Design and Hardware Implementation of Backstepping Controller Dedicated to the Photovoltaic Emulator

This paper proposes an accurate photovoltaic emulator using the Sepic converter controlled by a nonlinear controller. This emulator is able to reproduce the current/voltage characteristics as a function of weather conditions. In fact, the backstepping controller is designed to control the output current of the Sepic converter, while a modeled PV module is used to generate the reference of current. The modeling of the PV module is carried out by applying an analytic method, this method can identify the five unknown parameters, which are the series and parallel resistors $(R_{s},R_{sh})$, the ideality coefficient a, the reverse current Is0 and the photocurrent Iph0. Also, by using this method, it is possible to obtain an accurate mathematical model of any PV module by just introducing the information given in the datasheet. So, using the mathematical model with the identified parameters, the proposed PV emulator can mimic perfectly the characteristics of any PV model. The performances of the proposed PV emulator were tested and validated under the Matlab/Simulink environment. Also, the proposed controller is implemented on the Raspberry Pi 3 board and evaluated using the processor-in-the-loop test technique. According to the results, the proposed PV emulator is accurate and gives characteristics similar to those shown in the datasheet.