Digital Control Power System Used for Induction Heating

Abstract

The main purpose of this thesis is to propose a digital control power system used for induction heating The system is separated into two stages-the former a buck converter and the latter a full-bridge inverter The output power is limited through the buck converter while the system begins a one-time scan between 40 kHz ~ 60kHz searching for the absolute maximum resonant frequency in this interval Perturbation and Observation method is applied to the full-bridge inverter to realize Maximum Power Point Tracking The actual output power generated by induction heating is maximized by slightly adjusting the resonant frequency found before to maintain its local maximum When the parallel R-L-C resonant circuit formed by the resonant capacitor and load begins to resonate maximum power is transferred to the load causing it to begin to heat In this thesis the basic theory of induction heating is introduced initially Then the operating principles and control methods of the circuit are discussed and the design procedure is also described Finally a prototype of the system with input voltage 300 Vdc output power 6 kW and switching frequency between 40 kHz ~ 60 kHz is implemented to verify the theoretical analysis

Date of Award	2015 Aug 12
Original language	English
Supervisor	Jiann-Fuh Chen (Supervisor)