电力系统及其自动化学报2013，Vol.25Issue(2)：53-57,5.
自并励发电机后备保护改进方案
Improved Scheme of Backup Protection for Generators with Self-shunt Excitation
摘要
Abstract
With the expansion in size of power grid, the self-shunt excitation system is prevalently applied in turbine generator, however, the decay of short-circuit current may probably generate failure of relay tip. Based on the theoretical analysis, via the deduced equation of short-circuit current and relevant calculation, this paper summerizes the relationship between external short current and external impedance (i.e. the short current trendency caused by three-phase or two-phase short circuit of generators with self-shunt excitation in different locations). It can be concluded from above work that short-circuit currents decay in the circumstance of three-phase short-circuit fault and two-phase short-circuit fault near generator's terminal, but the decay of short-circuit current may probably generate failure of relay tip. On the basis of existing protection and the integration of engineering practice, two kinds of improved backup protection schemes have been put forward, and they are respectively plused low-voltage maintained component or low-voltage memorized circuit with unlocked trip.关键词
大型发电机/自并励励磁/短路故障/故障电流特性/后备保护Key words
turbine generator/ self-shunt excitation/ short-circuit fault/ fault current characteristics/ backup protection分类
信息技术与安全科学引用本文复制引用
刘振武,魏建忠,高仕斌..自并励发电机后备保护改进方案[J].电力系统及其自动化学报,2013,25(2):53-57,5.基金项目
国家自然科学基金重点项目(U1134205) （U1134205）
