Series Resonant Induction Heating Power Inverter Developed

This paper present a detail analysis of a PFM control on IGBT series resonant inverter for induction heating application. The control consists of three loops, power regulation loop, phase limitation loop, voltage limitation loop, which are analyzed in this paper, the structure of the compensation network and parameter are derived. The implementation of the control circuit is described and experiment results are shown.For the drawback of big switching current and angle in an over loading condition, current and phase double feedback are presented, which can reduce switching current in over loading condition, so reducing switching loss, and it do not change power regulation under rated load with a alterable coefficient of phase feedback, experiment results has prove itSome protect strategy are also presented based on the detail analysis on the short circuit event in the inverter or inductorium, some simulation and experiment results has prove it.To increase the power level of induction heating application, a new topology of LLC resonant are analyzed, which can restrain the shunt current of parallel inverter, the paper also give some compare in control strategy between LC and LLC, some simulation result are given.