SUMMARYA soft switching two-switch forward converter is presented to achieve zero voltage switching (ZVS) turn-on of switching devices. In the adopted converter, a buck-boost type of active clamp is connected in parallel with the primary winding of transformer. The energy stored in the transformer leakage inductance and magnetizing inductance can be recovered so that the peak voltage stress of switching devices is limited. The resonance between the transient interval of two main and auxiliary switches is used to achieve ZVS turn-on of all switches. The current doubler synchronous rectifier is used in the secondary side of transformer for reducing the root mean square value of output inductor current, transformer secondary winding current and output voltage ripple by cancelling the current ripple of two output inductors. First, the circuit configuration and the principles of operation are analyzed in detail. The steady-state analysis and design consideration are also presented. Finally, experimental results with a laboratory prototype based on a 380 V input and 12 V/30 A output were provided to verify the effectiveness of the proposed converter.
SUMMARYThis paper presents a zero voltage switching (ZVS) converter with interleaved pulse-width modulation scheme. An active clamp circuit is adopted in the proposed converter to recycle the energy stored in the leakage inductor of the transformer and reduce the voltage stress of the main power switch in the converter. The ZVS feature of switches can be achieved due to the resonance during the transition interval of two power switches. Two full-wave rectifiers with ripple current cancellation are connected in parallel at the output side to reduce the current stress of the secondary winding of transformers. Instead of the conventional interleaved forward converter, power switches in the proposed converter can perform the functions of both forward converter and active clamp at the same time. Therefore, the circuit components in the power circuit are less than that of in the conventional interleaved forward converter. The operation principle and system analysis of the proposed converter are provided. Some experimental results for a 240 W (12 V/20 A) prototype are provided to demonstrate the effectiveness of the proposed converter.
A new half-bridge converter with two currentdoubler rectifiers is proposed. Two transformers are used in the proposed converter. The primary windings of two transformers are connected in series to reduce the voltage stress across the magnetizing inductor, since each magnetizing inductor voltage is equal to one half of the input voltage. Two current-doubler rectifiers at the secondary sides are connected in parallel to reduce the current stress of secondary winding since the secondary winding current is less than one half of the load current. The asymmetrical pulsewidth-modulation technique is used in the proposed converter to regulate the direct current output voltage. The transformer leakage inductance and the output capacitance of switching switches are resonant during the transition interval between two switches in order to achieve zero voltage switching. The operation principle and design considerations of the proposed converter are provided. Experimental results for a 100-W (5 V/20 A) prototype are presented to verify the theoretical analysis and circuit performance.Index Terms-Asymmetrical pulsewidth modulation (PWM), current-doubler rectifier, half-bridge converter, zero-voltage switching (ZVS).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.