Comparison of 3 Level and 5 Level NPC Inverter using SPWM

Multilevel inverters are becoming increasingly popular for high and medium power applications. The diode clamped multilevel inverter (DCMLI) is an attractive high voltage multilevel inverter due to its robustness. For pulse generation the Sinusoidal Pulse Width Modulation (SPWM) technique is used. In this paper a comparative study of 3level multilevel inverter and 5 level multilevel inverter using Sinusoidal Pulse Width Modulation is done. The total harmonic distortion present in the output waveform of 5 level multilevel inverter is reduced compared to 3 level inverter. The inverter is connected to a 1HP induction motor and its performance analysis is done. Torque ripple is reduced in a 5 level inverter compared to 3 level inverter. The result is verified using Matlab simulation.