Partial Harmonic Current Compensation Applied to Multiple Photovoltaic Inverters in a Radial Distribution Line

The increase of the current harmonic content due to nonlinear loads is one of the main concerns in power systems. Therefore, the possibility to use the current margin of photovoltaic (PV) systems to provide harmonic current compensation have been addressed in several works. In this context, an important point is to ensure that the PV inverter current does not extrapolate its rated current peak. For this purpose, dynamic current saturation techniques are adopted, incorporating the partial harmonic current compensation capability in PV inverters. Thereby, this work proposes to implement the partial harmonic current compensation applied to multiple PV inverters using a dynamic saturation technique based on an open-loop algorithm. Furthermore, a radial distribution line is used to analyze the effects of harmonic compensation sharing among PV inverters under different solar irradiance conditions. The current margin of PV systems are combined to compensate nonlinear load currents in the line. Simulation results show the improvements in the grid power quality, ensuring a total demand distortion (TDD) lower than 5%, as recommended by the IEEE Std 519-2014.