Grounding faults of cascade battery energy storage system

Abstract

Grounding faults are inevitable when cascade battery energy storage system (CBESS) is in operation, so the detection and protection are very important in the practical application. The possible grounding fault types of the 10kV CBESS and the detection protection method were analyzed. It could be known that single point grounding fault in CBESS could be detected by monitoring CBESS neutral voltage, and there is no overcurrent in circuit. When two points grounding fault or multi-point grounding fault occurred, the faults could be detected by overcurrent protection or short circuit protection of power unit, and the cascaded battery energy storage system should stop operation.