Reduced Losses in PV Converters by Modulation of the DC Link Voltage

摘要

The efficiency of PV systems has improved by the fact that the researchers have used different techniques to increase their technical capabilities. This paper aims to present how the PV converter losses can be reduced by employing a polypropylene capacitor in the DC link and to modulate that DC voltage. This modification leads to problems with controllability and stability. In order to solve them two current control methods are presented - constant off time and a PWM type with second order high pass filter DC-link feedback. PV converters that utilize polypropylene capacitors do have lower losses and have lower cost. The PV converter simulation in Matlab SimulinkTM and lab experiment, presented in this paper, are based on a three-phase bridge APTGF50X60T3G, used to combine a step-up/step down and H-bridge in one package.