基于线性规划的中低压不平衡配电网电压无功实时优化  

Linear Programming-based Real-time Volt-var Optimization of Unbalanced MV-LV Distribution Networks

作　　者：苏向敬 彭赫 米阳 符杨 SU Xiangjing;PENG He;MI Yang;FU Yang(School of Electrical Engineering,Shanghai University of Electric Power,Yangpu District,Shanghai 200090,China)

机构地区：[1]上海电力大学电气工程学院,上海市杨浦区200090

出　　处：《电网技术》2023年第11期4719-4726,共8页Power System Technology

摘　　要：高间歇性、高波动性分布式电源(distributed generation,DG)的持续大量接入给配电网的无功电压管理带来严峻挑战,对无功优化的时效性提出了更高要求。现有电压无功控制研究普遍基于单一电压等级和三相平衡网络模型假设,但实际中低压配网两侧的DG、负荷通过配电变压器的耦合互动不断加剧。同时,由于换相缺失、线路不对称布置、负荷及DG不均匀接入等因素,配电网不平衡特性日益加剧,沿用单一电压等级和三相平衡网络可致电压无功控制决策结果不合理甚至不可行。为此,提出一种基于线性规划的中低压不平衡配电网电压无功实时优化方法。具体通过中压配网静止无功发生器(static var generator,SVG)和低压配网分布式光伏逆变器的协调控制,在满足电网运行约束和控制设备能力约束的情况下,实现中低压不平衡配电网节点电压偏差的最小化。同时,为满足高间歇性DG接入对电压无功控制实时性的要求,对上述非线性电压无功优化问题进行线性化逼近,并采用CPLEX求解器对相应线性规划问题进行有效求解。最后,基于某澳大利亚真实配网开展24h仿真,验证了所提基于线性规划的中低压不平衡配电网电压无功实时优化的有效性和优越性。The increasing penetration of the intermittent and uncertain distributed generations brings about great challenges to the voltage management of the distribution networks,imposing higher requirements on the rapidity of the volt-var control(VVC).The existing VVC studies are commonly based on the assumptions of the single-voltage level and the three-phase balanced network.However,the DGs and loads are interacting more significantly between the medium-voltage(MV)and the low-voltage(LV)distribution networks through the distribution transformers.Also,the distribution networks are becoming more unbalanced as a result of missing the phase shifting,the uneven feeder arrangement as well as the random connections of the loads and DGs.In this context,insisting on the single-voltage level and balanced network model may generate unreasonable and even unfeasible VVC decisions.To address the challenges above,this study presents a real-time VVC method for the MV-LV unbalanced distributions networks.Specifically,by coordinating the MV static var generator(SVG)and the LV distributed PV inverters,the voltage deviation of the MV-LV unbalanced distribution networks is minimized while meeting the constraints of the network operation and the component capability.Meanwhile,to support the real-time requirement on the VVC imposed by the highly intermittent DGs,the non-linear and non-convex VVC model of the MV-LV unbalanced distribution network is linearized with the linear programming problem effectively handled by the CPLEX solver.Finally,the 24-hour detailed simulations are carried out on a real Australian distribution network to verify the effectiveness and superiority of the proposed real-time VVC for the MV-LV unbalanced distribution networks.

关 键 词：中低压配电网 电压无功优化 三相不平衡 分布式电源 线性规划 

分 类 号：TM721[电气工程—电力系统及自动化]