Wide area measurement system based back-up protection method of multi-terminal high-voltage power transmission area

Abstract

The invention discloses a wide area measurement system based back-up protection method of a multi-terminal high-voltage power transmission area, belonging to the technical field of relay protection of electric power systems. In the method, the wide area measurement system based back-up protection of the multi-terminal high-voltage power transmission area and the synchronous real-time measurement on the voltage and current phasors of nodes provided with phasor measuring units are realized through adding centralized decision-making servers by utilizing the wide area measurement system of the multi-terminal high-voltage power transmission area, and a master station and a wide area back-up protecting server carrying out computation and analysis to accurately fix specific fault phases and fault line and issue control commands to execution substations of all lines in the area. The invention can make a decision within at most 200 milliseconds and sends the decision to every execution substation through adding the centralized decision making server and a remote control execution system, thereby realizing the wide area information based back-up protection of the multi-terminal high-voltagepower transmission areas and avoiding the fault of power failure in a large area due to protection misoperation after the fault occurs.

Description

Technical field [0001] The invention belongs to the technical field of power system relay protection, and specifically relates to a backup protection method for a multi-terminal high-voltage power transmission area based on a wide area measurement system. Background technique [0002] After the power grid fails, the line protection in the power system is used to automatically and quickly remove the faulty line and isolate the fault to ensure the safety of people and equipment and the normal operation of the fault-free part. According to the local information of the line, the main protection of the line will immediately open the local circuit breaker when the fault occurs, cut off the local line, and isolate the fault. The line backup protection is used to trip the local or other circuit breakers to isolate the line fault when the main line protection fails or the line circuit breaker fails. However, with the increasing complexity of the grid structure and the increasingly flexib...

AI Technical Summary

Problems solved by technology

However, as the power grid structure becomes more complex and the operation mode becomes more flexible, the traditional backup protection based on local information for decision-making and judgment has many defects: ①The backup protection coordination relationship is complicated, and the operation time is long, which may not meet the system stability in serious cases ②The configuration and setting of backup protection is very difficult, and it cannot track the change of system operation mode, and there may even be protection mismatch or insufficient sensitivity; ③When When the operation mode changes, in order to ensure the selectivity of the remote backup protection, the calculation workload of the fixed value is huge, and it may not even cooperate in the ultra-high voltage power grid; each component is often equipped with multiple backup protections, which makes the protection structure complicated and the cost increases

On July 1, 2006, the 500kV Songshan-Zhengzhou two-circuit transmission line was successively cut off due to faulty protection malfunctions, which directly caused multiple 220kV lines in western Henan and central Henan to be cut off by backup protection due to overload, resulting in a major blackout in western Henan

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