This paper, setting out from traditional wave theory, probed into algebra relationship between magnitude and frequency of water pressure fluctuation at a fixed point and that of the surface wave, present the expression of water depth at the fixed point in terms of fluctuation magnitude at the fixed point and the reference point, verified the correctness of the expression with numerical method by implementing code for electronic computing;

Optimum setting of hydroturbine governor is an interesting problem in practice. This paper presents a method to determine governor setting using the scaled conjugate gradient optimization algorithm. Optimum governor setting problem can be represented mathematically as a problem to find the goal function minima in the parameter space, the state equation of the control system being a constraint. For a typical hydroturbine control system, the state equation, the adjoint system equation and equations for calculating...

Optimum setting of hydroturbine governor is an interesting problem in practice. This paper presents a method to determine governor setting using the scaled conjugate gradient optimization algorithm. Optimum governor setting problem can be represented mathematically as a problem to find the goal function minima in the parameter space, the state equation of the control system being a constraint. For a typical hydroturbine control system, the state equation, the adjoint system equation and equations for calculating gradients have been deduced. Examples show that the scaled conjugate gradient descent method is quite effective and is good in convergency. The optimization processes in different parameter spaces, such as the space of absolute values. the space of inverses and the space of relative values, are investigated, and the parameter space of relative values is recommended for hydroturbine control system. Furthermore it is showed that the coefficient R. considering the water pressure fluctuation in the goal function, has a great influence on the governor optimum setting, and the transient history and the descent rate of the goal function can be used as terminating contition for optimization process.

The work condition of the hydro-turbine of the Three Gorges is characterzed by large variationin water head and long period operation in points deviated from the optimum zone. This paper introduces theexperiment of flow pattern observation and water pressure fluctuation performed on a model turbine for ThreeGorges Power Station. In the experiment, we have chosen 55 points for varied heads and loads with respect tothe Three Gorges turbine. For these points, following items were performed; observation and...

The work condition of the hydro-turbine of the Three Gorges is characterzed by large variationin water head and long period operation in points deviated from the optimum zone. This paper introduces theexperiment of flow pattern observation and water pressure fluctuation performed on a model turbine for ThreeGorges Power Station. In the experiment, we have chosen 55 points for varied heads and loads with respect tothe Three Gorges turbine. For these points, following items were performed; observation and description ofthe flow pattern of the inlet and outlet edge of the model runner with fiber endoscope and stroboscope under dif-ferent cavitation sigma; water pressure fluctuation test at 8 points arranged along the water passage under theplant sigma; water pressure fluctuation test at different points, for different cavitation sigma, under the samework condition. We also combine the efficiency hillchart with the cavitation critical curve of both pressure andsuction sides of blade inlet edge, critical curves of channel vortex and no-vortex zone. It is the first example inChina.

The vibration of frames and output power caused by water flow often affects the operating of Francis turbine at part load because of the pressure fluctuation in draft tube. The vibration and noise at full load or over full load are increased. These not only cause the difficulty for the operation of generating unit, but also threaten the safe of the generating unit seriously. In case of the performance of the turbine have been fixed and the generator's frequency is unable to be changed, the methods of air admission...

The vibration of frames and output power caused by water flow often affects the operating of Francis turbine at part load because of the pressure fluctuation in draft tube. The vibration and noise at full load or over full load are increased. These not only cause the difficulty for the operation of generating unit, but also threaten the safe of the generating unit seriously. In case of the performance of the turbine have been fixed and the generator's frequency is unable to be changed, the methods of air admission and the guide baffle are unruly adopted to decrdase the water pressure fluctuation in the draft tube. Up till now, it has not ripe experience for use at air admission and guide baffle because of the difference of turbine type and the limits of site conditions. The present writer designed kinds of guide baffles and different positions of air admission to be tested on the Three Gorges model turbine. The model test was carried out at the typical heads of Three Gorges turbine. The influence of efficiency, output, and results of decreasing the pressure fluctuation and frequency performance are showed.