Mitigation of Lower Order Harmonics in a Grid- Connected Single-Phase PV Inverter

Abstract

In this paper, among from the all topologies ordinary single-phase PV inverter topology considered which is
grid-connected, also single-phase inverter with an inductive filter, and a step-up transformer interfacing is
considered. Generally, this configuration will not introduce any lower order harmonics into the grid due to highfrequency PWM operation. However, an Unconventional factors in the system like core saturation-induced distorted
magnetizing current of the transformer and the dead time of the inverter, etc., participate to a significant amount of
lower order harmonics in the grid current. A proposed system of inverter current control that reduced lower order
harmonics is observed in this paper. An adaptive technique is used for the lower order harmonic compensation.
Furthermore, a proportional-resonant-integral (PRI) controller and its design are also presented. This controller
removes the dc component in the control system, which inject even harmonics in the grid current in the topology
considered. The complete design has been validated with Simulation results.