Research On Mid-term Generation Scheduling For Hydropower Station Under Consideration Of Forecast And Risk Information

With the improvement of meteorological hydrological forecasting level, making full use of the forecast information is one important way of increasing the benefit of the reservoir scheduling, considering the reservoir forecast information scheduling has become a hot research topic.Effectively combine mid reservoir scheduling, the medium-term forecast information has long foreseen period can be ensured and to gain the initiative in scheduling;Medium-term forecast accuracy has reached a higher level of availability and ensure the rationality of the actual operation and high maneuverability.Based on the prediction of the global climate system (CFS) of different forecast period of rainfall forecast information, as the runoff forecast of rainfall input factor, runoff forecast model is established based on BP neural network, and the forecast results are medium-term runoff forecast accuracy of classification and evaluation, as the reservoir scheduling prediction information basis of the data.Due to hydrologic forecast error is inevitable, and uncertainty of the runoff process will bring risk for the reservoir scheduling, especially in the reservoir impoundment natural flow is larger, the scheduling decisions may affect the reservoir benefit throughout the year.The risk of reservoir dispatching decision-making caused by uncertainty of forecast mainly lies in: because the error of rainfall and runoff forecast is inevitable, on the one hand, if the prediction drainage is not enough, which may cause the phenomenon of water loss, on the other hand, if the prediction drainage is too over, this may cause the loss of water head, and the reservoir can’t even rise back to the desired water level. Based on this, this paper puts forward the concept of water loss risk, through establishing a related model between drainage decision and water loss risk to quantify the risk of different decisions.Combining with the information of mid-term CFS forecast and regarding the water loss risk as a main condition to control the scheduling decision of reservoir drainage, this paper deeply studied the scheduling method of preliminary drainage decisions of hydropower station:the realization of method is based on the reservoir scheduling graph, combining with the rolling forecast information, adjust the current daily scheduling decision to limit the risk of water loss in a given range, and vary the risk of water loss to achieve the optimum drainage effect.Based on mid-term runoff forecast, regarding water loss risk as constraint conditions, a kind of mid-term optimal model of reservoir operation is put forward:take the mid-term forecast information of runoff as the input of reservoir operation system, take the the optimized risk threshold as constraint conditions, take the average water level result of long-term optimal operation output as the expected beginning water level and ending water level of mid optimal model, limit the water loss risk of current period in a given range, then based on the proposed data to maximize generation output, hoping to to reduce the amount of water loss and electricity caused by uncertainty of forecasting.In some power plant as the research object of the scheduling results show that the medium-term power generation scheduling methods or models in this paper, the proposed method and model for hydropower station can reduce the amount of water loss, at the same time can increase the generaion output, improve the utilization of water resources, thus to provide a new way for mid-term reservoir operation.