Abstracting frequency spectrum characteristics of insulators leakage current in safety zone to forecast the contamination condition

作者：Yao Chen Guo^*; Li Jing Yan; Mi Yan; Sun Cai Xin; Li Xian Zhi

来源：Proceedings of the CSEE, 2007, 27(30): 1-8.

• Contaminate insulators
• Contamination condition
• Frequency spectrum characteristic
• High frequency energy
• Humidity
• Safety zone

Time domain characteristics of leakage current of insulators have been used to forecast contamination condition, but abundant forecast information in frequency components of leakage current has still been ignored. To solve this problem, new analysis method using FFT conversion and power spectrum estimation is used. Two characteristic values in frequency domain are abstracted as forecasting parameters of insulators'; contamination condition: the ratio of amplitude value between third order harmonic and fundamental component (k) and the ratio of high frequency energy and total energy (α). This paper studied frequency spectrum characteristics of leakage currents in safety zone (< 20 mA) under operating voltage when environment humidity and contamination condition are changed. The main aim is to bring forecast of contamination condition of insulators forward to safety zone. Testing results show that frequency spectrum characteristics (K and α) can be used to forecast condition of environment humidity and contamination condition of insulators effectively.

• 出版日期2007