Effects of the penetration of inverter-based generators on voltage sags in HV networks: Analysis of the Sardinian network

This study aims at evaluating the impact of the current changes in power generation on voltage sags (dips) in HV networks. This changing process started about 15 to 20 years ago and concerns the increasing diffusion of inverter-based generators (IBGs) and the contemporary reduction of synchronous generators (SGs). A major effect of this ongoing transition is the reduction of short-circuit currents/powers in the electrical grid, with consequent changes of the voltage sags caused by faults in the grid. This study is the first ste p of a larger research project involving the whole Italian HV network. The goal is a quantitative evaluation of the effects of the transition from an “old” power park (with only SGs) to a present power park (with less SGs and IBGs) on voltage sags in a HV network. In this paper, the analysis concerns the real HV network of Sardinia, which comprises 262 nodes altogether. Despite some simplifying assumptions, the results—consistent with the sag classification of the Standard EN 50160—give a clear and original quantitative evaluation of the negative effects of the considered change of produc tion units on voltage sags.