Comparative Analysis of the Dynamic Efficiency of Commercial Photovoltaic Inverters Under Standardized Irradiance Profiles
Abstract
The assessment of the dynamic performance of photovoltaic inverters has largely been based on the tracking efficiency of the maximum power point, as defined by IEC 62891:2020. Although this assessment provides important information, it does not take into account losses in the conversion stage, which leads to an underestimation of performance under dynamic conditions. Given this scenario, this work proposes the evaluation of total dynamic efficiency, which includes, in addition to MPPT tracking, conversion efficiency. The combination of these two parameters makes it possible to characterize the behavior of inverters under variations in irradiance. Experimental tests were carried out with trapezoidal irradiance profiles on ten commercial inverters, five of which were microinverters and five were string inverters. The results indicate that the microinverters showed lower total dynamic efficiency values, with an average of 79.32% for the five devices evaluated, especially in low irradiance conditions. In contrast, string inverters maintained a high and stable performance, with an average of 95.78%. These results reinforce the importance of considering the conversion stage in the normative assessment.
Keywords
commercial photovoltaic inverters, maximum power point tracking, dynamic efficiency, irradiance profile, standard procedure