A Low-Cost Multi-Port Type HVDC Breaker for HVDC Grids

Abstract

Hybrid HVDC breaker (H-DCB) is recognized as an effective way to deal with the DC fault in HVDC grids, but it still has some problems such as expensive cost, large usage, et al. In order to solve these problems, a low-cost multi-port type HVDC breaker (LM-DCB) is proposed in this paper and the control strategy for fault isolation is described. Based on the design philosophy of H-DCB, H-DCBs connected to the same DC bus are integrated into the LM-DCB, to redesign the HVDC breaker by the overall concept and to optimize the equipment utilization value. The proposed breaker can handle DC fault with competitively low cost, and its operating speed is as fast as the H-DCB. A three-terminal HVDC system model is developed in PSCAD/EMTDC to verify the validity of the proposed breaker. Simulation results prove the validity and feasibility of the proposed solution.