一种自动适应电力系统运行方式变化的新型突变量选相元件  

A Novel Adaptive Phase Selector Based on Fault Component

作　　者：鲁文军[1] 林湘宁[1] 黄小波[1] 刘沛[1] 

机构地区：[1]华中科技大学电力工程系,湖北省武汉市430074

出　　处：《中国电机工程学报》2007年第28期53-58,共6页Proceedings of the CSEE

基　　金：国家自然科学基金项目(50407010)。~~

摘　　要：针对传统电流突变量和电压突变量选相元件不能同时满足强弱电源系统侧保护要求的缺点,提出一种新的突变量选相原理。该选相元件在电压突变量基础上引入单相电流突变量进行极化,不但能自动适应系统运行方式的变化,尤其在系统正负序阻抗不等导致传统突变量选相元件失效的场合,更能体现出其优越性。值得指出的是,该选相元件对单相短路故障和相间短路(接地)判断均有很高的灵敏度。直流系统电磁暂态仿真结果表明,即使在正负序严重不对称的场合,该元件也具有很好的选择性。当系统参数大范围变化时,该选相判据也能实现正确选相,比传统突变量选相方案具有更高的可靠性。A novel superimposed phase selector aiming at improving the performance of phase selector in the event of a wide range change of power system operation mode is presented. In this new scheme, the fault component of phase-phase voltage difference is polarized with the fault component of the third phase current. With this arrangement, this element not only adapts to various operating modes of power systems, but is superior to the traditional superimposed phase selectors. For instance, the superimposed phase-phase current difference based phase selector or the superimposed phase-phase voltage difference based phase selector, in terms of selectivity and sensitivity. The advantages of this phase selector can be highlighted especially in the case of the positive-sequence impedance not being equal to the negative-sequence impedance. In addition, this phase selector can reliably identify the single-phase-earth fault and the phase-to-phase fault. The results of electro-magnetic transient in DC system（EMTDC） simulation show that the outstanding phase selection performance can be achieved even when the negative-sequence system impedance is extremely unequal to the positive-sequence system impedance. Besides, this phase selector has higher reliability compared to the traditional superimposed based schemes.

关 键 词：输电线路 自适应 突变量 选相元件 弱馈 

分 类 号：TM771[电气工程—电力系统及自动化]