Research And Application Of Key Technique In Multi-hydropower-station Economical Operation System

With the electrical industry gradually leading to the commercial market, hydropower station can be operated more allodially and flexibly. The main job of hydropower station is how to maximize the power production and enhance the power efficiency under the present situation of equipments and staff. The paper analyzes two kinds of critical technique respectively, which are the medium-and-long-range hydrologic forecast methods of reservoir runoff and real-time optimal operation model, such as follows:Part one: After reviewing the present research situation of medium-and-long-range hydrologic forecast methods of reservoir runoff in China and abroad, the paper puts forward cycle forecasting model based on the Wavelet transform. The model not only utilizes the good characteristics of wavelet transform's nice analyses capability in the time scales and frequency scales, but also exerts the advantage of period mean superposition method. In the paper the model's reliability was proved by an idiographic sample of a reservoir in the Three-Gorges, indicating a higher precision of this method.Part two: This paper analyzed the degree of predicting precision affected by decomposing scale coefficient of wavelet cycle model and various kinds of reservoir inflow runoff series. The results showed that the precision is relatively worse when the scale value less than three, and the precision can't be improved while the scale value arrived at some level. There is relationship between the forecasting precision of model and the interval of time series. Too long or too short length of the interval of time series will have an effect on the forecast accuracy. The control areas of reservoirs also influence the forecast accuracy. And the forecast accuracy is not so well under the situation of small control area, fluctuant runoff series and unsteady phases of reservoirs.Part three: The real-time optimal operation model for the multi-hydropower-station is studied in the paper. Aiming at the operation pattern of the electrical industry, a layered coupling model system is established with different time intervals and regulation periods. The practicability of the model is improved by insetting one layer model to another. It had been practically proved that optimal operation model embody the simple and practical characteristics.