基于负荷曲线峰型特征的梯级水电站日前发电计划编制方法

A Method for Day-ahead Generation Scheduling of Cascade Hydropower Stations that Based on the Characteristic of Daily Load Curves

水电站日前发电计划编制问题旨在确定次日各时段最优的机组出力与启停计划,提高发电效益和水资源利用效率。提出了一种基于负荷曲线峰型特征的梯级水电站日前发电计划编制方法:首先基于提出的典型日负荷曲线线型判别指标从历史同期日负荷过程中筛选出双峰型与单峰型的典型日负荷曲线;再对典型日负荷曲线进行放缩及调整使其满足日发电量需求并避开不可调控区;将调整后的典型日负荷曲线代入梯级水电站短期经济运行模型,采用双层嵌套优化算法计算得到不同峰型的能耗最小的日负荷曲线。以清江梯级水电站开展实例研究,结果表明:提出的典型日负荷曲线线型判别指标可有效筛选出典型的双峰型和单峰型日负荷曲线;最优的双峰型及单峰型日负荷曲线相较实际发电过程可分别节省水能3.13%及1.05%。

Day-ahead generation scheduling of hydropower stations aims to determine the optimal power output and on/off statuses of units during each operation period,which can increase economic benefits of the hydropower station by improving water use efficiency.In this paper,a method for day-ahead generation scheduling of cascade hydropower stations based on the characteristic of daily load curves is proposed.Firstly,typical daily load curves with double-peak or single-peak shape are selected by using a novel judging index.These typical load curves are amplified or narrowed to meet the daily electricity demand,and then they are adjusted to avoid hydropower output’s falling into the prohibited operating zones.The water consumption corresponding to each typical load curve is then calculated by using a two-layer nested optimization algorithm for the short-term economic operation model of the hydropower station.The typical load curve with the minimum water consumption is selected to formulate day-ahead generation plan.A case study using Qingjiang cascade hydropower stations indicates that:(1)the proposed judging index can effectively identify those typical daily load curves with double-peak or single-peak shape;and(2)compared with actual operations,the generation plan using the best daily load curve with double-peak and single-peak shapes can save water energy consumption by 3.13%and 1.05%respectively.