摘要
高压大容量自耦变压器在高、中压侧常配有零序电流差动保护,以提高对接地故障的灵敏性,但其受电流互感器饱和影响较大,不易整定.据此提出一种自耦变压器零序电流方向纵联保护原理,通过比较自耦变高、中压侧零序电流和中性点零序电流相位实现保护判别,该原理能够灵敏地反应变压器的匝地和匝间故障,受电流互感器饱和影响小.仿真和动模试验数据验证了该方法的可行性.
In order to enhance the sensitivity of ground fault protection, zero-sequence current differential protection is often applied to large capacity autotransformers. With the influence of current transformer saturation, it＇s difficult to choose a proper setting threshold. To solve this problem, a new type zero-sequence current directional comparison protection is proposed in this paper. The new method compares the phase angle of high-voltage side zero-sequence current, middle-voltage side zero-sequence current and the neutral current to decide the fault region. It can sensitively detect the coil-ground, coil-coil fault in transformer, and can basically avoid the infection of current transformer saturation. Computer and dynamic simulation results verify the above characteristics of the proposed protection method.
出处
《电力科学与技术学报》
CAS
2008年第4期27-32,共6页
Journal of Electric Power Science And Technology
基金
国家自然科学基金(50677051)
国家科技攻关计划(2005BA208C)
关键词
自耦变压器
零差保护
故障方向
TA饱和
autotransformer
zero-sequence current differential protection
fault direction
current transformer saturation
