Grid effect on stability of pumped-storage hydro station

The ability of pump storage hydropower stations to provide a rapid response to changes in system loading means that they are often used as a measure of controlling Grid frequency. When used in this role, the response of an individual unit is determined by the behaviour of its governor, the stiffness of the connected grid and the interaction between the governor and the grid. The governor settings, and in particular the loop gains, are therefore critical to achieving optimum levels of station performance. However, the level of interaction between the governor and the grid means that in order to achieve optimum performance the governor loop gains should be continually modified to take account of grid loading.