210014 - P7001 - E02 - 0019 -00.pdf

DOCUMENT SUBMISSION STATUS: FOR CONSTRUCTION

00

28.11.2012

Issued for Construction

BA

MK

RSR

PC

25.07.2012

Issued for Approval

BA

MK

RSR

PB

22.05.2012

Issued for Approval

BA

MK

RSR

PA

21.05.2012

ABB Internal Review

BA

MK

RSR

DESCRIPTION

PREPARED

CHKD

APPD

REV D

ATE

OWNER

EPC CONTRACTOR

EPC CONTRACTOR’S CONSULTANT

PP-IMECO Consortium

ENGINEERING &CONSTRUCTION

PROJECT TITLE

KDL 120MW COMBINED CYLE POWER PLANT PROJECT

SUB-CONTRACTOR

ABB

ABB PTE LTD.

DOCUMENT TITLE

150kV KDL Substation – Earthing Design Calculation DOCUMENT NO

210014 - P7001 - E02 – 0019 - 00

REV

00

DATE 22-05-2012

PAGES 2

27

Earthing Grid Calculation for 150kV KDL Substation

Project

150kV KDL Substation Approved

Resp Dept

Gopal

PSP-SG

Prepared

Date

MK

2012-11-27

Title

Rev Ind

00

Earthing Grid Calculation 150kV KDL Substation Document No

ABB AB

Sheet

1 Cont

210014-P7001-E02-0019

2

Summary The design of the earthing grid is based on IEEE 80-2000, with the tolerable touch and step voltages as prescribed. The design current for the earthing grid, in respect of touch and step voltages, is 50 kA for the 150 kV KDL Substation. Critical points in the substation area are identified by graphical analysis, with colour coding according to safety thresholds. The calculated ground resistance is 0.238 Ω and the ground potential rise is 8599.16V The potential plots from this calculation shows that the station is designed to be safe using selected earthing grid, see plots in clause 9.

Table of Content 1.

COMPUTER PROGRAM ......................................................................................................................................... 3

2.

OBJECTIVE ............................................................................................................................................................... 3

3.

SOIL RESISTIVITY .................................................................................................................................................. 3

4.

FAULT CURRENT .................................................................................................................................................... 3

5.

EARTHING GRID MODEL ..................................................................................................................................... 4

6.

INPUT TO CYMGRD ................................................................................................................................................ 4

8.

OUTPUT FROM CYMGRD ..................................................................................................................................... 6

9.

RESULT....................................................................................................................................................................... 6 9.1 9.2 9.3

3D POTENTIAL PLOT.............................................................................................................................................. 6 2D POTENTIAL PLOT ............................................................................................................................................... 7 POTENTIAL PROFILE PLOTS .................................................................................................................................... 8

10

CONCLUSION ...................................................................................................................................................... 10

11

REFERENCES ...................................................................................................................................................... 10

12

CYM GRID REPORT .......................................................................................................................................... 10

Project

150kV KDL Substation Approved

Resp Dept

Gopal

PSP-SG

Prepared

Date

MK

2012-11-27

Title

Rev Ind

00

Earthing Grid Calculation 150kV KDL Substation Document No

ABB AB

Sheet

2 Cont

210014-P7001-E02-0019

3

1. Computer program The calculation is based on a computer program called CYMGRD by CYME International Inc. It is developed by Hydro-Quebec in Canada. CYMGRD utilises a finite element analysis algorithm, which is more accurate than the approximate formulas provided in IEEE 80-2000 Guide [1]. The finite element analysis algorithm enables CYMGRD to analyse earthing systems of either symmetrical or asymmetrical configuration of ground conductors and rods.

2. Objective The objectives of grounding system in KDL Substation project is 

To provide low impedance to ground fault current return path i.e., less than one ohm and in-turn activate the ground fault protection relay as soon as possible.



