摘要
我国发变组的升压变压器都是Y0/△-11或Y/△-11接线,其传统的低阻抗保护装在主变低压侧为三个低阻抗继电器(线电压及相电流之差的0°接线方式)构成“或”门延时出口。通过分析及动模试验,认为这种传统方案是不宜采用的,主要理由是主变高压侧两相短路时,这三个继电器的测量阻抗都远大于短路点至保护安装点之间的阻抗,都会拒动,它不能保护主变高压侧的两相短路。还分析了若干种正确的Y0/△-11变压器低阻抗保护方案的特征及其优缺点。
The key of transformer protection is to distinguish magnetic inrush from fault current. Effective simulations for magnetic inrush and fault current of transformer are the foundation of right division. In this paper, based on the study on the model of electrical transformer in EMTDC （Electro-Magnetic Transient in DC System）, the simulations for magnetic inrush and fault current of three-phase transformer are done. And analysis is given to the simulation. The results show that EMTDC can effectively simulate the magnetic inrush and fault current of transformers under different conditions.
出处
《继电器》
CSCD
北大核心
2007年第4期6-10,共5页
Relay
