Battery Dynamic Balancing Method Based on Calculation of Cell Voltage Reference Value

Abstract

The article is devoted to solving the problem of charge equalization of multi-element batteries with rated voltage up to 1000 V, operating in dynamic modes with different charge and discharge depths. This article proposes a method of balancing the voltages of power battery elements. The essence of the proposed method is to form a reference signal equivalent to the reference voltage of the battery element for the current state of charge. The novelty of the method presented in this article, in comparison with relevant existing techniques, lies in active control over the balancing circuit proportional to real cell voltage deviation from the reference value. The proposed method can be used both for passive balancing techniques based on ballast resistors, and for circuits made on electromagnetic energy redistribution systems between galvanic cells. A number of Simulink models were developed to determine the electrical parameters of active and passive balancing circuits. Performance and accuracy study of balancing a multi-element battery in charge and discharge modes was conducted by Simulink models. It was established that, compared to classical methods, the proposed balancing method enhances the accuracy by 1.43 times and improves dynamic indices of the balancing process at any state of charge of batteries. The proposed balancing method is a perspective for energy storage systems based on multi-element batteries for power supply nodes of high-power loads with pulsed and repeated short-term operation modes.