To limit potential rise of grounding system as such GPR does not exceed a value which could damage electrical equipment or affect continuity of service



To provide a safe environment for operating personnel, i.e, to assure that a person in the vicinity is not exposed to the danger of electric shock by limiting touch voltage & step voltage to safer limit in particular areas

3. Soil resistivity The resistivity of the soil is based on the soil resistivity report measured with Wenner method. A Single-layer soil model has been used for the calculations, see Figure 1 for resistivity layer values.

Figure 1 : Calculated resistivity from measured values.

A 0.2m thick layer of gravel is going to be laid over the area. The resistivity of the layer is approximately 3000Ωm. Shock duration time is equal to 0.5s.

4. Fault current Maximum ground fault current considered for earthing system is 50kA for earthing design of 150kV KDL Substation. Project

150kV KDL Substation Approved

Resp Dept

Gopal

PSP-SG

Prepared

Date

MK

2012-11-27

Title

Rev Ind

00

Earthing Grid Calculation 150kV KDL Substation Document No

ABB AB

Sheet

3 Cont

210014-P7001-E02-0019

4

5. Earthing grid Model The earthing grid model taken for the substation earthing design is shown in Figure 2. The dimension of conductor in ground for the earthing grid is 300mm2 & depth of laying is at 600mm below ground level. And earth electrodes of 6 metre length of 16mm diameter of copper rod.

Figure 2: Earthing grid model for 150kV KDL Substations.

6. Input to CYMGRD

1.

Symmetrical fault current in substation for

If

=

50000

A

conductor sizing 2.

Fault current diversion factor

Sf

=

0.7

3.

Duration of shock for determining allowable body

ts

=

0.5

4.

current Surface Gravel layer resistivity

s

=

3000

5.

Surface Gravel layer thickness

hs

=

0.2

6.

Soil resistivity



=

39.91

7.

Depth of Burial of earth material

h

=

8.

Body Weight

0.600

=

s

m

m m

m

50 Kg

Project

150kV KDL Substation Approved

Resp Dept

Gopal

PSP-SG

Prepared

Date

MK

2012-11-27

Title

Rev Ind

00

Earthing Grid Calculation 150kV KDL Substation Document No

ABB AB

Sheet

4 Cont

210014-P7001-E02-0019

5

7. Conductor Sizing The Earthing grid thermal design will be based on full fault currents in the grid (50kA).The current that can be allowed through a conductor without damage due to heating and can be expressed, according to IEEE 80 [[1]] as following formula below: 1

Type of conductor

2

Reference Temperature for Material Constants

Tr

=

Copper Annealed Soft drawn c 20

3

r

=

0.0039

/ c

4

Thermal Coefficient of Resistivity at Reference Temperature Fusing Temperature of Conductor

1083

Ambient Temperature below ground

=

20

6

K0  1  r  Tr Resistivity of Conductor at Reference Temperature Thermal Capacity per Unit Volume Time duration for sizing the earth mat conductor

Tm Ta K0

=

5

=

234

c c c

r

=

1.72

μΩ-cm

TCAP tc

= =

3.42 1

J cm3 c

7 8 9

s

Cross section area of conductor required based on calculation is 178.7 Sq.mm. Minimum Conductor diameter required dminimum= 15.08mm As per "Design of steel Earthing Grids in India" IEEE transaction on power Apparatus and System, Vol. PAS 98 No. 6 Nov./Dec 1979. pp 2126-2134, Corrosion allowance is recommended as per following rule Maximum Corrosion allowance of copper conductor for 8 years = 6Mils Maximum Corrosion allowance of copper conductor for 30 years = 22.5Mils 1 mil 22.5 mil

= 0.0254mm = 0.571mm

dminimum = dminimum + Corrosion Allowance =15.08 + 2 x 0.571 = 16.222mm Minimum Conductor diameter with corrosion allowance is 16.222mm Minimum Cross Section required with corrosion allowance is 206Sq.mm Based on Contract specification conductor chosen is 300Sq.mm

