Hydro-Québec EMT Simulation of a Radial Network with a High Penetration of Wind Generation to Validate System Operating Limits

The paper presents an EMT‑based assessment of a radial transmission network in the Gaspésie region, where wind generation penetration exceeds local demand and creates weak‑grid conditions. Motivated by the limits of phasor‑domain transient (PDT) tools in representing fast inverter‑based resource (IBR) dynamics, the study uses EMTP simulations to validate the operational active‑power transfer limit of the main transmission corridor. The modeled system includes over 2,250 MW of wind generation, HVDC links, series‑compensated lines, and OEM wind farm black‑box models in accordance with CIGRÉ TB‑881 guidelines. Contingency analyses—including three‑phase and phase‑to‑ground faults—reveal significant discrepancies between EMTP and PDT results, with EMTP predicting much higher wind‑generation losses and stronger voltage‑instability phenomena. The findings demonstrate that EMT simulations are essential to accurately capture IBR control interactions, assess transient voltage and frequency stability, and validate safe operating limits in weak‑grid environments with high renewable penetration. - Francis Lavigne (Hydro-Québec)