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A reliable decision-making algorithm Chapter | 18  491



               TABLE 18.8 Test results and confusion matrix of wavelet packet energy
               and bagged decision tree-4 module for classification of shunt fault during
               the power swing (stable).

                     Data segmented             Actual class        Accuracy
               Case study    Predicted class
                        (%)          0  1  2  3  4  5  6  7  8  9  10  (%)
                                0   3999   1
                                1      585
                                2    1    584
                                3            585
                                4              585
                Case–1  80–20   5                 585               99.96
                                6                    585
                                7               1      584
                                8                         585
                                9                            585
                                10                              585
                                0   3999                     1
                                1      585
                                2    1    584
                                3            585
                                4              585
                Case–2  70–30   5                 584      1        99.95
                                6                    585
                                7               1      584
                                8                         585
                                9                            585
                                10                              585
                                0   3998   1         1
                                1      585
                                2         585
                                3            585
                                4              585
                Case–3  60–40   5                 585               99.97
                                6                    585
                                7                      585
                                8                         585
                                9                            585
                                10                              585
                                0   3998   1       1
                                1      585
                                2    1    584
                                3            585
                                4              585
                Case–4  50–50   5                 585               99.94
                                6                    584     1
                                7               1      585
                                8                         585
                                9                            585
                                10                              585
             The confusion matrix for the tested cases has been reported in Table 18.8,
             which confirms high accuracy of prediction of the fault classification mod-
             ule. A detailed discussion and analysis of appropriate case studies are
             reported in further subsections.
             18.5.4.1 Performance in case of varying fault parameters
             In real-time situation, fault may occur at any time, that is, at varying fault
             inception angle ðφ Þ in the transmission line and in general the ground fault
                            f
             resistance ðR f Þ is in the range of 10 20 Ω; however, in some cases, namely,
             conductor falling on a high-resistance path such as rock, sand, asphalt, it
             may vary from 0 to 100 Ω approximately. Therefore in order to investigate
             its impact on proposed relaying scheme an extensive simulation studies have
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