DESIGN OF HELICAL SHAPED HEATING COIL AND LOAD CIRCUIT FOR H. F. MIRROR INVERTER BASED INDUCTION HEATER

A high frequency series resonant mirror inverter based induction-heated system has been developed with helical shaped heating coil in its primary. To reduce the skin effect loss & proximity loss, the heating coil is made of litz wire. The coil inductance & a.c resistance have been determined using analytical method under on load conditions. With the different secondary metallic objects in its secondary the determined values of inductance & a.c resistance have been found to change significantly. For industrial applications stainless still is preferred due to its high permeability and resistivity. The lab prototype of induction heated system is experimented with water as fluid & stainless still plates as secondary metallic object and for different frequencies efficiencies have been obtained. Finally to decide the load structure the system is tested with single layer, double layer & triple layer metallic sheets made of different metal combinations.