超级电容器组均衡充电系统

Charge Equalization System for Ultracapacitor Series

串联超级电容器组中各单体能量维持均衡是安全使用并充分发挥电容器组性能的重要保证。在分析比较几种均衡充电方案的基础上,提出一种双电源结构的均衡充电系统,实现了充、放电全过程的能量均衡,可有效避免超级电容器单体的过充、过放,有利于提高电容器组能量存储效能,延长其循环使用寿命。简要介绍了充电电源缓冲式软开关Buck变换器和均衡电源半桥隔离变换器,并给出了以FPGA为核心的监控系统的结构以及软硬件设计方案。

To maximize performance and reliability, the individual ultracapacitor energy in a series connected pack must be fairly uniform. Otherwise, some cells will be damaged permanently resulting from overcharging or over-discharging. Based on the analysis of several equalization circuits, a charge equalization system is proposed. This system is consisted of double power supplies, one is the charging power supply, which is a buck converter with snubber, and the other is the equalization power supply, which is a half-bridge converter with the isolation transformer. A FPGA-based controller is used to control the whole system. This system maintains the ultracapacitor cell voltage at an equally charging/discharging level, so it can prevent ultracapacitor cell from overcharging and over-discharging and it is propitious to improve energy efficiency and enhance the cycle life of ultracapacitor.