Estimating parameters of photovoltaic modules based on current–voltage characteristics at operating conditions

Abstract

Output characteristics of photovoltaic (PV) systems are greatly affected by both external and internal aspects. The external features, such as irradiance and temperature, are measured by the weather station. However, the irradiance and the temperature measured from measurement instruments are not representative of the energy and the heat that the PV modules receive. The internal factors, such as resistance, are difficult to identify since they are not physically present in the PV modules. One of the trending research directions is to utilize the output characteristics of the PV module to determine the operating conditions of the PV module. This paper presents a method to identify external features (solar irradiance and temperature) and internal resistances by employing the I–V characteristics of the PV module. The proposed method is based on the regression model, which uses the experimental I–V values from the I–V​ tracer. In addition, a method to obtain irradiance from the maximum power point current in the recent literature is employed for the comparison. The simulation results show that the estimation accuracy of the proposed method is higher than that of the referenced method.

Keywords

• Photovoltaics
• Solar irradiance estimation
• PV cell temperature estimation
• Resistance estimation
• Regression model