摘要
以风电、光伏为代表的分布式电源接入配电网后容易导致系统电压波动变大以及局部电压越限.以二阶锥优化为代表的松弛技术在优化时为了保证松弛后解的精确,约束条件极为严苛并且在功率的极端注入下容易导致对偶间隙增大.针对上述问题,该文提出基于改进凸内逼近法的主动配电网有功-无功优化方法.首先,基于支路潮流方程定义与支路电流、节点电压和视在功率流相关的非线性项的凸包,并与剩余线性元素结合形成凸内部近似,建立完善的数学模型;进一步提出网络容许性判据以及引入KKT条件收缩最优解的对偶间隙.最后,基于IEEE 33系统及PG&E69节点系统,利用Yalmip等平台求得电网中各有功、无功决策变量的出力区间,验证所提方法的稳定、精确与高效性.
Abstract
When distributed power generation,primarily represented by wind and photovoltaic energy,is connected to the distribution network,it tends to exacerbate system voltage fluctuations and readily causes local voltage to exceed permissible limits.In order to ensure the accuracy of the solution after relaxation,the relaxation technique represented by the second-order cone optimization has extremely strict constraints,and the dual gap will become larger under extreme power injection.To solve the above problems,this paper proposes an active-reactive power optimization strategy for active distribution network based on improved convex internal approximation method.First,based on the branch power flow equation,the convex hull of nonlinear terms related to branch current,node voltage and apparent power flow is defined,which is then combined with the remaining linear elements to form convex internal approximation,and a mature mathematical model is established.Furthermore,the network tolerance criterion and the KKT condition are introduced to shrink the dual gap of the optimal solution.Finally,the IEEE 33-node test system and the PG&E 69-node test system are used for simulation calculation,and the output interval of each decision variable in the power grid is obtained by using Yalmip and other platforms,which verifies the stability of optimization,accuracy of relaxation and efficiency of calculation.
基金项目
江苏省重点研发计划(BE2021094)
江苏省优势学科建设工程(PAPD)()
国网江苏省电力有限公司科技项目(J2020014)
国网江苏省电力有限公司科技项目(J2020151)
Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)()
国家科技期刊平台
NSTL
万方数据