源荷匹配下梯级水电站对新能源极端波动的调节能力量化评估OA

The scissors difference regulation demand formed by the persistent extreme fluctuations of new energy output and the surge of power load under extreme weather has become a huge challenge for the power and energy balance of the power grid.It is of great significance to quantify the regulation capacity of large watershed cascade hydropower stations for the continuous extreme fluctuations of new energy.Using the historical actual daily output data of new energy in a power grid in Southwest China from 2016 to 2024,six types of extreme fluctuations of new energy were identified by the double-threshold definition method,and the load fluctuation law during the occurrence of extreme events was obtained.The potential trends and correlations between extreme fluctuations of new energy and changes in load demand were revealed through linear equation fitting and Pearson correlation analysis.On this basis,considering the complex hydraulic and electrical connections,a quantitative evaluation model for the regulation capacity of cascade hydropower stations for the associated extreme fluctuations of load and new energy was established,which was efficiently solved by the Gurobi solver.Based on different load fluctuation scenarios,the regulation capacity of cascade hydropower under the working conditions of drawdown period and impoundment period was analyzed.The results show that extreme wind power fluctuations and extreme photovoltaic fluctuations occur 22 times and 20 times per year on average,respectively,and combined wind-solar extreme fluctuations occur 3 times per year on average.Among all extreme events,the probability that the direction of load fluctuation is opposite to that of extreme new energy fluctuation is about 48%,and only the extreme low photovoltaic fluctuation amplitude has an obvious downward trend and negative correlation with the load fluctuation amplitude.When cascade hydropower stations are in the drawdown period or impoundment period with moderate water levels,they have a certain regulation capacity for both associated extreme high and low fluctuations of load and new energy,and the regulation capacity in the impoundment period is stronger.The overall regulation capacity for combined wind-solar extreme fluctuations is weaker than that for single new energy extreme fluctuations.Therefore,when associated extreme fluctuations of load and new energy occur,cascade hydropower stations can provide certain support capacity for the power grid.However,for more extreme reverse fluctuations of load and new energy,it is necessary to resort to energy storage and other means,which provides a decision-making basis for the power grid to defend against such extreme events.