EFFECTUAL SVPWM FOR 3-LEVEL NPC-MLI WITH GRID CONNECTED PV SYSTEM

This paper proposes an effectual space vector pulseiwidth modulation (SVPWM) for 3-phase neutral point clamped multilevel inverter (NPC-MLI) which is suitable forigrid connected (PV) system. The use of NPC topology helps in reduction of common mode voltage. The main task of the system is to control the output voltage by tracking the voltage vectors. This strategyiconsists in defining three hexagonal hysteresis bandsiaround the error vector. A lookup table is needed for vector selection with respect to area and sector detection, which determines the switching states of the inverter. Balancing of neutral point voltage is done by redundant inverter switching states. Total harmonicidistortion (THD) factor in the output is decreased by effectual SVPWM algorithm. The input for the inverter is taken from PV source and the output is given to grid connected system. Reduction of switching losses is the other added benefit for the inverter configuration. The proposed structure is verified using MATLAB/SIMULINK and the simulation results were obtained