Fault Detection and Identification in MVDC Radial and Ring Distribution System by Wavelet Decomposition /

Abstract

The use of renewable energy systems (RES), as distributed generation (DG) units, in distribution systems is growing in recent years. The challenge is faced by conventional AC distribution system is integration of RES based DG’s in distribution system. DC distribution system is provide more feasible solution for the integration of renewable energy-based DGs as compared in the Distribution system. Protection issue in DC distribution is the main issue because of low line impedance that causes high fault current in short circuit faults. During fault situation, DC-Link capacitor discharging and low line impedance, result in high fault currents that can damage the distribution components. And disruption of faults using conventional breaker in DC distribution is not possible because lack of natural zero crossing of DC current. Wavelet decomposition based protection scheme is proposed which identify the fault section in the distribution system and also identify which type of fault is occurred. Voltage and current signals, both are analyzed through wavelet. Sequence voltages are used for the input signal to wavelet decomposition for fault type identification. A communication channel is used between lines relays for the identification of faulty sections in distribution. A bipolar ring and radial type DC distribution systems are modeled on MATLAB/Simulink and different fault events are simulated.