通过超椭圆模型的渐近解对太阳能电池I-V特性进行参数化

Abstract The computation of I-V characteristic curves is vitally important for tasks related to the design, sizing, and simulation of photovoltaic modules, as it allows them to evaluate the performance of different PV technologies under changing weather conditions. A simple and computationally efficient way to calculate I-V curves involves using the explicit super-ellipse model. However, this model is complicated to parameterize, as it requires numerically solving complicated systems of nonlinear equations. In response to this problem, this paper presents analytical methodologies for parameterizing the super-ellipse model. Two approaches are developed: one utilizing the maximum power point (MPP) and another employing two measured points from the I-V curve. The methods use asymptotic approximations to solve the equations, avoiding computationally intensive numerical techniques. The model is validated with experimental corresponding to six PV technologies and 18 weather and irradiance conditions using RMSE as the evaluation metric. The results show that the asymptotic solutions achieve performance comparable to numerical methods while offering simplicity and computational efficiency, presenting a RMSE of less than 0.0705 W for the methodology that uses the MPP and 0.027 A for the one that uses the measurement of two points on the I-V curve. In addition, it was verified that this model complies with the IEC EN 50530 standard. This study also shows the dependencies of Super-ellipse model parameters with irradiance and temperature. The proposed approaches address limitations of prior models, and enhance the representation of I-V curves under diverse operational scenarios.