Induction cooker design and experimental results with quasi resonant topology and jitter method

Abstract

This thesis presents an induction cooker design and its detailed experimental results. The design is based on Quasi Resonant Topology and is unique in terms of the particular Jitter Method it employs to drive the semiconductor switches (IGBTs). Most induction cookers are based on Half Bridge Topology. Although Quasi Resonant Topology offers a more cost effective implementation, it introduces more EMI problems. However, we solve these problems with our Jitter Method. Although there are other works in the literature that solve the EMI issues by some sort of jitter methods (i.e., spread spectrum methods), these methods do not address the high voltage stress created across the IGBTs. However, the Jitter Method proposed in this thesis also reduces collector-emitter voltage stress besides improving EMI. Note that jitter methods also prevent mechanical vibration (i.e., resonance), which cause audible noise. Another thing that makes this thesis unique in the literature is the rich set of experimental results it contains ? based on an experimental prototype we built with a power rating of 2300W. While the existing literature mostly contains theoretical treatment, we have produced detailed experimental results for Quasi Resonant Topology and show that the current harmonics (drawn from the utility) stay within the published standards (TS EN 61000-3-2). We also include experimental results for Delivered Power Detection, Pan Detection, and Protection Circuits.