基于广义H桥电路的混合式直流断路器

A hybrid DC circuit breaker based on a generalized H-bridge circuit

基于多端直流电网快速发展的现状,针对直流故障清除问题,提出了一种基于广义H桥电路的高压混合式直流断路器。利用H桥结构电流双向流动的特点,将转移开关和主断部分以二极管H桥的形式实现复用,并且取消了常见的反并联二极管,在保证直流故障处理能力不变的前提下,所需IGBT(绝缘栅双极型晶体管)数量大幅减少。为了验证基于广义H桥电路的混合式直流断路器及其故障隔离方法的有效性,在PSCAD/EMTDC平台搭建了四端直流电网测试系统,仿真验证了其可行性。同时将本方案和其他方案进行了拓扑、器件成本方面的对比,结果表明本方案具有良好的经济性。

Given the rapid development of multi-terminal DC power grids and the treatment of DC faults, a high-voltage hybrid DC circuit breaker based on a generalized H-bridge circuit is proposed. Given the bidirectional cur⁃ rent flow of the H-bridge circuit structure, the transfer switch and main disconnecting part are multiplexed in the form of a diode H-bridge, and the common anti-parallel diode is eliminated, so that the required insulated gate bipo⁃ lar transistors (IGBTs) are reduced dramatically with DC fault clearing capability unchanged. To verify the effective⁃ ness of the hybrid DC circuit breaker based on a generalized H-bridge circuit and its fault isolation method, a four-terminal DC grid test system is built on the PSCAD/EMTDC, and its feasibility is verified by simulation. Moreover, the scheme is compared with other schemes in terms of topology and device cost. The results show that the scheme is very economical.