Project

150kV KDL Substation Approved

Resp Dept

Gopal

PSP-SG

Prepared

Date

MK

2012-11-27

Title

Rev Ind

00

Earthing Grid Calculation 150kV KDL Substation Document No

ABB AB

Sheet

5 Cont

210014-P7001-E02-0019

6

8. Output from CYMGRD Maximum permissible touch voltage Maximum permissible step voltage Calculated maximum touch voltage within the switchyard Calculated maximum step voltage within the site area Calculated ground resistance Ground Potential Rise

768.48 2581.78 741.32 430.54 0.238 8599.16

V V V V Ω V

9. Result The program CYMGRD calculates the actual step and touch voltages for each part of the grid. The result is presented with equipotential graphs of surface and touch potentials with simultaneous dynamic display of actual station coordinates for detailed safety analyses. The plot shows that the station is safe with regards to step and touch voltage. This is guaranteed when maximum allowable step and touch voltage are higher than actual voltage in the plots below. Upto fence area the touch and step voltages are under the permissible limit. The result and the plots below shows that the step and touch voltages are guaranteed.

9.1 3D Potential Plot contour plot, of touch potentials presented in 3 dimensions.

Figure 3: 3D potential plot of the Substation.

Project

150kV KDL Substation Approved

Resp Dept

Gopal

PSP-SG

Prepared

Date

MK

2012-11-27

Title

Rev Ind

00

Earthing Grid Calculation 150kV KDL Substation Document No

ABB AB

Sheet

6 Cont

210014-P7001-E02-0019

7

9.2

2D potential plot Touch potentials presented in 2 dimensions, colour code as

Potential profile 1

Figure 4: 2D Potential plot of the station

Potential profile 2

Calculated maximum touch voltage within the switchyard

741.32 V

Project

150kV KDL Substation Approved

Resp Dept

Gopal

PSP-SG

Prepared

Date

MK

2012-11-27

Title

Rev Ind

00

Earthing Grid Calculation 150kV KDL Substation Document No

ABB AB

Sheet

7 Cont

210014-P7001-E02-0019

8

9.3 Potential profile plots For the coordinates for the plot see

.

Project

150kV KDL Substation Approved

Resp Dept

Gopal

PSP-SG

Prepared

Date

MK

2012-11-27

Title

Rev Ind

00

Earthing Grid Calculation 150kV KDL Substation Document No

ABB AB

Sheet

8 Cont

210014-P7001-E02-0019

9

Figure 5: Potential profile plot 1, diagonal.

FROM ABOVE GRAPH VALUES ARE LISTED BELOW Maximum permissible touch voltage

-

768.48 V

Calculated maximum touch Voltage within the switchyard

-

741.32 V

Maximum permissible step voltage

-

2581.78 V

Calculated maximum step Voltage within the switchyard

-

430.54 V

Maximum permissible Ground Potential Rise

-

8599.16 V

Calculated maximum Potential Rise

-

8411.79 V

Project

150kV KDL Substation Approved

Resp Dept

Gopal

PSP-SG

Prepared

Date

MK

2012-11-27

Title

Rev Ind

00

Earthing Grid Calculation 150kV KDL Substation Document No

ABB AB

Sheet

9 Cont

210014-P7001-E02-0019

10

Figure 6: Potential profile plot 2, diagonal.

FROM ABOVE GRAPH VALUES ARE LISTED BELOW Maximum permissible touch voltage

-

768.48 V

Calculated maximum touch Voltage within the switchyard

-

741.32 V

Maximum permissible step voltage

-

2581.78 V

Calculated maximum step Voltage within the switchyard

-

318.46 V

Maximum permissible Ground Potential Rise

-

8599.16 V

Calculated maximum Potential Rise

-

8414.44 V

Project

150kV KDL Substation Approved

Resp Dept

Gopal

PSP-SG

Prepared

Date

MK

2012-11-27

Title

Rev Ind

00

Earthing Grid Calculation 150kV KDL Substation Document No

ABB AB

Sheet

10 Cont

210014-P7001-E02-0019

11

10 Conclusion The calculated ground resistance is 0.23 Ω. And step voltages & touch voltages are under permissible limit. The potential plots from this calculation shows that the station is designed to be safe using selected earthing grid, see plots in clause 9.

