Contents I. Introduction
The number of consumer-owned photovoltaic (PV) systems has been increasing rapidly during the past two decades. Nowadays, a lot of consumers are transforming into "prosumers", referring to users that have a capability to absorb and/or produce energy from/to the utility grid. Moreover, the advancement of technologies and communication infrastructures enable two-way communications between the distribution system operator (DSO) and prosumers (e.g. possibly via a third actor, like an aggregator). These phenomenons enable the transformation of distribution grids into large variety of connected microgrids [1]. The high integration of PV systems in distribution grids uncovers potential benefits for both DSOs and prosumers. It can reduce transmission losses for the utility by producing energy closer to the point of consumption and lower the prosumer’s energy bill from self-consumption and by selling their excess production to the grid. However, the intermittent nature of solar radiance may lead to serious voltage fluctuations beyond the accepted limits in cases where the PV installation are not properly sized. If conventional grid assets (e.g., on-load tap changer or capacitor bank) are not enough to ensure the voltage regulation, the PV production must be curtailed which incurs possible economic loss of revenue for the prosumers. Therefore, a control and coordination between the DSO and prosumers is key for this prominent issue, to ensure the voltage levels of the grid and while fully harnessing the most economical benefits for the different stakeholders.
