Reliability Evaluation of Large Scale Battery Energy Storage Systems

Abstract— The reliability of large scale bat-tery storage systems consisting of multiple battery modules. The whole system reliability assessment is based on the reliability evaluation of system components including individual battery modules and power electronic converters. In order to evaluate the reliability of a battery module, a reliability model based on the state of health of individual battery cells is introduced. The state of health of a battery cell is calculated based on the capac-ity fade of the cell using a weighted Ampere-hour throughput method. A universal generating function-based method is then introduced to evaluate the reliability of the battery module. The reliability model of dc/ac power electronic converters is also pre-sented in this paper. The reliability analysis is conducted for battery storage systems with different system configurations and management strategies, and the influence of system configura-tion on the reliability of battery system is studied. Comparative studies are conducted for a classic battery energy storage sys-tem (BESS) and a reconfigurable BESS (RBESS) to demonstrate the advantages of having a reconfigurable system topology. The comparison results show that the proposed RBESS has higher system reliability and more power outputs than the classic BESS. < final year projects >