Apparatus for automatically controlling the active power produced by the generator of a hydraulic turbine-generator unit

An apparatus for automatically controlling the active power produced by a generator of a unit including a generator and a hydraulic turbine having a gate for controlling water flow to the runner of the hydraulic turbine, said apparatus comprising:

• means for providing a reference signal corresponding to a desired power level;
• an active power measuring means to measure the power developed by said generator;
• a gate opening sensing means responsive to the extent of opening of said gate;
• a gate opening control means for adjusting the extent of opening of said gate;
• a first summing means having two inputs and an output, a first of said inputs of said first summing means being coupled to said reference signal providing means, and said output of said first summing means being coupled to said gate opening control means;
• a second summing means having two inputs and an output, a first of said inputs of said second summing means being coupled to said gate opening sensing means, and said output of said second summing means being coupled to the second of said inputs of said first summing means;
• and
• an integrator having two inputs and an output, a first of said inputs and said output of said integrator being coupled, respectively, to said output and second of said inputs of said second summing means so as to form a negative feedback circuit comprising said second summing means, and the second of said inputs of said integrator being coupled to said active power measuring means.