An Advanced Controller for Improving the Performance of Single Phase 7-Level Inverter for Grid Connected PV System
This paper proposes a fuzzy controller for advancing the performance of a seven level multilevel inverter for grid connected photovoltaic system. This topology gives reduced THD and improved wave shape rather than conventional controlled seven level inverter. Here we are using three identical reference signals (Vref1, Vref2, and Vref3) with offset value same as amplitude of the triangular carrier (V carrier) signal to generate the PWM signals. Pv based inverter providing seven levels of output voltage and it recounts the improvement of novel modified H-bridge single phase multilevel inverter, it has two diode bidirectional switches and a novel pulse width modulation technique. By controlling the modulation index, the required number of levels of the inverter’s output voltage can be achieved. This topology is advantages in MPPT system. Multilevel inverter with FUZZY control implementation is advantages in improved output waveform, lover the THD and fast error correction. The proposed system was verified through MAT lab/Simulation program.
M. Murali Krishna, P. Chandra Babu