高比例分布式电源配电网中低压柔性互联协调规划

Coordinated Planning of Medium-Voltage and Low-Voltage Flexible Interconnection for Distribution Networks with High Proportion of Distributed Generation

柔性互联技术是解决高比例分布式电源(distributed generation,DG)配电网面临诸多问题的有效手段之一。提出了一种基于多层优化的配电网中压与低压柔性互联协调规划方法。首先,建立基于电力电子柔性互联设备(flexible interconnected devices,FID)的中低压柔性互联配电网潮流模型。然后,构建三层协调规划模型,上层以低压FID年运行成本及台区变压器负载率的年方差最小为目标,中层以中压FID年运行成本及从上级电网年购电成本最小为目标,分别决策低压和中压FID的安装位置与容量,下层以各场景的从上级电网购电成本最小为目标优化系统运行,并采用自适应粒子群优化和二阶锥规划相结合的混合算法求解。最后,采用含高比例DG的IEEE 33节点配电网进行算例分析,通过柔性互联规划系统的年综合运行成本降低了19.01%,台区变压器负载率的年方差减少了82.59%,验证了所提规划模型的有效性。

Flexible interconnection technology is one of the effective means to solve numerous problems faced by distribution networks with high proportion of distributed generations(DGs).A multi-layer optimization based coordinated planning method for medium-voltage and low voltage flexible interconnection of distribution networks is proposed.Firstly,a power flow model for distribution network with medium-voltage and low-voltage flexible interconnection based on power electronics flexible interconnected devices(FID)is built.Then,a three-layer coordinated planning model is constructed.With the upper layer aiming to minimize the annual operating cost of low-voltage FIDs and the annual variance of transformer load rate in substation areas,and the middle layer aiming to minimize the annual operating cost of medium voltage FIDs and the annual electricity purchasing cost from the higher-level power grid,they respectively determine the installation location and capacity of low-voltage and medium-voltage FIDs.The lower layer optimizes the system operation with the goal of minimizing the electricity purchasing cost from the higherlevel power grid in each scenario.A hybrid algorithm based on adaptive particle swarm optimization and second-order cone programming is adopted for solution.Finally,an IEEE-33 node distribution network with a high proportion of DGs is used for case study,and the results indicate that through flexible interconnection planning,the annual comprehensive operating cost of the example system is reduced by 19.01% and the annual variance of transformer load rate in substation areas is reduced by 82.59%,showing the effectiveness of the proposed planning model.