Active Device-Less Voltage Equalization Charger Using Capacitors, Diodes, and an AC Power Source

作者：Uno Masatoshi^*; Tanaka Koji

来源：Electrical Engineering in Japan, 2012, 181(3): 39-48.

DOI：10.1002/eej.21288

• voltage equalization charger
• voltage equalizer
• energy storage cell
• electric double-layer capacitor (EDLC)
• symmetrical configuration

Conventional cell/module voltage equalizers or equalization chargers based on traditional DC-DC converters require numerous switches or transformers as the number of series connections increases; therefore, their cost and complexity tend to increase and their reliability decreases as the number of connections increases. This paper proposes a novel voltage equalization charger that consists only of passive components such as capacitors, diodes, and a transformer. The fundamental operating principle, major features, and derivation of equivalent DC circuits are presented. A symmetrical configuration is also proposed to mitigate the RMS current flowing through energy storage cells in the charging process. Simulations and experimental charging and cycle tests were performed on series-connected electric double-layer capacitor modules to demonstrate the equalization performance. The experimental and simulation results were in good agreement, and the voltage imbalances were gradually eliminated as time elapsed even during charge-discharge cycling.

• 出版日期2012-11-30