Distributed Control for State-of-Energy Balancing of Supercapacitor Modules in Light Rail Vehicles

Supercapacitor energy storage systems (ESS) play a significant role in light rail vehicles LRV with no need for overhead lines and the pantograph. As the ESS of LRV demand short charging time and high-power supply, it is crucial to achieve the rapid energy balancing for series-connected supercapacitor modules of the ESS. To address this issue, this paper proposes a distributed control scheme for state-of-energy (SoE) balancing of supercapacitor modules. In order to provide the sufficient balancing current, the push-pull converter is introduced to transfer the energy among supercapacitor modules in the low working voltage. Then, the distributed SoE balancing strategy is proposed by regulating the balancing circuit according to the SoE deviation of neighboring supercapacitor modules. The ESS prototype is built to validate that the proposed strategy can reduce the balancing time and improve the energy balancing efficiency.