Analysis on the use of non-resonant inverters in single-phase induction heating applications

Induction heating plays an important role in industrial processes and is becoming increasingly important for household appliances such as induction cookers. Most commonly, series or parallel resonant circuits based on IGBT technology are used due to their low cost. In contrast to these, non-resonant converter types are described in this paper for the first time regarding their use in single-phase induction heating applications up to 2 kW. The analysis is based on simulation and measurement results. The proposed non-resonant converter designs offer a very small size and allow full control of the output power. Different pulse pattern for controlling the induction power are investigated. It is found that the full-bridge inverter using block or PSM pulse pattern delivers the best performance and enough power capability. For the test system, the measured average electrical efficiency is 96.8 % over the input power range of 500 W to 1750 W.