Temperature control in microwave combination ovens Original Research Article

The combined action of microwaves and convection heating increases the flexibility of thermal process operations for conduction dominant materials. This is so since microwaves favour internal heating, while convection promotes surface heating. Accordingly, the simultaneous action of both energy sources offers the possibility of accomplishing, in an optimal fashion, different trade-offs involving safe and high quality operation. However, real-time implementation of such operations is hampered by undesirable coupling effects and disturbances which call for easily implementable and efficient on-line controllers. In this article, we discuss the main issues associated with the operation of microwave combination ovens and demonstrate the ability of simple adaptive model-based controllers in tracking constant and variable oven temperature profiles.