A new instantaneous-current controller for three-phase buck-boost and buck converters with PFC operation

Abstract

A new instantaneous-current controller for three-phase buck-boost and buck power converters with power factor correction (PFC) operation is proposed. Based on the idea of a three-phase equivalent pulse-current-source with delta-form, the controller simply generates three-phase switching-patterns for PFC operation. Additionally, the controller employs a pulse-space-modulation technique to compensate modulation errors caused by ripples in the DC-inductor current and to reduce the size of the inductor. The modulation technique is further extended to realize a discontinuous-switching scheme to reduce switching losses. The paper describes the theory and the implementations. To show the validity of the theory, experimental waveforms, spectra and static characteristics, obtained by a 3 kW setup are introduced. Finally, conclusions are drawn and abilities and problems for future study are described.<>