无人机锂电池剩余电量估算方法

SOC Estimation Method for UAV Lithium Battery

为准确估算无人机三元动力锂电池的剩余电量,创新性地构建二阶戴维南等效电路模型,模拟电池充放电过程中的电压变化情况,运用混合脉冲功率性能测试实验对模型参数进行辨识,分析参数变化规律并建立精确的模型状态空间表达式。运用电池测试设备模拟锂电池的充放电,以真实放电电流数据为输入,在Simulink中经过仿真得到的电压波形与实际电压数据进行对比分析,能很好地跟随电压变化曲线。同时在二阶戴维南模型基础上运用扩展卡尔曼算法估算剩余电量,初始误差在20%的情况下能快速修正荷电状态值,控制估算误差在2%以内。

In a view to exactly estimate the remaining capacity of the UAV ternary power lithium battery, the second-order thevenin equivalent circuit model was constructed to simulate the battery voltage variation during its charging and discharging process, including making use of the hybrid pulse power performance characteristic (HPPC) to identify model parameters, analyze the variation of parameters and establish model state space expressions. Through applying the battery test equipment to charge and discharge the lithium battery under simulated conditions, taking real discharge current data as input as well as comparatively analyzing the the voltage waveform obtained by simulation in Simulink and the actual voltage data, the voltage curve were followed very well. At the same time, basing on the second-order thevenin model, the extended Kalman filter algorithm was used to estimate the remaining power and as for 20% initial error, the SOC value can be quickly corrected along with an estimation error less than 2%.