干式空心并联电抗器现场故障诊断技术研究

发布时间：2018-11-27 07:13

【摘要】：干式空心并联电抗器在电网中可以起到补偿无功功率,限制工频过电压等作用。随着电网电压等级的提升,干式空心并联电抗器的容量越来越大,并联支路数也随之增加,在制造过程中可能存在匝数上的偏差,运行或运输过程中也可能出现匝间短路或断股故障。现有的方法对上述缺陷诊断非常困难,针对这一类问题,本文提出通过测量分布电流的方法判断电抗器缺陷,并对测量装置进行了研制。本文通过建立干式空心并联电抗器电路模型,对电气参数特性进行分析,给出了正常电抗器与故障电抗器支路电流的计算方法,并以一台型号为BKDK-20000/35干式空心并联电抗器为例进行计算。通过解析和仿真的方法计算了电抗器自身运行产生的磁场,针对现场运行电抗器对被测电抗器的工频干扰进行分析。为避免工频干扰,通过设计的25Hz电源对电抗器进行测量,将采集卡采集的数据利用谐波分析,准同步采样算法进行数据处理。针对磁场的干扰对传感器设计了磁屏蔽。最后对干式空心电抗器样品进行试验验证。研究结果表明:当干式空心电抗器发生匝间短路、断股故障和匝数偏差时,电抗器总电流变化很小,故障位置处支路电流变化量很大。在25Hz功率电源下通过磁屏蔽电流传感器对电抗器支路电流进行测量,利用准同步采样及谐波分析法对采集到的数据进行处理,得到的测量结果与理论值一致,验证了采用25Hz试验电源和准同步谐波分析法抗工频干扰能力强,准确度高,能够准确得出分布电流测量结果。
[Abstract]:Dry hollow shunt reactor can compensate reactive power and limit power frequency overvoltage in power grid. With the increase of power grid voltage grade, the capacity of dry hollow shunt reactor becomes larger and larger, and the number of parallel branches also increases, which may lead to the deviation of the number of turns in the manufacturing process. There may also be inter-turn short-circuit or broken strands during operation or transportation. The existing methods are very difficult to diagnose the defects mentioned above. In view of this kind of problems, the method of measuring distributed current is put forward to judge the defect of reactor, and the measuring device is developed. In this paper, the circuit model of dry hollow shunt reactor is established, the characteristics of electrical parameters are analyzed, and the calculation method of branch current of normal reactor and fault reactor is given. A model of BKDK-20000/35 dry hollow parallel reactor is taken as an example. The magnetic field generated by the reactor itself is calculated by analytical and simulation methods, and the power frequency interference of the reactor is analyzed according to the field operation reactor. In order to avoid power frequency interference, the reactor is measured by the designed 25Hz power supply, and the data collected by the acquisition card is analyzed by harmonic analysis, and the quasi-synchronous sampling algorithm is used to process the data. A magnetic shield is designed for the sensor due to the interference of the magnetic field. Finally, the dry hollow reactor samples were tested and verified. The results show that the total current of the reactor changes little and the branch current changes greatly when the inter-turn short circuit occurs in the dry hollow reactor, the fault of broken strands and the deviation of the number of turns. The current of reactor branch is measured by magnetic shielding current sensor under 25Hz power supply. The collected data are processed by quasi-synchronous sampling and harmonic analysis. The measured results are in agreement with the theoretical values. It is verified that the 25Hz test power supply and the quasi-synchronous harmonic analysis method have strong ability of resisting power frequency interference and high accuracy, and can accurately obtain the results of distributed current measurement.
【学位授予单位】：哈尔滨理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM472

【参考文献】