Power Factor Analysis in Distribution Network with Roof Photovoltaic Units

In last decade considerable efforts have been made in the study of impact of photovoltaicunits on the power system performance. Maintaining the power factor at the connection point of photovoltaicunits is important since it allows greater flexibility of supply and power quality demanded by consumers. In this paper a power factor analysis of group of fixed roof photovoltaic power plants (PVPPs) connected to the low voltage distribution network is presented. Power factor analysis was based on the extensive yearly measurement of electricity production of seven PVPPs, recording maximal mean 15-minutes power as well as one-minute power at the 20 kV feeder head and PVPPs connecting points. The correlation between power factor of the feeder and electricity production of the PVPPs for the specific period of day are obtained. Besides, the effects of the power factor of PVPPs on the voltage conditions in the low voltage network are analyzed. Discussions of the results and conclusions that may be of interest to improve the performance of small and medium size on-grid PVPPs, are presented.