Abstract
Since three-phase circuit has phase-interference, control/modulation in three-phase converters becomes very complicated compared with those of single-phase converters. Even though, the phase-interference-problem has not been discussed in depth in published work.
As the primary objective, this paper describes an analysis of the phase-interference in a threephase voltage-fed converter cirucuit and resultant phase-decoupled equivalent-circuits expressed with local-averaging-value (or averaging-value in control/modulation period). Then, a simplification of a predictive-instantaneous-current-control for voltage-fed high-power-factor converter is introduced as the secondary objective. By combining the proposed techniques, a simple control/modulation scheme for three-phase high-power-factor converters is obtained.
A controller/modulator for experimental setup is introduced to demonstrate the simplicity achieved by the proposed theories. The pulse-space-modulation scheme, employed in the modulator to compensate modulation errors caused by ripples of the output voltage, is also introduced. To show the validity and applicability of the proposed theory, experimental results obtained from a 2-kW setup are shown. Finally, the paper draws conclusion from this work.
