Design and Application of Superconducting Fault Current Limiter in a Multiterminal HVDC System

Voltage source converter based HVdc (VSC-HVdc) systems are prone to high short-circuit current during transmission line faults. The situation for multiterminal HVdc (MTDC) systems is worse. The characteristics of superconducting material are ideal to limit the fault current in HVdc systems. This paper presents a novel use of the resistive type of superconducting fault current limiter (SFCL) in the MTdc network with the function of limiting the high current. The working principles of fault current limiter and a three-terminal HVdc system are modeled in detail using PSCAD/EMTDC software. The hybrid operation of the SFCL in the three-terminal HVdc system is tested in this paper for the fault response of the MTdc system. The performances of SFCL under different fault conditions are analyzed. The simulation results show that the fault current is effectively restrained and the SFCL can act as an efficient protective device for VSC-based multiterminal HVdc systems.