A New Hybrid High Power Factor Three-Phase Unidirectional Rectifier

This paper presents a new unidirectional hybrid three-phase rectifier composed by the parallel association of a single switch three-phase boost rectifier with a PWM three phase unidirectional rectifier. The objective to be reached is to reduce the harmonic content of input currents by processing a fraction of output active power with the PWM rectifier. The proposed structure allows to obtain a THD varying between 0 and 32%, just depending on the power processed by PWM three phase unidirectional rectifier. So, if the PWM rectifier is settled to process 45% of the total output power, the THD obtained is 0. Decreasing the PWM power to about 33% of the load power is possible to achieve the standards requirements. The rectifier topology conception, the principle of operation, control scheme and simulation results are also presented in this paper.