Impact of HVDC Technology on the Probabilistic Power Flow of the Italian Power System

The rapid evolution of worldwide power systems needs accurate numerical models to forecast their correct operation. In this paper, two power flow algorithms developed at the University of Padova, named PFPD_PRB and PFPD_ACDC, are merged to analyze the static behavior of the Italian power system in a hypothesized scenario. These two algorithms allow evaluating the probabilistic (PFPD_PRB) and the AC/DC power flows (PFPD_ACDC) by exploiting the matrix approach. The presence of the planned Tyrrhenian and Adriatic HVDC links and of a given renewable energy scenario are considered. In fact, a 20% variable renewable energy generation on a low-load Italian scenario (22.5 GW of power absorption) is assessed. In particular, the solutions are given in terms of uncertainty of the power flow results, showing that these increase as the HVDC power import increase, and that such uncertainties are higher near the location of the vRES plants (i.e., Southern region of the Italian network). The methodology is general and can be applied to any transmission network including HVDC links and renewable energy sources.