3-Phase Inverter Using Frequency Divide Function of Ferro-resonant Circuit

Ferro-resonant type power supplies are highly reliable, and are therefore used as power supplies for electronic devices. Recently a three-phase inverter (called a phase-conversion type inverter), a combination of a single-phase square-wave inverter and a phase converter utilizing the phase conversion function of a ferroresonant circuit, has been proposed. However, the use of a phase converter causes difficulties, in that the output voltages are not balanced and the efficiency remains at about 60%. This paper reports experiments, analyses and reviews three-phase inverters (frequency-divide type inverters) which combine a phase converter utilizing a frequency-divide function with a single-phase square-wave inverter. As a result, the device characteristics were determined, and a high output balance and high system efficiency were achieved.