Novel fast operating moving coil actuator with compensation coil for HVDC circuit breakers

DC circuit breakers are major enabling components for multi-terminal HVDC systems. Their key design targets are operating speed and efficiency. This paper proposes a novel moving coil actuator using a compensation coil topology to operate mechanical circuit breakers. This topology aims to significantly improve the magnetic field saturation and reduce the system inductance, so that the operating speed is increased. Four possible connection methods for the compensation coils are proposed and analyzed using finite element modeling, ensuing simulation results are compared and discussed. The operating speed of the moving coil actuator with compensation coils is significantly improved compared with the original moving coil actuator. The moving coil actuator with compensation coils can open a distance of 5 mm within 2.8 ms and the peak efficiency is 47%.