Abstract: In terms of the high operation density and regenerative braking power of the urban mass transit, the flywheel energy storage system(FESS) can effectively reduce the DC traction network voltage fluctuation and the traction energy consumption. Because the charge or discharge operation for the FESS is just based on the high or low DC traction network voltage, so the regenerative braking power may not be identified accurately in addition, the state of charge (SOC) of the FESS cannot be automatically adjusted which leads to the incorrect response to the traction network voltage in the actual operating conditions. In this paper, the unload transit network voltage identification and the SOC optimized control strategy is adopted to solve these problem, the effectiveness of the proposed control strategy is verified by rail transit platform test.

Key words: urban mass transit, flywheel, regenerative braking, optimized control strategy