Practical study of a laboratory undersized grid-connected PV system

This paper portrays a practical study performed on an undersized grid-connected PV system. The study was achieved in the workshop of the Electrotechnics Department of the Faculty of Technological Sciences-University Constantine 1, Algeria, using the PV panels installed on the roof of the workshop. The study concerned the realization of a conversion chain based on a DC boost chopper and a two-level voltage inverter. The control circuit of the DC chopper was analogically performed on the basis of the hysteresis technique. The method of the short-circuit current was used for determining the MPPT and carrying out the reference current. The two-level inverter was numerically controlled using a carrier-based PWM implemented in a dSPACE board interface compatible with MATLAB/Simulink software. For storing the produced PV energy, four acid sulfuric batteries were utilized. The realized conversion chain was interconnected with a grid of a very low voltage. The presented practical results focused on the analogical MPPT hysteresis controller output and the digital carrier-based PWM controller output. The obtained results seem to be in perfect agreement with the presented theory and to be very promising.