Improved voltage regulation strategies by PV inverters in LV rural networks

The growth of world energy demand and the environmental concerns lead to an increase of renewable energy production over the last decade. The increased number of grid-connected photovoltaic (PV) systems gave rise to problems concerning the stability and safety of the utility grid, as well as power quality issues. Lately, PV generators are required, according to the new German Grid Code (GC), to contribute to the grid stability and to provide grid classical functions during normal and abnormal operation. The purpose of this article is to investigate and optimize the standard voltage regulation methods for low voltage (LV) grid-connected PV systems. Reactive power supply strategy proposed by the German GC Q(U) is investigated and simulated performing load flow analysis on a European residential network benchmark. In order to improve the reactive power transfer in the system, an optimized algorithm of voltage regulation is designed with the aim of minimizing the losses in the system for a better integration of PV power generation into the grid.