电力系统保护与控制2024，Vol.52Issue(12)：1-12,12.DOI:10.19783/j.cnki.pspc.231512
基于双层负序差值与负序测距的风电场集电线不对称故障定位
Bi-level negative-sequence difference and negative-sequence fault distance calculation-based fault localization for asymmetric faults of collecting lines in wind farms
摘要
Abstract
The collecting line in wind farms is accessed in a dense fashion by complex power sources.This makes existing fault localization methods inapplicable.Therefore a fault localization method for asymmetric faults is proposed based on bi-level negative-sequence difference and negative-sequence fault distance calculation.First,the fault current characteristics of wind turbines(WTs)are analyzed,based on which mathematical models of WTs can be constructed from the perspective of negative-sequence.The equivalence of wind farm negative-sequence networks is further implemented considering the structural characteristics of wind farms.Then,introducing a fault simulation strategy,the difference between simulated and actual faults is characterized by the negative-sequence voltage difference to identify the first node of faulty areas.The variation trend of negative-sequence voltage from actual fault scenarios to specific simulated fault scenarios is explored,and the negative-sequence voltage ratio is defined to eliminate the effect of fault point current.From this a criterion based on the negative-sequence voltage ratio difference is proposed to achieve identification of the second node of faulty areas.Finally,fault locations are determined by a fault distance calculation formula derived from the two-terminal negative-sequence quantity of faulty areas.Verification results from PSCAD/EMTDC show that the proposed method can accurately locate various asymmetric faults of collecting lines by just a few measurement points.The applicability to collecting lines with line branches is also considered.The localization performance is not affected by fault locations,fault resistance,WTs,wind speed distribution or asynchronous data.关键词
负序电压差值/负序电压比差值/负序测距/风电场/集电线/不对称故障/故障定位Key words
negative-sequence voltage difference/negative-sequence voltage ratio difference/negative-sequence-based fault distance/wind farm/collecting line/asymmetric fault/fault localization引用本文复制引用
丁嘉,朱永利,魏源..基于双层负序差值与负序测距的风电场集电线不对称故障定位[J].电力系统保护与控制,2024,52(12):1-12,12.基金项目
This work is supported by the National Natural Science Foundation of China(No.51677072). 国家自然科学基金项目资助(51677072) （No.51677072）
