1.State Grid Jiangxi Power Company;2.College of Electrical Engineering，Zhejiang University
National Natural Science Foundation of China under Grant 61963030, Science Foundation of State Grid under Grant 5218A020003A
The lithium-ion battery equalization system in Low-earth orbit (LEO) satellite power supply is an important part to guarantee the consistency of battery cells, make full use of battery pack capacity, and improve battery reliability and cycle life. Passive equalization technology is dominant in DC bus satellite power supply systems due to its simple structure and easy control. However, passive equalization has the disadvantage of complex thermal design and often equalizes only when the battery is charging, which can lead to inconsistent control of the battery"s individual depth of discharge, thus affecting the battery pack life. Active equalization technology has higher efficiency and equalization speed, and can use digital control methods, which is the mainstream development direction of Li-ion battery equalization technology. Active equalization technology often requires a large number of switches and energy storage devices, complex control algorithms, and has the disadvantage of large size and low reliability. Most of the existing active equalization techniques cannot be directly applied to DC bus satellite power systems. In this paper, based on the operating characteristics of the low-orbit satellite power storage battery, an active-passive hybrid equalization topology based on the switching matrix were proposed, which has the advantages of simple structure, easy control and high reliability, and its feasibility has been proved through experiments.