汽轮发电机绝缘监测中脉冲型噪声的传播特性

Transmission character of pulse shaped noise in insulation monitoring for turbo generators

了解脉冲型噪声在单元机组网络中的传播规律，是汽轮发电机局部放电在线监测中实现这类噪声抑制的前提。文中采用在电厂单元机组网中选点注入模拟脉冲的方法，选择主变高压侧、母线断口、转子为脉冲注入点，研究了脉冲经由主变的传播特性，以及三相母线对所传播脉冲的作用。并考察了汽轮发电机转子侧产生的噪声脉冲通过定转子间的耦合作用对局部放电信号检测的影响，说明了这些噪声脉冲传播途径的传递特性。并讨论了实验结果的可靠性，以及实验结果对于抑制来源于除主机外其它高压电力设备、电力系统及转子侧大功率电子开关的脉冲型噪声的意义。

Comprehension of the propagation characteristic of pulse within single machine power network means lot to suppression of pulse shaped noise in on line monitoring of insulation condition. In this paper, a simulated pulse signal is injected in some points, including high voltage side of transformer, bus breaker, rotator side of machine. On the basis of these tests, the way that the transformer and bus act on the pulse signal passing through them is studied. It is also presented that noise pulse originating from rotator side may couple into the partial discharg detecting circuit which is located on stator side. The transfer characteristics of some possible noise propagation channel are shown. The reliability of test results is discussed. The significance of these results to the rejection of pulse shaped noise coming from other HV apparatus and rectifier power electronic circuits is illustrated.