含逆变型分布式电源和分支负荷的配电网自适应电流差动保护  

Adaptive Current Differential Protection for Distribution Networks With Inverter-interfaced Distributed Generators and Branch Loads

作　　者：王钢[1] 冯婧桐 李杰 WANG Gang;FENG Jingtong;LI Jie(School of Electric Power Engineering,South China University of Technology,Guangzhou 510641,Guangdong Province,China)

机构地区：[1]华南理工大学电力学院,广东省广州市510641

出　　处：《电网技术》2024年第6期2593-2602,I0099-I0102,共14页Power System Technology

基　　金：国家自然科学基金项目(51477057);广州市科技计划项目(2023A04J1589)。

摘　　要：电流差动保护具有良好的选择性和灵敏性。但是,逆变型分布式电源(inverter-interfaced distributed generator,IIDG)和分支负荷接入改变了配电网的故障特性,现有配电网的电流差动保护面临拒动或误动的风险。为解决以上问题,该文在计及P/Q控制的IIDG和分支负荷的故障等值建模基础上,从故障点、IIDG和分支负荷的相对位置出发,挖掘配电网线路两端正序电流差的幅值特征以及正序电流故障分量的相位特征。在此基础上,提出一种正序电流幅值与故障分量相角阈值配合的双比例制动系数自适应差动保护方案,并且利用幅相平面分析所提保护判据的可靠性和灵敏性。最后通过PSCAD/EMTDC验证了所提保护方案的有效性,仿真结果表明该方案适应不同故障类型、位置和过渡电阻,且不受IIDG以及分支负荷接入的影响。A current differential protection has a good selectivity and sensitivity.However,the access of the inverter-interfaced distributed generators(IIDGs)and the branch loads has changed the fault characteristics of distribution networks,which increases the risks of the false or failure operations for the existing current differential protection of distribution networks.Based on the fault equivalence model of the PQ-IIDGs and the branch loads,this paper investigates the magnitude characteristics of the positive-sequence currents and their phase characteristics of the fault components,taking the relative positions of the fault points,the T-connected IIDGs and the branch loads as the datum point.An adaptive double-proportional-restraint-coefficients-based differential protection using the positive-sequence current amplitude and the fault-component phase is proposed.The reliability and sensitivity of the proposed protection criterion are analyzed using the amplitude and the phase planes.The effectiveness of the proposed method is validated by the PSCAD/EMTDC simulation.Results show that the scheme has a good adaptivity to different fault types,locations and fault resistances without being affected by the access of the IIDGs and the branch loads.

关 键 词：配电网 逆变型分布式电源 分支负荷 自适应电流差动保护 正序故障分量 

分 类 号：TM721[电气工程—电力系统及自动化]