Paralleling voltage oscillation forecast method of energy device based on hysteresis curve equation

摘要

Power battery is widely used in backup power and new energy vehicles. Many countries have paid more and more attention to the safety of power battery. At present, the battery combination mode of series connection to parallel connection is conducive to the fast combination and unloading of high voltage system energy. It is an effective way for modular design and production of the power battery system. However, the voltage oscillation may appear when the voltage difference exists between the parallel modules. The phenomenon may affect the performance and safety of electric power and electric equipment. The voltage oscillation standard deviations in paralleling with different voltages were analysed, the voltage oscillation distribution map can be drawn. The reasonable parallel voltage range can be obtained by hysteresis curves, which were used to predict the limit of paralleling voltage. Lithium-ion+ battery experiment was carried out and the result shows that the proposed method can predict the large voltage oscillation in battery paralleling, it can ensure the safety of battery module and it provided an effective forecast in paralleling for the new energy power electric system.