A Neutral Point Clamped Grid Feeding Voltage Source Inverter with an Improved Control Technique for Solar PV System

This paper presents a neutral point clamped (NPC) multilevel inverter (MLI) with an advanced controller for a three-phase grid-tied photovoltaic (PV) system. NPC inverter is the promising candidate among all MLI to mitigate total harmonic distortion (THD) of inverter current for grid-tied PV system. Controller is another crucial part for designing grid-tied power system. In this paper, a PI+HC controller is proposed to improve the control performance of a fifteen-level (15L)-NPC inverter fed grid tied PV system. The proposed controller is based on the linear PI controller which is connected with a feedback of harmonic compensator (HC) to show excellent performance in terms of injected grid current THD, steady state error, sudden load change response, and the capability of handling different fault conditions than existing controllers. The designed controller is simulated in MATLAB/Simulink environment. The simulated results present the excellent performance of the proposed controller.