Design of Zero-Current Parallel-Switched-Capacitor Voltage Equalizer for Battery Strings

摘要

In the conventional Zero-Current Switched-Capacitor (ZCSC) method, the limitation is the low balance speed, especially in a long battery string. In order to improve the performance, a Zero-Current Parallel-Capacitor (ZCPC) method is proposed in this paper. In this architecture, multiple LC resonant tanks can balance the corresponding batteries simultaneously, then all LC resonant tanks are connected in parallel to exchange the energy. Therefore, energy can be transmitted from cell to cell directly, which reduces the energy transmission path and improves the balance speed. The simulation results show that the proposed circuit in the eight-battery system reduces balance time by 75% and 35% compared with the conventional ZCSC circuit and the Parallel-Capacitor (PC) circuit, respectively.