A comparative evaluation of SMR converters with and without active input current waveshaping

A comparative evaluation is presented of high-frequency voltage-source fed (VSF) and current-source fed (CSF) switch-mode rectifier (SMR) converters supplied from single-phase AC mains and operating under large input voltage and load fluctuations. For medium power applications (i.e. 3 kW), VSF SMR converters use passive waveshaping techniques. CSF SMR converters, on the other hand, use active waveshaping techniques. Use of active waveshaping techniques increases the input power factor from approximately 0.5 to 0.9-1.0. It is shown that when the active input current waveshaping stage is also used to regulate the SMR DC bus voltage, the converter performance can improve substantially. These improvements include reduction in switching stresses of the power semiconductor switches and reduction in the size and ratings of associated reactive components. Key theoretical results are verified experimentally.>