All-solid-state DC breaker and control method thereof

Abstract

The invention discloses an all-solid-state DC breaker and a control method thereof. The all-solid-state DC breaker, including a long-term flow passage branch, a current cut-off branch and an energy absorption branch that are connected in series, is characterized in that the long-term flow passage branch includes at least one half-control device and at least one full-control device that are in series connection, and a full-bridge circuit is adopted to achieve bidirectional flow passages; the current cut-off branch is formed by a circuit break unit including a full-control device, an RCD absorption circuit and a lightning arrester that are connected in series, and a full-bridge circuit is adopted to achieve bidirectional flow passages; and the energy absorption branch includes at least one lightning arrester. The all-solid-state DC breaker is simple and novel in topological structure and low in on-state loss, the number of full-control devices is reduced, and the control complexity and costs are reduced. Faulty currents can be removed quickly. The faulty currents are prevented from increasing through separate control of cut-off units, so the breaker effectively copes with short circuit and overload faults in a DC system while having a current limiting function. The DC system can be protected and runs safely.

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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