Impact of Dynamic Voltage Support of Large-scale PV Plants on Frequency Stability in the Senegalese Power System

In modern grid codes, non-synchronous power plants are required to provide dynamic voltage support (DVS) to preserve the grid stability in the event of a fault. However, this function remains to be explicitly defined for LSPVPs in the Senegalese power system (SPS), and is subject of investigation in this paper. The impact of enabling the DVS in large-scale photovoltaic plants (LSPVPs) is compared to the momentary cessation mode during low voltage ride-through (LVRT) on power system voltage and frequency stability. As case study, the Senegalese power system is simulated in PowerFactory software. The results demonstrate that enabling DVS strengthens the point of interconnection and prevents the disconnection of large-scale PV plants during transmission line faults. Furthermore, the implementation of DVS improves the frequency stability while increasing the share of large-scale PV penetration in the power system. For a total wind and LSPVPs penetration of 55.7 %, the frequency nadir is enhanced by 1.48 % and the steady-state frequency deviation by 0.9 %. At a penetration rate of 66.8 %, the DVS of LSPVPs avoids triggering underfrequency load shedding; and improve the frequency nadir and the steady-state frequency deviation a by 4.17% and 1.5%, respectively.