Thermal modeling and temperature control of an all-vanadium redox flow battery

Previous studies have demonstrated that the electrolyte temperature of an all-vanadium redox flow battery (VRB) has a significant influence on the safety and efficiency of the battery. Therefore, an effective cooling strategy is required, especially for large-scale batteries. In this paper, a dynamic thermal model of a VRB with heat exchangers is presented, in which the internal losses, pump energy losses and reversible entropic heat are taken into account. Based on this model, a robust adaptive backstepping control scheme is proposed so that the stack temperature can track the desired temperature in spite of the presence of unknown parameters, external disturbance and control saturation. To avoid the problem of the "explosion of complexity" in the conventional backstepping method, a dynamic surface control technique is introduced in this paper. The anti-windup technique is used to compensate for the effect of control saturation. Simulation results verify the effectiveness of the proposed controller under varying operating conditions.