Research and Implementation on the Active Equalization for the Battery in the DC System

The battery system in the DC system is an important link to ensure the safe and stable operation of power plants and substations. The LiFePO4 battery will replacement of lead-acid batteries in the DC system is a trend in the future, because of its high energy density, wide operating temperature, long cycle life. The battery system in the DC system is consisted of a large number of cells, and the capacity is high, due to individual differences, will cause the battery imbalanced, resulting in a reduction in the usable capacity of the battery pack. This may cause battery pack life to decrease or damage the battery. In this article, a switching matrix type active equalization topology and its equalization strategy are designed, which is easy to be modular, simple and efficient. The experimental results verify the feasibility of the design.