| Abstract |
This paper describes a new constant-frequency variable power (CFVP) high-frequency load-resonant half-bridge inverter operating at soft-switched PWM scheme and using the latest developed IGBTs for soft-switching. This type of quasi-resonant soft-switched inverter is more suitable for small scale induction-heating cooking appliances with two or more burners. The operating principle of this inverter circuit and its power regulation characteristics are presented
on the basis of computer-aided simulation analysis and experimental results. The proposed quasi resonant
inverter system configuration has the significant advantage of being capable of suppressing the irritating acoustic noise generated from the cooking burners composed of multiple load-resonant inverters. Furthermore, this quasi-resonant half-bridge type inverter using a reverse blocking power switch (IGBT) and a reverse conducting one has many attractive features including lowered switching losses, reduced electrical dynamic stresses, considerable reduction of EMI noise level, snubberless arrangement, high-efficiency, lighter weight, lower cost, high-power capability, easy regulation of output power at a fixed operating frequency and harmful acoustic beat interference noise. The experimental verifications of the soft-switched PWM quasi-resonant half-bridge inverter with CFVP function operating under unity power factor correction and sinewave line current shaping, were carried out and evaluated from a practical point of view. |
