Commercial utility frequency AC to high frequency AC soft switching power conversion circuit with non smoothing DC link for IH dual packs heater

In this paper, a novel topology of soft switching PWM high frequency AC power conversion conditioning and processing circuit without DC smoothing capacitor filter link from the voltage grid of utility frequency AC power supply source with 60 Hz-100 V or 60 Hz-200 V is proposed and introduced for innovative consumer induction heating (IH) boiler applications as a hot water producer, steamer and super heated steamer. The operating principle of utility frequency AC-high frequency AC power frequency conversion circuit defined as high frequency cycloinverter is described, which can efficiently operate under a principle of zero voltage soft switching and regulate by means of positive and negative alternate asymmetrical PWM synchronized with the utility frequency single phase AC voltage. The dual mode control scheme based on high frequency PWM and commercial frequency AC voltage PDM for high frequency cycloinverter are discussed in order to extend its soft switching commutation operating range in spite of power regulation. This power frequency changer as high frequency cycloinverter is developed originally for the high frequency induction heating boiler in consumer and industrial fluid pipeline system. It is verified on the basis of experiment and simulation results in the steady state operation of the high frequency cycloinverter using IGBTs which is suitable for the business-use IH boiler using new electromagnetic induction heating dual packs fluid heater. Finally, the power regulation characteristics in addition to utility AC side line current harmonic components and power factor characteristics and power conversion efficiency characteristics of this high frequency cycloinverter are evaluated and discussed from an experimental point of view.