A new algorithm for increasing balancing speed of switched-capacitor lithium-ion battery cell equalizers

Abstract

Switched-capacitor converters (SeC) are electromagnetic component less converters in their power stage for converting or transforming electrical power. But, they only use capacitors in the power stage as the power storage or power transformer component. Low volume, high power density, and integration ability are the most important features of these converters. Among various active cell balancing topologies, sees are used for battery cells balancing because they can easily be implemented with low volume and low cost. However, one of the most important problems of the sees is their low balancing process speed of the battery cells when their numbers is increased. In this paper, a new algorithm is proposed to increase the balancing process speed of the connected several cells in series. Here, principles of this algorithm are described in detail, and it is compared to the conventional algorithms. Balance process speed improvement of the proposed algorithm is confirmed by computer simulation that shows a meliorated balancing speed of the proposed approach.

A Novel RC-Based Architecture for Cell Equalization in Electric Vehicles

“…In this waveform, it is assumed that the operating voltage in cell V 1 is greater than V 2 ; on the contrary, the equalization currents are negative. This strategy is simple to understand and control since only a PWM signal in the SPDT switches is enough for two adjacent cells to reach the equalization in a natural manner [13,22,23]. Nevertheless, in this method, large current stresses in the cell and a large equalization time are present [24,25].…”