6 December 2012
We are members of the Group of Power Electronics and Microelectronics (GEPM) of the University of Zaragoza. Among our projects, we are focused on the design of induction heating appliances in collaboration with the Bosch and Siemens Home Appliances Group (BSH). The research carried out in this field is mainly focused in three areas: power electronics, digital control and magnetic component design.
The advances in these areas have allowed a significant development of induction heating appliances, and they have become one of the most advanced, reliable and efficient domestic heating technologies.
The study presented in this Letter is a step towards implementing higher efficiency induction heating appliances. Recent developments in wide band-gap semiconductors, such as SiC or GaN, have allowed the design and implementation of higher frequency and higher efficiency power converters. However, the gate drive circuits required by these devices are usually more complex and less efficient. In this Letter, we have proposed an optimised gate drive circuit for a SiC-based junction gate field-effect transistor with optimised efficiency and low cost.
The circuit proposed in this paper is initially intended to provide an efficient and cost effective driver to implement high-efficiency induction heating appliances. This will improve not only the environmental impact of induction heating appliances, but also their reliability and performance. In spite of this, the proposed circuit and operation mode can be extended to any other resonant converter used in other applications such as ballasts or wireless power transfer systems, among others.
The circuit presented in this Letter is just the first step to implement higher efficiency power converters for induction heating appliances. Next steps include the selection of an optimised power converter topology using wide band-gap devices, the design and optimisation of an appropriate induction coil and the design of a digital controller to obtain the desired performance.
Induction heating appliances are one of the most advanced appliances currently present in a home. Current design trends pursue the implementation of higher efficiency appliances with improved performance. One of the latest developments, which lead most of the research activity, is based on a total active surface appliance where the user can place any pot anywhere, significantly improving user performance. The research and development is usually classified in three major fields: power converters, digital control system, and magnetic component design.
Power converters are evolving towards more efficient and more flexible topologies. In order to obtain higher efficiency, new topologies featuring reduced power loss and improved devices are being studied. In addition to this, multiple-output converters are being developed to implement total active surface appliances.
Digital control systems are evolving to implement accurate on-line measurements and automatic pot detection, and to provide advanced power and temperature control. To enable these advances, FPGA technology is being used in order to test the final ASIC implementation for high production volumes. Last but not least, the design of the induction coil has to be optimised through analytical models and finite element simulation. State-of-art inductor designs allow delivering up to 4.5 kW to a single pot.
Since the first available commercial products in the late 80s, induction heating appliances have quickly evolved to become the technology of choice in many European and Asiatic countries. Currently, induction heating is a reliable and efficient technology outperforming most of traditional heat sources such as electric or gas.
From our point of view, the outlook for next years of induction heating technology is promising. On one hand, higher efficiency and higher performance induction heating appliances will be available, increasing even more the technological advantage of induction heating. On the other hand, total active surfaces will become lower cost and widely available, changing the current cooking paradigm.
A PDF version (new window) of this interview is available.
Browse or search all papers in the latest or past issues of Electronics Letters on the IET Digital Library.