Table 7 Quantitative analysis for the characteristics of the protection scheme.

From: Digital protection scheme based on Durbin Watson and Pearson similarity indices for current signals practically applied to power transformers

Laboratory system instance

Number of scenarios

Malfunction times

The total number of trips (correct + incorrect)

840

7

The total number of normal operations

75

0

Estimation of the characteristics of the protection scheme

Y1 = The total number of experiments = 915

Malfunction times = 7

Y2 = The total number of trips

 = 840

Y3 = The times of correct trips

 = 833

Y4 = The times of tripping failures

 = 8

Y5 = The times of desirable trips

 = 833 + 8 = 841

Y6 = The times of incorrect trips

 = 840 − 833 = 7

Y7 = Y5 + Y6

 = 841 + 7 = 848

\(D= \frac{Y3 }{Y5}\times 100\) %

= \(\frac{833}{841}\) \(\times\) 100 = \(99.05 \%\)

\(S= \frac{Y3}{Y2}\times 100 \%\)

= \(\frac{833}{840}\times\) 100 = \(99.17 \%\)

\(R= \frac{Y3}{ Y7}\times 100 \%\)

= \(\frac{833}{848}\times\) 100 = \(98.23 \%\)

\(A= \frac{Y1-Y4-Y6}{Y1}\times 100 \%\)

= \(\frac{915-8-7 }{915} \times\) 100 = 98.36%

  1. D Dependability, S security, R reliability, A accuracy.