Coordination protection of low-voltage AC distribution network in vessel DC Zonal Electrical Distribution System

For traditional radial AC distribution network supplied by generators, its protection is carried out by setting the circuit breakers according to the time-current coordination principle. However, as the power supply of the low-voltage AC distribution network in vessel DC Zonal Electrical Distribution System (DC-ZEDS), the DC/AC power conversion module (PCM) is required to provide enough fault current to trip the circuit breakers. This paper makes a deep analysis of the coordination protection for the DC/AC PCM and downstream circuit breakers in the DC-ZEDS. The solutions to the problem are explored through the structure design, control algorithm of DC/AC PCM, and configuration of circuit breakers. A model for simulation is established in the PSCAD/EMTDC. The simulation results show that the method of protection is practicable and effective enough to achieve the objects of selective protection.