The irradiance incident on photovoltaic (PV) generators can considerably exceed the expected clear sky irradiance. Due to this phenomenon, called cloud enhancement (CE), the maximum power of the PV generator can exceed the rated power of the inverter connecting the generator to the grid. CE event characteristics and the effects of CE on the electrical operation of PV generators were studied based on measured irradiances and cloud edge velocities. Over eleven months in San Diego, California, the highest measured peak irradiance was 1466 W/m2. In addition, the highest simulated average irradiances for up to 1 MW generators were over 1400 W/m2. The largest lengths for CE events exceeding 1000 W/m2 were multiple kilometers. These results indicate that even large utility-scale PV power plants can be affected significantly by CE events. Moreover, the operation of three PV plants was simulated during around 2400 measured CE events with a detailed spatiotemporal model. The effects of inverter sizing on the operation of the plants were also studied, and the negative impacts of CE on the operation of PV systems were shown to increase with the increasing DC/AC ratio. During the CE events, the energy losses due to power curtailment were from 5% to 50% of the available energy production. While CE affects the operation of the PV plants, these effects were small in terms of aggregate energy since CE events that most strongly impact PV system operation are very rare, meaning that CE does not cause major problems for the operation of PV systems.

中文翻译：

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基于云速传感器测量的云增强现象及其对光伏发电机的影响分析

光伏 (PV) 发电机上的入射辐照度可能大大超过预期的晴空辐照度。由于这种称为云增强 (CE) 的现象，光伏发电机的最大功率可能会超过将发电机连接到电网的逆变器的额定功率。基于测量的辐照度和云边缘速度，研究了 CE 事件特征和 CE 对 PV 发电机电气运行的影响。在加利福尼亚州圣地亚哥 11 个月内，测得的最高峰值辐照度为 1466 W/m2。此外，高达 1 MW 发电机的最高模拟平均辐照度超过 1400 W/m2。超过 1000 W/m2 的 CE 事件的最大长度为数公里。这些结果表明，即使是大型公用事业规模的光伏电站也会受到 CE 事件的显着影响。而且，在大约 2400 次测量的 CE 事件期间，使用详细的时空模型模拟了三个光伏电站的运行。还研究了逆变器选型对电厂运行的影响，结果表明 CE 对光伏系统运行的负面影响随着 DC/AC 比的增加而增加。在 CE 事件期间，由于限电造成的能源损失占可用能源产量的 5% 到 50%。虽然 CE 影响光伏电站的运行，但这些影响在总能量方面很小，因为对光伏系统运行影响最大的 CE 事件非常罕见，这意味着 CE 不会对光伏系统的运行造成重大问题。还研究了逆变器选型对电厂运行的影响，结果表明 CE 对光伏系统运行的负面影响随着 DC/AC 比的增加而增加。在 CE 事件期间，由于限电造成的能源损失占可用能源产量的 5% 到 50%。虽然 CE 影响光伏电站的运行，但这些影响在总能量方面很小，因为对光伏系统运行影响最大的 CE 事件非常罕见，这意味着 CE 不会对光伏系统的运行造成重大问题。还研究了逆变器选型对电厂运行的影响，结果表明 CE 对光伏系统运行的负面影响随着 DC/AC 比的增加而增加。在 CE 事件期间，由于限电造成的能源损失占可用能源产量的 5% 到 50%。虽然 CE 影响光伏电站的运行，但这些影响在总能量方面很小，因为对光伏系统运行影响最大的 CE 事件非常罕见，这意味着 CE 不会对光伏系统的运行造成重大问题。