Switched-Inductor Based High Voltage Gain Step-up DC-DC Converter for Photovoltaic Micro-Inverter Application

Traditional boost converter cannot offer a high voltage gain due to the conduction losses in the ESR of capacitor and DCR of inductor, at higher duty cycles. Therefore, traditional boost converter cannot be employed for voltage conversion in occasions that need very high voltage boosting such as the grid-connected photovoltaic micro-inverter. In this paper, a high voltage gain step-up converter, utilizing a switched-inductor (S-L) cell, is proposed. The input current of the suggested converter is continuous because of the presence inductor at source side that makes the input filter design easier. This converter produces very high output voltage at a lower duty cycle, which makes it suitable for photovoltaic micro-inverter application. The basic operation principles and steady-state analyses of the proposed step-up converter are discussed to derive the voltage gain and voltage/current stresses across each component. The proposed boost converter is finally simulated in MATLAB/Simulink to verify all theoretical analyses.