# A Review of Fault Diagnosing Methods in Power Transmission Systems
## 8 Comparison of Fault Location Methods  
A comparison of various fault location techniques is given in Table 3 considering the algorithm employed, input, test system, complexity level, features, and results. Where, complexity is defined by considering the number of inputs and rules involved in algorithm development as simple, medium and complex. Further, the selection of complexity level is achieved based on feature training and testing time, accuracy, convergence, and variance along with data required.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**No.** & **Algorithm** & **Input** & **Test System** & & & \\ \hline
1 & ANN & Pre-fault current and & La Lomba-Herrera 380 kV, & FAILENUR software is used to train & The maximum error noted & [146] \\  & & voltage samples & 189.3 km long T\({}_{1}\), Spanish & FLANER software data. & Medium & The maximum error noted & [147] \\  & & voltage samples & 189.3 km long T\({}_{1}\), Spanish & FLANER software data. & Training time varies from 5 s to 2.5 min to & minimum error in locating \\  & & power system (50 Hz) & & & fault distance. & \\ \hline  & & & BP based on Leverberg-Marquardt & & & \\  & & & optimization technique is selected. & & & \\  & & & & The ‘ansig’ is selected as a transfer function & & \\  & & & for the hidden layer, and the linear & & & \\  & & & function for the output layer. & & & \\ \hline
2 & Least error square & Current and voltage & Length of TL is 100 km, & The sampling frequency is 6400 Hz. & Simple & 0.0099\% is the relative error & [147] \\  & & magnitudes & 400 kV, 50 Hz & 20 ms is the duration of the data window. & & \\ \hline
3 & Impedance-based & Voltage profile & 500 kV, 200 miles TL, 50 Hz & Shunt capacitance is neglected of the TL & & \\  & & & which is desirable for online applications. & Simple & 1\% error is recorded for IBA & [148] \\ \hline
4 & Neuro-fuzzy systems and WT & Current and voltage profiles & Hybrid transmission system: 606 km cable and 14 km TL with 154 kV operating voltage & DC offset is removed via FIR. & & \\  & & & operating & & D44 mother wavelet is used and & \\  & & & 14 km TL with 154 kV operating voltage & & D45 mother wavelet is used and & & \\  & & & & decomposed into three levels. & & \\  & & & & & \\  & & & & & \\  & & & & & \\ \hline
5 & WT & Current samples & 50 Hz, 60 km, 400 kV & D50 Hz wavelet is used and & & & \\  & & & decomposed into three Levels. & & & \\  & & & & The sampling frequency is 380 Hz with 64 samples/cycle. & & \\ \hline  & & & & & D40 mother wavelet is employed and & & \\  & & & & dissolved up to three levels by WPT. & & \\ \cline{3-4}
6 & ANN and wavelet packet transform & Current and voltage & 360 km, 380 kV and 50 Hz & The 10 kHz is the sampling frequency. & Complex & Minimum and maximum errors in finding fault & \\  & & & & The computation burden is reduced as it is & & location are 0.06\% and 1.67\%, respectively & \\  & & & & & \\ \hline \end{tabular}
\end{table}
Table 3: Comparison of different fault location finding methods.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**No.** & **Algorithm** & **Input** & **Test System** & **Feature** & **Complexity** & **Result** & **Ref.** \\ \hline  & RBF-based SVM & Positive sequence & The 5 kHz is selected as the sampling rate. & & & \\  & conjugate gradient & voltage and line & 150 km double circuit TL, & The 2e-200k s time to locate the fault. & & & Maximum fault error \\  & (SCALCC)-based & & currents & 400 kV is operating voltage & RBF kernel is used to extract principal eigenvectors of the feature space and to & & \\  & NN approach & & & & & \\  & & & & & \\ \hline  & Nelder-Mead simplex & Post-fault Voltage & 320 km, 500 kV, 50 Hz & 960 Hz is the sampling rate. & & 2.7\% error is expected with \\  & & simplex & phasors & Current transformer (CT) errors are avoided by not using post-fault current. & Complex & \(\pm\)5\% error in post-fault voltages \\ \hline  & & & & & Wavelet entropy and energy features are extracted from the decomposed signal. & & \\ \hline  &