Analysis, design and implementation of an improved two‐switch zero‐current zero‐voltage pulse‐width modulation forward converter

Abstract

In this study, an improved two-switch zero-current zero-voltage switching pulse-width modulation (ZCZVS-PWM) forward converter, which employs a simple resonant lossless snubber circuit, is introduced. A simple resonant snubber circuit consists of a capacitor, an inductor and two diodes. In proposed converter, switch Q 1 operates under exactly zero-current switching at turn-on, and exactly zero-voltage switching (ZVS) at turn-off, and switch Q 2 operates under exactly ZCZVS at turn-on, and ZVS at turn-off, and the all-passive semiconductor devices operate under soft-switching at turn-on and turn-off. The proposed converter has no current and voltage spikes in the switches in comparison with the hard-switching forward converter counterpart and is suitable for high switching frequency and high-power operation. The proposed converter is analysed and various operating modes of the improved two-switch ZCZVS-PWM forward converter are discussed. Analysis and design considerations are presented and the prototype experimental results of a 160 W (32 V/5 A) proposed converter operating at 300 kHz switching frequency, confirm the validity of theoretical analysis.

Dual‐passive snubber dual‐switch forward converter

“…Thus, the efficiency is decreased. To overcome these limitations, a zero‐current and zero‐voltage‐switching DSF is proposed in [4]. At this topology, the upper switch is switched under hard condition at light load, and the efficiency is decreased extremely in the load lower than 50% full load.…”

“…However, the single-switch forward converter has some drawbacks, such as the transformer reset, hard switching and the high voltage stress on power switch. Some studies have introduced dual switches forward converter topology to solve these problems [1][2][3][4].…”

“…Fig. 4d shows the efficiency comparison of the DPS-DSF converter with converter in [4]. i s1 (t),i s2 (t) = 2 A/div i Llk = 2 A/div i Lr1 = i Lr2 = 2 A/div n s1 = n s2 = 100 A/div V D4 = 50 V/div V D3 = 50 V/div i D3 = 5 A/div i D4 = 5 A/div n Cr1 = Cr2 (t) = 100 V/div ZCS…”

Soft‐switching forward DC–DC converter using a continuous current mode for electric vehicle applications

“…However, it adds many components and keeps the two transformers, so the volume is still large. Other alternatives for the TSFC are in [9, 10], where more compact active snubbers are added. These topologies have few components, but efficiency is high only at the maximum output power; for lower output power efficiency is poor.…”

Modelling, control and realisation of the single‐ended forward converter with resonant reset at the secondary side

“…Another solution to avoid additional winding and reduce voltage stress across the main switches is the use of dual switch [8][9][10][11][12]. The voltage across each switch is the same as the input voltage; however, a complex auxiliary circuit is added.…”