LAUSR

Current overshoot in the charging is an undesired behavior that accelerates the aging of both chargers and batteries. This phenomenon is even more severe in parallel-connected multicharger systems of supercapacitor trams, as the overshooting of each charger is stacked up in the charging current. To address this issue, in this article, we propose a current-overshoot-suppression charging method for supercapacitor trams. First, the system modeling of the charging system is developed and the motivation of this article is highlighted. Then, a cooperative charging protocol is designed to achieve the current balancing of chargers, and a set point modulation method is presented to adjust the set-point of chargers smoothly with the aim of suppressing the current overshoot. The implementation of the proposed method is illustrated with a physical case study. A laboratory testbed has been built to verify the effectiveness of the design. Experiment results show that the proposed method can suppress the current overshoot without prolonging the settling time.