Harmonic reduction in a three-phase rectifier with sinusoidal input current

In this paper, a new approach to reduce the harmonics generated by a three-phase diode rectifier is proposed. The proposed approach uses input filters, 6 controllable switches, a high frequency isolation transformer and a three-phase diode rectifier. A novel pulse-width modulation (PWM) scheme implemented in an XC4006 field programmable gate array (FPGA) modulates the switching of the controllable switches. This approach realizes sinusoidal input current waveforms with low electromagnetic interference and arbitrary output voltage. The output voltage can be controlled by variation of the modulation index between in the range (0/spl les/M/spl les/0.98). Experimental results to compare performance with and without the proposed approach are carried out to confirm its feasibility.