Ground Fault Location of Cable Using Wavelet in DC Microgrid

Abstract

As the proliferations of distributed generation and power electronic equipment in power systems, more and more researchers put focus on the DC microgrid. This study is based on cables in DC community microgrid. Single ground fault is considered in the cables connected hub garage and participating garages. With long length compared to other cables in the system, it is necessary to study the method to locate the ground fault when the fault happen in the buried cables. Two approaches are studied. The traveling wave method is applied for analysis of transient process when the fault happens while the stable parameter analysis method used for the stable process after the fault already happened. The cable model is defined using precise distributed element concept and packaged as a PLECS model. The simulation is based on the DC microgrid model in the Simulink environment with PLECS blocks. The wavelet packet decomposition is applied in the processing of signal processing procedure. The wavelet packet helps to extract the key signal and eliminate the interference in both methods respectively. The results are analyzed to show the effectiveness of location methods and wavelet packet.