退役动力锂电池在光储微电网的集成与应用

Integration and application of retried LIBs in photovoltaic and energy storage micro grid

为实现退役动力锂电池在光储微电网系统中的集成与应用,从整包利用的角度出发,检查80 V-60 A·h电池包的外观、铭牌、开路电压、BMS通讯情况对其进行初选,通过充放电测试对电池包完成二次筛选,并依据容量大小对电池进行分组,结合多通道储能变流器将电池成组,应用于光储微网系统中。结果显示:80个电池包有8个存在外观、开路电压和BMS通讯问题,22个存在容量和CD-OCV曲线异常。剩余50个电池包容量最大值为49.46 A·h,容量最小值为45.58 A·h,极差值为3.88 A·h,占额定容量的6.5%,一致性较好;在0.1、0.2、0.3、0.5 C等不同倍率下对电池进行充放电,成组后的电池CD-OCV曲线离散度较小;按0.05 C倍率充电、0.1 C倍率放电进行削峰填谷,充电量为111 kW·h,放电量为103 kW·h,转化效率92.79%。表明筛选和成组后的电池充放电性能正常,具备梯次利用价值。

To fulfill integration and application of retired Li-ion batteries in a PV and energy storage micro grid system,from the perspective of whole package using,checking appearance,nameplate,open circuit voltage(OCV),BMS communication of the 80 V-60 A·h batteries for initial filtration,then finishing second filtration through charging and discharging batteries,sorting batteries in accordance with valid capacity,grouping batteries by multichannel power conversion system(PCS),then applying in a PV and energy storage micro grid system.The results show the following:There are eight batteries that have a problem with appearance,OCV,or communication of the BMS,and 22 batteries also cannot be reused due to the capacity and the CD-OCV curve being unqualified.In the 50 remaining batteries,the maximum capacity is 49.46 A·h,and the minimum capacity is 45.58 A·h;so,the difference in value is 3.88 A·h,which is only 6.5%of the rated capacity,meaning these batteries present good uniformity.By charging and discharging under different rates,such as 0.1,0.2,0.3 and 0.5 C,the dispersion of the CD-OCV curves is small after grouping;when charging at a rate of 0.05 C and discharging at a rate of 0.1 C for peak cutting and valley filling,the charging energy is 111 kW·h and the discharging energy is 103 kW·h;so,the efficiency is 92.79%.This shows that the characteristics of the batteries are normal after filtrating and grouping,and the batteries have cascade utilization value.