The most commonly used multilevel inverter is the diode clamped inverter, in which diode is used as the clamping device to clamp the dc bus voltage so as to achieve proper steps in the output voltage. Thus, the main concept of this type of inverter is to limit the voltage stress across the power devices with the help of diodes. An n level inverter needs (n-1) voltage sources, 2(n-1) switching devices and (n-1) (n-2) diodes. By increasing the number of voltage levels, the quality of the output voltage is improved and the voltage waveform becomes closer to a sinusoidal waveform.