Impacts on voltage quality of single phase PV systems in Gävle Energis low voltage network

In recent years, the number of photovoltaic systems (PV systems) has increased in Sweden. According to the Swedish Energy Agency the number is expected to continue to increase in the future, much thanks to the declining prices of PV systems. The government´s goal of 100% renewable electricity generation in 2040 can be achieved if half of all small houses in Sweden install PV systems.The 31st of December 2017, Gävle Energi had 39 PV systems whereof 16 had installed capacity of less than 5kW, corresponding to 0,16% of the Swedish PV installations of less than 5kW. In this report a study of how the voltage quality is affected by installation of an increased number of single phase PV systems is presented. The study is performed on 4 different rural area distribution grids and the voltage is analysed with respect to the following quality criteria’s: • Voltage change in connection point, max 5% • Voltage change in interconnection point, max 3% • Voltage variation, ±10% of nominal value (207-253V) 2 different scenarios have been considered for each area: • ”The two houses with largest impedances have PV systems” • ”50% of the houses in one area have PV systems” The simulations performed in this study show that the voltage exceeds one or more of the electrical quality requirements listed above for all four of the studied areas. Measures such as cable reinforcement in connection points and/or interconnection points is recommended