Published Paper Details:

In general Pulse width modulation (PWM) techniques of a voltage source inverter (VSI) need a sinusoidal reference signal and triangular carrier signal to generate the required modulating signals for the desired output. Modifications in modulating techniques can be considered in two ways, namely modified reference and modified carrier. The existing multilevel carrier based pulse width modulation (PWM) strategies have no special provisions to offer good quality output, besides lower order harmonics are introduced in the spectrum, especially at low switching frequencies. In this paper an analysis has been made by using pulse width modulation (PWM) scheme for five level diode clamped and cascaded multilevel inverters. The modified PWM scheme generates the inverter leg switching times using only the sampled amplitudes of reference phase voltages. The modified PWM signal generation scheme can be used for any multilevel inverter configuration. The main objective of this work is know the most relevant control and modulation methods by a new reference/carrier based PWM scheme for a Diode clamped and Cascaded multilevel inverters are for 5-level inverters. The performance indexes used in this comparison is total harmonic distortion (THD).