高电压技术2024，Vol.50Issue(11)：4837-4849,中插4-中插5,15.DOI:10.13336/j.1003-6520.hve.20240624
复杂多端柔直配电网短路故障全过程全网特征量计算方法
Short-circuit Calculation Method of Whole Network Characteristic Quantity During the Whole Fault Process in Complex Multi-terminal Flexible DC Distribution Network
摘要
Abstract
Multi-terminal flexible DC distribution network has small short-circuit damping and low inertia,and the fault development presents the characteristics of strong nonlinearity and stage due to the existance of a large number of power electronic devices in the system.Conventional short-circuit calculation methods concern fault characteristics of"points"and"lines",making it difficult to consider the network-level characteristics.Therefore,this paper focuses on the whole process of short-circuit fault from capacitor discharge to AC-side feed current,and introduces the theory of DC fault ports.On this basis,the fault network is simplified by using high-frequency equivalent characteristics,and then the approximate solution of the fault current in the capacitor discharge stage is obtained by the Laplace inverse transformation.Subse-quently,the characteristic quantity of the whole network is obtained by fault-port impedance.In the steady-state AC feed stage,the converter port transfer matrix is established,the series-connected nodes in the network are eliminated after commutation overlap correction,and then the steady-state short-circuit calculation method suitable for multi-terminal flexible DC power grids is obtained.Finally,a simulation model is built based on PSCAD/EMTDC platform,which veri-fies the accuracy of the proposed short circuit calculation method under different fault locations and fault resistances.关键词
多端柔直配电网/短路计算/故障口/高频等效/换相重叠Key words
multi-terminal flexible DC distribution network/short circuit calculation/fault port/high-frequency equiva-lence/commutation overlap引用本文复制引用
戴志辉,李涵伟,李毅然..复杂多端柔直配电网短路故障全过程全网特征量计算方法[J].高电压技术,2024,50(11):4837-4849,中插4-中插5,15.基金项目
国家自然科学基金(51877084).Project supported by National Natural Science Foundation of China(51877084). （51877084）
