干式空心电抗器匝间短路在线监测系统研制

Study on Turn-to-turn Short Circuit On-line Monitoring System for Dry-type Air-core Reactor

针对干式空心电抗器匝间短路故障后引起电流变化小,故障监测困难的问题,设计了一种基于阻抗变化量的匝间短路在线监测系统。数值解析了在不同位置发生匝间短路故障后电抗器等值电阻与等值电抗的变化量,理论分析了基于谐波分析和准同步算法的监测方法。硬件以单片机为数据处理和逻辑控制的核心,对电抗器电压与电流信号进行数据采集。软件利用上述监测方法计算出阻抗变化量后,上传给计算机,实现对匝间短路故障的监测。对设计的在线监测系统进行了试验验证。研究结果表明:干式空心电抗器发生匝间短路后等值电阻增加,等值电抗减小,其中等值电阻变化更明显。试验结果验证了该监测方法的正确性和监测系统的可行性。

The change of current value caused by turn-to-turn short circuit of dry-type air-core reactor is so little that failure detection is difficult to be carried out. In order to solve this problem, a new on-line monitoring system based on impedance variation of turn-to-turn short circuit is pro The numerical method is applied to analyze the variation of equivalent resistance and equivalent reactance when dry-type air-core reactor winding short circuit happens in different places, and the monitoring method based on harmonic analysis method and quasi- synchronization sampling method is analyzed by theory. The hardware system, which takes single-chip microcomputer as the core of data processing and logic control, completes data acquisition of voltage signal and current signal of the reactor. In the respect of software design, the impedance variation will be uploaded to the PC after it has been calculated by using the above monitoring method, and then monitoring of turn-to-turn short circuit fault will be realized. Finally, the design of on-line monitoring system is studied by testing. The research result shows that, the equivalent resistance increases and the equivalent reactance decreases when turn-to-turn short circuit occurs, and the variation of equivalent resistance is more obvious than equivalent reactance. The experiment results prove that this monitoring method is true and the on-line monitoring system is feasible.