Current-fed three-phase rectifier with optimum PWM-based sinewave line current shaping and unity power factor correction schemes

This paper describes a new method to select the optimum sinewave PWM patterns of a large-capacity current source-fed active PWM AC/DC converter and a practical procedure to design its input AC side low-pass filter which is used to suppress higher harmonics flowing Into the utility-grid power source. A feasible test is carried out using a 500 kVA active PWM converter which is designed and operated for unique considerations mentioned above. It Is verified that these new considerations are more effective to minimize higher harmonic current components flowing into the utility-grid AC line. Furthermore, this experimental work provides highly efficient AC/DC converter characteristics under a unity power factor correction and sinewave line current shaping schemes.