A quasi-resonant ZCS Boost DC-DC Converter for Photovoltaic Applications

Abstract

Renewable energy generation systems, based on photovoltaic modules, currently represent the most suitable solution, for low power levels, to reduce the energy consumption produced by oil and gas. Moreover, they are becoming more and more attractive as the price per watt of the photovoltaic modules is decreasing. However, the conversion efficiency of commercial photovoltaic modules is still rather low so it is particularly important to be able to achieve, in every operating situation, the maximum possible energy. The paper focuses on a predictive current control for quasi-resonant Zero Current Switch (ZCS) DC-DC boost converters suitable for photovoltaic (PV) conversion systems based on transformerless multi-string topology.

Current Source Topologies for Photovoltaic Applications: An Overview

“…Because of the resonance between L r and C r , the current through Q 1 tends to oscillate to a negative value, aiming for Q 1 to have a natural commutation, and the turn-off state is determined by the resonant frequency ( f r ), which cannot be freely varied. A common topology obtained by applying a resonant switch is the boost converter [42][43][44] (Figure 4a). This topology can be analyzed as a constant current (I 1 ) that feeds a voltage load V 2 (Figure 4b).…”

A Zero-Voltage transition full bridge DC-DC converter for photovoltaic applications

“…Usually the analysis of resonant converters considers their employment in switching power supply applications where a wide range of the ratio between input and output voltages is required. On the contrary, in PV conversion systems such ratio is quite limited and the most important requirement concerns the conversion losses [7][8].…”