Table 6 Case study 1: Actual vs. estimated zero-sequence line impedance
From: Relay performance verification using fault event records
Event | Zero-sequence line Impedance (Ω) | Error | ||
|---|---|---|---|---|
Carson’s equation | Estimated | Magnitude | Phase angle | |
(%) | (degrees) | |||
4 | 19.72+j56.22 | 24.06+j55.03 | 0.79 | 4.29 |
3 | 23.60+j54.30 | 0.63 | 4.16 | |
2 | 21.84+j56.75 | 2.05 | 1.72 | |
1 | 26.12+j57.37 | 5.79 | 5.15 | |