Automatic Control of Small Hydroelectric Plants

A new model for depicting the dynamic behavior of reservoirs is introduced and its usefulness demonstrated in the design of automatic controllers for small hydroelectric plants. For plants equipped with propellor type turbines a flowrate bandwidth concept is defined and used to show that the propellor blade pitch angle performs the major flow control function in such installations. Regulation of the head is shown to be very desirable under run of the river mode operation and a simple and inexpensive modification to presently used governors is proposed to perform the head control. A complete system model for small hydroelectric plants is presented and its behavior illustrated with the results of digital computer simulations.