Study of a single stage buck-boost three-phase rectifier with high power factor operating in discontinuous conduction mode (DCM)

This paper presents a three-phase Buck-Boost rectifier operating in discontinuous current mode (DCM). The main advantage of the proposed circuit is to provide, with a single stage, output voltages lower or higher than input voltage peaks. The command is very simple, with all switches simultaneously powered by the same pulse. The control of the structure is achieved by a voltage loop only. This can be accomplished because in DCM operation the input current shape is determined by the input voltage. Practical results of a 90 V input voltage project are presented. Sinusoidal currents with lower distortion and high power factor on Buck and Boost modes were obtained. Principle of operation, theoretical analysis and practical result are presented.