【作者】 王天施； 曹国臣；

【Author】 WangTian-shi Cao Guo-chen (Northeast China Institute of Electric Power Engineering,Jilin 132012.China)

【机构】 东北电力学院研究生部；

【摘要】 为了避免小电流接地系统中电流速断保护的性能受到故障类型和系统运行方式的影响,利用正序故障分量测定系统的综合阻抗来确定故障前系统的运行方式；利用短路电流正、负序分量的有效值相加得到的综合测量值作为保护判据,以消除故障类型对速断保护的影响。自适应的调整保护定值,使保护始终处于最佳动作状态。更多还原

【Abstract】 For avoiding the influence of fauLt type and system operating condition on the performance of current protection in isolated neutral system,the positive sequence fault components are used to solve synthesized impedance of system,namely to define the pre-fault system operating condition.At the same time,the virtual value sum of positive and negative sequence components of fault current are used to be settings to avoid the effect of the fault type.Based on these calculations,the scheme adjusts the setting of the instantaneous current relay automatically to make the protection in an advantageous position all the time.更多还原