【作者】 杨文荣；

【导师】 杨庆新；

【作者基本信息】 河北工业大学 ， 电机与电器， 2000， 硕士

【摘要】 随着国内外配电网自动化改造的深入，电网中性点经消弧线圈接地已成为城市配电网减小单相接地电流、消除接地故障的一个重要手段。本文讨论的“中性点经消弧线圈接地的电网脱谐度测量方法的研究”的课题具有较大的实用价值。 现有的消弧线圈的调谐方法很多，但各有其优缺点。本文在对大量参考文献分析的基础上，提出基于外加信号法调谐的新方法，弥补了现有各种调谐方法的不足之处。本方法采用带PT的消弧线圈，从PT低压侧注入零序恒流信号，通过频率扫描确定系统的谐振频率，再由公式计算出脱谐度，然后根据脱谐度的预先设定的偏离值调节消弧线圈分接头，实现消弧线圈的调谐。外加信号法测量脱谐度是在系统正常运行情况下进行的，不影响系统正常运行，且不受系统运行的影响，对于具有多个消弧线圈的配电网，只需选定一个消弧线圈进行测量，就可完成整个配电网脱谐度的测量，无需通讯配合。采用外加变频信号法可以使电网脱谐度的测量由PT高压侧移至低压侧，使测量更加安全、方便。 在测量电路中，电网中性点电压传递到PT低压侧的值比被测信号电压高几倍甚至十几倍，为消除工频电压的影响，我们设计了有源带阻滤波器，该滤波器在50Hz时输出为零，而其它频率（包括49Hz和51Hz）基本不衰减且相位不变。 本课题根据上述测量原理研制了一个脱谐度测量装置，并用该装置对邯郸阜阳电站进行了测量，整个测量过程不足5分钟（不含接线时间）即得出满意的结果。测量方便、快速、准确。本装置在配以微机控制系统后可以实现消弧圈的自动跟踪调谐。更多还原

【Abstract】 With the further reconstruction of distribution network automation, neutral resonant grounding has been one of important method to suppress the one-phase grounding fault current and to clear the earth fault in urban distribution network. As the subject of dissertation for master degree, 搕he Study on Measurement Method of Off Tuning Degree in the Distribution Network of Neutral Resonant Grounding? has important practical value.However, there exist some defects to the present resonant regulation niethod, a new method of resonant regulation based on injecting current is presented in this paper. Various frequency constant current is injected to second side of PT (potential transformer) which the petersen coil is the first side. Petersen coil tuning system is implemented, which is based on measuring the system resonance frequency. This principle is not affected by syctem operation. It has high precision and high reliability.In measuring system, a band elimination filter (BEF) is designed to eliminate the interference of noise signal, which is caused by the nature displacement voltage and is higher by many times than the measured volt4e. The BEE抯 output is zero at 50Hz and is constant on amplitude and phase at other frequencies.A device for measuring off tuning degree based on the principle above-mentioned is developed, which have passed the practical test through measurement in Fuyang power station in Hebei province. Operational experience shows that this method is effective. If it operates with the microcomputer control system, automatic tracking resonant regulation will be obtained.更多还原