Nonlinear Control Strategy of Hybrid Energy Storage System Based on Feedback Linearization

In view of the nonlinear characteristics of the hybrid energy storage system (HESS), a nonlinear control strategy based on feedback linearization theory is proposed. The control objectives of the strategy are battery/super capacitor current and DC bus voltage. Firstly, by analyzing the state equation of the circuit, the affine nonlinear model of the circuit is established. Then, the input-output feedback linearization and sliding mode surface are designed to realize the current tracking control of the battery and super capacitor. Finally, the classic voltage closed-loop control is used to realize the bus voltage stability. The simulation model is established on Simulink, and the simulation results show that the proposed control strategy is effective.