Variable Speed Hydropower for Provision of Fast Frequency Reserves in the Nordic Grid

The main purpose of this article is to demonstrate the grid support capability of variable speed hydropower (VSHP). The hypothesis is that active power control of VSHP plants can improve both the frequency stability and the transient rotor angle stability by contributing to virtual inertia (VI), fast frequency reserves and power oscillation damping. Fast active power control is made possible by po...