Current Control Of Grid Tied Inverter through SHEPWM Method

The grid connected inverters are increasingly used nowadays in distributed generation and smart grid. But the main challenge in grid connected systems is their compatibility with grid utility and also to maintain the harmonic contents of output current. To overcome these challenges, different current control techniques are used so far. This paper presents a multilevel inverter for single phase grid connected system. The switching of the inverter is based on Selective Harmonic Elimination PWM method where switching angles are calculated by Newton Raphson (NR) method. The main objective is to inject power in to the grid, to reduce the harmonics of grid current and to synchronise the grid frequency with inverter frequency. The results are verified through MATLAB/Simulink and experimentally using low cost microcontroller.