稳态量分相电流差动保护判据制动特性的改进  

Improvement on Restraining Characteristic of a Dispersed Phase Current Differential Protection Criterion Using Steady Currents

作　　者：汤俊[1] 王晓茹[1] 桑丙玉[1] 

机构地区：[1]西南交通大学电气工程学院

出　　处：《电力系统自动化》2008年第11期44-48,共5页Automation of Electric Power Systems

摘　　要：定义了区内故障穿越电流。对穿越电流的研究显示,传统稳态量差动保护区内故障时的保护灵敏度受负荷电流影响大,带过渡电阻能力与故障点位置相关。通过在制动特性中引入穿越电流,提出了一种改进的稳态量电流差动判据。理论分析表明:改进判据与传统稳态量差动保护判据区外故障的安全性完全相同,但改进判据在区内故障的灵敏度以及带过渡电阻能力大大提高了。对一条750kV线路故障和保护的仿真试验,证明了改进判据的上述优越性,是一种比较理想的超特高压输电线路电流差动保护判据。The through currents in transmission lines with internal faults are defined. The studies on through current show that internal faults of transmission lines with heavy-loads have an effect on the sensitivity of the traditional current differential protection under condition of steady currents, and the different fault location has different abilities of detecting high resistance internal faults. By improving the restraining characteristics, an improved steady current differential protection criterion is proposed. The comparison between the improved criterion and traditional one shows the same security on external faults, and the improved criterion has higher sensitivity and capability of detection on the faults with higher fault resistance. The simulation results from the faults with the two protection criteria in a 750 kV line verify that the proposed one has achieved a great improvement on sensitivity of internal faults and the abilities of detecting high resistance internal faults. It is an ideal current differential protection criterion for high voltage and ultra high voltage （UHV） transmission lines.

关 键 词：分相电流差动保护 特高压 故障过渡电阻 穿越电流 

分 类 号：TM77[电气工程—电力系统及自动化]