Table 5 The numerical values of the current imbalance coefficients based on the Durbin-Watson factors.
Experiment number | Fault position | The current imbalance coefficients based on the Durbin-Watson factors for the protection scheme Imbalance coefficients during the fault period UFi1 = The maximum value of (UFia1, UFib1, or UFic1) | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
Unbalance/balance | DWia | DWib | DWic | DWim | UFia1 (%) | UFib1 (%) | UFic1 (%) | UFi1 (%) | ||
Experiment 1 | Winding-to-neutral fault (C1-N) | Unacceptable imbalanced current (Tripping action) | 5.00 | 19.04 | 3.50 | 9.180 | 45.54 | 107.4 | 61.88 | 107.4 |
Experiment 2 | Winding-to-neutral fault (C2-N) | 0.72 | 0.90 | 1.16 | 0.927 | 22.30 | 2.8777 | 25.18 | 25.18 | |
Experiment 3 | Winding-to-neutral fault (C3-N)) | 75.0 | 115.1 | 25.0 | 71.7 | 4.60 | 60.53 | 65.13 | 65.13 | |
Experiment 4 | Winding-to-neutral fault (B1-N) | 1.06 | 0.58 | 0.75 | 0.797 | 33.05 | 27.20 | 5.86 | 33.05 | |
Experiment 5 | Winding-to-neutral fault (B2-N) | 12.0 | 30.0 | 85.51 | 42.5 | 71.77 | 29.42 | 101.2 | 101.2 | |
Experiment 6 | Turn-to-turn fault (A1-A2) | 19.98 | 6.50 | 6.80 | 11.09 | 80.11 | 41.41 | 38.71 | 80.11 | |
Experiment 7 | Turn-to-turn fault (A2-A3) | 0.827 | 0.40 | 0.05 | 0.426 | 94.28 | 6.03 | 88.25 | 94.28 | |
Experiment 8 | Winding-to-winding fault (B1-C1) | 0.00 | 49.39 | 47.6 | 32.33 | 100.0 | 52.77 | 47.23 | 100.0 | |
Experiment 9 | Winding-to-winding fault (B2-C2) | 0.00 | 109.0 | 109.0 | 72.67 | 100.0 | 50.00 | 50.00 | 100.0 | |
Experiment 10 | Winding-to-winding fault (B3-C3) | 0.00 | 269.5 | 175 | 148.2 | 100.0 | 81.88 | 18.11 | 100.0 | |
Experiment 11 | Phase A loss | 0.513 | 0.00 | 0.00 | 0.171 | 200 | 100.0 | 100.0 | 200 | |
Experiment 12 | Power transformer shutdown | 65.0 | 50.0 | 133.8 | 82.93 | 21.62 | 39.71 | 61.33 | 61.33 (Actually, the tripping has been accomplished) | |
