【作者】 魏哲；

【导师】 刘艳；

【作者基本信息】 华北电力大学 ， 电力系统及其自动化， 2019， 硕士

【摘要】 随着以风力发电为代表的新能源发电技术的快速发展,分布式电源(Distributed Generation,DG)已广泛接入配电网中。当配电网因主网故障失去电力支持,利用DG优先进行配电网停电后的初期负荷恢复可以最大限度地降低停电损失,对保证重要负荷的供电可靠性具有重要意义。其中,DG出力和负荷需求的不确定性对恢复方案的制定具有较大影响。为此,本文针对考虑DG的配电网初期负荷恢复问题开展了如下工作:首先,通过PSCAD/EMTDC仿真软件搭建含有DG的配电网初期黑启动小系统仿真模型,通过仿真结果证明了其进行黑启动的可行性。所搭模型包括柴油发电机、风力发电机和部分重要负荷。根据不同类型DG的出力特性确定了初期小系统黑启动的启动控制策略,总结阐述了相应的黑启动步骤,并通过系统频率波形图、柴油发电机和风力发电机出力图分析验证了可行性。然后,为了计及风电出力不确定和负荷波动对配网故障恢复的影响,采用风险价值方法对二者不确定性进行定量描述,且通过相关性分析建立风速负荷二元正态分布模型,以此为基础,建立了以恢复路径为决策变量,以等效失负荷量最小为优化目标,风速、负荷为扰动变量,考虑潮流安全约束的计及风电负荷相关性的配电网鲁棒恢复模型。该模型可在指定置信水平及风速负荷相关系数场景下,可实现等效失负荷量最小,保证重要负荷的优先恢复。最后,针对所建计及风电负荷相关性的配电网鲁棒恢复模型,采用YAMIP工具箱、GUROBI数学规划优化系统和MATLAB对模型进行求解。以含有多个DG的IEEE-69节点标准配电系统为例进行仿真,结果表明:计及风速负荷相关性之后,两种因素的不确定区间将发生变化,可以更细致地量化表征鲁棒模型中场景的恶劣程度,从而形成具有不同鲁棒控制水平的初期负荷恢复方案,为调度人员提供了更为详细的负荷恢复决策支持。更多还原

【Abstract】 With the rapid development of new energy generation technology represented by wind power generation,distributed generation(DG)has been widely connected to distribution network.When the distribution network loses power support due to the main network failure,the initial load recovery after the power grid is out of power with DG priority can minimize the power outage loss,which is of great significance to ensure the reliability of the important load.Among them,the uncertainty of DG output and load demand has a great impact on the formulation of recovery plan.For this reason,the following work has been done for the initial load recovery of distribution network considering DG:Firstly,PSCAD/EMTDC simulation software is used to build the simulation model of small black-start system with DG in the initial stage of distribution network.The simulation results prove the feasibility of black-start.The model includes diesel generators,wind turbines and some important loads.According to the output characteristics of different types of DG,the starting control strategy of black start of small system in initial stage is determined,and the corresponding steps of black start are summarized.The feasibility is verified by the system frequency waveform,the output of diesel generator and wind generator.Then,in order to take into account the influence of uncertainties of wind power output and load fluctuation on distribution network fault recovery,the risk value method is used to quantitatively describe the uncertainties of the two factors,and a binary normal distribution model of wind speed and load is established by correlation analysis.Based on this model,the recovery path is taken as the decision variable,the minimum equivalent load loss is taken as the optimization objective,and the wind speed and load are taken as the disturbance variables.Distribution network robust restoration model considering power flow security constraints and wind load correlation is proposed.The model can minimize the equivalent load loss and ensure the priority recovery of important loads under the scenarios of specified confidence level and wind speed load correlation coefficient.Finally,aiming at the robust restoration model of distribution network considering wind power load correlation,the model is solved by using YAMIP toolbox,GUROBI mathematical programming optimization system and MATLAB.Taking the standard distribution system of IEEE-69 bus with multiple DGs as an example,the simulation results show that the uncertain intervals of the two factors will change after taking into account the correlation between wind speed and load,which can quantify the bad degree of scenarios in the robust model more carefully,thus forming initial load recovery schemes with different robust control levels,and providing more detailed information for dispatchers.Decision support for load recovery.更多还原