Level Shifted Pulse Width Modulation in Three Phase Multilevel Inverter for Power Quality Improvement

This paper emphasize on harmonics elimination by using 5 level cascaded H-bridge (CHB) inverter. The CHB inverter is having more importance in power electronics application due to reduction in switching losses to other type of inverter. The inverter is adopted with level shifted carrier PWM (LSCPWM) technique. The reference harmonics compensating current signal is generated by synchronous reference frame (SRF) theory and DC side voltage of inverter is regulated by using PI controller. The inverter functions as a DSTATCOM for reduction of harmonics and improvement of power factor. System is designed in MATLAB/SIMULINK for 11kV distribution system.