A busbar protection method and device based on redundant differential current judgment

Abstract

The invention discloses a bus protection method based on redundant differential current judgment. The current data of the current transformers on all the branches on the bus and current data of two bus-connected current transformers on the two sides of a bus-connected circuit breaker are collected to be substituted into the bus large difference ratio criterion, the I bus differential ratio criterion, the II bus differential ratio criterion and the redundant differential current criterion. If it is judged that the fault occurs outside the bus area or inside the bus area, the redundant differential current criterion is not open, and the bus large difference, the I bus small difference and the II bus small difference in the bus large difference ratio criterion, the I bus differential ratio criterion and the II bus differential ratio criterion directly select to trip. If it is judged that the fault occurs between the two bus-connected current transformers, the redundant differential current criterion is opened and the bus where the fault is located is selected and cut off. The purpose of avoiding the situation of cutting the two buses because of inconsistent fault bus selection of twosets of bus protection in case of the fault occurring between the two bus-connected current transformers can be realized.

Description

technical field [0001] The invention relates to the field of power system protection, in particular to a bus protection method and device based on redundant differential current judgment. Background technique [0002] As the connection hub of each electrical unit, the busbar of the power system plays a pivotal role in the safe and stable operation of the power system. Whether the busbar protection can correctly remove the fault points in the busbar area has become particularly important. Busbar protection usually adopts double-set protection configuration. The two bus-tie current transformers used in the two sets of bus-tie protection are usually located on both sides of the bus-tie circuit breaker. When a fault occurs between the two bus-tie circuit breakers, the two sets of bus-tie protection One of them will be judged to be in the small differential area of ​​bus I, while the other set will be judged to be in the small differential area of ​​bus II. Finally, all the two b...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide a busbar protection method based on redundant differential current judgment, aiming to solve the problem of two sets of busbar protection selection when the power system busbar in the prior art fails between two busbar current transformers. The faulty busbars are inconsistent and the two busbars are completely cut off, resulting in a technical problem with serious consequences of power failure in the whole station

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