光伏组件退化评估及环境因素敏感性分析

Photovoltaic module degradation assessment and environmental factors sensitivity analysis

光伏组件在实际运行过程中会受到环境温度、环境湿度、太阳辐照、风速多种环境因素及其耦合作用的影响,发生不同程度及类型的退化,特别是输出功率的退化难以被准确评估。文章基于有限元和失效动力学建立了综合考虑多环境因素及其耦合影响的光伏组件输出功率退化模型,并以龙游光伏电站为例,评估了光伏组件在该运行条件下的输出功率退化量。开展步降应力加速退化试验,并借助加速因子,得到光伏组件输出功率的真实退化数据,并与退化模型的评估结果对比,验证了模型的有效性。最后基于正交试验和退化模型,探究了四种环境因素对光伏组件性能退化的影响程度及其敏感性排序,结果显示,环境湿度对性能退化的影响最为明显,太阳辐照对性能退化的影响最小。

The photovoltaic(PV)module is affected by various environment factors such as ambient temperature,ambient humidity,solar irradiation,wind speed and their coupling effects during the actual operation.Different degrees and types of degradation occur,and the performance degradation,especially the degradation of output power,is difficult to accurately assess.Based on the finite element method(FEM)and failure dynamics,a degradation model of output power is proposed,where environment factors and their coupling effects are considered.The degradation data of output power of PV module in Longyou power plant is obtained.The step-down stress accelerated degradation-Test(SDSADT)is carried out,and the actual degradation data of output power is obtained with the help of acceleration factor.The validity of the degradation model is verified by comparing the results assessed by the SDSADT with the results assessed by the model.Based on orthogonal experiment and degradation model,the influence degree of four environment factors on performance degradation of PV module and the sensitivity sequence of the four environment factors is explored.The results show the influence of ambient humidity on performance degradation is the most obvious,and solar irradiation has the least impact on performance degradation.