Abstract:

In order to aid optimizing operate condition and designing control strategy, a dynamic model for the electrochemical reaction, pump loss and temperature change of the vanadium battery(VRB) was established. The model consisted of three sub-models: electrochemical model, hydraulic model and thermal model. The electrochemical model takes into account the concentration, activation, ohmic and ionic polarization losses and the vanadium ion crossover. The hydraulic model describes the hydraulic circuit of the electrolyte and determines the pumps loss. The reversible entropic heat and pumps loss are included in the thermal model. The simulation results show that the mean absolute percentage error between the simulation value and the experimental value of the stack voltage varied with the state of charge (SOCs) is 6.84%, so the accuracy of the model is verified. The model is applied to study the effects of current, electrolyte flow rate and temperature on the charge and discharge characteristics.

Key words: all-vanadium flow battery, dynamic model, non-isothermal, oriented control, simulation