光伏组件形状参数工程解析模型

Shape Parameter Engineering Analytical Model of PV Module

光伏组件由光伏电池串联组成,光伏电池的经典单二极管模型物理参数意义明确,但输出特性隐式超越方程求解困难;通过拟合外特性建立的新型解析数学模型方程形式简洁,但所取形状参数物理意义不明确。结合上述2种模型的优点,提出了形状参数工程解析模型。考虑到光伏组件的物理性能会随工作年限逐渐变化,该模型用当前实际测试条件(real test conditions,RTC)下实测输出数据替换出厂前标准测试条件(standard test conditions,STC)下输出数据,拟合得到RTC下形状参数。基于形状参数与物理参数相互间的解析关系,根据环境变化修正后的物理参数解析求取相应形状参数,得到任意环境下输出特性的解析结果。通过单晶硅光伏组件在典型室外环境下输出特性的实测,验证了该模型的准确性。

A PV module refers to a number of PV cells connected in series, whose classical single-diode model with specific physical meaning parameters has an implicit transcendental output characteristic whose equation is difficult to solve, and a new analytical mathematical model based on fitting external characteristics with concise equation has shape parameters without specific physical meaning. A shape parameter engineering analytical model is proposed combining advantages of above two models in this paper. Since physical performance of a PV module is changing with age, its output data under Standard Test Conditions （STC） are replaced by the measured ones under Real Test Conditions （RTC） fitted to get shape parameters under RTC, and analytical results of the output characteristics under any environment are obtained by getting shape parameters from correcting the physical parameters according to environmental change based on analytic relationship between above two kinds of parameters. Accuracy of the proposed model was validated through experiments performed for measuring the output characteristics of a mono-crystalline silicon PV module under typical outdoor environments.