IGBT for high performance induction heating applications

Power Semiconductor IGBT has been the enabling technology for induction heating power inverters. In this paper key IGBT device design techniques and their attributes will be described. It will be shown that IGBT is amenable to fine dialing for soft and hard switching which requires IGBT suppliers to possess sophisticated design, process and applications test capability. The advantages of advanced high voltage IGBTs along with freewheeling diodes will be described for IH quasi-resonant and half-bridge converters. Emphasis will be placed on trench gate IGBT as the most efficient device structure. The power processing efficiency will be presented in terms of overall system efficiency, and particularly, power-loss temperature rise. As a crucial system design criteria for induction heating applications, case or board temperature is emphasized. 1200V, 600V and 1350V platforms, their topology and IGBT device selection will be discussed. The turn off energy (Eoff) and saturation voltage drop (Vcesat) that are optimized by device design represent the most influential factors on system level efficiency and power dissipation. It is shown that precipitous reduction of board temperature of induction cookers is achieved by techniques that simultaneously reduce Eoff and Vcesat.