Tackling PV-caused overvoltages - synthesis of Monte-Carlo simulation outputs and multi-criteria assessment of mitigation measures

Due to the rapid increase in residential PV capacity, it gets more and more difficult for a Low Voltage (LV) grid to absorb power at peak hours due to overvoltage issues causing concerns to DSOs and prosumers, who are temporarily unable to inject power into the grid. Multiple mitigation measures exist against PV-caused overvoltages in LV distribution grids, among which the following have been investigated via statistical analyses (Monte-Carlo simulations) in previous papers: larger neutral conductor sizing, PV inverter P-Q control, manual tap change of MV/LV transformer, manual household phase swapping, use of an On-Load Tap Changer (OLTC) of MV/LV transformer, use of a neutral point compensator, use of a line voltage regulator/stabilizer or use of centralized battery. A comparison of those options is proposed in this paper and insights are provided based on M-C simulation results, notably regarding the best implementation practices. The comparative analysis notably highlighted that some technologies can either be very effective or not at all depending on the feeder circumstances, such as the potential role of phase unbalance in the overvoltage issue. A simplified decision-making process for DSOs is also proposed to help in the selection of the most suitable solution on a case-by-case approach.