Abstract
Long-term runoff forecasting important reference significance for the long-term planning of cascade hydropower stations. The traditional forecast accuracy evaluation is based on the deviation between the predicted runoff and the measured hydrological sequence, but fails to consider the effect on long-term scheduling. In this paper, a runoff forecasting evaluation method for long-term scheduling is presented. First, a monthly distribution method based on the forecast value of annual runoff is proposed to describe the uncertainty of the forecast. Then, a power generation plan model with the maximum generation objective and an actual generation benefit evaluation model are established to study the effect of runoff forecasting in scheduling. At last two indexes of “Incremental generation” and “Incremental benefit” based on the comparison of actual benefit with and without a forecast plan are given to evaluate the performance of forecasting. The case study shows that the proposed evaluation method can reflect the actual benefit brought by the forecast information, which provide more practical guidance for the hydropower station.
Highlights
In domestic reservoir management, power generation dispatching plan is the basis of future operation, and runoff process is an important input condition of power generation plan
The uncertainty of runoff process has a great influence on the implementation of power generation scheduling, and how to evaluate the performance of forecasting is the key to determine whether the prediction data can be used to guide the scheduling plan
The forecast accuracy is mainly expressed by absolute error, relative error, deterministic coefficient and other indexes [6,7] by calculating the differences between forecast value and measured data, which fails to judge the availability of forecast information based on the objective of operation
Summary
Power generation dispatching plan is the basis of future operation, and runoff process is an important input condition of power generation plan. Runoff descriptions for a given year are usually based on measured historical data, statistically generated sequences or forecast time series[1,2,3].Hydrological forecast information has been applied to guide reservoir operation in the existing studies [4,5], and valuable conclusions have been drawn. The uncertainty of runoff process has a great influence on the implementation of power generation scheduling, and how to evaluate the performance of forecasting is the key to determine whether the prediction data can be used to guide the scheduling plan. Based on the comparison the actual scheduling results under the unforecasted and the forecasted scheduling plan, two indexes, namely “incremental generation” and “incremental benefit”, are put forward to evaluate the runoff forecast benefit quantitatively. Taking Xiluodu-Xiangjiaba cascade hydropower station of Jinsha River as an example for research, the results show that the evaluation method based on dispatching target can better characterize the runoff forecasting effect, and is more conducive for long-term power generation
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
