Analysis of induction heating apparatus controlled by two excitation coils with different frequencies

摘要

This paper describes analysis of an induction heating (IH) apparatus for hardening iron rods. The examined IH apparatus is equipped with two excitation coils to control heating characteristic of target materials by changing frequencies of applied voltages. As a fundamental investigation, beat phenomenon due to excitations at different frequencies, which cause instability of control process, are examined by analyzing magnetic fields and eddy currents under various exciting conditions by means of the finite element method. The beat phenomenon of coil currents and flux densities in a target material to be heated are discussed.