高阻抗变压器相间短路后备保护灵敏度的提高  

Sensitivity enhancement of backup protection for high impedance transformer phase-to-phase faults

作　　者：贺元康[1] 姜山[1] 郑州[1] 吕艳萍[1] 

机构地区：[1]武汉大学电气工程学院,湖北武汉430072

出　　处：《电力系统保护与控制》2010年第3期67-71,共5页Power System Protection and Control

摘　　要：高阻抗变压器的整定计算中,高阻抗变压器的相间短路后备保护配置的复压过流保护和阻抗保护的灵敏度往往不能满足要求。根据一个工程中的整定计算实例对不完全差动保护的原理、不完全差动保护比率特性曲线、动作电流和制动电流的计算方法、动作判据、整定计算、变压器三侧绕组容量比为100/100/50时的灵敏度校验,以及单变和双变并列运行时的灵敏度、动作时限进行了研究。研究结果表明,配置不完全差动保护可以有效的提高灵敏度,并且其原理简单易于实现,并指出不完全差动保护应用于大电流接地系统中时,防止区外故障时保护误动作的方法。During the relay protection setting calculation of high impedance transformer, the sensitivity of the overcurrent protection with composite start-up voltage and impedance protection of high impedance transformer often can not meet requirement. According to an setting calculation example in actual project, this paper analyzes the principle, ratio characteristic curve, calculating method of action current and brake current, action criterion, relay protection setting calculation, the sensitivity when the transformer three sides winding capacity ratio is 100/100/50, the sensitivity when transformer in parallel operation or individual operation, and time delay of the incomplete differential protection. The results show that the high impedance transformer configured with incomplete differential protection can improve the sensitivity effectively and the principle is simple and easy to be applied. This paper also points out the method when the incomplete differential protection used in the direct-ground system to prevent the external fault＇s misoperation.

关 键 词：高阻抗变压器 相间短路 后备保护 整定计算 灵敏度 不完全差动保护 

分 类 号：TM772[电气工程—电力系统及自动化]