SYSTEM AND METHOD FOR CLOSED-TRANSITION TRANSFER OF DC BATTERY BANKS ON A GRID SCALE BATTERY ENERGY STORAGE SYSTEM

摘要

An energy storage system comprising a main bus, a transfer bus, and a pair of anti-parallel thyristors electrically coupled to the main bus and the transfer bus. The system also includes a first and second group of battery cells electrically coupled to the main bus and the transfer bus, and a switching network including a plurality of switches that selectively connect the first and second groups of battery cells to the main bus and the transfer bus. A controller controls the position of the switches and a bias voltage applied to the first and second thyristors so as to seamlessly transition power from the first group of battery cells to the second group of battery cells when the group of battery cells are being discharged and seamlessly transition power between the first group of battery cells and the second group of battery cells when the battery cells are being charged.