关于避免500kV GIS开关站PT谐振的运行操作方法探讨

On the Operation Methods of 500kV GIS Switch Station to Avoid PT Resonance

基于某电站500kV GIS开关站进线PT及母线PT在对应设备停电过程中曾多次发生PT铁磁谐振,通过对其原因分析,认为根本原因是设备参数匹配不合理,同时也与开关的停电操作顺序有一定的关系。传统停电操作顺序为依次先将停电范围内开关转热备用,再将设备转冷备用。经研究提出了一种新的开关停电操作顺序,逐一将开关由运行转冷备用。经过对两种开关操作顺序下PT铁磁谐振情况进行对比,采用新的停电操作顺序,PT谐振得到比较明显的改善,要么谐振强度减小,要么谐振时间缩短,既可避免500kV GIS开关站PT谐振,又具有较好的可实施性。

In a 500 kV GIS switch station of a hydropower station, ferromagnetic resonances are repeatedly observed in the incoming line PT and the busbar PT. Analysis shows that the problem is caused primarily by the improper matching of the equipment parameters, and also related to the power-off operation sequence of the switches. The traditional power- off operation sequence is to turn the switches successively to the hot standby state and then to the cold standby state. A new effective and feasible operation sequence is thus proposed, in which the switches are successively turned from the operational state to the cold standby state. It shows that the new power-off sequence could dramatically alleviate the PT ferromagnetic resonance problem to either reduce the resonance intensity or shorten the resonance time.