Dual range flyback topology for high efficiency at dual voltage mains

Abstract

This study introduces a dual range flyback converter, which overcomes low efficiency of the conventional flyback converter for universal mains voltages, i.e. 220 and 110 V AC mains. The topology comprises of reconfigurable primary power loops enabled by additional state switches. This combination allows the converter to run in parallel or series modes, enhancing the performance at 220 V AC high line or 110 V AC low line mains. It reduces the voltage rating of devices, supports two working points that operate in boundary conduction mode under fixed frequency and improves the utilisation of the devices. A 100 kHz, 60 W, 110 V AC or 220 V AC to 13 V DC converter has been designed and tested. The experimental results of the proposed converter have been compared against a conventional flyback converter. The results show a small improvement of performance at low voltage (110 V AC) and considerable performance improvement at high voltage (230 V AC): 0.6 and 2.3% efficiency improvement at full load, respectively.

Dual Voltage Forward Topology for High Efficiency at Universal Mains

“…Typically, a low-stress requirement from a device enables the selection of lower-cost smaller parts. For example, MOSFET with lower breakdown voltage can achieve lower cost and/or better performance (low Rds(on) than a higher breakdown MOSFET; as presented in [17], 400 V MOSFET with lower Rds(on) than 800 V MOSFET is about half the price.…”

“…However, due to low-voltage stress, their size decreases dramatically [17], to the point in which the two low voltage input capacitors of the DVFW have a similar size to a single high voltage capacitor of the conventional forward converter. Note that the DVFW additional state switches and diode have very low stress.…”