IGBT module-cascade unidirectional direct current breaker and application method thereof

Abstract

The invention relates to an IGBT module-cascade unidirectional direct current breaker and an application method thereof. The breaker comprises a main through-flow branch, a transfer current branch andan energy absorption branch which are connected in parallel. The main through-flow branch is formed through connecting a rapid mechanical switch K and a full control power electronics unit in series.The energy absorption branch is formed by a lightning arrester group. The transfer current branch is formed by IGBT module units in a cascade connection mode. The application method comprises the following steps that under a stable state, the rapid mechanical switch of the main through-flow branch is locked, and the full control power electronics unit is conducted; when a breaking command is received, the full control power electronics unit of the main through-flow branch is locked, and simultaneously the transfer current branch is triggered to carry out cascade connection on the novel IGBT modules; the rapid mechanical switch is disconnected; and the transfer current branch is locked and cascade connection is performed on the novel IGBT modules, and a current is commuted to a lightning arrester. The direct current breaker can realize unidirectional, rapid and arcless breaking of a direct current, a high overload capability is possessed, a breaking current can reach tens of kA, and offshore wind power grid connection and routine multi-terminal direct current power transmission system application demands can be satisfied.

Description

technical field [0001] The invention relates to a circuit breaker and an application method thereof, in particular to a one-way DC circuit breaker with cascaded IGBT modules and an application method thereof. Background technique [0002] With the demonstration application and planning construction of multi-terminal flexible DC and DC grid technology based on voltage source converter (VSC), the application demand of high-voltage DC circuit breaker, as the key equipment to ensure the stable, safe and reliable operation of the system, is becoming increasingly urgent. Mixed use of mechanical switches and fully-controlled power electronic switch DC circuit breaker technology combines the low loss characteristics of mechanical switches and the fast breaking characteristics of power electronic switches. It is currently the most effective technical approach for DC breaking in high-voltage transmission systems. [0003] The existing hybrid DC circuit breaker has bidirectional curren...

AI Technical Summary

Problems solved by technology

So far, the hybrid DC circuit breakers that have been successfully developed abroad are limited by the breaking capacity of a single fully-controlled device, and all of them have the problem of relatively low breaking current. However, the unidirectional DC circuit breaker formed based on the existing bidirectional topology scheme cannot It is difficult to meet the application requirements of high-voltage and large-capacity DC systems when the current breaking capacity is doubled

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