Fault Locator App On Google Play Store

Would you like to view and analyze COMTRADE files - fault current and voltage - taken from protection relays in electrical power systems? Would you like to calculate fault impedance and fault location on the electrical power systems transmission lines?

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The sections of the app :

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This app is an essential tool for electrical power system engineers especially substation protection and control engineers. Use this app for viewing COMTRADE files, and analyzing fault and disturbance on electrical power systems. This app calculates fault impedance and fault location on electrical power system transmission lines.

For downloading this app, search electrical power system phrase on Google Play Store.

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This app uses line impedance and fault currents and voltages to calculate :

  • Phase-Earth and Phase-Phase loop impedances
  • Fault location
  • Positive-, negative- and zero-sequence components of current and voltage
  • The zero sequence compensation factor (K0, RE, XE)

This app also plots fault currents and voltages , Positive-, negative- and zero-sequence components of fault current and voltage.

The App calculates Phase-Earth and Phase-Phase loop impedances to determine the fault location.

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First of all enter line characteristics. Then you can use the CFG files or enter fault voltages and currents.

Line Characteristics Section

Enter :

  • Positive and zero sequence impedances of the line
  • Line length
  • Current transformer ratio
  • Voltage transformer ratio

    (To calculate primary and secondary values)

You can enter the impedances

  • In cartesian or polar form
  • In secondary or primary values
  • In (Ω/KM) or total impedace of line
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Comtrade File Section

Open CFG File

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For downloading this app, search electrical power system phrase on Google Play Store.

Fault currents and voltages

If you do not have CFG file enter the data manually. You can also correct the data of the CFG file if there is a problem.

  • Fault current in each phase
  • Fault voltage in each phase
  • You can enter data in primary or secondary values
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  • Click on Calc In button to calculate : In = Ia + Ib + Ic
  • Click on Calc Vn button to calculate : Vn = Va + Vb + Vc

Click on Calc All button to activate :

  • Calc K0 button
  • Calc In button
  • Calc Vn button
  • Sequences of fault current
  • Sequences of fault voltage
  • Plotting fault currents and voltages
  • Fault impedance loops
  • Fault location
  • Plotting fault impedance
  • Getting the results
For downloading this app, search electrical power system phrase on Google Play Store.

Plotting fault currents and voltages

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For downloading this app, search electrical power system phrase on Google Play Store.

Fault impedances

Here this app calculates all impedances. Depending on the current and voltage in each phase you can determine in which phase the fault occurred and see the impedance of the fault. You can show impedances in primary or secondary values

Phase-Earth loop calculations

Zan = Va / Ia = ZL + ZE + RF

Zan = Ran + JXan

ZL = RL + JXL

ZE = K0 * ZL

K0 = K0r + JK0x

Zan = RL + JXL + K0r*RL + JK0r*XL + JK0x*RL - K0x*XL + RF

RL = (R1/X1)*XL

Xan = XL + K0r*XL + K0x*(R1/X1)*XL

XL = Xan / (1+K0r+K0x*(R1/X1))

Ran = RL + K0r*RL - K0x*XL + RF

RF = Ran - (RL + K0r*RL - K0x*XL)

Phase-Phase loop calculations

Zab = (Va - Vb)/(Ia - Ib) = ZL + RF/2

ZL = RL + JXL

Zab = RL + JXL + RF/2

Zab = Rab + JXab

XL = Xab

Rab = RL + RF/2

RL = (R1/X1)*XL

RF = (Rab - RL) * 2

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For downloading this app, search electrical power system phrase on Google Play Store.

Plotting fault impedances

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Fault location

This app calculates all locations in each impedance loop. Depending on the fault current and voltage in each phase you can determine in which phase the fault occurred and see the fault location.

This app calculates the location in percent of line length or in KM

Location = (Length*XL)/X1

Percent = (XL/X1)*100

Trulli For downloading this app, search electrical power system phrase on Google Play Store.

Example

Line characteristics :

Z1 = R1 + JX1 = 8.918 + J60.146

Z0 = R0 + JX0 = 15.993 + J101.775 Length = 145 KM

Data : Primary , Rectangular , the total of line impedance

CT:1200/5 --> CT Pri = 1200 , CT Sec = 5

VT:230KV/100V --> VT Pri = 230000 , VT Sec = 100

CT Ratio = (CT Pri)/(CT Sec) = 240 VT Ratio = (VT Pri)/(VT Sec) = 2300

Relay Ratio = (CT Ratio)/(VT Ratio) = 0.104

Z(Sec) = Z(Pri) * (Relay Ratio)

K0 = (Z0 - Z1)/3Z1 = 0.231∠-1.213

Currents and voltages of fault :

Data : Primary

Ia = 529∠-152 , Ib = 81∠51

Ic = 2118∠57 , In = 1755∠65

Va = 133020∠-5 , Vb = 135510∠-127

Vc = 125360∠110 , Vn = 8333∠-14

Impedance of fault :

Data : Primary

Zcn = Vc / Ic = ZL + ZE + RF

Zcn = Rcn + JXcn

Zcn = 125360∠110/2118∠57 = 35.620 + J47.269

ZL = RL + JXL

ZE = K0 * ZL

K0 = K0r + JK0x = 0.231 - J0.005

Zcn = RL + JXL + K0r*RL + JK0r*XL + JK0x*RL - K0x*XL + RF

RL = (R1/X1)*XL

Xcn = XL + K0r*XL + K0x*(R1/X1)*XL

XL = Xcn / (1+K0r+K0x*(R1/X1))

XL = 47.269 / (1+0.231-0.005*(8.918/60.146))

XL = 38.422

Rcn = RL + K0r*RL - K0x*XL + RF

RF = Rcn - (RL + K0r*RL - K0x*XL)

RL = (8.918/60.146)*38.422 = 5.696

RF = 35.620 - (5.696 + 0.231*5.696 + 0.005*38.422)

RF = 28.41

Location of fault :

Location = (Length*XL)/X1

Location = (145*38.422)/60.146 = 92.62 KM

Percent = (XL/X1)*100

Percent = (38.422/60.146)*100 = 63.88 %

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