Modeling and Simulation of an Ultra-Fast Resonant DC Circuit Breaker Based on Current Source Module

A novel hybrid circuit breaker is proposed that utilizes a fast-ramping resonant current source and an ultra-fast vacuum interrupter (VI) for medium voltage dc (MVDC) applications. The design offers a compromise between mechanical and purely solid-state dc circuit breakers with high efficiency and fast fault interruption speed. The breaker consists of 3 parallel branches: the resonant current source (RCS) module, vacuum interrupter, and energy absorption branch. In normal operation, the vacuum interrupter is closed and conducts load current, resulting in high efficiency. During fault operation, the resonant current source ramps up to oppose the fault current in the vacuum interrupter to force a zero current crossing. In post-fault operation, the metal oxide varistor in the energy absorption branch clamps overvoltages and dissipates residual line current and energy. Gallium Nitride switching devices are used to configure the RCS modules to achieve higher frequencies and lower switching losses than the conventional silicon counterparts. Modeling and simulation results from PLECS software are presented to prove the functionality of this design in a 2.4 kV MVDC propulsion system for electric aircraft.