Direct current circuit breaker with opening current reducing effect and direct current fault treatment strategy thereof

Abstract

The invention discloses a direct current circuit breaker with opening current reducing effect and a direct current fault treatment strategy thereof. The direct current circuit breaker comprises a normal current flowing branch circuit, a current opening branch circuit, an energy consumption branch circuit, a super-conduction current limiter, a reactor and an isolation switch, wherein the normal current flowing branch circuit is formed by connecting a super-quick mechanical switch and a load transfer switch in series; the current opening branch circuit consists of a main circuit breaker; the energy consumption branch circuit consists of a lightning arrester; the load transfer switch is formed by connecting a plurality of submodules with bidirectional current flowing ability in series and parallel; the main circuit breaker is formed by connecting a plurality of enhanced semi-bridge submodules in series and parallel. The direct current circuit breaker has the advantages that the ascendingspeed and amplitude of the fault current are inhibited by the super-conduction current limiter, and then the opening current of the circuit breaker is reduced; the number of the submodules of the maincircuit breaker is greatly reduced, the engineering cost and operation loss are greatly reduced, and the strong reference meaning and use value in the engineering are realized.

Description

technical field [0001] The invention belongs to the technical field of power electronic systems, and in particular relates to a DC circuit breaker capable of reducing breaking current and a DC fault processing strategy thereof. Background technique [0002] There are two basic network construction methods for DC power grids: the first network construction method uses a modular multilevel converter (MMC) plus DC circuit breaker scheme based on half-bridge sub-modules. This network construction method is suitable for any number of terminals. The second network construction method uses MMC with DC fault self-clearing capability, such as the MMC based on the full bridge sub-module, but does not require DC circuit breakers. This network construction method is suitable for small-scale networks with less than 10 terminals DC grid. When the half-bridge sub-module MMC plus DC circuit breaker is used to construct the network, the converter station is usually required to continue to o...

AI Technical Summary

Problems solved by technology

Therefore, DC circuit breakers are still the fundamental technical bottleneck in the development of DC grids

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