Lithium batteries must be connected in series to achieve large capacity and high-power output. Battery management system (BMS), which is designed to protect battery pack from damage and increase battery life, is important in electrical power system. The present equalisation techniques have many disadvantages: The passive balancing wastes energy and generates heat, while active balancing is complex. This study proposes an intelligent BMS with dynamic equalisation (DBMS) which contains active and passive balancing circuit independently per cell. Experimental results indicate that DBMS can reduce the inconsistency among cells. Moreover, the DBMS can assist battery stack to store and release more energy. Besides, the battery stack with DBMS gives an energy efficiency of 96.5% which is 7.7% higher than that without balancing. In addition, the battery stack with DBMS can reduce the maximum state of charge difference of cells from 10.415% to 4.51% after three charge-discharge cycles. What is more, the DBMS is simple and can decrease the auxiliary power level and the system heat. Such a DBMS will help us to provide a high-performance battery pack.
ASJC Scopus subject areas
- Control and Systems Engineering
- Electrical and Electronic Engineering