基于辐射场窄带测试的电晕放电远距离探测技术研究

利用电磁辐射场实现对电晕放电的探测,多采用宽带测试,带内干扰多、信噪比低、测试距离近.为此,提出了基于窄带测试的电晕放电远距离探测方法,通过分析电晕能量分布及背景干扰,合理选择窄带测试频段,实现对电晕放电目标的远距离探测.测试结果表明:较之宽带测试,窄带测试信噪比较高、抗干扰能力强、测试距离远;120～315 MHz频段内的电晕放电信号,背景干扰少,信噪比不低于4 dB,适宜用作电晕放电信号远距离测试的特征窄带频段.提出的窄带测试方法具有普遍性,结合现代检测技术和信号处理技术将会大大增加测试距离,对丰富现有电晕放电远距离探测手段具有重要意义.

Remote detection technology of the corona discharge based on narrow-band testing of radiation field

Currently corona discharge detection can be achieved by measuring its electromagnetic radiation field in a wide-band. However, the wide-band test brings in more electromagnetic interference, resulting in a low signal to noise ratio(SNR), and limits the detection distance. Hence, the narrow-band testing method for remote detection of corona discharge is proposed. The principle is to select a suitable narrow-band frequency with a high SNR to test the radiation field by analyzing corona energy distribution and the background electromagnetic interference. A test experiment is carried out and its result is analyzed. Comparing with wide-band test, the narrow-band test has remoter detection distance for higher SNR and anti-interference ability. The frequency band from 120 MHz to 315 MHz in which has few interference and high SNR of more than 4 dB, is suitable for remote detection for corona discharge. The proposed narrow-band-test method, by which the detection distance becomes further after signal processing, is general and has a great significance for developing the current remote detecting technologies of corona discharge.