CAJ | 학술논문

针对传统的距离保护应用于交直流混联系统,特别是当直流系统发生换相失败时存在暂态超越的问题,分析发现交直流混联系统直流侧发生换相失败时,故障暂态信号中含有大量衰减缓慢的低频分量、非周期分量及高频分量,这是引起距离保护暂态超越的根本原因.同时,给出一种先利用分布参数模型将保护安装处的电压、电流补偿至整定点,再采用R-L线路模型建立微分方程,识别出整定点与故障点之间距离的保护方案.动模数据仿真结果表明,该方案在特高压、长线路末端故障时能够有效地防止暂态超越,不受线路分布电容、低频分量以及非周期分量的影响,提高了长线距离保护的动作可靠性.
침대전통적거리보호응용우교직류혼련계통,특별시당직류계통발생환상실패시존재잠태초월적문제,분석발현교직류혼련계통직류측발생환상실패시,고장잠태신호중함유대량쇠감완만적저빈분량、비주기분량급고빈분량,저시인기거리보호잠태초월적근본원인.동시,급출일충선이용분포삼수모형장보호안장처적전압、전류보상지정정점,재채용R-L선로모형건립미분방정,식별출정정점여고장점지간거리적보호방안.동모수거방진결과표명,해방안재특고압、장선로말단고장시능구유효지방지잠태초월,불수선로분포전용、저빈분량이급비주기분량적영향,제고료장선거리보호적동작가고성.
The traditional distance protections applied to the AC-DC power system usually induce transient overreach, especially for the Inverter commutation failure in DC system. It is found that the transient overreach in AC-DC power system is due to fault transient signals containing a large number of low-frequency components of the slow decay and non-periodic components and high frequency components. The voltage and current of tuning point based on distributed-parameter model are calculated, and the equations for identifying the distance between tuning point and the point of failure by R-L model are established to put forward a protection scheme. The simulations show the ability for distinguish internal fault from external fault and preventing transient overreach.