Stability Limits of Hydroelectric Power Plants

Abstract

It is well known that the inertia of the water in the penstock is the main unstabilizing factor for the stability of a hydropower plant. Most of the analytical studies on this subject use the lumped‐system approach to include the water‐hammer effects. However, the elasticity of the pipe walls and the compressibility of the water column could have in many cases significant detrimental influence on the governing characteristics of a plant. An analytical criterion for the stability of a single, isolated hydro‐unit is derived including the effects of elastic water hammer. It is concluded that for a system having Allievi parameter (p) less than one, the elastic effect of the conduit should be taken into consideration.