Capacitor-less induction heating system with self-resonant bifilar coil

In this work, a capacitor-less self-resonating coil-based induction heating (IH) system with magnetic resonant coupling has been proposed. In the conventional heating system, the inclusion of additional capacitor for creating the resonance results in poor efficiency of overall system. To overcome this issue, a bifilar coil system is implemented, which leads to series resonance at a particular frequency. The key mechanism is self-resonance wireless power transfer concept to IH system; hence, no capacitor is needed in the system. The coil has a series association of the coil inductance and capacitance at the resonant operating condition. A mathematical modeling and steady state analysis is performed for the conventional (solenoidal) coil and bifilar coil to estimate the actual value of the capacitance and inductance of the coil. The performance of the bifilar coil system is tested through COMSOL multiphysics simulation tool and parameters like eddy current, magnetic flux, and temperature distribution in the work piece are analyzed. The experimental setup of the bifilar coil-aided IH system is implemented with PIC16F877A microcontroller, and FLIR thermal imager is used to analyze the temperature distribution on the work piece. The experimental results are compared with the simulation results, and the bifilar coil system provides a promising solution.