A new zero-voltage transition pulse width modulated boost converter

Abstract

In this study, a new active snubber cell is proposed for pulse width modulated (PWM) converters. This snubber cell provides zero-voltage transition (ZVT) turn on and zero-voltage switching (ZVS) turn off for the main switch. In the converter with the new snubber cell, auxiliary switch is turned on with zero current switching and turned off with ZVS. Also, the main diode and all of auxiliary diodes are operating with soft switching (SS). At the same time, in this converter, all SS energy stored in the snubber inductance is transferred effectively to the output by a transformer, and so the current stress of the auxiliary switch is reduced significantly. Also, this transformer provides possibility of using the capacitors required for ZVS turning off of the main and auxiliary switches. In this converter, no semiconductor device has any additional voltage and current stresses and SS-operating conditions are maintained at very wide line and load ranges. In this study, detailed steady state analysis of the new ZVT-PWM boost converter is presented, and this theoretical analysis is verified experimentally by a 1 kW and 100 kHz prototype.

A ZVT–ZCT PWM synchronous buck converter with a simple passive auxiliary circuit for reduction of losses and efficiency enhancement

“…Table 2 shows the comparison of recent topological circuits with the proposed circuit. As shown in the Table 2, the circuits are modern ZVT-ZCT PWM topologies [22][23][24] are prominent in curtailing the spike of the main switch and diminishing the reverse recovery (RR) problem of the synchronous switch Refs. [22][23][24].…”

“…The RR problem of main diode is eliminated. In [22,23] the coupled inductors are used in the auxiliary circuits which in turn expands the volume of the total circuit. The proposed auxiliary circuit not only exceeds the advantages of the contemporary circuits, but also obliges both switches to operate under soft-switching conditions.…”

“…Table 2 and the results proclaim that the proposed auxiliary circuit has accomplished comparable efficiency enhancement over the hard switching circuit to a decent value. The proposed converter does not use the coupled inductors as [22,23] and also it has a simple design with ease of control.…”

“…Because of its low additional conduction losses and its operation which almost replicates as of PWM converters, the soft-switching techniques have allured the attention in the recent times [18][19][20]. In ZVT-ZCT converters [19][20][21][22][23][24] generally the auxiliary switch actuates just before the main switch is made active and culminates after it is executed.…”

Zero-voltage transition–zero-current transition pulsewidth modulation DC–DC buck converter with zero-voltage switching–zero-current switching auxiliary circuit

“…The total time of the transient periods is long in the circuits in [1,3,4,6,15]. The amount of components used in the snubber cell suggested in [12,18] is more than other ZVT or ZCT snubber cells. Moreover, in the study [6] the snubber cell diode placed on the main current line in the converter.…”