A prototype has been designed and constructed that has fed 3kW into a
Commercial workcoil at 150 kHz. Another lower power inverter has been
built. This was developed with ease of production in mind to aid the
transfer of technology to the sponsoring company. The company have
adopted this unit and are manufacturing it.
The thesis reviews induction heating power supplies with emphasis on
those able to operate above 100 kHz. Members of the MOSFET family are
described and critically assessed for the application
Prototypes of various configurations have been constructed and
experience of these has led to the choice of current fed topology as the
best for the application.
The design and layout of a three phase current fed full bridge inverter
that can feed 5 kW into an industrially relevant coil at 400 kHz and a
single phase 2.5 kW version are described. Results of tests carried out
on the units are presented.
A microprocessor system has been selected which has been used for closed
loop control of power, temperature and housekeeping tasks such as the
supervision of interlocks.
A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy of Loughborough University.