高周波IH応用単相ダイレクトAC-ACコンバータの固定周波数電力制御手法

抄録

The direct ac-ac converter is an effective circuit topology for high-efficient power conversion in induction heating (IH) applications. The conventional pulse frequency modulation (PFM)-based power control scheme causes audible noises between the adjacent IH loads which operate at different switching frequencies. As a solution for the technical issue, a new fixed-frequency power control methodology for a single-phase direct ac-ac converter is proposed in this paper, featuring a wide range of soft switching operation and robustness for abnormal load conditions. The principle of the proposed pulse modulation is explained in detail with the logic circuit diagram of controller. The performances of the ac-ac converter and power controller are demonstrated by simulation, after which the effectiveness is revealed in terms of the power control range and soft switching operation.