高压输电线路距离保护克服过渡电阻能力研究

高压输电线路中存在较大的过渡电阻,很容易引起距离保护拒动或误动.分析特高压单侧电源经长线路出口故障和双侧电源长线路出口故障时过渡电阻对距离保护工作的影响,探讨单侧电源助增电流网络、外汲电流网络中过渡电阻对测量阻抗的影响,并给出2种网络结构在不同地点处保护测量阻抗的计算公式.研究能较好躲过渡电阻特性的零序电抗继电器、自适应接地距离继电器、神经网络距离继电器,分析比较不同方法的优缺点及适用场合.

Research on the ability of ultra-high voltage transmission line distance protection standing fault resistance influence

In HV transmission lines,the existence of large fault resistance may easily result in tripping missing or maloperation of distance protection.The influences of fault resistance to distance protection are analyzed in the paper.The fault resistance influences in distance protection are analyzed with fault happened at the end of long UHV line with one-terminal or two-terminal power supply.And the fault resistance measuring is also discussed in one-terminal sources infeed current network and outfeed current network.The calculation formulas of measuring resistance in the two networks are proposed.Some relays of standing fault resistance,including zero-sequence reactance relay,adaptive earth fault distance relay,neural network distance relay,are presented.Their merits,drawbacks and application situations are analyzed and compared.