Abstracts Category : Other

Dynamic control of an induction heating process to reduce energy consumption

by Bernado Javier Campos

Masters Research - Master of Philosophy (MPhil) This thesis deals with the need to reduce the electricity demand in induction heating processes, in particular those used in the steel industry where a large amount of electrical energy is used. Current practices are almost entirely based on open loop schemes where the surface temperature of steel rods is the main target. No consideration is given to energy efficiency. A human operator controls manually the power setting to the electronic converters to modify the rod temperature and therefore the use of electricity. New techniques to reduce the energy demand based on a combination of traditional open-loop strategies and novel closed-loop control are developed in this thesis and some industrial experiments are carried out. The proposed techniques include closed loop strategies such as non-linear model predictive control and off-line optimizations. Some of them are presented from a theoretical perspective while a few of them could be implemented in the industrial environment. The need of a large industrial facility of several Mega Watts to test the improvements implied that only a few number of trials could be implemented. One of the off-line optimizations carried out in this thesis consisted in seeking the best balance of power across an induction heating process formed by two furnaces. The modification of this power balance resulted in a saving in energy whilst satisfying all the metallurgical constrains of the process described in details in Chapter 3. Indeed for the studied process, our results show that a saving range of 2% to 5% can be achieved according to the production conditions. It is believed that a combination of several techniques described in this thesis has the potential to reduce the energy in more than 10 % when compared to a traditional open loop strategy. Future work will be aimed at customizing the methodologies towards full industrial implementation of closed loop control.Advisors/Committee Members: University of Newcastle. Faculty of Engineering & Built Environment, School of Electrical Engineering and Computer Science.