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Electrical Engineering

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Symmetrical and Unsymmetrical Faults

Power System Faults in Sequence Networks

Description

Power system faults can be analyzed by moving between the phase domain and the sequence domain. This approach helps relate fault currents and voltages for three-phase bus faults and keeps the fault impedance in the model. Fault impedance is zero for a bolted fault, equal to the arc impedance for an arcing fault, and it repre...

Transcript

考虑从一相到地的单线接地故障 a 在三相母线上发生接地故障时,包含故障阻抗。对于金属性短路,该阻抗为零;对于电弧故障,其值等于电弧阻抗;在输电线路绝缘子闪络期间,代表总的故障阻抗。

相域中的故障情况被转换到序域中,从而推导出序分量电流和相电流。

相间发生线对线故障 bc与之前类似,将相域条件转换到序域,以建立相电流与序电流之间的关系。

通过故障阻抗在故障端子处将正序网络和负序网络并联,可满足这些故障条件。

最后,发生了一起相线对地双线故障 b 相变 c 通过故障阻抗接地。

随后确定相域中的故障情况,并将其变换到序域,通过在...