摘要
气体绝缘金属封闭式组合电器(GIS)具有绝缘性能好、占地面积小、检修周期长、运行安全可靠、不受外界环境影响等优点,得到了广泛应用。而GIS内部发生接地故障或隔离开关动作时,会产生高幅值、陡前沿的快速暂态过电压(VFTO),对GIS内部电气设备、外部连接设备及二次设备构成威胁,因此对VFTO抑制方法的研究已成为国内外普遍关注的重点问题。针对某500 kV交流超高压变电站GIS的VFTO抑制措施,利用ATP-EMTP电磁暂态分析软件对500 kV GIS变电站、金属氧化物避雷器、铁氧体磁环进行建模,并对500 kV GIS变电站内由故障或隔离开关动作等引起的VFTO的抑制方法进行探究。研究结果表明,在GIS的出线套管外装设避雷器后,VFTO幅值出现明显下降,避雷器降低GIS内各点VFTO幅值的效果随着各点与避雷器距离的增大而减弱,且避雷器不影响VFTO的陡度;在GIS隔离开关附近导杆处装设磁环后,能在降低VFTO幅值的同时,削弱VFTO的陡度;避雷器与磁环相结合,能极大降低VFTO幅值,并削弱其波形陡度,降低VFTO对GIS内外电气设备的威胁。
Gas-insulated metal-enclosed switchgear(GIS)has many advantages,such as good insulation performance,small footprint,long maintenance cycle,safe and reliable operation,and not being affected by the external environment,and has been widely used.However,when a ground fault occurs inside the GIS or the isolation switch is activated,a high-amplitude,very fast transient overvoltage(VFTO)will be generated,which poses a threat to the internal electrical equipment,external connection equipment and secondary equipment of the GIS.Therefore,the research on VFTO suppression methods has become a key issue of general concern at home and abroad.Aiming at the VFTO suppression measures of a 500 kV AC ultra-high voltage substation GIS,the ATP-EMTP electromagnetic transient analysis software is used to model the 500 kV GIS substation,metal oxide arrester,and ferrite magnetic ring.In addition,the method to suppress VFTO caused by faults or disconnecting switch actions in 500 kV GIS substations is explored.The results show that the amplitude of VFTO decreases obviously after installing arrester outside the outlet bushing of GIS.The effect of arrester reducing VFTO amplitude of each point in GIS decreases with the increase of the distance between each point and arrester,and the arrester does not affect the steepness of VFTO.After installing a magnetic ring on the guide rod near the GIS isolation switch,it can reduce the VFTO amplitude while weakening the VFTO steepness.The combination of lightning arrester and magnetic ring can greatly reduce the amplitude of VFTO,weaken the steepness of its waveform,and reduce the threat of VFTO to electrical equipment inside and outside the GIS.
作者
张倩
李壮优
ZHANG Qian;LI Zhuangyou(Henan Pinggao Electric Co.,Ltd.,Pingdingshan 467001,China)
出处
《电工技术》
2021年第13期16-19,共4页
Electric Engineering
