**4.2 Fault location identification**

Referring to Fig.10, ANFIS2 and ANFIS3 are developed to identify fault location in respective X and Y coordinates. According to previous literature, most of the methods in identifying the fault location for power distribution network are in fault distance from a substation or zone. This approach considers geometrical coordinates in determining fault location in which it produces more accurate and precise fault location identification. From

Fault Diagnosis in Power Distribution Network

in a 47 buses practical system

current data at each fault point.

respectively.

**4.2.2 A procedure for identifying fault location** 

system.

Using Adaptive Neuro-Fuzzy Inference System (ANFIS) 327

represented by each ANFIS module. ANFIS2 consists of 64 modules that are labeled as ANFIS2-1 up to ANFIS2-64 whereas for ANFIS3, its total module is 45 from ANFIS3-1 to ANFIS3-45. The signal input to the ANFIS2 and ANFIS3 is a three-phase RMS post-fault current while the signal output is in terms of X and Y coordinates respectively as shown in Fig.11. Table 3 shows the input and output parameters of the 47 buses practical

**ANFIS module Input Output** 

ANFIS2-1 Post-fault 3-phase RMS current 1.7

ANFIS2-64 " 9.1

ANFIS3-1 " 0.3

ANFIS3-45 " 5.2

Table 3. Input and output parameters of ANFIS2 and ANFIS3 for identifying fault location

The procedure for locating fault in a power distribution network by the implementation of ANFIS2 and ANFIS3 modules is clearly shown in Fig.12. The first stage is a selection of power network for testing. Then the network layout is drawn in XY plane for locating the selected fault points along the feeder and radial lines. Fig.13 presents an example of the layout. The detail specification of the network is in the next sub-section. This network layout is embedded in fault analysis simulation software such as PSS-ADEPT to collect the fault

Next, the three-phase RMS post-fault current is collected at the main substation through a simulation of fault analysis to the selected power distribution network. The fault analysis is applied to every point of the fixed coordinates while considering 10 types of fault and several fault resistors (Rf). For example, by using three fault resistors and 163 fault points, there are 1335 simulations for single fault to ground and about 486 simulations for double fault to ground. Meanwhile, about 643 simulations are required for phase to phase and three-phase faults. Therefore, the total simulation is about 2464 for power distribution network in the 47 buses practical system. The data collected is arranged in such a way that it has three columns of input parameters and one column of target values. The target is either X or Y coordinates in which they are used to train ANFIS2 and ANFIS3

Fig.10, three-phase RMS post-fault current with (IF) and without (IU) fault are compared to investigate the fault in the power system. If current is IF higher than current IU, the current IF is recorded with the merging fault type.

Fig. 10. A procedure for identifying fault location

#### **4.2.1 ANFIS2 and ANFIS3 designs for identifying fault location**

The structure of ANFIS2 and ANFIS3 are configured according to selected fault points as shown in Fig.11. For a 47 buses practical system, there are 163 fixed fault points with 64 'X' coordinates and 45 'Y' coordinates. Thus, the total coordinate point is 109. Those points are

Fig. 11. ANFIS2 and ANFIS3 design for identifying fault location in a 47 buses practical system

Fig.10, three-phase RMS post-fault current with (IF) and without (IU) fault are compared to investigate the fault in the power system. If current is IF higher than current IU, the current IF

Start

Record the three-phase RMS post-fault current (IF) and three-phase RMS current without fault (IU)

Is IF >> IU ?

is recorded with the merging fault type.

Fig. 10. A procedure for identifying fault location

1.7

STKNA2-1

Post-fault three-phase RMS current No

Develop ANFIS2 module for identifying the fault location in term of X coordinate

**4.2.1 ANFIS2 and ANFIS3 designs for identifying fault location** 

The structure of ANFIS2 and ANFIS3 are configured according to selected fault points as shown in Fig.11. For a 47 buses practical system, there are 163 fixed fault points with 64 'X' coordinates and 45 'Y' coordinates. Thus, the total coordinate point is 109. Those points are

X Y

Yes

Develop ANFIS3 module for identifying the fault location in term of Y coordinate

Fig. 11. ANFIS2 and ANFIS3 design for identifying fault location in a 47 buses practical system

64 'X' coordinates 45 'Y' coordinate

0.3

5.2

STKNA3-45

Post-fault three-phase RMS current

STKNA3-1

Post-fault three-phase RMS current

9.1

STKNA2-64

Post-fault three-phase RMS current represented by each ANFIS module. ANFIS2 consists of 64 modules that are labeled as ANFIS2-1 up to ANFIS2-64 whereas for ANFIS3, its total module is 45 from ANFIS3-1 to ANFIS3-45. The signal input to the ANFIS2 and ANFIS3 is a three-phase RMS post-fault current while the signal output is in terms of X and Y coordinates respectively as shown in Fig.11. Table 3 shows the input and output parameters of the 47 buses practical system.


Table 3. Input and output parameters of ANFIS2 and ANFIS3 for identifying fault location in a 47 buses practical system
