考虑合环约束的配电网重构方法

为避免用户停电,配电网合解环操作是电网调度部门通过重构调整运行方式的重要手段。文中建立了考虑合环约束的配电网重构模型,模型以线损最小为目标,同时考虑了正常运行方式和合环运行方式下的节点电压和线路功率限值约束。提出改进的贪婪自适应搜索算法求解所建模型,采用基于戴维南等值定理的配电网合环潮流算法验证合环安全性。该方法可求得配电网重构的具体合环操作步骤,确保重构过程中无新用户停电。两个系统算例的计算结果验证了所述方法的正确性和有效性。

考虑合环约束的单双环配电网负荷重组均衡优化

针对单双环配电网中负荷分布不均衡、负载率波动较大等问题,根据单双环配网的特殊结构,提出一种考虑合环约束的线路负荷分层重组方法。首先,依据开关站内部结构及单双环配网的简化模型,建立了主干环网和支线网络的双层拓扑模型。其次,综合考虑负荷均衡、峰值下降幅度等因素,以负荷均衡评价指标最小为目标,在主干环网层提出了开关站母线负荷优化重组模型;同时,在母线负荷重组方案操作过程中,为满足配网安全运行约束,提出了多场景下合环电流校验模型。在此基础上,为进一步提升负荷均衡度,在支线网络层提出了支线负荷重组模型。最后,以华东某城市实际配网负荷均衡为例,对比传统重构方法的计算结果,同时对负荷重组进行效益分析,验证了所提方法的有效性和实用性。

Environmental Integration of Small Hydropower Development

On the basis of cooperative research with European professionals, problems relating to environmental and ecological protection were discussed while small hydropower development in China currently was introduced in this paper. Guidelines of small hydropower development dealing with environmental protection were sug- gested hereby. Various specific technical environmental solutions focusing on small hydropower development applied in European and other developed countries were also introduced in this paper. Main environmental solutions are discussed as follows： integrated design should be advocated during plan/design stage,＂ ecohydraulic engineering and its utilization in SHP design and construction; effective technical approaches to relieve and eliminate the impact of river interception and fix the reasonable minimum biological flow; environment-friendly mitigation and compensation measures for high/low-head hydropower schemes applied in diversion works, intake, nature-like fish-passes, penstock and powerhouse design; study and application of the new technology, material and equipments; launching renovation of environmental protection in existing stations; emphasiz- ing public participation and their acceptability for the SHP environment; coordinated inter-disciplinary study at national level, etc. Two case studies in Sweden and Australia are given here.