Improved modelling of induction and transduction heaters.

摘要

This thesis starts by describing research on the design of low frequency induction heaters usinga series equivalent circuit model. Limitations associated with this design method are explained.An alternative called the transformer equivalent circuit (TEC) model is then presented. Thismodels the induction heater as a single turn secondary transformer. Its advantage is that thecurrents and voltages associated with components of the induction heater are what you wouldexpect to measure on components of an actual induction heater. Finite element analysis (FEA)is also used to predict the performance of induction heaters. The performances of these modelsare compared, with experimental veri cation on a small induction heater unit.The research is then extended to transduction heaters, a combination of transformer and in-duction heaters, which include a secondary winding to boost performance. The transformerequivalent circuit method is used to predict the performance of transduction heaters as theycannot be modelled using the series equivalent circuit model. The performances of the trans-former equivalent circuit and nite element analysis models are compared with results from aset of experimental transduction heaters.Modi cations are then made to the components of the TEC model to improve its performancepredictions. The accuracy of TEC modelling is con rmed with a second design and veri edwith experimental results. This forms the basis for the nal design and implementation of anindustrial unit.The improved TEC model is then used to predict the performance of a 40kW transduction uidheater that was designed, built and tested. Comparisons are made between the TEC and FEAmodels calculated results and test results. The TEC calculated results yielded much closer valuesto those measured.