Resonant voltage limiting technique of single-ended resonant inverter for induction heating

Single-ended resonant inverter topology is widely used in domestic induction heating (IH) application due to its concise structure and cost effectiveness. Whereas high resonant voltage caused by the energy transfer between load inductor and resonant capacitor in the IH system may negatively affect the operation of system and long-term reliability. Generally, 1200V rating IGBT is popularly used for single-ended IH cookers. However, abnormal conditions of AC supply suddenly increases the resonant voltage thereby IGBT can be destructed. Resonant voltage limiting technology is proposed by restricting the maximum current flow to the load inductor in order to relieve the voltage stress across the IGBT. The effectiveness of the proposed method is verified for AC supply distortion by using 1.35 kW single-ended IH system.