大规模特高压直流水电消纳问题及应用实践

Large-scale Ultra High Voltage Direct Current Hydropower Absorption and Its Experiences

随着金沙江、雅砻江、澜沧江流域溪洛渡、向家坝、糯扎渡、锦屏等巨型水电站陆续全部竣工和集中并网发电,中国水电输送规模急剧扩大,大规模水电输送直接影响到中国电力资源大范围合理配置,其消纳和对受电端电网的调峰矛盾凸显。然而,由于送端电网水电调节性能弱和消纳能力有限,中国现行的按照电站自身的运行要求或者送端电网的电力盈余安排输送计划的方式,极易出现"直线"或者"反调峰"水电输送计划,加重了受电端电网调峰压力,不利于水电大规模消纳和发挥其优质的调峰作用。如何根据送受端电网负荷特性差异,发挥跨流域梯级水电站群相互补偿作用,利用不同电源特性以最大程度消纳水电和发挥水电的调峰作用,需要研究水电大规模输送的网网协调、网省协调、厂网协调优化调度方法、补偿机制、调峰阀值和协调策略等。上述问题是中国现阶段特高压直流水电大规模输送核心所在,其研究将能够更加合理配置中国电力资源,缓解受电端电网调峰压力,改善长三角洲、珠江三角洲电源结构,减轻这些地区的雾霾压力,切实保障中国电网安全、经济、环保、可靠运行。

With huge hydropower plants, such as Xiluodu, Xiangjiba, Nuozhadu and Jingping located in Jinshajiang River, Yalongjiang River and Lancangjiang River being completed and put into production, hydropower transmission capacity of ultra high voltage direct current（UHVDC） were expanded rapidly in China. Large-scale hydropower transportation have a strong impact on optimizing configuration of electric power resource in nationwide scope, especially absorbing hydropower for sending power grids and shaving peak load for receiving power grids. Because of the limited regulation capacity of hydropower plants, transportation schedules of hydropower are subject to operating requirement of plants itself and extra electricity in sending power grids. The ＂straight line＂ and ＂opposite peak shaving＂ transportation schedules occur frequently and have aggravated pressure to peak shaving load in receiving power grids. A new challenge for the coordinating operations is how to utilize load peak and off-peak difference and the characteristics of different power source to absorb surplus hydropower from sending power grids and to shave peak load for receiving power grids. The problem involves optimization scheduling methods, compensation mechanism and coordination strategy among regional power grids, province power grids and plants. The study for the above problems is crucial to the large-scale UHVDC hydropower absorption at the present stage and will be beneficial to rationally allocate power resource, alleviate the pressure of the receiving power grid peak shaving, reduce the pressure of fog in these areas and ensure the safety, reliability, and economy and environmental protection of China＇s power grids.