Impact of active power curtailment on overvoltage prevention and energy production of PV inverters connected to low voltage residential feeders

As non-controllable power sources, photovoltaics (PV) can create overvoltage in low voltage (LV) distribution feeders during periods of high generation and low load. This is usually prevented passively by limiting the penetration level of PV to very conservative values, even if the critical periods rarely occur. Alternatively, one can use active power curtailment (APC) techniques, reducing the amount of active power injected by the PV inverters, as the voltage at their buses increase above a certain value. In this way, it is possible to increase the installed PV capacity and energy yield while preventing overvoltage. This paper investigates a number of approaches for sizing and controlling the PV power generated by 12 net-zero energy houses equipped with large rooftop PV systems in a typical 240 V/75 kVA Canadian suburban radial distribution feeder. Simulations of a one year period with typical solar irradiance and load profiles are conducted with PSCAD to assess the performance of the different approaches in terms of overvoltage occurrence, sharing of the burden for overvoltage prevention per house and total energy yield of the residential PV feeder.

► Overvoltages on LV residential feeders with solar houses are discussed.
► Reducing installed PV capacity can prevent overvoltages, but limits energy yields.
► Using APC one can use the desired installed PV capacity and avoid overvoltages.
► But, using APC, houses located downstream on the feeder curtail more energy.
► With APC-OPLS, the later can be avoided and prevents overvoltages.