A Simulation Study of Active Snubber Cell for A PWM DC-DC Boost Converter

Abstract

This paper introduces a study of a new boost converter with an active snubber cell which is developed to overcome most of the drawbacks of conventional zero-voltage transition (ZVT) and zero-current transition (ZCT) converters. In the proposed work, the EMI noise is reduced by increasing the power density and efficiency of the pulse width modulation. In this converter, the snubber cell and all semiconductor devices will operate at soft switching even at higher switching frequencies. Further, additional current and voltage stress across the main and auxiliary components is limited. Simplicity in structure, ease of control and soft switching are the main advantages of the circuit. The results of the proposed topology are studied in detail through simulation and results are presented with a high efficiency of 98%. The proposed work demonstrates the feasibility of the converter through simulation results. KEYWORDS:Boost Converter, Snubber cell, zero-current transition, zero-voltage transition. I.INTRODUCTIONSwitching frequency plays an important role in the operation of the converters. PWM dc-dc converters with high frequencies have been widely used in various power electronic applications such as power factor correction, battery charging, and renewable energy applications because of their high power density, fast transient response, and ease and simplicity in control. However, due to high-frequency operation switching losses occur, and has higher electromagnetic interference (EMI), and poor converter efficiency [1]. Switching losses and EMI noises of PWM converters are mainly generated during turn-on and turn-off switching transients [2].Conventional converters operate with hard switching or traditional switching and are known as hard switching converters. During turn ON period, the voltage across the switch tends to increase and the current tends to decrease, which results in some switching losses. Similarly during turn OFF period the voltage tends to increase and the current tends to decrease across the switch. Again it leads to some switching losses. Recently, switch-mode power supplies have become smaller and lighter due to higher switching frequency. However, higher switching frequency causes lots of periodic losses at turn ON and turn OFF, resulting in increasing losses of the whole system. Operating at high frequency with traditional hard switching pulse-width-modulation (PWM) converters is limited because of substantial switching loss. Again it leads to some switching losses that adversely affect the efficiency of operation. High switching losses furthermost reduce the power-handling capabilities of the converters hence reducing their life span and causing limited efficiency. Also transition intervals take long time and cause conduction losses over one switching cycle [3].