GIS设备内外部紧固松动机械缺陷振动特性对比分析研究

Comparative Analysis and Research on Vibration Characteristics of Internal and External Fastening Loose Mechanical Defects of GIS Equipment

气体绝缘组合电器(gas insulated switchgear,GIS)机械性缺陷是导致设备故障的重要原因。当GIS存在机械缺陷时,在交流电动力的作用下会产生异常振动信号,通过测量GIS外壳上的机械振动信号能够实现对设备机械缺陷的检测和诊断。GIS设备内部或者外部紧固松动是现场常见的机械性缺陷,然而目前对于内外部紧固松动缺陷的振动信号特性尚不清楚,制约了现场对于该类型缺陷的检测与诊断。针对于此,文中在550 kV实体GIS试验平台上构建了内部屏蔽罩松动和外部地脚螺栓松动两类缺陷,对比分析了不同缺陷下的振动信号时、频域特征,以及信号特征和负载电流的关联关系。结果表明,内外部缺陷均不会引起100 Hz基频振动信号发生变化,而仅导致其余频率点信号略有升高,因此无论是内部还是外部松动缺陷都不会引起设备振动信号幅值的明显升高;相比较而言,内部松动缺陷主要引起200、300 Hz等低频信号分量的升高,而外部松动缺陷主要引起1500 Hz以上高频信号分量的幅值升高;内部松动缺陷引起的低频信号分量升高程度随着负载电流的增加明显增加,而外部松动缺陷引起的高频分量升高程度与负载电流相关性较小。文中的研究成果为现场GIS内外部松动缺陷的检测和分析提供了理论支撑。

The mechanical defect of gas insulated switchgear(GIS)is an important cause of equipment failure.In case of mechanical defects in GIS,abnormal vibration signals will be generated under the action of AC electrodynamic force.The detection and diagnosis on the mechanical defects of equipment can be achieved by measuring the mechanical vibration signals on the GIS enclosure.Either internal or external fastening looseness of GIS equipment is a common mechanical defect on site.However,at present,the vibration signal characteristics of internal and external fastening looseness defects are unclear,which restricts the detection and diagnosis of this type of defects on site.In view of this,such two kinds of defects as internal shield looseness and external anchor bolt looseness on real 550 kV GIS test platform are constructed,and the relevant relations among frequency domain characteristics,signal characteristic and load in case of vibration signals at different defects are compared.The result shows that neither internal nor external defects will cause the variation of 100 Hz fundamental frequency vibration signal,but only cause the slight increase of signal of other frequency points.Therefore,both internal and external looseness defects will not cause obvious increase of vibration signal amplitude of equipment;Comparatively speaking,the internal looseness defects mainly cause the increase of low-frequency signal components such as 200 Hz and 300 Hz,while external looseness defects mainly cause the increase of amplitude of high-frequency signal components above 1500 Hz;The increase amplitude of low-frequency signal component due to internal looseness defect increases significantly with the increase of load current,while the increase amplitude of high-frequency component due to external looseness defect has little correlation with load current.The research result in this paper has provided theoretical support for the detection and analysis of internal and external looseness defects in field GIS.