Reconsideration of solar array simulator based on Thévenin equivalent circuit for low-power applications

Abstract

The installation of photovoltaic (PV) plants has increased considerably, reaching high-power plants, residential consumers and low-power stand-alone applications. Along with the new PV panel technologies, power electronics have been developed to connect and control these systems, such as PV inverters and charge controllers. The testing and certification of these devices requires controlled power and voltage conditions, which led to the development of solar array simulators (SAS). This work reconsiders the use of the Thévenin equivalent circuit (TEC) for solar array simulator realization. The approach is based on taps to change the value of voltage and resistance for different solar irradiance conditions, while keeping the total error of power and voltage within acceptable limits. The TEC-SAS is compared with a commercial emulator, which shows worse behavior than the TEC-SAS at low-power conditions. Also, the results show that the proposed TEC-SAS can achieve less than 10% error for the range of irradiance from 0 to 1000W/m2 by using 16 resistance taps.