Boundary searching method of last circuit breaker

Abstract

The invention discloses a boundary searching method of a last circuit breaker. From the point of view of a mathematical set, the operating condition of a current converter serves as a big set, the big set is decomposed into six small sets, the expression of each small set is firstly written out, and then the expressions of the small sets are combined to obtain the expression of the operating condition. The operating condition and a non-operating condition are clearly and simply divided according to whether the expression of the operating condition is met. If a certain condition meets the expression of the operating condition, but the expression of the operating condition is not met any longer after an originally closed circuit breaker is separated, the current condition is judged to be a critical condition, and the current circuit breaker is the last circuit breaker. The above process can be automatically completed by a set of program, and manual intervention is not needed, so that the efficiency and reliability for searching the last circuit breaker are improved.

Description

technical field [0001] The invention relates to the technical field of power systems, in particular to a boundary search method for a final circuit breaker. Background technique [0002] The AC field of the existing DC project is generally a double-female three-half connection with multiple AC strings, and the converter, AC line, AC filter, busbar and other equipment. When the number of connected devices increases, the number of AC strings will also increase, and the resulting switching conditions will increase exponentially. If there are N breaker intervals, there will be 2 N A switching condition. [0003] In a certain switching condition, if one of the circuit breakers is separated, which will cause the converter to lose all current paths and stop running, then this circuit breaker is the last circuit breaker, and this working condition is the critical point between DC operation and shutdown. Switching condition. [0004] In order to avoid DC blocking caused by wrongl...

AI Technical Summary

Problems solved by technology

[0006] This method requires a lot of human subjective judgment, the efficiency is extremely low, and the judgment result is very unreliable; it is necessary to program each critical working condition, and write dozens or even hundreds of programs, resulting in a large, cumbersome and error-prone program; it cannot automatically search out All last breakers, unable to form interlocking table, no availability

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