A Novel Burst Mode Control Algorithm for SE-IH Applications to Reduce Switch Current Spikes With Improved System Reliability and Power Conversion Efficiency

Abstract

This article presents an efficient burst mode control algorithm (BMCA) designed to reduce the turn-on switch current spike in the power control of a single-ended induction heater (SE-IH). Modern SE-IH uses two control modes: square wave control at heavy loads and burst mode control at light loads to effectively control power flow to the induction heating load. First, the former achieves soft switching, i.e., zero voltage switching, at higher load conditions by properly controlling the switching frequency or duty ratio. Second, the latter often encounters inefficiencies and potential hazards due to current spikes at the switch turn-ON instant, caused by the sudden discharge of the dc-link capacitor through the resonant capacitor at lower load conditions. These current spikes result in significant power loss and thermal stress, which can ultimately cause the power switch to burn out. This article proposes a novel BMCA that optimizes burst mode operation to significantly reduce current spikes and enhance system reliability and overall power efficiency. The proposed algorithm, thoroughly tested, demonstrates superior performance compared to conventional commercial SE-IHs. Experimental results from a 2.6 kW SE-IH prototype using a TMS320F28377D control board validate the proposed solution’s efficacy under various load conditions. © 2005-2012 IEEE.