Ultraviolet fluorescence (UVF) imaging is a widely used technique to analyze encapsulant discoloration, which is one of the prominent degradation modes in photovoltaic (PV) modules. Conventionally, UVF is done during nighttime or in a dark room, but performing UVF imaging during nighttime causes several inconveniences including safety due to snakes and other animals and inconvenient scheduling issues for the plant owners. Similarly, performing UVF imaging indoors requires dismounting the modules from the racks and moving them to the laboratory, which are labor-intensive and time-consuming tasks and could damage the module or may cause the energy loss due to partial/complete plant/array shutdown. Moreover, the manufacturer/installer warranty may be voided if the modules are removed from the racks. An outdoor UVF setup that can be used during the daylight can be a better alternative to the indoor or nighttime setup, provided it ensures there is no leakage of ambient light into the covered testing structure. We propose a unique, portable, and user-friendly outdoor UVF setup design that can tackle the issue of the ambient light leaking in, give uniform UV light, and provide enough room to accommodate the UV light source and camera to capture module images. We also classify the encapsulant discoloration into three classes depending on the discoloration intensity level. Furthermore, using the image processing technique, the percentage of browning was calculated in each cell/module.

中文翻译：

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户外日光紫外荧光成像装置的设计和开发：一种用于检测光伏模块退化的廉价工具

紫外荧光（UVF）成像是分析密封剂变色的一种广泛使用的技术，它是光伏（PV）模块中最显着的降解模式之一。通常，UVF是在夜间或在黑暗的房间中进行的，但是在夜间执行UVF成像会带来一些不便，包括由于蛇和其他动物引起的安全性以及对植物所有者的不便调度问题。同样，在室内执行UVF成像需要从机架上卸下模块并将其移至实验室，这是劳动密集型且耗时的任务，并且可能会损坏模块或由于部分/完全关闭工厂/阵列而导致能量损失。此外，如果从机架上卸下模块，则制造商/安装人员的保修条款可能会失效。可以在白天使用的室外UVF设置可以更好地替代室内或夜间设置，前提是要确保环境光不会泄漏到覆盖的测试结构中。我们提出一种独特，便携式且用户友好的户外UVF设置设计，该设计可以解决环境光泄漏的问题，提供均匀的UV光，并提供足够的空间来容纳UV光源和相机以捕获模块图像。我们还根据变色强度级别将密封剂变色分为三类。此外，使用图像处理技术，计算了每个单元/模块中的褐变百分比。我们提出一种独特，便携式且用户友好的户外UVF设置设计，该设计可以解决环境光泄漏的问题，提供均匀的UV光，并提供足够的空间来容纳UV光源和相机以捕获模块图像。根据变色强度水平，我们还将密封剂变色分为三类。此外，使用图像处理技术，计算了每个单元/模块中的褐变百分比。我们提出一种独特，便携式且用户友好的户外UVF设置设计，该设计可以解决环境光泄漏的问题，提供均匀的UV光，并提供足够的空间来容纳UV光源和相机以捕获模块图像。根据变色强度水平，我们还将密封剂变色分为三类。此外，使用图像处理技术，计算了每个单元/模块中的褐变百分比。