考虑跨电压等级电压-功率灵敏度的交直流配电网动态分区方法

A dynamic partitioning method for AC-DC distribution networks considering voltage-power sensitivity across voltage levels

分布式电源大量接入配电网导致电压越限问题凸显,传统集中式电压优化控制方法面临计算效率低和通信难度大等挑战,分布式控制能降低控制复杂度并保证电压合理分布,而动态分区和主导节点选择是配电网分布式控制的基础。首先,考虑变压器、电压源型换流器(voltage source converter,VSC)等设备功率传输特性,推导跨电压等级交直流配电网灵敏度计算公式;其次,构建中低压交直流配电网动态分区评价指标,包括区域内耦合度、区域间离散度、有功平衡度和无功平衡度;然后,采用遗传算法进行分区方案优化,并根据系统可观性和可控性选择分区主导节点;最后,通过算例仿真,结果表明所提跨电压等级灵敏度计算方法能够更为准确地刻画中低压、交直流网络各节点功率与电压之间的关联,采用动态分区方法能够获得更科学合理的分区方案和主导节点,从而使配电网分布式控制能够快速、有效地应对电压越限问题。

The large number of distributed power sources accessing the distribution network leads to the voltage exceeding limits problem,and the traditional centralized voltage optimization control method faces the challenges of low computational efficiency and communication difficulty.Distributed control can reduce the control complexity and ensure the reasonable distribution of voltage,while dynamic zoning and dominant node selection are the basis of distributed control in distribution networks.Firstly,considering the power transmission characteristics of transformers,VSCs and other devices,the sensitivity calculation formula for cross voltage level AC/DC distribution networks is derived.Secondly,construct dynamic partition evaluation indexes for medium-low voltage AC/DC distribution networks,including intra-area coupling degree,inter-area dispersion degree,active balance degree and reactive power balance degree;Then,the genetic algorithm is used to optimize the partition scheme and select the dominant node of the partition according to the system observability and controllability.The simulation results show that the proposed cross-voltage sensitivity calculation method can more accurately portray the correlation between power and voltage of each node in the MV-LV and AC/DC networks.The dynamic partitioning method can obtain a more scientific and reasonable partitioning scheme and dominant node,so that the distributed control of the distribution network can quickly and effectively cope with the voltage overrun problem.