Zero voltage switching DC converter for high-input voltage and high-load current applications

• Published in: IET power electronics Vol. 7; no. 1; pp. 124 - 131
• Main Authors: Lin, Bor-Ren, Chen, Chih-Chieh
• Format: Journal Article
• Language: English
• Published: Stevenage The Institution of Engineering and Technology 01.01.2014; The Institution of Engineering & Technology
• Subjects: centre‐tapped rectifiers; clamped diodes; Converters; DC‐DC power convertors; DC‐DC pulse‐width modulation converter; Diodes; Direct current; Electric potential; flying capacitor; LLC converter; power switches; Pulse duration modulation; PWM power convertors; rectifier diodes; Rectifiers; resonant power convertors; reverse recovery losses; series–parallel resonant converter; Switches; switching convertors; switching losses; three‐level PWM circuit; transformer windings; Voltage; zero current switching; zero voltage switching; zero voltage switching DC converter; rectifier diodes; PWM power convertors; zero voltage switching DC converter; flying capacitor; resonant power convertors; DC-DC pulse-width modulation converter; zero voltage switching; centre-tapped rectifiers; rectifiers; reverse recovery losses; DC-DC power convertors; three-level PWM circuit; series–parallel resonant converter; power switches; switching convertors; LLC converter; transformer windings; zero current switching; clamped diodes; switching losses
• ISSN: 1755-4535; 1755-4543; 1755-4543
• DOI: 10.1049/iet-pel.2013.0128

A new DC/DC pulse-width modulation (PWM) converter with the functions of zero voltage switching (ZVS) for power switches and zero current switching (ZCS) for rectifier diodes is presented for high-input voltage and high-load current applications. Three-level PWM circuit with two clamped diodes and one flying capacitor is adopted to achieve ZVS turn-on for all power switches, to balance two input capacitor voltages and to limit the voltage rating of each switch at one-half of input voltage. Two three-level PWM circuits with the same power switches are used to share the load current for medium power applications. Series–parallel resonant converter or LLC (Lr, Lm and Cr) converter is adopted to achieve ZCS turn-off for rectifier diodes. Thus, the switching losses of power switches are reduced and the reverse recovery losses of rectifier diodes are eliminated. In order to high load current application, four centre-tapped rectifiers are connected in parallel to reduce the current rating of rectifier diodes and transformer windings. Experiments are provided to verify the effectiveness of the proposed converter.