基于I-V特性的多晶硅光伏组件故障及失效研究

STUDY ON FAILURE MECHANISM OF POLYCRYSTALLINE SILICON PV MODULE BASE ON I-V CHARACTERISTICS

调研了光伏电站中不同故障和失效类型的多晶硅光伏组件,通过测试获得了组件的I-V特性曲线和红外图像,并从I-V特性曲线中提取了不同故障和失效类型光伏组件的特征;然后通过建立太阳电池的数学模型和失配下的反偏模型,分析了不同故障和失效类型光伏组件的I-V特性曲线,得到以下结论:老化使组件等效串联电阻增加;前板玻璃碎裂使组件I-V特性曲线阶梯段呈现抛物线趋势;电势诱导衰减使组件的开路电压减小;阴影遮挡使组件失配,且I-V特性曲线出现平坦阶梯段;热斑造成组件I-V特性曲线出现折线段。进一步实验后发现,老化可以通过判断光伏组件串联电阻的情况来辨别,热斑可以通过判断电池单元并联电阻的情况来辨别。

After testing I-V curves of different failed and fault types PV modules from PV power plants and extracting the failed parameters,a reverse bias model was established to analyze the failure mechanism of PV module.The results show that the equivalent series resistance of PV modules increases with aging time.The cracking of the front panel glass makes the I-V curve transformed and shows a stepped parabola with several segments.The potential-induced degradation(PID)reduces the open circuit voltage of the PV module.The shading makes the PV module mismatched and the I-V curve has a flat step.The hot spots enable I-V curve to appear the shape of polyline segment.Moreover,the aging test of PV modules can be simulated by series resistance,while hot spots test can be simulated by paralleling resistance,respectively.