Sinusoidal Pulse Wiedh Modulation Techniques

Abstract

The five level inverter is most widely used inverter in medium and high voltage applications as it has many advantages compared higher level inverters. Modulation is the technique or process in which the characteristics of the carrier wave or signal such as amplitude, frequency and phase are changed in accordance with the instantaneous value of the original or message signal. . Modulation techniques are of two types they are continuous wave modulation and pulse modulation. When the carrier wave is a continuous in nature, the modulation is known as continuous wave modulation or analog modulation. At the point when the carrier wave is a pulse type waveform, the modulation process is known as pulse modulation. There are different Sinusoidal Pulse width Modulation techniques such as In Phase Disposition(IPD), Anti Phase Disposition(APD), Phase Opposition Disposition(POD), Phase shift(PS), Anti-Phase Shift(APS), Variable Frequency(VF), Anti-Variable Frequency(AVF) and Carrier Overlap(CO).The THD of different Sinusoidal Pulse width Modulation techniques are found as carrier frequency is varied and compared.