BMS 에너지 효율 향상을 위한 리튬 배터리 SOC 계수 보정 알고리즘

This paper describes a battery equivalent model’s SOC(state of charge) coefficient calibration method to improve the accuracy of the battery equivalent model. The battery SOC difference between each cells is a major factor of decreasing the battery life. BMS (battery management system) has been developed in order to reduce the inter-cell battery SOC deviation. however, since the general battery cell balancing techniques operate by measuring only the voltage of the battery cell, they can not keep up with the electrical characteristics due to variation of the internal resistance of the capacitor. In this paper, we propose the battery equivalent model’s SOC coefficient calibration algorithm : (1)choses the battery and battery model, (2)measure the battery charging and discharging characteristics, (3)extracting the resistance and the capacitor value on the simulation, following the actual battery charge and discharge characteristic curve. in this paper, we use a 3.7 V, 280 mAh and 650 mAh lithium battery. And a RC Tank based battery equivalent model is adopted. The maximum error of charging and discharging characteristic between measurement and modeling is approximately 2.13 %.