A Comparative Evaluation of SMR With and Without Active Input Waveshaping Converters Current

Absrract-This paper describes the comparative evaluation of highfrequenc) 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 up to medium power applications (i.e., 3 KW) VSF SMR converters (Fig. 1) use passive waveshaping techniques. CSF SMR converters (Fig. 2), on the other hand, use active waveshaping techniques in conjunction with one of the current control methods described in 161. Use of active waveshaping techniques increases the input power factor from approximately 0.5 to 0.9-1.0. This paper shows 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. Finally, key theoretical results are verified experimentally.