The flywheel energy storage system (FESS) is considered to be an ideal choice for the energy recovery and utilization of regenerative braking in rail transit due to its high energy density

long life

fast response and environmental friendliness. The control of the flywheel energy storage system is a key part to ensure the stable and efficient operation of the system. In view of the limitations of the traditional PI controller in controlling the flywheel energy storage system

an improved Active Disturbance Rejection Control (ADRC) strategy was studied. Firstly

the cascaded nonlinear expansion state observer is used to enhance the estimation ability of the system to estimate the disturbance

and the control performance is improved. Then

considering the problem that there are many parameters in the nonlinear ADRC with unclear physical meaning and difficult to debug

combined with the advantages of the Sliding Mode Control (SMC) parameter with clear physical meaning

strong robustness and strong anti-disturbance ability

the Sliding Mode-Active Disturbance Rejection Control (SM-ADRC) is constructed to improve the control performance of the system. Secondly

in view of the complexity of the parameter setting of the SM-ADRC controller

the Particle Swarm Optimization (PSO) algorithm was used to tune the control parameters

which improved the efficiency of parameter tuning. Finally

the feasibility and effectiveness of the proposed control strategy in the charging and discharging conditions of flywheel energy storage system are verified by experiments.