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This paper discusses about the fixed frequency pulse mask control based high frequency AC conversion circuit for industrial induction heating applications. Conventionally, for induction heating load, the output power control is achieved using the pulse with modulation based converters. The conventional converters do not guarantee the zero voltage switching condition required for the minimization of the switching losses. In this paper, pulse mask control scheme for the power control of induction heating load is proposed. This power control strategy allows the inverter to operate closer to the resonant frequency, to obtain zero voltage switching condition. The proposed high frequency AC power conversion circuit has lesser total harmonic distortion in the supply side. Modeling of the IH load, design of conversion circuit and principle of the control scheme and its implementation using low cost PIC controller are briefly discussed. Simulation results obtained using the Matlab environment are presented to illustrate the effectiveness of the pulse mask scheme. The obtained results indicate the reduction in losses, improvement in the output power and lesser harmonic distortion in the supply side by the proposed converter. The hardware results are in good agreement with the simulation results.

This paper discusses the design and simulation of pulse width modulated based circuit for induction melting application. This high frequency inverter topology have the practical advantages of energy saving, clean environment, high output power due to low switching losses, less electromagnetic noise and low total harmonic distortion. This two stage power converter has single phase full bridge rectifier, DC filter, zero voltage switching pulse width modulation controlled high frequency inverter. In this work, the steady state operation and control strategy of pulse width modulated high frequency inverter is analyzed. In order to achieve energy efficiency switching losses are reduced by operating the inverter above resonance frequency. Input side supply harmonics is also reduced using EMI filter. The simulation of the designed high frequency power supply is carried out at a frequency of 20 kHz using MATLAB simulink tool. Simulation results proof the energy saving due to reduction in switching losses of the presented control strategy and reduction in harmonic distortion of the presented power supply for induction heating load.

This paper presents a double half bridge resonant inverter for induction heating (IH) system composed of two partly coupled coils. Induction coils are electrically characterized by their electrical equivalents, usually a series RL circuit, where the inductance is determined by the magnetic energy stored in the system and the resistance is associated with the power dissipated in the load. Pulse width modulation based control strategy for double half bridge resonant inverter based power supply circuit is presented. The aim of this work is to simulate and obtain the electrical equivalent of the inductor system for accurate power study with two concentric coils by considering the frequency dependent eddy current losses associated with both the pan and the coil. This paper gives an idea about the in new control modes taking advantage of the coupling between coils in order to provide the target output power. The performed analysis includes the description of the operation and principle of the control strategy. The power converter system is designed and the simulation results are presented to prove the performance of the double half bridge inverter for partly coupled induction heating coil.