PWM-controlled soft-switching SEPP high-frequency inverter for induction-heating applications

A novel single-ended push pull (SEPP) soft-switching high-frequency inverter for induction-heating applications with a continuous output power regulation scheme at a fixed frequency incorporating a novel lossless snubber circuit is presented. Conventional SEPP high-frequency inverters have been finding their home-electronic applications owing to their simplified circuit constitutions. However, their soft-switching operations were restricted in a relatively narrow output power range when they were controlled by a PWM technique. The proposed high-frequency inverter topology is based on the conventional SEPP high-frequency inverter together with a novel lossless snubber circuit operated at an auxiliary resonant frequency so that it can be operated under soft-switching as well as PWM regulations. Hence, the soft-switching operation range of the proposed inverter can be widened considering accompanied by a high efficiency compared with the conventional SEPP inverter. Uses can include a home-cooking application with a high thermal efficiency and high safety at a fixed frequency of 20 kHz. The operating principle, is described and the results of computer-aided simulation analysis of the circuit operation and evaluation of the performance of the proposed inverter are given, which show its high utility.