An all-solid-state DC circuit breaker and its control method

Abstract

The invention discloses an all-solid-state DC circuit breaker and its control method. It is composed of a long-term flow branch, a current breaking branch, and an energy absorption branch connected in parallel. It is characterized in that the long-term flow branch is routed by at least one half-control device It is formed in series with at least one full-control device, and adopts a full-bridge circuit to realize bidirectional current flow; the current breaking branch is composed of a full-control device, RCD absorption circuit, and a circuit breaker composed of a surge arrester in series, and uses a full-bridge circuit to realize bidirectional current flow; energy The absorption circuit consists of at least one arrester. The invention has simple and novel topological structure, low on-state loss, reduces the number of full-control devices, and simplifies the complexity and cost of control. The present invention has a fast fault current clearing speed, and at the same time can use the separate control of the current breaking unit to limit the rising rate of the fault current, so that the circuit breaker has a current limiting function at the same time, and can effectively deal with short circuit and overload faults in the DC system. Protect the safe operation of the DC system.

Description

technical field [0001] The invention belongs to the technical field of power electronics, and in particular relates to a topology of an all-solid-state DC circuit breaker and a control method thereof. Background technique [0002] With the development of DC transmission and distribution technology, traditional DC transmission and light DC transmission technology have become an important direction for the future development of power grids. In the multi-terminal DC transmission system, as a fault protection device, the DC circuit breaker has become one of the important devices for the safe operation of the system. When the DC circuit breaker cuts off the fault current, there is no current zero crossing point. Therefore, the development of DC circuit breakers is facing more difficulties. [0003] In order to solve the arc problem in the process of breaking the current, the DC circuit breaker composed of mechanical switches needs to add an auxiliary oscillating circuit to crea...

AI Technical Summary

Problems solved by technology

Ordinary all-solid-state DC circuit breakers require multiple fully-controlled power devices to be directly connected in series, resulting in relatively high loss and cost, and higher requirements for control consistency of fully-controlled devices.

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