不接地系统单相断线故障的诊断研究

Analysis on Diagnosis of Single-Phase Break Fault in Ungrounded System

摘要: 由于纵向断线故障在电力系统中发生的概率较小，并没有引起相关部门的重视，因此当故障发生时运维工作人员没有足够的经验及时判断并处理该类故障，会对电力系统稳定运行造成严重影响。单相断线故障相对两相、三相断线故障发生的概率稍高些，对单相断线故障进行理论分析，得知故障前后负序电流数值的变化较大，因此可以把负序电流的变化量作为判断断线故障的依据。通过Matlab/Simulink仿真验证了单相断线故障中负序电流数值的变化较大。

Abstract: Since the probability of failure of longitudinal break in the power system is small, and does not cause the attention of relevant departments, when the faults occur the operation and maintenance staffs do not have enough experience to judge and deal with such failures promptly, which will severely affect the stable operation of the power system. The occurrence probability of single-phase break fault is slightly higher than two-phase and three-phase one. After theoretical analysis of the single-phase break fault, it is found that the negative sequence current value varies in a large range before and after the failure, which thus can be used to judge the break fault. Matlab/Simulink simulation verifies that negative sequence current value varies in a large range in the single-phase break fault.