针-板局部放电辐射电磁波频率特性的实验研究

Experimental Study on Frequency Characteristics of Electromagnetic Radiation from Needle-plate PD

高压设备局部放电时会辐射出具有一定频率的电磁波。设计了一种典型的针-板电极放电实验模型,搭建一局部放电试验装置,用以模拟高压设备局部放电,对辐射出的电磁波频率特性进行研究。结果表明,在50 MHz-1 GHz测试频率范围内,这种局部放电能够辐射出能量较强的电磁波信号,并且连续分布于整个测试频段(包括超高频段0.3-1 GHz);通过比较屏蔽装置内外测得的放电频谱,证实辐射出的电磁波可通过开孔处耦合到设备外部,并能被检测,特征也基本不变。这些特性为高压设备局部放电非接触式超高频检测技术和此种放电类型的识别提供了实验依据。

A certain frequency electromagnetic wave is radiated from partial discharge （PD） of high voltage equipment. A typical needle-plate electrode discharge experiment model is designed, and the partial discharge test equipment is built to simulate PD of high voltage equipment,then frequency characteristics are studied. The results show that,in the 50 MHz-1 GHz frequency range,the strong electromagnetic energy signal from PD is confirmed throughout the entire test section continuously （including uhra-high frequency （UHF） band 0.3-1 GHz）. By contrasting to discharge spectrums measured inside and outside the shielding equipment,it is found that the electromagnetic waves can be coupled to the outside of the device through the opening, which can be detected and has basically unchanged characteristics. All features above can provide experimental basis for non-contact UHF detecting technology of high voltage equipment PD and discharge identification of such type.