7. Operation

7.1 Stand-alone power plants

In the case of a stand-alone power plant feeding into an isolated network, frequency and voltage must be kept constant. This requires speed and voltage regulation.

Speed control can be provided by either a mechanical or an electronic controller, which operates the valve device via a cylinder or motor. Mechanical regulators are of the tachometric or accelerotachometric type. Their operating principle is based on the ball controller. In the event of strong load variations, the regulator must rapidly modify the water intake flow rate, which can lead to destructive water hammer in the pipes. This can be achieved by increasing the unit's moment of inertia, commonly referred to by hydraulic engineers as PD ^2...