An Auxiliary Circuit for Synchronous Buck Converter to Achieve All Switches ZVS/ZCS Switching in Wide Load Range

2021 ◽  
pp. 699-707
Author(s):  
Jinwei Zhong ◽  
Bingyang Luo ◽  
Song Xiong ◽  
Guorong Zhu
Keyword(s):  
Buck Converter ◽  
Load Range ◽  
Auxiliary Circuit

scholarly journals ZVS Auxiliary Circuit for a 10 kW Unregulated LLC Full-Bridge Operating at Resonant Frequency for Aircraft Application

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1850 ◽  
Author(s):  
Yann E. Bouvier ◽  
Diego Serrano ◽  
Uroš Borović ◽  
Gonzalo Moreno ◽  
Miroslav Vasić ◽  
...  
Keyword(s):  
Resonant Frequency ◽  
Power Density ◽  
High Efficiency ◽  
Harmonic Approximation ◽  
Maximum Efficiency ◽  
Voltage Gain ◽  
Load Range ◽  
Transition Analysis ◽  
Aircraft Application ◽  
Auxiliary Circuit

In modern aircraft designs, following the More Electrical Aircraft (MEA) philosophy, there is a growing need for new high-power converters. In this context, innovative solutions to provide high efficiency and power density are required. This paper proposes an unregulated LLC full-bridge operating at resonant frequency to obtain a constant gain at all loads. The first harmonic approximation (FHA) model is not accurate enough to estimate the voltage gain in converters with high parasitic resistance. A modified FHA model is proposed for voltage gain analysis, and time-based models are used to calculate the instantaneous current required for the ZVS transition analysis. A method using charge instead of current is proposed and used for this ZVS analysis. Using this method, an auxiliary circuit is proposed to achieve complete ZVS within the whole load range, avoiding a gapped transformer design and increasing the efficiency and power density. A 28 Vdc output voltage prototype, with 10 kW peak output power, has been developed to validate the theoretical analysis and the proposed auxiliary circuit. The maximum efficiency (96.3%) is achieved at the nominal power of 5 kW.

scholarly journals A Novel Soft-Switching Synchronous Buck Converter for Portable Applications

2008 ◽  
Vol 2008 ◽  
pp. 1-9
Author(s):  
Anup Kumar Panda ◽  
Swapnajit Pattnaik ◽  
K. K. Mohapatra
Keyword(s):  
Pulse Width ◽  
High Efficiency ◽  
Low Voltage ◽  
Buck Converter ◽  
Soft Switching ◽  
Pulse Width Modulated ◽  
Zero Voltage Switching ◽  
Overall Efficiency ◽  
Zero Voltage ◽  
Auxiliary Circuit

This paper proposes a zero-voltage-transition (ZVT) pulse-width-modulated (PWM) synchronous buck converter, which is designed to operate at low voltage and high efficiency typically required for portable systems. A new passive auxiliary circuit that allows the main switch to operate with zero-voltage switching has been incorporated in the conventional PWM synchronous buck converter. The operation principles and a detailed steady-state analysis of the ZVT-PWM synchronous converter implemented with the auxiliary circuit are presented. Besides, the main switch and all of the semiconductor devices operate under soft-switching conditions. Thus, the auxiliary circuit provides a larger overall efficiency. The feasibility of the auxiliary circuit is confirmed by simulation and experimental results.

Sign in / Sign up

Export Citation Format

Share Document