A comparison of voltage mode soft switching methods for PWM converters

Abstract

-A comparison study was conducted to characterize the loss mechanisms, component stresses, and overall efficiencies of a group of voltage-mode softswitching PWM methods including two newly developed methods. All soft-switching methods in the selected group allow zero voltage turn-on and turn-off of the main switch and utilize a single auxiliary switch with some resonant components. Advantages and disadvantages are identified for each method. Experimental verification for each soft-switching method are provided. It was found that not all the existing methods improved efficiency over most of the load range, but only those methods that softly switch the auxiliary switch, minimumize redirection current, and recover the auxiliary circuit energy.

A family of improved ZVT PWM converters using an auxiliary resonant source

“…It controls the current flux between main power and auxiliar circuits. In addition, it also controls the current through the auxiliary switch without additional current stresses on main switch as presented in Yang (1993), Moschopoulos (1995Moschopoulos ( , 1996, Smith (1997) and Tseng (1998).…”

“…• higher main switch current stresses, Yang (1993), Moschopoulos (1995) and(1996), Smith (1997) and Tseng (1998);…”

A classification methodology for zero-voltage transition PWM converters

“…To realize such task an auxiliary path must be introduced to divert the current I from main diode to it. This way, the auxiliary circuit can be viewed as a controlled current source (Vlatkovic and Borojevic, 1994;Smith and Smedley, 1997) and a snubber capacitor placed across the switch terminals, Fig 2(a). In practical applications, the controlled current source i a can be emulated by an inductor L a in series with a controlled voltage source v ty , as shown in the shaded area of Fig 2(b).…”

High Efficiency Buck-Converter with Short Circuit Protection

“…The pulses generated by the comparator generate a pulse, which is applied to the NMOS switch and PMOS switch via the logic controller. [5][6][7]. Fig.…”