Mismatching operating conditions negatively affect the extracted energy in photovoltaic (PV) systems. They may also lead to dangerous localized heating phenomena (hot spots) that can cause, in turn, accelerated ageing and reduced reliability. Since the adoption of bypass diodes or smart active switches does not prevent the occurrence of hotspots, it is necessary to investigate alternative strategies. A promising solution is represented by the proper regulation of the operating point of the PV cells in the current vs. voltage (-) or power vs. voltage (-) planes when mismatching conditions occur. In particular, in this paper, the existence of operating points allowing a suitable compromise between maximization of the extracted power and minimization of thermal stresses, due to hot spots, is experimentally evidenced. Experimental results highlighting the link existing between the operating point in the - plane and the PV cell temperature distribution under uniform and mismatching operating conditions are presented and discussed. On the basis of the obtained experimental results, it is possible to state that, when mismatching conditions occur, it is mandatory to properly choose the operating point: the global maximum power point may not be the best operating point. Hence, it is crucial to gain information about the eventual occurrence of mismatching conditions in order to be able to properly choose the best operating point. Therefore, another crucial aspect that is evidenced in this paper is represented by the fact that the detection of the occurrence of mismatching conditions, based on the analysis of the shape of the - and/or - characteristics, is effective only if the analysis is carried out for both positive and negative voltages.

中文翻译：

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不匹配条件下光伏阵列工作点与温度分布之间的联系

不匹配的操作条件会对光伏 (PV) 系统中提取的能量产生负面影响。它们还可能导致危险的局部加热现象（热点），进而导致加速老化和降低可靠性。由于采用旁路二极管或智能有源开关并不能阻止热点的发生，因此有必要研究替代策略。当不匹配条件发生时，在电流与电压 (-) 或功率与电压 (-) 平面中适当调节 PV 电池的工作点代表了一种有前景的解决方案。特别是，在本文中，实验证明了工作点的存在允许在提取功率最大化和热应力最小化之间进行适当的折衷，由于热点。实验结果强调了在均匀和不匹配的操作条件下，平面中的操作点与 PV 电池温度分布之间存在的联系并进行了讨论。根据获得的实验结果，可以指出，当出现不匹配条件时，必须正确选择工作点：全局最大功率点可能不是最佳工作点。因此，获取有关失配条件最终发生的信息至关重要，以便能够正确选择最佳工作点。因此，本文中证明的另一个关键方面是基于对 - 和/或 - 特征形状的分析，检测不匹配条件的发生，