چكيده انگليسي :
Design Construction of A 250KW Parallel Resonant Induction Furnace Ali Mohammadi Najafabadi Date of Submission 2015 03 9 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor Hamidreza Karshenas karshen@cc iut ac ir Abstract This thesis is concerned with analysis and design of a power supply with parallel resonantconfiguration for use in induction furnace applications Induction heating takes advantage of the losses generated in conductive materials by the eddycurrents when exposed to alternating magnetic field The first types of alternating magnetic field wereobtained using motor generator sets and spark gap generators The advances made in late 60 s tomanufacture reliable semiconductors caused the motor generators to be replaced by solid stateconverters Nowadays most power supplies for induction heating applications are based on high powersemiconductor technologies and use SCR IGBT and MOSFET devices A popular topology used inhigh power static converters is parallel resonant topology also known as current source topology Inthis topology the inverter generates high frequency high current square wave output and feeds aparallel resonant tank consisting of a capacitor and induction coil The induction coil contains the workpiece to be heated or melted This coil along with the work piece is usually modeled by a series RLcircuit The resistor in this circuit represents the losses in the work piece In this thesis thecharacterization of the inductor work piece system is performed A model is obtained to understandthe load s behavior based on analytical methods The fundamental expressions and graphs governingthe heating mechanism caused by eddy currents are studied These expressions are particularly becomecomplex in the case of ferromagnetic materials in which the B H characteristic is highly nonlinear Consequently the heat generation mechanism also become more complicated The simulation of aparallel resonant converter is presented in details Simulation waveforms are shown and discussed Expressions governing the operation of parallel resonant circuit and the relationship between variousparameters are discussed in details The design and implementation of a 250 kW power supply ispresented Various experimental waveforms are shown Keywords Induction Parallel Resonant
