Performance assessment of a three-phase distribution network with multiple residential single-phase PV systems

About 90% of solar photovoltaic (PV) systems installed in the UK belong to the category of residential systems with individual ratings <4 kW. With the falling cost of PV systems, the number of residential PV systems being installed can be expected to grow. The literature discussing the impact of PV on the electric power system typically uses a clustered model, lumping all single-phase PV systems into a single three-phase PV system at 11 kV or higher voltage, thereby ignoring the impact of the distribution of PV systems and the unbalances. This study aims to analyse the performance of a distribution network with multiple single-phase PV systems. The main contribution of the study is the quantification of the percentage of PV penetration at which the presence of PV may adversely affect the performance of the distribution network and the usage of a more probable worst-case scenario than a theoretical worst-case scenario. The use of PV for reactive power compensation to improve the power factor at the substation is also studied. Though voltage profile is generally discussed as the parameter worst affected by the presence of PV, the analysis indicates that it is the last parameter to be adversely affected.