Analysis, design, and performance evaluation of zero‐voltage‐ripple buck dc–dc converter

Abstract

A buck dc-dc converter with ripple reduction has been proposed previously. However, detailed characterisation and performance analysis were not conducted. This study presents steady-state analysis, design, and performance evaluation of the zero-voltage ripple (ZVR) buck dc-dc converter in continuous conduction mode (CCM). The ZVR buck converter is capable of eliminating the output voltage ripple by employing a two-winding auto-transformer. The expressions for steady-state current and voltage waveforms are given. The equations for the design of the converter components are derived. A step-by-step procedure to design the auto-transformer for the ZVR buck converter using the area-product method is introduced. Derivations of expressions for the power losses in passive components, magnetic core, windings, and semiconductor devices are presented. A laboratory prototype of the ZVR buck converter in CCM with input voltage 12 V, output voltage 5 V, output power 10 W, and switching frequency 500 kHz was designed, built, and tested. Simulation results showing the superior performance of the ZVR buck converter over the poly-phase converters are given. Experimental results are provided to validate the theory. It was observed that the ZVR buck converter produces nearly zero ripples at any duty cycle with efficiency in the order of 90%.