Date of Award


Document Type

Open Access Master's Report

Degree Name

Master of Science in Electrical and Computer Engineering (MS)

Administrative Home Department

Department of Electrical and Computer Engineering

Advisor 1

Wayne W. Weaver

Committee Member 1

Paul L. Bergstrom

Committee Member 2

John T. Lukowski


This report develops a control system to keep an induction heater in resonance. When a metallic workpiece is inserted in the air core of the workcoil, the resonant frequency changes. Different workpiece materials affect the resonant frequency and power. This presents a problem since changing the resonant frequency of the circuit while keeping the frequency constant reduces the maximum power of the circuit. Finite element analysis is used to find the circuit parameters of the workcoil and workpiece interaction. A non-linear controller which oscillates based on the resonant frequency of an LC tank is created. Nyquist and describing function analysis is used to find sustained oscillation points of the circuit. A hardware induction heater with a non-linear controller is created to prove the design.