Stability of a pump storage hydro-power station connected to a power system

The operational flexibility of pumped storage hydropower stations means that they are often used for the control of power system frequency. When used in this role, the response of the power station is determined by the behaviour of its governor, the stiffness of the connected grid and the interaction between the governor and the grid. An investigation into the governor settings at Dinorwig power station in the UK has been undertaken in order to establish the optimum governor settings for different loading conditions, providing as close to an ideal response as possible without endangering the stability of system frequency control. The gain and phase margins of the open loop transfer function of the system were examined to determine the stability of the power system, and the effect of the droop settings and the grid size are included in the study. Information on stability of the power station is presented for a variety of operating and grid conditions