Transfer and measurement of power plant transients on a high-performance closed-loop test rig

Abstract As hydro power plants become more and more flexible in their operation, the associated transient processes and the resulting loads on the hydraulic machinery are becoming increasingly important. In addition to numerical analysis, measuring of the transient processes using model test rigs plays an important role. The aim is to determine the effects of the transient operating modes in model tests and to transfer the knowledge gained to the prototype. Therefore, the real transient processes of a hydro power plant and the load on the hydraulic machine must first be reproduced on the test rig. The transient turbine start-up of a hydro power plant is analysed in more detail. The first step is to model the entire hydro power plant and calculate the corresponding start-up process. The boundary conditions applied to the hydraulic machine are transferred to the model machine on the test rig using similarity laws; a time scale adjustment is made using the Strouhal number. The time dependent boundary conditions at the model machine are set by varying the rotational speed of a service pump arranged in the test rig and the transient start-up process is measured.