Some Researches On Calculation Of Transients In Hydropower Station

The calculation of transients in hydropower station and its analysis is one of important items for study in project design and operation as well as maintenance of hydropower station. On the basis of summarizing the existing research results in this paper, several key and technical problems in this aspect are explored comparatively deeply.1. The method for data processing of synthetic characteristics curve of hydraulic turbine is proposed, the corresponding mathematical model and the condition of constraint is established. It is not necessary to set up the concrete expression of functional relation by using this method, the fittness of known discrete datum can be carried out and the prediction of datum in unknown region with combination of constrain condition at boundary is done, thereby improving the work efficiency and datum precision of data processing of synthetic characteristics curve of hydraulic turbine.2. By simple mathematical methods, the correction expression for transition and processing of synthetic characteristics curve of reversible unit is found, by which the problem such as being difficult to describing the traits when the opening is zero by advanced Suter method, and which also provides a treatment method featuring with convenience to use and great precision for the calculation in transition of reversible unit.3. For hydropower station of different water heads, the research on optimal choice of the wicket gates closure and opening law types of unit is done. The characteristics of optimal wicket gates closure and opening law types of unit in hydropower station of different water heads are compared and analyzed.4. The effect of wave velocity adjustment of water hammer on calculation for optimal choosing of the wicket gates closure and opening law types of unit is analysing. Base on that, the matters needed attention and measures needed to being taken are put forward when the calcultion for optimal choosing of the wicket gates closure and opening law types of unit in hydropower station of different water heads is carried out.5. In according to basic differential equation of unstady flow in open channel, the characteristic method for calculation of unsteady flow in channel with linear and variable trapezoidal cross-section is deducted, the effectiveness of which is confirmed by computational examples.6. In order to making use of the exsiting program for hydranlic transition calculation of hydropower station and for calculation of unsteady flow in open channel, the iterative method is adopt in this paper, which provides a simple, effective and rational method for calculation in hydraulic transient of conveying system in hydropower station with tail channel including some variable cross-section pieces.