Generally, photovoltaic (PV) panels are affected by variety of internal and external faults. Hotspot is regarded as an internal and permanent fault that is highly destructive in solar panels. In this study, a novel approach based on PV output current trajectory is proposed for hotspot detection in PV strings. The hotspot detection criterion consists of two parts. First, the Teager‐Kaiser energy operator technique is applied for current change detection. Then, a novel hotspot detection index based on the cumulative rate slope calculation of PV current is applied. The proposed index has the advantage to distinguish between hotspot condition and other faults only by utilization of current measurement. The thermal behavior and the current trajectory are evaluated during hotspot condition. It is shown that the current characteristic of the cell during hotspot condition has a unique behavior, which is also justified by mathematical analysis. Different shading scenarios are considered in this study. However, the proposed approach can easily detect the one which cause hotspot condition and distinguish it from other type of scenarios. Therefore, the proposed approach can detect hotspot fault before the solar cell destruction. MATLAB simulations are applied in order to confirm the effectiveness of the proposed approach.

中文翻译：

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基于电流的光伏串热点检测方法

通常，光伏（PV）面板会受到各种内部和外部故障的影响。热点被视为内部永久性故障，在太阳能电池板中具有很高的破坏性。在这项研究中，提出了一种基于PV输出电流轨迹的新颖方法来检测PV串中的热点。热点检测标准包括两部分。首先，将Teager-Kaiser能量运算符技术应用于电流变化检测。然后，基于PV电流的累积速率斜率计算，应用了一种新颖的热点检测指标。提出的指标具有仅通过利用电流测量来区分热点状况和其他故障的优点。在热点条件下评估热行为和电流轨迹。结果表明，热点条件下电池的电流特性具有独特的行为，这也可以通过数学分析来证明。在这项研究中考虑了不同的阴影方案。然而，所提出的方法可以很容易地检测出引起热点条件的原因，并将其与其他类型的场景区分开。因此，所提出的方法可以在太阳能电池破坏之前检测热点故障。为了确认所提出方法的有效性，应用了MATLAB仿真。所提出的方法可以在太阳能电池破坏之前检测热点故障。为了确认所提出方法的有效性，应用了MATLAB仿真。所提出的方法可以在太阳能电池破坏之前检测热点故障。为了确认所提出方法的有效性，应用了MATLAB仿真。