| Issue |
La Houille Blanche
Number 2, Avril 1999
|
|
|---|---|---|
| Page(s) | 34 - 40 | |
| DOI | https://doi.org/10.1051/lhb/1999017 | |
| Published online | 01 August 2009 | |
Stabilisation d'une pompe-turbine mono-étage présentant une instabilité en marche à vide
Stabilization of a single-stage turbine-pump presenting an instability when operated at speed-no load
1
EDF-CNEH, Le Bourget-du-Lac, France
2
Tata Electric Companies, Mumbai, Indes
3
Sulzer Hydra Ltd., Zurich, Suisse
Abstract
When operated at speed-no load, the vertical single-stage pump-turbine at Bhira pumped storage plant (India) exhibited at rated speed oscillations of speed, head and guide vane opening with a period of 15 seconds. The original PID speed governor could not stabilise this phenomenon. At 105% of rated speed an additional oscillation with a period of 3.75 seconds was observed. Feedback of the measured penstock pressure in the speed governor improved the stability of speed control at rated speed; but the instability at high speed remained. This problem has been solved by changing the start-up procedure. The turbine inlet valve is opened only partially until synchronisation. The artificial head loss renders the hydraulic condition stable. A series of field tests showed that the novel procedure entails no harmful mechanical side effects.
© Société Hydrotechnique de France, 1999