Solar PV Grid Interfaced System with Neutral Point Clamped Converter for Power Quality Improvement

This paper deals with neutral point clamped converter which is connected to photovoltaic (PV) system. Carrier based pulse width modulation technique with proper voltage balancing of capacitors at neutral point is achieved. Here a maximum power point tracking is realized by the help of incremental conductance method which has faster rate of convergence. The major attribution of multilevel converters is its very less harmonic distortion as compared to conventional voltage source converters. Emphasis on switching frequency is also given as actual motive is to seek the improved performance at reduced switching frequency. The power from PV is injected into the grid in order to have reduction in grid current harmonics. Here in accordance to the control strategy, the three level PWM waveform is shown on AC side. The controller action is in such a way that inner loop acts as a current controller and outer one is voltage controller. A decrease in multiple stage in turn helps to improvise the overall impact for the system. Validation of results is also carried by MATLAB simulations. Power quality analysis is carried out in order to determine the validation under IEEE-519 standard.