PWM STRATEGY FOR THREE PHASE VOLTAGE SOURCE INVERTER WITH MINIMUM HARMONIC DISTORTION

In this paper, comparison between two different Pulse Width Modulation (PWM) techniques employed for three phase Voltage Source Inverter (VSI) is discussed. A suitable PWM technique is employed to obtain the required output voltage in the line side of the inverter. The PWM generation techniques used in this paper mainly based on Space Vector based Pulse Width Modulation (SVPWM) and Modified Space Vector based Pulse Width Modulation (MSVPWM). MSVPWM method involves the comparison of the three phase reference modulating signals with a common triangular carrier wave to generate the pulses for the three phases. Whereas, in SVPWM method, a revolving reference voltage vector is provided as voltage reference instead of three phase modulating waves. This paper analyses the two Pulse Width Modulation techniques for three phase VSI and the current THD is maintained at the level of below 5%. The two Pulse Width Modulation techniques for three phase Voltage source inverter are compared by the current THD values to select the method with lower THD values