典型天气形势与溪洛渡电站发电供求关系的影响

Impact of Typical Weather Circulation Situation on Relationship Between Power Supply and Demand of Xiluodu Hydropower Station

本文利用2015—2017年溪洛渡电站逐日入库及出库流量、逐日电站出力资料、广东逐日用电负荷数据及NCEP逐日再分析资料,针对溪洛渡右岸电站汛期弃水严重、枯期水量不足,电站发电与广东用电需求存在矛盾的几种生产情景,划分为供不应求型、供过于求型和非典型供过于求型3种类型,选取典型个例分析不同类型对应的环流形势和天气成因,并提出今后溪洛渡电站调度的建议。结果表明:每年5、6月,广东常受副热带高压控制,用电需求较大,而宜宾以上流域大多受一致的偏西或西南暖湿气流控制,冷空气活动较弱,不利于产生大范围降水,使得溪洛渡电站发电能力与广东用电需求多呈供不应求型;7—9月,宜宾以上流域多受高原槽及切变线影响,有利于出现明显降水,电站具备满发能力,而华南一般有低涡切变或台风活动,有利于广东出现降水,由于不受副高控制且出现降水,广东用电需求降低,导致出现供过于求型;如广东在副热带高压控制之下,用电需求旺盛,但溪洛渡右岸具备满发能力而出现弃水的情景,往往是因为西南地区降水总体较强,其他水电站加大出力,而电网送出受限等多方面因素影响,导致电网对溪洛渡右岸的电能需求减少,即出现非典型供过于求型。在实际发电生产中可根据天气环流形势提前研判,更加有针对性地开展水库调度、优化电站运行,增加汛期水电电能的有效消纳以及水能资源充分利用。

Based on the daily inbound and outbound flow and output data of Xiluodu Hydropower Station,the daily electricity load data of Guangdong,and the daily re-analysis data of NCEP from 2015 to 2017,this paper divides the production scenarios of Xiluodu Right Bank Hydropower Station into three types:short supply,oversupply and atypical oversupply.They are characterized by insufficient water in the dry season,severe water abandonment in flood season,and contradiction between power generation and power demand of Guangdong Province.Typical cases are selected to analyze the circulation situation and weather causes corresponding to different types,and suggestions for future dispatching of Xiluodu Hydropower Station are put forward.The results show that in May and June of each year,Guangdong is often controlled by subtropical high pressure,and the demand for electricity increases significantly.The drainage area above Yinbin is mainly located on the northwest side of the anticyclonic circulation and is controlled by a uniform westward or southwestern warm and humid air.There is no cold air activity,which is not conducive to large-scale precipitation.As a result,the power generation capacity of Xiluodu Hydropower Station is insufficient and the demand for electricity in Guangdong exceeds supply.The drainage area above Yinbin is mostly affected by plateau troughs and shear lines or cold air from the east from July to September,conducive to significant precipitation.During this period,the power station has full capacity.However,when Guangdong is affected by the typhoon system or is located on the north side of the subtropical high pressure,the power demand in Guangdong decreases,resulting in an over-supply type.If Guangdong is under the control of subtropical high voltage,the electricity demand is high.However,water abandonment on the right bank of Xiluodu happens frequently due to the increased output of other hydropower stations in the southwestern region and limited power transmission,which has led to a decreased demand for power from the power grid on the right bank of Xiluodu.This situation corresponds to atypical oversupply.In actual power generation productions,it is possible to study and judge in advance according to weather circulation situation and better carry out reservoir dispatching,optimize power station operation,and increase the effective consumption of hydroelectric power and full utilization of hydropower resources during flood periods.