CAJ | 학술논문

分析、计算了各种运行情况下电动机的负序电流,分析了各种运行方式下出现负序电流对电动机的危害,粗略估算了各种运行方式下出现负序电流的允许时间,并分析了各种运行方式下正序电流与负序电流、负序功率方向的关系,指出无负序功率方向闭锁负序过电流时常用整定值存在的问题,在区外不对称短路时易引起误动。对不同负序过电流保护动作判据、不同保护功能给出了正确的整定计算方法,提出采用负序功率方向闭锁的负序过电流保护,作为高压电动机定子绕组两相短路的辅助保护,有较为满意的保护功能。
분석、계산료각충운행정황하전동궤적부서전류,분석료각충운행방식하출현부서전류대전동궤적위해,조략고산료각충운행방식하출현부서전류적윤허시간,병분석료각충운행방식하정서전류여부서전류、부서공솔방향적관계,지출무부서공솔방향폐쇄부서과전류시상용정정치존재적문제,재구외불대칭단로시역인기오동。대불동부서과전류보호동작판거、불동보호공능급출료정학적정정계산방법,제출채용부서공솔방향폐쇄적부서과전류보호,작위고압전동궤정자요조량상단로적보조보호,유교위만의적보호공능。
Motors＇ negative sequence（NS） current calculation and its harms for motors under various operation conditions are analyzed.Allowance time of NS current appeared under different operational conditions are roughly calculated.Relationship between positive sequence current and NS current,and relationship between positive sequence current and NS power direction are also analyzed.Problems existing in frequently used settings for blocking NS overcurrent without involving NS power direction are pointed out and it is easy to cause mal-operation when off-site asymmetric short-circuit fault occurs.Proper settings calculation methods for different NS overcurrent protection acting criteria and different protection functions are given.Satisfactory protection function can be obtained for the stator windings two-phase short-circuit of high-voltage motors by adopting NS overcurrent protection with NS power direction blocking as the auxiliary protection for the stator windings two-phase short-circuit of the high-voltage motors.