A digitally implemented photovoltaic simulator with a double current mode controller

This paper presents a microcontroller- and DC-DC converter-based photovoltaic (PV) simulator which emulates the output characteristics of a real solar panel. In particular, the PV simulator designed is portable and has a maximum output power of 85W. The control mechanism is based on a double current mode controller in combination with an IV curve look-up-table that generates the output reference current based on the measured output voltage. Stability analysis is performed based on the classical phase margin and gain margin criteria. Finally, the performance of the PV simulator is examined in terms of its steady state IV curve matching capabilities and the convergence time to the PV module IV curve of interest corresponding to a step change in load. The result shows a well behaved and responsive PV simulator that can be treated just like a real PV module in most situations.