基于多时间断面信息的T接风电场并网线路单相接地故障单端测距研究

Multiple-terminal transmission lines are widely used in power system with wind farm connections due to the limitaiton of wind sources dsitribution and some other factors. Fault location technique based on synchronous mutiple-end information is usually adopted in traditional multiple-end lines. But this type algorithm cannot be used in wind farms' T-connection line since the real-time information at wind farms is unavailble, and metered power components are usually polluted with large errors caused by frequency variation after fault. In response to this problem, a novel single-end fault location algorithm is researched in this project with only using the information at power system side. It is based on the fact that, the topology of transmission line keeps constant at multiple time-sections: time at fault occurrence, and those after multiple-terminal fault phase circuit breaker trippings. Hence, firstly, multiple time-sections information will be used to identify fault branch and to calculate fault distance based on impedance algorithm. After that, a novel travelling wave based fault location algorithm will also be researched using the relationships of travelling waves refractions and reflections, which are originated from the occurance of fault and sequent operations of circuit breakers. After that, a combined fault location algorithm will also be researched based on the distributed parameters transmission line model to couple single-end impedance location and travelling wave location algorithms.The location deveice will be developed and promised to pass the functional and EMC tests. The most valuable theory innovation in this project is the digging of inherent characerristics using multi-time section information to fault phenomenon, which can also be extended to the practical applications in distribution system.

受风资源分布等因素影响，风电场T接并网输电线路广泛应用；具备低穿能力的风电场侧不安装保护，无实时量测数据，且并网线路故障后风场侧电气量受频率影响量测误差大，多端时钟同步保持困难，传统基于多端同步的故障测距方法无法适用，严重制约着风电场并网线路的快速修复；针对该问题，项目提出仅立足于系统侧信息，基于永久性接地故障单相切除前后输电线路拓扑结构保持不变的实际，利用故障后系统侧延时跳闸，主动控制T接风电场侧断路器故障相依次跳闸，而产生的多时间断面信息，研究故障分支定位与单端阻抗测距算法；利用故障发生、风场侧断路器重合闸而产生的行波源多时间注入与折反射特征，研究单端行波测距算法；最终基于分布参数线路模型，综合阻抗法的稳定性与行波法的精确性，研究单端实用化组合算法；研制测距装置，通过功能与型式试验测试；项目充分挖掘多时间断面故障信息的内在耦合性，理论成果可推广到配电网中应用，理论意义与实用价值并重。

风电场故障等值阻抗时变、单端故障测距信息不完备等特点造成送出线路故障测距不准确，故障排查困难。.项目提出了风电机组低电压穿越核心参数通用辨识方法；提出了使用故障后线路两端断路器相继动作产生的多时间断面信息的单端故障测距算法；针对风电场并网双端、T接输电线路单端精确测距问题，改变现有测距立足系统侧，转为立足风电场侧，有效规避了风电场故障后等值阻抗动态变化对故障测距的影响，并针对风电场侧电流量测值偏小导致的故障测距精度显著下降的问题，提出了不受故障类型影响的直接求解方程测距新算法，能够直接计算得到故障距离和过渡电阻值，实现了精确测距。利用不同容量、不同风机类型风电场表现出的差异性，提出了T接风电场并网线路故障分支辨识算法。针对风电场并网输电线路易发生高阻故障的问题，基于汤逊原理首次提出了适用于故障测距的电弧对数解析表达式及故障测距算法。针对单端行波测距反射波头易受噪声混叠影响难以甄别的难题，提出了利用Prony分解与多尺度小波变换结合的互感器一次侧行波重构算法，提出了单端行波测距与单端工频阻抗测距算法结合的单端组合测距方法。.研制了故障测距装置，完成了实验室测试，并在张北鹿原风电场投运，运行状况良好。采用历史故障录波数据验证了装置的测距精度，测距相对误差小于0.5%。项目成果作为核心内容通过了中国电机工程学会组织的成果鉴定，专家委员会认为：项目解决了当前大规模风电汇集系统保护与测距的关键技术问题，项目研究成果达到国际领先水平。.项目发表学术论文31篇，其中SCI源刊8篇，中文核心期刊论文16，参编专著1部，主编译著1部，获授权国家发明专利10项，新申请国家发明专利7项，获得了2016年吉林省科技进步一等奖、2017年度国家技术发明二等奖，2017年国网冀北电力有限公司科技进步一等奖等，获得了2015年中国电力优秀青年工程师奖、2018年IEEE PES China Outstanding Young Volunteer Award、2018年度JEET最佳副编辑奖等人物奖4项，协助培养毕业博士研究生3名、培养毕业硕士研究生4名。