Modeling and Simulation of VRLA Batteries Dynamic Behavior With Internal Oxygen Cycling

摘要

Predicting transient behavior of lead-acid batteries during charge and discharge process is a very important factor in many applications including Hybrid Electric Vehicles (HEV). When the battery is subjected to a very high discharge or charge current (for example in HEV) side reactions like oxygen cycle and hydrogen evolution are present in battery. To predict these phenomena, an accurate model based on first principles is needed. In the present study, an improved mathematical model for VRLA batteries based on Computational Fluid Dynamics (CFD) and Equivalent Circuit Model (ECM) has been developed. The proposed model not only predicts battery dynamical characteristics but also unlike the classical ECM model, is capable to solve distributed parameters such as acid concentration distribution versus time. With this model the chemical and electrochemical reactions of the battery and their interconnections are mathematically modeled and simulated. In addition, it inherits accuracy of CFD model and physical understanding of ECM. Moreover, it is very fast which makes it quite suitable for real-time simulations. The present approach is verified by previous CFD models and experimental data. The results show that this model has a good accuracy and the execution time is quite fast enough for real time purposes.