Harmonic Reduction and Unity Power Factor by Using PWM Controlling In Dc Motor Load

The paper shows the modeling, simulation and analysis of an AC-DC converter based single phase PWM rectifier fed dc separately excited motor. It provide a suitable controlling for a pulse width modulation rectifier which reduce ripple from the DC output side, reduced harmonics as well as shape the input current . The main objective of a PWM rectifier is to regulate the DC output voltage and also a sinusoidal input current and power factor should be unity. This is implemented by MOSFET switches connected in anti-parallel mode across the rectifier diodes. The output voltage is controlled by switching these MOSFET and higher order ripples at the output can be easily eliminated by using filters. Lower order harmonics are throwing off using PWM technique. The PWM generates gating pulse and give the output rectifier. The output of this PWM is the gating pulses to be applied to the input single phase rectifier. By this PWM control method, we have tried to diminish the input current harmonic distortion and bring the input current and voltage in same phase as well as make it sinusoidal. This paper presents the state in the field of single phase rectifiers with reduced input harmonics and improved power factor. The simulation results of the presented techniques have been demonstrated and concluded for various load resistance.