摘要
长距离电缆存在金属护层交叉互联和负载电流造成电压降的问题,因而与短距离电缆绝缘的在线监测存在很多不同。提出了一种新的在线监测方法,即双端同步测量损耗因数(tanδ)法,对该方法的原理进行了分析,给出了计算tanδ值的理论依据;对存在同步误差、电压误差时该方法可行性进行了论证,运用Matlab软件对三相电缆等效电路进行了仿真。仿真结果表明,选取两端电压的相量和的一半作为参考电压,电缆绝缘tanδ值不会随负载电流变化而变化;对于电缆绝缘的不同故障,可以通过tanδ值的变化来判断三相电缆的绝缘状况,因此可知利用双端同步测量tanδ法来测量长距离电缆绝缘状况是正确的、可行的。
On-line insulation monitoring technique for long distance power cable is different from the short one. This is due to the cross-linked of metal sheath and voltage drop caused by load current. In order to solve the problem, two terminal synchronous tanδ measurement as a new method of on-line insulation monitoring were put forward. The working principle of the method and the calculation theoretical basis for tanδwere given. The feasibility of the method was demonstrated when there were synchronization error and voltage error in the system. The equivalent circuit of three-phase cable was simulated by using Matlab software. The results show that load current will not influence on tanδ when choosing the half of vector sum of voltage across as voltage reference. The insulation condition of three-phase cable can be judged by the change of tanδ for different insulation fault. The method was proved to be valid and feasible.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2015年第8期2079-2086,共8页
Proceedings of the CSEE
基金
国家重点基础研究发展计划项目(973项目)(2012CB 723308)
黑龙江省研究生创新基金重点科研项目(YJSCX2012-078HLJ)~~
