特高压电网带并联电抗器线路自适应重合闸研究

项目名称： 特高压电网带并联电抗器线路自适应重合闸研究

项目编号： No.50877062

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 电工技术

项目作者： 宋国兵

作者单位： 西安交通大学

项目金额： 35万元

中文摘要： 特高压线路输送容量大，对电网稳定性有重要影响。线路故障多具有单相瞬时性的特点，重合闸可提高供电可靠性，但重合于永久故障时系统将再次遭受冲击，因此，对具有永久性故障识别能力的自适应重合闸的研究具有重要意义。特高压电网大都装设并联电抗器，它降低了瞬时故障的恢复电压，使基于恢复电压的自适应重合闸判据不再适用。对双端电抗器线路而言，受拍频特性影响，电气量判据的灵敏度和快速性差。与电气量相比，网络结构和参数的变化则更具本原性，本项目提出将参数识别原理用于自适应重合闸，用参数判据替代电气量判据以改善了性能；用电抗器电流进行参数识别，解决了恢复电压幅值低、可信度差的问题；用故障定位确认策略保证了永久性故障判别的准确性；研究了线路两端重合闸及分闸动作顺序和时限，防止了特高压电网重合过电压；研究的重合闸动作时间具有二次电弧熄灭时间自适应能力，最大限度的限制盲目重合，提高电力系统稳定性。

中文关键词： 特高压线路；并联电抗器；自适应重合闸；电流量；参数识别

英文摘要： Ultra-high-voltage (UHV) transmission system plays an important role in the stability of the power system. Statistical data show that the most faults on UHV transmission lines are transient single-phase to ground type, so the application of single-phase autoreclosure can improve the reliability of transmission system. However, reclosuring onto a permanent fault may aggravate the operation condition of the system and the equipments. Therefore, it is important to study the adaptive single-phase reclosure (SPAR) that aims to distinguish permanent faults from transient faults. Normally, UHV transmission line are equipped with compensated shunt reactor, which lowers the recovering voltage amplitude of the tripped phase and limits the application of the voltage-based SPAR technique. To the transmission lines with two-terminal shunt reactors, the sensitivity and speed of the schemes using electrical components are limited by the oscillation character. Compared with the electrical component based method, the technique based on structure and parameters of the circuit is of higher performance. Therefore, the proposed scheme based on parameter identification principle has been used to improve the performance of SPAR. Moreover, using current component to realize parameter identification is helpful to solve the problems caused by the low recovering voltage and bad reliability of secondary voltage circuit. Besides, fault location scheme is employed to ensure the correctness of a permanent fault estimation. Furthermore, the sequence and time of the reclosing and opening are proposed to avoid over-voltage. At last, the relationship of the reclosing time of the SPAR and the secondary arc extinction time is investigated, which aims to improve the success rate of the reclosure and stability of the power system.

英文关键词： UHV transmission line; shunt reactors; adaptive reclosure; current component; parameter identification