Control of Grid Connected PV Systems with Grid Support Functions

The increased number of grid connected photovoltaic (PV) inverters gave rise to problems concerning the stability and safety of the utility grid, as well as power quality issues. The aim of this project is to investigate and improve the standard regulation methods for grid connected PV inverters with focus on voltage support in LV distribution networks. Reactive power supply strategies proposed by the German grid code (cos(P) and Q(U)) were investigated and simulated performing load flow analysis on a typical LV distribution system. An improved Q(U) method was implemented which aims to minimize the reactive power consumption of the distribution system (DS) using the communication protocol IEC 61850. The Ethernet communication based on server/client architecture was used to exchange information.