[Back]

D.-L. Schultis, S. Petrusic, A. Ilo:
"Modelling of low-voltage grids with high PV share and Q(U)-control";
CIRED - Open Access Proceedings Journal, 1 (2020), 4 pages.

Climate challenges foster the integration of rooftop photovoltaic (PV) appliances. The associated inverters are often equipped with local Q( U) control to mitigate the voltage limit violations in low-voltage feeders. Their presence strongly modifies the behaviour of low-voltage grids. The common lumped model of the latter, which is used for load flow analysis in medium-voltage level, cannot describe their new behaviour. In this study, two lumped models of low-voltage grids are analysed and compared: the common or simplified one that does not consider the effect of the grid itself and the inverters´ different working points in the Q( U) characteristic; and the exact one. Power flow simulations are performed in low- and medium-voltage test grids for maximal PV production. Results reveal high errors of the simplified lumped model that lead to incorrect power flow in medium-voltage grid.

power grids; invertors; power system simulation; load flow control

http://dx.doi.org/10.1049/oap-cired.2021.0101

https://publik.tuwien.ac.at/files/publik_296825.pdf