Abstract
This paper is mainly concerned with a performance analysis and a design method of a newly-developed zero-current switching quasi-resonant high frequency inverter (ZCS-QRI) using a single reverse-blocking power device (high-frequency GATT). As a matter of fact, GATT is replaced by the latest MOS-gate power semiconductor devices, MOSFET, IGBT, MCT and Bi-MOSGTO Thyristor.
The frequency-modulated single-ended inverter circuit, which incorporates an auxiliary diode & large reactor cascade branch in parallel with a resonant capacitor connected into the transformerlink series-resonant tuned tank load circuit can stably and efficiently operate in the frequency range from 20kHz up to 50kHz or so. It is proved that the ZCS-QRI is more suitable for several kW induction-heating and-melting power supplies and high-intensity ultrasonic generator, and switched-mode DC-DC converters.
This simple high-frequency ZCS-QRI for induction-heating load model is analyzed introducing normalized resonant and load circuit parameters and control variable on the basis of the computeraided simulation. The load and frequency regulation characteristics of ZCS-QRI and ZCS operation range are illustrated with a normalized expression in addition to voltage and current peak values and stresses of the power semiconductor device. The practical computer-aided design procedure using the inverter characteristics in steady-state expressed in the normalized technique is demonstrated and discussed including a design example. The simulation results of ZCS-QRI are illustrated and compared with the experimental results in trially-produced breadboard.
