Soft-switching Full-bridge DC-DC Converter Research Articles

Inverter optimization of soft-switching DC-DC converter*

The paper describes the influence of the magnetizing inductance of the transformer on zero-voltage switching of the primary transistors in a soft-switching full-bridge dc-dc converter with a controlled rectifier and turn-off snubber. The optimized version of the transformer allows for achieving a full zero-voltage and zero-current turn-on of the primary transistors in a full-bridge soft-switching DC-DC converter. The analysis is verified by measurements on a laboratory model of the converter. The influence of undischarged output capacitances on the efficiency is measured as well. Also, the impact of the GaN transistors on the zero-voltage switching is discussed.

A Soft Switching Full-Bridge DC-DC Converter with Active Auxiliary Circuit

DC-DC converters are widely used in many applications such as power supplies, PV system, renewable energy systems and industrial applications. One of the main problems in dc-dc converters is the switching loss which affects efficiency and also the power density of the converter. To alleviate the switching loss problem this paper proposes novel soft switching PWM isolated dc-dc converters topology. The proposed full bridge dc-dc converter with active auxiliary circuit is designed and tested with full-bridge rectifier diode. The proposed converter is designed and evaluated in term of soft switching. In the proposed topology, the soft switching operations are achieved by charging and discharging process of the capacitor and additional switches. In the proposed topology, all the power switches operate under soft-switching conditions. Therefore, the overall switching loss of the power switches is greatly reduced. The output voltage of the converter is varied by PWM control. The effectiveness of the new converter topology is evaluated by experimental results of a laboratory scale down prototype. The obtained experimental results are found agreed with theoretical and soft switching is achieved.

Novel soft-commutation DC–DC power converter with high-frequency transformer secondary side phase-shifted PWM active rectifier

This paper presents a novel circuit topology of the voltage source type zero voltage soft-switching (ZVS) full bridge DC-DC power converter with an isolated high-frequency transformer, which incorporates zero-current soft-switching (ZCS) phase-shifted (PS)-PWM active power switches in series with diodes of two bridge arms of a full-bridge rectifier on the high-frequency transformer secondary side. This high-frequency linked DC-DC power converter can achieve ZVS for noncontrolled active power switches on the primary side of the transformer and ZCS for PS-PWM active switches on the secondary side of the transformer under wide load variations as well as a wide PS-PWM regulation range. The switching power losses and conduction power losses of the active devices of the proposed DC-DC converter can be considerably reduced. The proposed DC-DC converter blocks circulating current flowing through the semiconductor switching devices on the transformer primary side as compared to the lossless snubbing capacitor and transformer leakage and magnetising inductor-assisted soft-switching full-bridge DC-DC converter with ZVS PS-PWM scheme on the transformer primary side. The steady-state operating principles of the proposed DC-DC converter are evaluated and discussed, based on the simulation and experimental results obtained from a 2 kW-40 kHz breadboard set-up using IGBTs.

Analysis and design of a saturable reactor assisted soft-switching full-bridge DC-DC converter

Analysis and design considerations for a saturable reactor assisted soft-switching full-bridge DC-DC converter are presented. The converter has advantages such as low switching losses with no substantial increase in conduction losses, wide load range, and constant frequency operation. To show how to utilize the analysis results, a 350 W, 500 kHz converter is chosen as a design example. The results are verified experimentally on a prototype converter.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>