中性点绝缘系统电压互感器三角形绕组短路问题分析  

Analysis of Short-Circuit Fault Occurring at PT Delta Windings in Neutral-Isolated Systems

作　　者：李云阁 王倩[2] 蒲路 马军[3] 高宇 王南 

机构地区：[1]国网陕西省电力公司电力科学研究院,陕西西安710054 [2]西安理工大学,陕西西安710048 [3]国网甘肃省电力公司,甘肃兰州730050

出　　处：《电网与清洁能源》2016年第7期6-10,共5页Power System and Clean Energy

基　　金：国家自然基金项目(51507135)

摘　　要：中性点绝缘系统中在电压互感器(PT)一次侧中性点接消谐电阻(消谐电阻)是较常采用的抑制铁磁谐振措施。当PT二次三角形绕组误接短路时,互感器和消谐电阻烧毁,此时往往误认为事故原因为采取消谐措施不当或发生了铁磁谐振。通过实验室和ATP两种方法模拟,明确互感器和消谐电阻烧毁系由PT二次三角形绕组短路所致。同时,通过实验室测量数据,计算得PT漏抗为激磁电抗的0.29%,在涉及同类PT时可用该数据估算其漏抗。除此之外,模拟得到当系统发生单相接地时消谐电阻的电压和功率,可为消谐电阻的制造、选用及标准制定提供参考。In neutral-isolated systems, the common prac- tice to constrain ferroresonance is to insert a nonlinear resis- tanee between the neutral point of the primary side of a potential transformer（PT） and the ground. If the delta windings on the PT secondary are short-circuited by mistake, the/）T and the nonlinear resistance may be destroyed. The incident is often wrongly considered as the consequence of inappropriate ferrore- sonance-eonstraining means or ferroresonance. This paper presents the results of both full-scale simulation in laboratory and digital simulation with ATP where the short-circuit is identified as the cause of the incident. By using data acquired from the laboratory measurement, the leakage inductance of the PT is calculated to be 0.29% of its exciting inductance. This value is recommended for estimation of the leakage inductance of the PTs of the same type. In addition, values of voltage and power consumption related to the ferroresonance-constraining resistance are acquired, which can be referenced to in the manufacture and selection and the standard drafting of the ferroresonanee-eonstraining resistor.

关 键 词：ATP 铁磁谐振抑制 中性点绝缘系统 电压互感器 漏抗 

分 类 号：TM451.3[电气工程—电器]