摘要
基于输电线路等传变理论分析可知,电容式电压互感器(capacitive voltage transformer,CVT)的暂态特性会造成参与距离保护计算的电压和电流经过的传变环节不一致,是引起距离保护暂态超越的重要因素。因此提出一种等传变快速距离保护方案,使保护安装处的三相电压和电流与故障点电压经过相同的传变环节,新方法主要包括3个步骤,即故障点电压的重新构造、虚拟数字传变以及求解R-L模型微分方程。ATP仿真结果表明,所提方法能有效地减小了CVT引起的暂态误差,故障后15 ms左右测距误差不超过5%,明显优于基于CVT暂态误差估计或系统线路阻抗比的各种自适应保护算法(测距误差不超过5%一般需要30 ms以上)。
Based on the theory of equal transfer process of transmission lines,the transfer feature of the voltages used by the distance protection is different from that of the currents due to the transient characteristic of capacitive voltage transformers（CVT）,which is an important reason of the transient overreach of protections.Therefore,a novel high-speed distance relay scheme was proposed in order to solve the above problem.In the novel scheme,the three-phase voltages and currents at the relay location and the voltage at the fault point were made to have the same transfer links.There are three major steps in the novel method,that is,re-structuring of the voltage at the fault point,virtual digital transferring and solving the R-L differential equation.The ATP simulation results show that the proposed method can effectively reduce the transient error caused by CVT.The distance measuring error is within 5% at approximately 15 ms after the fault occurrence.The proposed algorithm is superior to various adaptive protection algorithms based on CVT transient error estimation or source impedance ratio（SIR）,which need at least 30 ms with the distance measuring error less than 5%.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2012年第4期145-150,6,共6页
Proceedings of the CSEE
基金
国家自然科学基金项目(51077061
50837002)~~
关键词
电容式电压互感器
距离保护
等传变
虚拟数字传变
输电线路
暂态超越
capacitive voltage transformer（CVT）
distance relay
equal transfer process
virtual digital transfer
power transmission lines
transient overreach
