Electrochemical impedance describes the internal electrochemical process of batteries and is related to temperature,state of charge and state of health.The on-board sinusoidal current source was designed to measure the battery AC impedance.The frequency range of the AC current source was confirmed via a series of lithium ion battery electrochemical impedance tests.And the H-bridge unit was shared with the designed on-board charger to decrease the cost and volume.The state space average model was derived to analyze the closed-loop system.The synthetical control method combining the inner instantaneous output current control loop with the outer output current amplitude control loop was proposed.The method was simulated with Matlab/Simulink and verified with a prototype,indicating that the synthetical control method properly works.%电池的电化学阻抗反映了电池内部的电化学过程,与电池的温度、荷电状态和老化状态等变化相关.为了能够测量电池的交流阻抗,设计了车载正弦电流源.通过锂离子电池的交流阻抗实验确定了所设计电流源的输出电流频率范围,并且与车载充电机共用H桥单元以降低系统成本、体积;建立了系统状态空间平均方程并分析了闭环系统的输出特性,提出了输出电流瞬时值内环和输出电流幅值外环综合控制方法;通过Simulink仿真和原理样机验证,表明提出的控制方法具有较好控制效果.
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