Impact assessment of distributed generation on the power quality and reliability of distribution grid

This paper presents the development of a methodology aimed to assess the impact of distributed generation, specifically Photovoltaic systems (PV) and battery storage, on the power quality and reliability within a distribution network. Reliability is evaluated by means of SAIFI and SAIDI indicators, evaluation of power quality is performed reviewing voltage drops, sags and fluctuations indicators. As different PV and storage penetration scenarios were considered, the amount of generation capable of improving the system power quality performance could be determined. The generation limits represent the amount of distributed generation above which the network performance begins to be undesirable. These limits were determined by means of the recently published concept of hosting capacity (HC). Finally the paper shows that some scenarios of GD penetration reduce potential interruptions but increase voltage sags.