Study on Grid-Injected System with Regenerative Braking Energy for Subway

At present, the rate of energy utilization is low for the transit regenerative braking on urban rail; most of the energy is consumed by the resistance heating. In this paper, a regenerative braking energy injected-grid device is designed, which makes use of regenerative braking energy and effectively reduce the temperature rise caused by the resistance in the tunnel. The paper describes the composition and the design procedure of regenerative braking energy injected-grid device and presents a control strategy of device. The simulation of the single train model verifies that the stability of DC-bus voltage can be maintained and more power can be feedback to the grid by the proposed device when the train is braking. The feasibility and effectiveness of the proposed control method are validated by the experimental results.