Single-Switch High Step-Up DC-DC Converter Research Articles

A Single Switch High Step-Up DC-DC Converter Based on Tri-Winding Coupled Inductor for Renewable Energy Applications

This article introduces a novel nonisolated single-switch high step-up DC-DC converter using a tri-winding coupled inductor (TWCL) for renewable energy applications such as PV systems. Also, the voltage multiplier cell (VMC) is used to attain a high voltage gain. The used VMC acts as a passive clamp circuit and reduces the voltage stress across the power switch. So, a low voltage-rated power switch can be used in the presented converter. The suggested topology uses only one power switch with low on-state resistance (RDS-ON), which leads to a simple control circuit and decreases the conduction losses. Highefficiency, operating with low duty cycle, low peak voltage over semiconductor elements, low turns ratio, the number of the coupled inductor, and high voltage conversion ratio are the significant benefits of the recommended DC-DC converter. To show the achievement of the presented structure, operational mode principles, steady-state, efficiency calculations, and comparison results are provided. Finally, a 120 W experimental prototype with 200 V output voltage and 50 kHz switching frequency is built to prove the usefulness of the suggested high step-up converter. The efficiency is measured 92.11% at rated power.

Analysis of Switching Frequency Characteristics of Single-switch High Step-up DC-DC Converter with Three-winding Coupled Inductor

Analysis of Switching Frequency Characteristics of Single-switch High Step-up DC-DC Converter with Three-winding Coupled Inductor

Single-Switch High Step-Up DC-DC Converter with a Resonant Voltage Doubler and low Duty Ratio

High voltage gain can be easily achieved by utilizing a coupled inductor, but high voltage stresses of switching devices can result from its leakage inductance. Hence, snubber circuits are required to alleviate voltage stresses but these can generally lead to power losses. In this paper, a single-switch high step-up DC-DC converter with a coupled inductor and low duty ratio is proposed. A resonant voltage doubler is integrated to obtain higher voltage gain. Zero-current-switching (ZCS) for the diodes in the voltage doubler is achieved by exploiting resonance of the leakage inductance. Additionally, there is no surge voltage in any of the switching device and this makes dissipative snubber circuits unnecessary. Furthermore, maximum voltage stresses of switching devices are much lower than the output voltage and high voltage gain with low duty ratio can be obtained due to the modified cascade boost structure. All this helps to improve overall power efficiency. The operational principle and characteristics of the proposed converter is provided in detail. Experimental investigation using an output 400V-140W prototype at an input 24V- 48V is conducted to verify its functionality.

Single‐switch high step‐up converter based on coupled inductor and switched capacitor techniques with quasi‐resonant operation

This study presents a novel single-switch high step-up dc-dc converter employing a quasi-resonant operation with high efficiency and low ripple continuous input current characteristics. In order to achieve a high voltage gain, a combination of coupled inductor and switched capacitor techniques is used in the proposed dc-dc converter. Moreover, utilising a series resonance capacitor with the leakage inductance of the coupled inductor leads to a resonant circuit. Subsequently, by employing a quasi-resonant operation, the switching loss of the proposed dc-dc converter has been reduced significantly. Operational analysis, mathematical derivation, component voltage and current ratings are well demonstrated in this study. Finally, the performance of the proposed circuit is evaluated through a 200 W laboratory prototype with 25 V input voltage and 400 V output voltage. The maximum efficiency achieved at full load is 96.4%.