A Study on Fault Current Stress Analysis for HVDC Circuit Breakers in Multi-terminal HVDC Grid

Abstract

Multi-terminal High Voltage DC (HVDC) grids (MTDC) is a promising solution for coping up with increasing demand of electric power by integrating distant renewable energy resources with existing AC networks. Protection of such networks through HVDC circuit breakers (DCCB) is the most important factor in ensuring their reliability and continuity of service. This paper presents a study on the relationship of increasing number of converter stations in MTDC networks and their effect on the fault current interruption requirement of DCCBs. Fault analysis for various MTDC networks were performed through simulations and fault current stress for DCCB was analyzed. Moreover, the paper also illustrates the importance of DCCB response time and its bidirectional blocking capability requirement when installed in a HVDC line.