Constrained PV penetration level in LV distribution networks based on the voltage operational margin

In this paper, an approach to the critical photovoltaic penetration level is presented, based on the capacity of a DSO to regulate the voltage in a MV/LV substation by means of Off-Load Tap Changers. The performance of off-load tap changers to cope with an increasing amount of PV is investigated, by introducing the concept of the Voltage Operational Margin: the range of voltage where the tap can be set in order to avoid under-voltage or over-voltage.