基于振荡波局部放电检测的配电网电缆典型缺陷分析与状态评价

Typical Defects Analysis and State Evaluation of Power Distribution Cable Based on Oscillating Wave PD Detection

随着浙江电网配电网电缆使用规模的快速扩大及配电网运行可靠性要求的日益提高,在复杂多变的现场环境下,在有限的停电时间内对电缆健康状态进行准确评价,并对检修方案进行科学决策仍然是一大难点。介绍了在实验室开展的配电网电缆典型绝缘缺陷的模拟试验及局部放电特征分析,结合在G20保供电期间开展的大量现场试验结果分析,发现热缩电缆终端的老化问题、冷缩式应力管握力衰减、电缆附件施工工艺、电缆内部及线芯进水为电缆缺陷的5类主要原因。通过对典型案例分析表明,综合考虑局部放电位置、投运年限、放电量水平,细化、优化基于振荡波局放检测的状态评价依据,能够有效指导配电网电缆运行维护的决策。

With the rapid increase of distribution cables and the increasing demand for operation reliability in Zhejiang power grid, it is quite difficult to accurately assess the health state of distribution cables and make scientific decision in complex field environment in limited outage duration. The paper introduces simulation test on typical insulation defects of distribution cables in laboratory and partial discharge feature analysis.Based on field test result analysis during G20 summit, causes of heat shrink cable terminal aging, decreased gripping power of cold shrink stress tube, construction technique of cable accessories, water leakage of cable interior and line core. By typical case analysis, PD location, operation duration and discharge level are considered, and state evaluation basis based on oscillation wave PD detection is refined and optimized to support decision-making of distribution cable operation and maintenance.