摘要
电池的不一致性是指同一规格、同一型号的电池在电压、内阻、容量等方面的参数差别。其中,电压不一致性的表现相对直观,也容易被测量。在MW级电池储能电站中,需要通过串并联成组来满足储能系统的电压等级和容量需求,电池单体数量高达几万节,而单体电池不一致性的存在,将不可避免地影响储能系统整体性能。针对200 kW/200(kW·h)锂电池储能系统和250 kW/1(MW·h)锂电池储能系统在不同时间阶段进行容量标定实验,经过长期运行后,分析单体电池电压不一致性对电池系统容量衰减的影响。结果显示:经过2年的运行,250 kW/1(MW·h)锂电池储能系统充电性能衰减了4.24%,放电性能衰减了2.6%,单体电压不一致性变化不大,而200 kW/200(k W·h)锂电池储能系统充电性能衰减了25.976%,放电性能衰减了27.120%,说明具备充放电均衡控制策略的锂电池储能系统能够很好地改善单体电压不一致性变化;250 kW/1(MW·h)储能系统已累计运行相当于100%DoD(depth of diacharge)充电27.11次,相当于100%DoD放电23次,充放电次数是造成该储能系统容量衰减的主要原因。
Among the same specifications and the same type of battery,cell inconsistency refers to the difference of voltage,internal resistance,capacity,etc. Among them,the performance of voltage inconsistency is relatively intuitive,which is easy to be measured. In megawatt battery energy storage power station,the voltage level and capacity needs of the energy storage system are met by series-parallel groups. The number of batteries cell is up to tens of thousands. Due to the inconsistency of battery cell,the overall performance of the energy storage system will be affected. This paper carries out the capacity calibrated experiments for 200 kW /200（ k W·h） and 250 kW /1（ MW ·h） lithium battery energy storage systems during different time periods. After long time running,this paper analyzes the influence of the voltage inconsistency of battery cell on the capacity attenuation of battery system. The results show that,the charging performance of 250 kW /1（ MW·h） lithium battery energy storage system is attenuated by 4. 24% after 2 year running,the discharging performance is attenuated by 2. 6%,and the voltage inconsistency of battery cell changes little,while the charging performance of 250 kW /1（ MW·h） lithium battery energy storage system is attenuated by 25. 976%,the discharging performance is attenuated by 27. 120%. The result shows that the lithium battery energy storage system with charging and discharging equalization control strategy can improve the voltage inconsistency change of battery cell. This energy storage system has run the equivalent of charging 27. 11 times with 100% DoD（ depth of diacharge）,or discharging 23 times with 100% Do D. The number of charging and discharging is the main reason for the capacity attenuation of the energy storage system.
出处
《电力建设》
北大核心
2016年第11期23-28,共6页
Electric Power Construction
基金
中国电力科学研究院科技创新基金项目(DG84-15-003)
北京市科技新星计划(Z141101001814094)
关键词
锂电池储能系统
容量衰减
单体电压
不一致性
lithium battery energy storage system
capacity attenuation
cell voltage
inconsistency
