二次谐波分量下锂离子电池安全运行区间研究

STUDY ON SAFE OPERATION RANGE OF LITHIUM-ION BATTERY UNDER SECOND HARMONIC COMPONENT

针对光储系统直流侧主要二次谐波分量对储能电池影响的问题,该文通过电化学模型分析直流侧不同大小的二次谐波分量对锂离子电池内外特性影响的机理和规律,发现影响电池寿命的主要因素是电池充放电状态期间的电流平均值而不是电流有效值。根据该因素对电池寿命的影响程度提出可将电流中二次谐波分量大小分为3个区间,相对应分为不显著影响电池寿命、减缓电池寿命衰减及加速电池寿命衰减,最后通过仿真以及实验验证了这3个区间,基于这3个区间可为工程应用中优化光储系统与电网交互影响下锂离子电池安全运行区间提供参考,降低储能直流侧滤波器成本。

For the main second harmonic component of the DC side of the photovoltaic storage system on the impact of energy storage batteries,the paper analyzes the mechanism and law of the influence of different sizes of second harmonic components on the internal and external characteristics of the Li-ion battery through electrochemical modeling,and finds that the main factor affecting the battery life is the average value of the current during the charging and discharging state rather than the effective value of the current.Based on the influence of this factor on the battery life,it is proposed that the second harmonic component of current can be divided into three intervals,which are not significantly affecting the battery life,slowing down the battery life decay and accelerating the battery life decay,and finally these three intervals are verified by simulation and experiment.These three intervals provide a reference for optimizing the safe operation interval of lithium-ion batteries under the influence of interaction between photovoltaic storage system and power grid in engineering applications and reducing the cost of DC-side filters for energy storage.