Page 528 - Decision Making Applications in Modern Power Systems

A reliable decision-making algorithm Chapter | 18 487

TABLE 18.6 Test results and confusion matrix of wavelet packet energy
and bagged decision tree-1 module for detection of system condition
(no-fault, power swing).

Case Data Predicted Actual class Accuracy
study segmented class (%)
0 1 2
(%)
Case-1 90 10 0 2000 100
1 8820
2 1710
Case-2 80 20 0 2000 100
1 8820
2 1710
Case-3 70 30 0 2000 100
1 8820
2 1710
Case-4 60 40 0 2000 100
1 8820
2 1710
Case-5 50 50 0 2000 100
1 8820
2 1710

18.5.2 Discrimination of power swing condition
(stable and unstable)
A stable PS is initiated by creating a fault in the adjacent line connected to the
monitored bus and clearing the fault before the critical clearing time (CCT),
whereas if the fault is cleared after the CCT then it will initiate unstable PS in
the system. For instance, a three-phase to ground fault has been incepted at
1.001 seconds on a single-circuit transmission line of 60 km length which is
connected between NTPC and Sipat in Fig. 18.1 and the same has been
cleared by tripping the circuit breakers of both the ends at 1.15 seconds, that
is, fault clearing time is 7.5-cycles. In order to identify the state of the system
during this stressed condition, that is, the PS is stable or unstable; WPE_BDT-
2 module is tested, and the test results are demonstrated in Fig. 18.7.The
three-phase current and voltages of the monitored double-circuit line are