To operate photovoltaic power plants at maximum capacity, it is desirable to identify cell or module failures in the field at the earliest possible stage. Currently used field inspection methods cannot detect many of the electronic defects that can be revealed with luminescence‐based techniques. In this work, photoluminescence images are acquired using the sun as the sole illumination source by separating the weak luminescence signal from the much stronger ambient sunlight signal. This is done by using an appropriate choice of optical filtering and modulation of the cells' bias between the normal operating point and open circuit condition. The switching is achieved by periodically changing the optical generation rate of at least one cell within the module. This changes the biasing condition of all other cells that are connected to the same bypass diode. This method has the advantage that it can deliver high quality images revealing electrical defects in individual cells and entire modules, without requiring any changes to the electrical connections of the photovoltaic system.

中文翻译：

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具有阳光激发的光伏组件的室外光致发光成像

为了以最大容量运行光伏电站，期望在最早的可能阶段识别现场中的电池或模块故障。当前使用的现场检查方法无法检测出许多可以通过基于发光的技术发现的电子缺陷。在这项工作中，通过将微弱的发光信号与强得多的环境阳光信号分开，使用太阳作为唯一的照明源来获取光致发光图像。这是通过使用光学滤波和细胞的正常工作点和开路状态之间偏压的调制的适当选择来完成。通过周期性地改变模块内至少一个单元的光产生速率来实现切换。这会改变连接到同一旁路二极管的所有其他电池的偏置条件。该方法的优点在于，它可以传递高质量的图像，揭示单个电池和整个模块中的电气缺陷，而无需对光伏系统的电气连接进行任何更改。