Rapid line backup protection method with reliable selection based on wide area measuring system

Abstract

The invention discloses a line backup protection method. The method realizes simultaneous real-time measurement of voltages and current phasors on head ends and tail ends of all lines arranged with PMU in a network-wide area by the existing wide area measurement system; and accurately judges the specific line in which a fault occurs by a distinguishing method of the phase separated element current differential protection in a main station of the wide area measurement system on the basis of the data, then a faulty line tripping signal is instantaneously sent to a line tripping execution unit of a transformer substation by a control server added in a WAMS main station. The time coordination of the main protection and the backup protection is realized by the inherent delay of a communication system and a main station judgment and decision system, thus realizing quick action of the backup protection and the reliable selectivity under the condition that the main protection of the line fails. Under the condition of switch malfunction, all adjacent lines are selected to be cut off by topological analysis.

Description

technical field [0001] The invention belongs to the technical field of electric power system relay protection, in particular to a fast line backup protection with reliable selectivity based on a wide-area measurement system. Background technique [0002] The line protection in the power system is used to automatically and quickly cut off the faulty line and isolate the fault after the power grid fails, so as to ensure the safety of people and equipment and the normal operation of the non-faulty part. According to the local information of the line, the main protection of the line immediately trips the local circuit breaker in case of a fault, cuts off the local line, and isolates the fault. The backup protection of the line is used to trip the circuit breaker of the local or other lines to isolate the line fault when the main line protection fails or the circuit breaker fails. However, the existing line backup protection has the following problems: [0003] (1) Although the...

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Problems solved by technology

That is, reliable selectivity and rapid action cannot be achieved at the same time. As the scale and complexity of the power grid become larger and larger, this problem becomes more and more prominent, and it has not been well solved so far.

[0004] (2) In the high-voltage ring network system, there are difficulties in coordination in the ladder setting of line backup protection based on local information only

[0005] The above difficulties of conventional line backup protection are caused by making line backup protection decisions based on only local information

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