Topology, control and fault analysis of a new type HVDC breaker for HVDC systems

Abstract

In order to reduce the cost of the expensive hybrid HVDC breaker, a H-bridge type HVDC breaker is proposed in this paper, and different fault isolation strategies are studied in the combination of positive and negative poles. The key components and fault isolation principle of the hybrid HVDC breaker are used in the H-bridge type HVDC breaker. According to the characteristic of current flow direction of the H-bridge structure, the key components of hybrid HVDC breaker are integrated, and the number of IGBT in the HVDC breaker is greatly reduced by re-layout. The fault clearing capability of the H-bridge type HVDC breaker is equal to the hybrid breaker, but its investment cost is reduced dramatically. A model of a three-terminal monopolar HVDC grid is developed in PSCAD/EMTDC to verify the validity of the proposed breaker and its fault isolation strategies. Simulation results prove validity and feasibility of the proposed solution.