Research on Charging and discharging Strategies of Regenerative Braking Energy Recovery System for Metro Flywheel

Aiming at the problem that it is difficult to recycle the braking energy generated by the frequent braking of metro trains, this paper puts forward to store and utilize the regenerative braking energy by using flywheel energy storage device. When the subway starts, the flywheel decelerates to release the energy; when the subway brakes, the flywheel accelerates to absorb the energy, thus stabilizing the DC bus voltage and alleviating the voltage fluctuation of the traction network. The charge and discharge strategy of single flywheel and the control strategy of multiple flywheels running side by side are studied, and the double closed loop control strategy of single flywheel and three control strategies of multiple flywheels running side by side are put forward, which are equal power, equal-torque and equal-time-length discharge control strategy. The simulation results show that the flywheel energy storage device can achieve the desired effect, and the optimal control strategy for the parallel operation of several flywheels is obtained.