accessed into a distribution network to stably and quickly break electric equipment faults in the distribution network by the distribution firewall; the monostable permanent-magnet vacuum circuit breaker can realize the purposes of no-bounce switching on and switching off; time for the mechanical action of switching on or off each time is fixed; the monostable permanent-magnet vacuum circuit breaker has stable arc extinction capability; and the breaking time for arc extinction is stably within 42ms. The total design principle of the method for realizing the distribution firewall is safe and reliable, and faults can be removed in time. The method for realizing the distribution firewall has the advantages of few fault losses and high working efficiency and is quick to communicate.

Description

Technical field: [0001] The invention belongs to the technical field of electric power distribution equipment, and relates to a medium-voltage power distribution switch control equipment technology, in particular to a method for realizing a power distribution firewall with the function of protecting power consumption equipment in a power distribution network, or called having a firewall function control technology. Background technique: [0002] The feeder automation of the distribution network system is to monitor the operation mode and load condition of the feeder line. When the fault occurs in the distribution line, the fault section is accurately determined in time, the faulty section is quickly isolated, and the power supply of the healthy section is restored. At present, the most commonly used is to use the recloser to realize the automation of the feeder. The recloser is a switching device with its own control and protection functions. It can automatically perform th...

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Problems solved by technology

[0003] However, although the feeder automation system based on the recloser can accurately judge the fault section when a fault occurs, and can automatically isolate the fault section and restore the power supply in a healthy area, this form of trapped line automation still has some defects. Specifically: when a recloser or a circuit breaker is used to cooperate with a voltage-time sectionalizer, when the line fails, the sectional switch does not break immediately, but relies on the protection of the recloser or the outlet circuit breaker located in the main substation to trip , after the door line loses voltage, each section switch can be disconnected; when a recloser or a circuit breaker is used to cooperate with a sectionalizer for overcurrent pulse counting, it is also necessary to rely on the protection of the recloser or the outlet circuit breaker located in the main substation It is unsatisfactory for each sub-section switch to work in groups after tripping and causing the line to lose voltage. It is mainly manifested in the following aspects: first, it takes a long time to cut off the fault; The relay protection device of the recloser protects the entire feeder, which reduces the reduction; third, because the recloser or the outlet circuit breaker of the main substation must be disconnected, the scope of the accident is actually expanded; if the recloser refuses to open or the main The failure of the protection of the circuit breaker or the refusal of the circuit breaker will further expand the scope of the accident; Fourth, when the recloser and the voltage-time sectionalizer are used to isolate the faulty section of the ring network running in open loop, the contact switch should be used separately. All the switches in the healthy area on one side are connected at one time, causing a short-term interruption of power supply, which further expands the scope of the accident; especially in the distribution network system with high requirements for distribution network, the existing technology has greater limitations , mainly reflected in: the distribution network load center, the load density is high, the distribution network line has many points, the line is short, and the distribution is wide. Short, the impedance difference between the contacts in the interval is small, the short-circuit current has little difference, and it is not easy to set the fixed value; the load of the distribution network has higher and higher requirements on the quality of power supply, and the loss caused by the accident is large; in addition, maintenance needs to be searched on the whole line , the location of the fault point is inconvenient, and all loads on the entire line have to be restarted, the work is extremely heavy, and production is delayed at the same time, causing major losses; the distribution network system is subordinate to the end of the power system grid, and the relay protection time limit is allocated to the distribution network At this time, there is not much room for delay, and the conventional protection based on the time difference of 0.3s cannot be configured

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