Considerations on a High-Cell-Count Converter-Based Battery Storage System with Reduced Communication Effort

Abstract:
This paper presents a concept study on a very high-cell-count modular multilevel converter battery storage system. With its high number of cells, the system inherits known advantages like improved voltage/current ripple, low filtering effort, reduced semiconductor voltages, redundancy etc. In case of very high cell counts like n ≥ 100, which would be applicable for medium voltage applications, a drawback of such a topology however, is the high effort for the communication from the central controller to the n individual isolated switching cells. Addressing this challenge, a control/communication approach is presented which to be finally implemented in a truly wireless manner. Furthermore, the applicability of this method for second life batteries, as well as the effect on the control loop are discussed.