Runoff forecast uncertainty considered load adjustment model of cascade hydropower stations and its application

The power generation plan formulated based on the forecasted runoff is an important basis for the operation of hydropower station. However, due to the unavoidable forecast error, the ideal practical operation process usually does not match with the plan. In view of this, after a detailed analysis on the current processes of making and implementing power generation plan, this paper constructed an early warning mechanism according to different operation states of cascade hydropower stations, and considering the uncertainty of runoff forecast and the security constraints of power grid, a new load adjustment model with characteristics of real-time tracking, early warning and timely adjusting was proposed, and three basic principles of load adjustment were put forward in this model. Taking the cascade hydropower stations in Yalong River of China as an instance, two typical scenarios that threaten the operation safety of hydropower stations are simulated and analyzed. Results show that the proposed model can be used to scientifically adjust the output of hydropower stations through the proposed adjustment principles and strategies, and ensure the safe and stable operation of power grid, and avoid the output shortage and water abandonment of hydropower stations caused by the uncertainty of runoff forecast.