110kV电缆中间接头及本体典型缺陷局部放电特征分析

Partial Discharge Characteristics Analysis of Typical Defects for 110 kV Cable and Joint

针对110 kV XLPE电缆中间接头及本体制作了6种人工典型缺陷,并利用高频电流互感器耦合局部放电信号。对各类缺陷放电脉冲进行时域、频域特征分析,研究同一缺陷相同电压下不同放电时刻单脉冲波形和频谱规律,并对不同受损程度的电缆本体缺陷局部放电参数的变化进行分析。结果表明:当本体电缆波纹铝破损但未伤及主绝缘时,局部放电无法发现该类缺陷;当主绝缘破损时,在较低电压下便可检测到局部放电,但耐压试验依然可以通过,且随着主绝缘破损深度的增加,局部放电起始电压呈线性递减。

Six kinds of artificial typical defects of 110 kV cable and joint were produced, and high frequency current transformer （HFCT） was used to couple the PD signals. The PD pulse of different defects in time domain and frequency domain were analyzed. The monocycle pulse waveform and frequen-cy spectrum at different discharge moments of the same defects under the same voltage were studied, and the changes of PD parameters of the cable bulk defects with different degree of damage were analyzed. The results show that when the corrugated aluminum is damaged but the insulation of the cable is undamaged, these defects could not be detected by PD detection. Once the insulation of the cable is damaged, the PD can be detected under lower voltage, but the cable can pass through the with-stand voltage experiment. With the increase of the depth of insulation damage, the initial partial discharge voltage decrease linearly.