Analysis and simulation of the proactive hybrid circuit breaker

High Voltage Direct Current (HVDC) short circuit protection is a fundamental requirement for any HVDC transmission system. Presently, all point-to-point links are protected using circuit breakers on the AC side of the converters. In order to enable HVDC grids, a more advanced protection system must be developed. HVDC circuit breakers are one solution for the protection of future HVDC grids. Several designs have been proposed for DC circuit breakers but few are suitable for Voltage Source Converter (VSC) applications. To date, only a few industrial prototypes have been developed, which are seen to be suitable for the VSC HVDC applications. This paper presents analysis and simulations on one of these prototypes, the Proactive Hybrid Circuit Breaker (PHCB). Equations are derived from a state-space analysis of the circuit breaker. A model of the circuit breaker is suitably parameterized for a +/- 300 kV VSC system in PSCAD. Fault simulations are then performed and compared to the equations developed in a state space analysis. Discussion is then given to the design and testing of the Load Commutation Switch (LCS).