Method for stabilizing the rotation speed of a hydraulic machine with S-characteristics and installation for converting hydraulic energy into electrical energy

A installation for converting hydraulic energy into electrical energy, comprising a hydraulic machine with adjustable guide vanes, further comprising:

• a control loop feedback system having a controller for calculating an orientation to affect the guide vanes,
• a first calculator to calculate a set of internal states associated with the operating point of the machine,
• a second calculator to establish, in accordance with the set of calculated internal states, a linearized transfer function representing the machine rotational speed in function of the guide vanes orientation,
• a third calculator to calculate characteristic parameters of the controller in function of characteristic parameters of the established linearized transfer function so that the control loop feedback system is stable,
• a measuring tool to measure the rotation speed of the hydraulic machine,
• a comparison tool to compare the measured rotation speed with a target rotation speed, and
• a controller to adjust the orientation affected to the guide vanes so as to reduce the speed difference between the measured rotation speed and the target rotation speed.