Design and Analysis of 15 Level Multilevel Inverter with Reduced Number of Switches for Renewable Applications

Abstract

To reduce the environmental impact, power generation using solar power plants is increasing day by day. The generated DC needs to be converted to AC for the AC loads or to connect to the grid without disturbing the grid performance. Multilevel inverters is a good option as the output voltage of a Multilevel inverter is a stepped waveform which approaches a sinusoid providing lesser harmonic distortion. As the number of levels are increased the harmonic distortion reduces but at the same time the number of switching devices and the DC voltage sources required increases, thus increasing the complexity of the system design and control. Multilevel inverter proposed in this paper uses only 7 switches to provide 15 levels of output voltage for renewable applications such as solar PV. As the number of switches used are less, the complexity and the control is reduced. Keywords—Multilevel inverter; 15 level MLI; reduced number of switches; total harmonic distortion. Abbreviations: MLI, Multievel Inverter; EMI, Electro Magnetic Interference; PV, Photo Voltaic; NPC, neutral point clamped; PWM, Pulse Width Modulation; THD, total Harmonic Distortion.