This paper presents the overvoltage caused by single and three-phase connected PV to a low-voltage distribution grid. Statistics are obtained based on source-impedance data for 40 000 customers. A stochastic approach is applied to a 28-customer low-voltage network and the probability of overvoltage is assessed. It is shown that the voltage rise due to single-phase connected PV is six times the rise for three-phase connected PV.To mitigate the overvoltage, grid-reinforcement, reactive power compensation, curtailment and coordinated connection of PV can be used. It is shown that reactive compensation is not effective in LV grids due to high R/X ratio. Coordinated connection helps in reducing the overvoltages caused by single-phase PV.Policy suggestions towards three-phase PV installations and coordinated single-phase PV connections are included in the paper.
ISBN för värdpublikation: 978-2-9602415-0-1