Abstracto

Multi Level Invertors for Renewable Energy System

C. Santhana Lakshmi, M.E., (Ph.D)., B. Gandhimathi

Abstract—The flying capacitor multilevel inverter (FCMLI) is a multiple voltage level Inverter topology intended for high-power and high-voltage operations at low distortion. It uses capacitor, called flying capacitors, to clamp the voltage across the power semiconductor devices. A method for controlling the FCMLI is proposed which ensures that the flying capacitor voltages remain nearly constant using the preferential charging and discharging of these capacitors. A static synchronous compensator (STATCOM) based on seven-level flying capacitor inverters has been proposed. Control scheme for STATOM controllers had been developed and verified in terms of voltage control, power flow control, and power oscillation damping when installed in a renewable energy system. Simulation studies are performed in MATLAB/simulink to validate the efficacy of the control scheme and the FCMLI-based flexible alternating current transmission system (FACTS) controller. The modified PWM technique is used to reduce switching losses. Also the proposed topology can reduce the number of required power switches. The proposed circuit produces high output voltage and lower electromagnetic interference.