MULTILEVEL INVERTER WITH LEVEL SHIFTING SPWM TECHNIQUE USING FEWER NUMBER OF SWITCHES FOR SOLAR APPLICATIONS

Mahajan Sagar Bhaskar Ranjana, Pandav Kiran Maroti, Ruchita Maheshwari, Pachagade Ruchi M

Abstract: A multilevel inverter (MLI) is a popular inverter for solar based high power applications. The drawback of conventional H-bridge inverter is non-sinusoidal output voltage, which reduces the output quality of inverter. Later, the drawback of conventional Hbridge was overcome by conventional MLI. But, conventional MLI needs maximum number of diodes and switches. In order to overcome this drawback proposed MLI topology with level shifting sinusoidal pulse width modulation (SPWM) technique can be employed. Proposed MLI contain fewer number of switches and diodes, which helps in optimizing the circuit layout, reducing gate driver circuit for those switches. SPWM technique uses multicarrier waveforms with level shifting ensuring the reduction in total harmonics distortion (THD). In this Paper level shifting SPWM technique has been incorporated in which 5 kHz carrier wave is compare with 50Hz of sinusoidal wave with a modulation index of 0.8. THD of proposed 9-level inverter is 17.27% without filter and 4.29% with LC filter. Simulation of proposed inverter is carried out in MATLAB/SIMULINK.

Keywords: Solar, 9-level inverter, Level shifting SPWM, Power diodes and switches, Total Harmonics Distortion (THD)

DOI: https://doi.org/10.15623/ijret.2015.0410062