The state of the art advanced developments of series-resonant high-frequency inverter using static induction transistors/power modules

The development of a voltage-fed series resonant, high-frequency pulse-width modulation (PWM) inverter system using high-power static induction (SI) transistors/power modules for an induction-heating power supply is discussed. The inverter system, an alternate fast-response power regulation scheme incorporating either a fixed-frequency PWM or a variable-frequency PWM control strategy, as compared with the conventional PWM and PWM hybrid control strategy, is described, including the protection control hardware. It is shown the the load current-adaptive frequency tracking-based PWM control implementation using a two-channel, phase-locked loop system with protection logic hardware is effective in minimizing switching losses and stresses. It also reduces EMI noise level, accomplishes fast-response voltage regulation, and solves dead-short circuit problems that are due to fast-recovery diode characteristics in a power regulation process. Computer-aided simulation results and experimental results based on a 200 kHz-20 kW/40 kW breadboard using the optimum drive-circuit and interface of SI transistors are presented.<>