Study The Control Strategy Of Energy Saving System With Super Capacitor On-board Of Railway Vehicle For Urban Mass Transit

ABSTRACT:In urban mass transit, the regenerative braking energy can be absorbed by the adjacent vehicle on the same electrified line, if the energy can not be completely absorbed, so the surplus regenerative braking energy will make line network voltage rise rapidly, try to prevent regeneration cancellation, usually burn the surplus energy in braking resistance, which causes greatly waste and brings the temperature problem. In recent years, along with the super capacitor, flywheel storage technology development, using storage device to store the regenerative braking energy and re-use as the assist power for the required traction power is the hot topic in current researches. Therefore, this paper proposes an energy storage system with on-board of super capacitor to storage and re-use the regenerative braking energy, therefore the vehicle can make full use of regenerative braking force, realize the purpose of saving energy.In this paper the charging and discharging characteristics of super capacitor and vehicle energy characteristics are studied, the matching relation between them is also analyzed. The on-board super capacitor system simulation and experimental platform are built, based on the accurate mathematical modeling and performance analysis, this paper proposes a line net current compensation indirect energy control strategy, the control algorithm is analyzed in detail, and emphatically introduced the control algorithm of voltage and current logical relationship, and combined with the super capacitor state of charge (SOC) to revise the current control.To verify the correctness of the proposed control strategy, a novel vehicle simulation platform has been created in Matlab by using an'effect-causes'simulation tool, which can reflect the power flow in hybrid electric vehicle. Simulation results verify the correctness of the control strategy. Base on a 1.25 F super capacitor storage system experimental platform, simulation and experiment results show that the control strategy can accurately control super capacitor storage and reuse regenerative braking energy.