A discrete pulse group control-based series resonant inverter with complete ZCS-assisted inductors for consumer high frequency IH application

This paper presents a pulse density modulated (PDM) voltage source high frequency series load resonant soft switching inverter (SRI) for the HF induction heated fixing roller in the energy saving copy and printing machines. The proposed simple and high efficiency SRI based on PDM control operation can achieve complete zero current soft switching for wide output power regulation ranges. In this work, its transient and steady-state operating principle are described and analyzed on the basis of high frequency PDM. The operating performances as power conversion efficiency, power losses analysis and temperature rising characteristics of this SRI are demonstrated and discussed through experimental results with specific control processing. Finally, a comparative study of induction heated fixing roller and conventional halogen lamp heater are also discussed from a practical point of view.