A multi-function grid connected PV system with three level NPC inverter and voltage oriented control

In this paper a grid connected photovoltaic (PV) system is presented. The grid integration of the PV system is carried out via a three phase three level neutral point clamped (NPC) inverter. To control the inverter a modified version of voltage oriented control (VOC) method and the space vector pulse width modulation (SVPWM) technique have been applied. With the proposed modification the PV system operates as a shunt active power filter (SAPF), a reactive power compensator, and a load’s current balancer simultaneously. In this way the PV system operates more efficiently compared to the conventional PV systems and offers ancillary services to electric power system. The effectiveness of the proposed control scheme is established through simulation results with Matlab/Simulink in steady state and transient response of the electric power distribution system.

► In this study we examine the behavior of a PV system which provides ancillary services. ► We propose a modified version of the VOC method for three level NPC inverter. ► We proved that the proposed PV system is able to compensate the reactive power of the load. ► The proposed PV system is able to eliminate the asymmetry or the harmonics of the load’s current. ► The proposed PV system is a great solution for industrial applications and future smart grids.