Asymmetric snubberless current-fed full-bridge isolated DC-DC converters

Abstract

-This paper presents two isolated current-fed fullbridge DC-DC converters that can be used to interface a lower voltage source into a DC bus of higher voltage. The first topology uses a resonant circuit to force current redistribution between low-voltage-side transistors and a passive rectifier. The second topology utilizes an active rectifier with secondary modulation to achieve the same goal. The resonant circuit can be formed by using transformer leakage inductance and the parasitic capacitances of the switches. The converters feature soft switching of semiconductors over a wide range of operating conditions. This is achieved with decreased energy circulation when compared to existing topologies with symmetric control and with fewer semiconductors than in those with phase-shift control. The topologies can be implemented in renewable, supercapacitor, battery, fuel cell, and DC microgrid applications. Steady-state operation and design aspects of the converters are presented and verified experimentally with 400 W prototypes.

Snubberless boost full‐bridge converters: Analysis of soft switching performance and limitations

“…In general, these can be attributed to resonant [22][23][24][25][26][27] and secondary-modulated ones (also referred to as snubberless). [28][29][30][31][32] Although this assumption is not strictly defined and various interpretations are possible, in the present study, the authors assume that clamping in such systems is achieved without a separate dedicated passive or active circuit. Instead, it is achieved with special control principles, by utilizing equivalent inductance and capacitance present in the circuit.…”

“…At the same time, a number of CSC topologies exist that feature clamping and soft switching without auxiliary circuits. In general, these can be attributed to resonant and secondary‐modulated ones (also referred to as snubberless) . Although this assumption is not strictly defined and various interpretations are possible, in the present study, the authors assume that clamping in such systems is achieved without a separate dedicated passive or active circuit.…”

“…APRC topology with uncontrolled rectifier at the secondary side (A) and generalized operating principle (B) [Colour figure can be viewed at wileyonlinelibrary.com]…”

Analysis of Fault-Tolerant Operation Capabilities of an Isolated Bidirectional Current-Source DC–DC Converter

“…• Asymmetric secondary-modulated converter (A-SMC) [32,33], as shown in Figure 3a; • Flyback secondary-modulated converter (FBK-SMC) [34], as shown in Figure 3b; • Symmetric secondary-modulated converter (S-SMC) [35], as shown in Figure 3c.…”

“…Theoretically, reconfiguration to other topologies, like parallel-resonant converters [32,[36][37][38], is also possible. However, that requires significant changes in the control and strongly affects the regulation capabilities.…”