A Hybrid Control Strategy for Photovoltaic Simulator

This paper presents a hybrid control strategy for photovoltaic (PV) simulator, which emulates the output characteristics of PV arrays under different irradiation, temperature, and loads. The mathematic modeling of the I-V curve of PV arrays is investigated in this paper, and accordingly the voltage control or current control method is worked out for different segments of PV output characteristics. The proposed hybrid control strategy divides the I-V characteristics of PV arrays into three segments, by measuring the output voltage and current of the PV simulator, the control unit which is based on TMS320LF2407 DSP calculates and controls the voltage or current respectively. A 2-kW prototype has been built and tested with a variable resistive load and a constant power load as well. Experiment results show that the PV simulator could shift smoothly on its I-V characteristics, which fits well for further experiments of inverters and the maximum power point tracking in the PV system.