摘要
距离保护是基于电流、电压构成的方向性保护,距离保护不受系统运行方式、系统结构影响,被广泛应用于各电压等级的线路。由于正序电压具备故障前与故障后电压相位不变的特性,以正序电压作为参考标准的极化电压具有良好的方向性,距离保护圆特性一般采用正序电压作为极化电压。而在中性点不接地系统的单端电源运行方式下,以正序电压作为极化电压的圆特性距离保护作为电源侧的保护使用时存在反向相间故障误动的可能性。针对此不足,本文设计了一种圆特性距离保护的闭锁条件,即基于正负序电压和电流的逻辑判断条件。仿真实验表明该方法能够有效防止反向相间故障时距离保护误动,避免事故范围的扩大,提高了系统的安全运行水平。
Distance protection is a directional protection scheme based on current and voltage measurements.Its operation is inherently unaffected by system topology or operating conditions,and thus it is widely applied across power lines at various voltage levels.Due to the constant phase angle of positive-sequence voltage before and after a fault,it is commonly used as the polarizing voltage to provide strong directionality in distance protection with circular characteristics.However,in systems operating in a single-ended power supply mode with an ungrounded neutral,using positive-sequence voltage as the polarizing voltage may cause misoperation of distance protection in the event of reverse phase-to-phase faults on the source side.To address this issue,this paper proposes a blocking criterion for circular distance protection based on logical conditions derived from positive-and negative-sequence voltage and current measurements.Experimental results demonstrate that the proposed method can effectively prevent false tripping during reverse phase faults,thereby avoiding the escalation of fault impact and enhancing overall system safety.
作者
姜梦
陆帅
沈建国
周群
马玉庆
JIANG Meng;LU Shuai;SHENG Jianguo;ZHOU Qun;MA Yuqing(Nanjing Paneng Technology Development Co.,Ltd.,Nanjing Jiangsu 210000,China)
出处
《宁夏电力》
2025年第5期73-79,共7页
Ningxia Electric Power
关键词
距离保护
正序极化电压
反方向误动
distance protection
positive-sequence polarizing voltage
reverse fault misoperation
