A GTO Scherbius Drive with Sinnsoidal Current and High Power Factor

The paper discusses the strategy of reducing the harmonic currents of the inverter on the base of improving the power factor of conventional static scherbius drives. Not only the harmonic currents of inverter has been suppressed, but also the power factor of inverter has been improved with the aid of subharmonic PWM techniques for deter-mining optimal switching angles and making firing angle α vary between 180° and 270° using GTO thyristor instead of normal thyristor in inverter. The scherbius drive experiments employing the new inverter show that the power factor of leading current type is much higher than lagging current type and the lower order harmonic currents of the inverter have been grertly reduced. The structure and the control of the equipment is very simple.