英文摘要 |
In order to obtain more accurate results of fault line detection innon-solidly earthed systems, this paper puts forward the concept of faulttransient signal relative intensity (Q), and provides a reference values Q0 ofQ by simulation test for fault line detection. Based on this, a new methodof combining Hilbert-Huang transform (HHT) with the steady-state zerosequence current method is proposed. According the value of Q, whenQ < Q0, the HHT was used for fault line detection, and the Q ³ Q0,steady-state zero sequence current method was used instead. The proposedmethod makes full use of transient and steady-state line information,and overcomes the shortage of the previous method only using single criterion to detect fault line. Simulation results showed that this method isnot affected by the fault initial phase angle and grounding resistance, andalso has high accuracy and feasibility. |