IGBT-based High-power Induction Heating Power Supply

Induction heating power supply has been widely used in different heat treatment field. But the traditional induction heating power supply has many disadvantages which are low-efficient, low-power factor and so on. These disadvantages bring great loss for the user and the power grid.This article takes the induction heating power supply as research object. It simply states the operating principle and the latest development trend of the power supply. The issue focuses on the difference between series resonance and parallel resonance. By comparing the two resonant modes, the series resonance shows more stable and reliable on the high power condition. Three kind of power modulation have been emphatically stated yet. The result indicate the chopper power regulation has more adaptive compared the other two.For the induction heating power supply, the efficiency is one of the most important design indexes. But the high power supply is always poor efficiency. Aimed at this disadvantage, the soft switch technology which using the COT(Constant On Time) control mode has been applied to the DC/DC part of the power supply. The experimental result shows the AC power loss reduced significantly, the circuit worked stably at the same time. And the efficiency of the power supply is improved dramatically.Finally, a 10 k W/20 k H prototype has been realized, the experimental result meet expectations.