High-efficiency power converters for domestic induction heating applications

One of the most important features of classical induction heaters is the efficiency. Efficiency, defined as the output-input power ratio is directly related with these terms: environmental impact, the total amount of energy required in the cooking process is reduced as efficiency increases; device stress, efficiency determines the amount of dissipated power, and thus, determines the temperature stress in the electronic stage; maximum output energy, defined as the time-domain integration of the maximum output power. This concept is directly related with temperature regulations, caused by inefficiencies. The analysis of the classical domestic induction heaters reveals that efficiency can be improved by the use of the booster stages. These stages increase output voltage, reducing the required current levels for the same output power, and thus, increasing conduction efficiency in the overall power electronic scheme. A review of the state-of-the-art in boost converters applied to domestic induction heating is performed in this paper. The rectifiers, inverters, and recently studied, direct ac-ac converters have been considered in the analysis. Finally, a benchmark of the reviewed stages is performed based on two criteria: the number of active devices, directly related with cost, and the control complexity, directly related with development time and failure rate.