Full-selective protection strategy for MTDC grids […] DC circuit breakers
A novel protection strategy for multi-terminal high voltage direct current (HVDC) grids based on the implementation of breaking modules (BM) with both limiting and breaking capabilities will be presented. It incorporates a resistive-type superconducting fault current limiter (SFCL) in series with a mechanical DC circuit breaker (DCCB). The proposed arrangement of BMs allows an intrinsic selective fault identification criteria based on the quenching of the SFCL. The fault current limitation reduces the breaking capability, speed and energy requirements for the DCCB. Furthermore, a continuous grid operation can be assured by adding DC inductors and capacitors, assuring a constant power flow during and after the fault event. In this paper, a primary protection scheme is conceptually described and off-line simulation studies performed in EMTP-RV® are discussed.
