On the stability of Q(V) in distribution grids

This paper addresses the subject of possible stability or interaction issues of the decentralized Q(V) control. Therefore, accurate inverter models are integrated into distribution grids and the resulting systems are analyzed in detail. Using suitable evaluation criteria, the systems stability borders and transient responses are assessed and the results are compared to current requirements in standards. Against all concerns, the stability of Q(V) can be approved and it can moreover be shown that even more than the hosting potential could be integrated without exceeding a maximum percentage overshoot of 15 % at all generation units. For the stability limit to be reached, the hosting capacity would have to be multiplied at least with a factor of 100. The current Q(V) standard parametrization proves valid and should be preserved. According to the results in this paper, Q(V) can be unconditionally recommended.