Adaptive Terminal Sliding Mode Control for Hybrid Energy Storage Systems of Fuel Cell, Battery and Supercapacitor.

In this paper, a terminal sliding mode control strategy with projection operator adaptive law is proposed in a hybrid energy storage system (HESS). The objective of the proposed control strategy is to provide power for load in time, get good tracking performance of the current of the fuel cell, battery, and supercapacitor, and obtain a stable voltage of the dc bus. At first, the topological structure of the system is proposed, and the mathematical models are derived. Then, on the basis of the working characteristics of the energy storage unit, the load power is reasonably and effectively distributed to increase the service life of HESS and improve energy efficiency. Meanwhile, according to the tracking errors of reference and actual values, the terminal sliding surfaces can be set out. The controller can be designed by the constraint condition, combining the projection operator adaptive law. In addition, the HESS with the proposed control is proved to be asymptotically stable by using the Lyapunov method. Finally, the simulation results show that the proposed control strategy can make the whole system stable, and the control objective can also be better realized.