Direct-current circuit breaker based on auxiliary oscillation commutation device and control method of direct-current circuit breaker

Abstract

The invention relates to the technical field of flexible direct-current power transmission and distribution, and particularly provides a direct-current circuit breaker based on an auxiliary oscillation converter device and a control method thereof, and the direct-current circuit breaker comprises a main branch, a transfer branch and an energy absorption branch which are sequentially connected in parallel; the main branch is composed of a mechanical switch CB; the transfer branch is composed of a resonant inductor L, a resonant capacitor C and an auxiliary oscillation converter device AOD; the energy absorption branch is composed of a lightning arrester MOV. The technical scheme provided by the invention has the characteristics of short total current on-off time, large on-off current and the like, solves the problems of long total current on-off time of an existing mechanical direct-current circuit breaker and high cost of a hybrid direct-current circuit breaker, and can be applied to harsh working conditions such as full-range short-circuit current quick on-off required by a middle-high voltage flexible direct-current power grid.

Description

technical field [0001] The invention relates to the technical field of flexible DC power transmission and distribution, in particular to a DC circuit breaker based on an auxiliary oscillation converter device and a control method thereof. Background technique [0002] Compared with the AC grid, the DC grid based on the flexible DC system shows obvious advantages in large-capacity power transmission, distributed energy access, reactive power support of the AC system, etc., and is an important development direction of the future grid. In the DC power grid, it is necessary to apply a DC circuit breaker that breaks a large current within a few milliseconds to quickly remove the faulty equipment or line, so as to ensure the stable operation of the non-faulty part of the DC system and improve system reliability. Therefore, DC circuit breakers are key equipment for developing DC power grids. [0003] According to different breaking principles, DC circuit breakers can be divided in...

AI Technical Summary

Problems solved by technology

Among them, the passive DC circuit breaker has a simple structure and is easy to control, but it relies heavily on the instability and negative resistance characteristics of the arc. The value is limited, and the full current breaking time may be as high as tens or even hundreds of milliseconds, so that the breaking capacity of the DC circuit breaker of this solution type is limited. In addition, the practice of fault clearing is too long, so it cannot be applied to open the short circuit fault clearing of the high voltage flexible DC grid. Working conditions with large cut-off current value and short full current clearing time

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