基于二阶锥松弛和Big-M法的配电网分布式电源优化配置  

Optimal Distributed Generation Allocation in Distribution Network Based on Second Order Conic Relaxation and Big-M Method

作　　者：刘健辰[1] 刘山林 LIU Jianchen;LIU Shanlin(Faculty of Electrical and Control Engineering,Liaoning Technical University,Huludao 125105,Liaoning Province,China)

机构地区：[1]辽宁工程技术大学电气与控制工程学院

出　　处：《电网技术》2018年第8期2604-2611,共8页Power System Technology

摘　　要：提出一种基于二阶锥松弛和Big-M法的配电网DG（distributed generation,DG）优化配置的有效方法。通过适当处理PQ、PV、PI和PQ（V）4种类型DG的并网潮流约束,精确计及DG的运行控制方式对优化配置的影响。利用二阶锥松弛方法,将交流潮流约束、ZIP负荷约束和PI、PQ（V）型DG并网潮流约束转化为二阶锥规划问题,并通过适当设置优化目标函数,保证松弛误差趋于零。为了解决DG优化配置中的混合整数非线性约束、PV型节点无功功率越限和无功补偿整数约束问题,利用Big-M方法将其转化为便于有效求解的混合整数二阶锥规划问题。通过多个测试场景表明,所提出的二阶锥松弛方法具有非常高的求解精度,而且具备求解多类型DG多区域优化配置问题的能力。并且发现,适当调整DG的功率因数可以显著降低系统损耗;采用多DG分散配置比单DG集中配置的降损效果更好;增加电压偏移质量优化目标后,可以使电压分布更加扁平,显著提高系统电压质量。采用IEEE-33节点和PG＆E69节点配电系统的仿真结果验证了所提出方法的可行性和有效性。An efficient method is proposed for optimally allocating distributed generation in distribution network based on second order conic relaxation（SOCR） and Big-M method. By appropriately dealing with the constraints on grid-connecting power of four types of DGs including PQ, PV, PI and PQ（V）, the impacts of operation and control characteristic of DGs on their optimal allocation are considered precisely. By SOCR method, the AC power flow constraints, ZIP load constraints and the grid-connecting power flow constraints of PI and PQ（V） types of DGs are converted into second order conic programming. By properly setting the objective function, it is guaranteed that the relaxation errors converge to zero. To solve the problems in DG optimal allocation including mixed-integer nonlinear constraints, reactive power surpassing limits of PV type DG and integer constraints on reactive compensation, they are converted into mixed-integer second order cone programming by using the Big-M method, which can be solved effectively. Several testing scenarios illustrate that the proposed SOCR methods possess very high accuracy and the ability to solve the problem for multiple-area optimal allocation with multiple-type DGs. And it is found that the network losses can be reduced remarkably when the power factor of DG can be adjusted properly; better effects on reducing network losses can be reached if dispersal allocation scheme with multiple DGs is adopted, instead of central allocation scheme with single DGs; the voltage profile will become flatter and the voltage quality will be improved significantly if the optimization objective on voltage deviation quality is introduced. Simulation results on IEEE-33 bus and PGE69 bus distribution systems have verified the feasibility and effectiveness of the methods proposed in this paper.

关 键 词：分布式电源 优化配置 二阶锥松弛法 Big-M法 配电网 

分 类 号：TM721[电气工程—电力系统及自动化]