Study on magnetic flywheel energy storage system in urban rail transit

This paper developed a domestic magnetic flywheel energy storage system for brake energy regeneration in urban rail transit. To minimize the heating of flywheel, low-loss magnetic bearings and permanent magnet motor/generator are designed. Also the sensorless vector control based on sliding mode observer is discussed to achieve low cost and high reliability. The experimental results verify the robustness and practicability of the algorithm. The system has notable gains of power saving, and has broad application prospects in the field of urban rail transit.