Induction Heating of Two Magnetically Independent Loads With a Single Transmitter

Abstract

This paper introduces the design of a system capable to heat two magnetically independent ferromagnetic loads, placed on different horizontal planes, that uses a combination of induction heating and inductive coupling, called inductively coupled heating. The system uses a single primary inductor acting as transmitter to transfer power to a secondary inductor attached to the bottom, coupled load, which is connected electrically with a third inductor that heats the top, independent load. Since no more degrees of freedom are added, the delivered power to the second zone is entirely dependant on the system's geometry, materials and compensation capacitors. Therefore, the ratio of the delivered power to each of the zones becomes very relevant to the design. A finite element model is used to simulate the magnetic fields generated by inductor currents and calculate the impedance matrix. With the impedance, capacitor values and inductors' number of turns are selected with the objective of achieving a high power ratio between the top and bottom zone, as well as minimizing stress in the electronics. A prototype was built to validate the impedance results in the small signal regime first and then the full power regime was used to verify power and current simulations.

Study of half‐bridge series‐resonant induction cooker powered by line rectified DC with less filtering

“…The implementation of IH application with multiphase PFC rectifier and multiple modulation was in [13] to improve the flux distribution on a pan. In [14], only one energized inductor with impedance tuning was used to control the flux on two magnetically independent loads to obtain nearly equal flux gains. Other popular topics include [15] proposing a force model based on the developed Maxwell stress tensor to analyse the magnetic field distribution on the cookware.…”