SOC ESTIMATION METHOD FOR POWER BATTERY FOR HYBRID ELECTRIC VEHICLE

摘要

An SOC estimation method for a power battery for a hybrid electric vehicle. The method comprises: first, obtaining charging and discharging capability data of a battery under different temperatures, currents and SOC values through an experimental method, and fitting data through analysis to obtain charging and discharging capability coefficients of the battery; then, in the actual operating process of the battery, calculating Ah integrals through BMS sampled data, and at the same time, judging whether an SOC correction condition is satisfied, if so, conducting SOC correction to correct an SOC value obtained by the current Ah integral to an SOC value calculated via the correction condition according to the step length; otherwise, not conducting SOC correction. The method reduces the accumulated errors of Ah integrals so that a more accurate SOC value can be obtained while avoiding frequent correction, and is suitable for all hybrid electric vehicle battery control systems.