11 References [1] [2] [3]

IEEE Guide for safety in AC substation earthing, Std 80-2000 Earthing Layout, 210014-P7001-E06-0104. Report on soil resistivity for KDL Substations

12 CYM Grid Report

Project

150kV KDL Substation Approved

Resp Dept

Gopal

PSP-SG

Prepared

Date

MK

2012-11-27

Title

Rev Ind

00

Earthing Grid Calculation 150kV KDL Substation Document No

ABB AB

Sheet

11 Cont

210014-P7001-E02-0019

–

Soil analysis report

Friday, June 22, 2012, 10:37:17

Station Name

KDL

Project Study

KDL-150KV SUBSTATION KDL

Parameters Title

KDL

Soil Model Upper Layer Thickness Upper Layer Resistivity Lower Layer Resistivity

User Defined 100 meters 39.91 ohm-m 39.91 ohm-m

Safety Model Body Weight Surface Layer Thickness Surface Layer Resistivity Shock Duration

IEEE Std. 80-2000 50 kg 0.2 meters 3000 ohm-m 0.5 secs

Output Results Reduction Factor Cs Maximum Permissible Touch Maximum Permissible Step

10/29/12 16:08:30

0.81877 768.48 volts 2581.78 volts

1/1

KDL 43.419 42.919 42.419 41.919

Resistivity (ohm-meters)

41.419 40.919 40.419 39.919 39.419 38.919 38.419 37.919 37.419 36.919 36.419 35.919 0

5

10

15

20

25

30

35

40

45

50

55

60

Length (meters)

Calculated Points

65

70

75

80

85

90

95

105

Grid analysis report

Monday, October 29, 2012, 16:28:41

Station Name

KDL

Project Study

KDL-150KV SUBSTATION KDL

Parameters Equivalent Parallel Z Spec. Split Factor Nominal Frequency Bus ID LG Fault Current Remote Contribution Upper Layer Thickness Upper Layer Resistivity Lower Layer Resistivity

User Defined 0.7 50 hz 150kV SS 50000 amps 100 % 100 meters 39.91 ohm-m 39.91 ohm-m

Output Results Parallel Z Decrement Factor

0.555856 ohms 1.03134

Ground Potential Rise Calculated Ground Resistance Equivalent Impedance

8599.16 volts 0.238225 ohms 0.166757 ohms

Primary Electrode Elements X1 89.5 89.5 89.5 0 89.5 89.5 89.5 89.5 89.5 89.5 89.5 89.5 89.5 89.5 89.5 89.5 4.75 8.75 12.75 16.75 20.75 24.75 28.75 32.75 36.75 40.75 44.75 48.75 52.75 56.75 60.75

Y1 0 53 0 0 4 8 12 16 20 24 28 32 36 40 44 48 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

10/29/12 16:56:02

Z1 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75

X2 (meters) 0 0 89.5 0 0 0 0 0 0 0 0 0 0 0 0 0 4.75 8.75 12.75 16.75 20.75 24.75 28.75 32.75 36.75 40.75 44.75 48.75 52.75 56.75 60.75

Y2 0 53 53 53 4 8 12 16 20 24 28 32 36 40 44 48 53 53 53 53 53 53 53 53 53 53 53 53 53 53 53

Z2 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6

Length 89.5001 89.5001 53.0002 53.0002 89.5001 89.5001 89.5001 89.5001 89.5001 89.5001 89.5001 89.5001 89.5001 89.5001 89.5001 89.5001 53.0002 53.0002 53.0002 53.0002 53.0002 53.0002 53.0002 53.0002 53.0002 53.0002 53.0002 53.0002 53.0002 53.0002 53.0002

Radius (mm) 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8

Current (amps) 1969.491 2088.8081 1138.7672 1146.8406 726.851 644.2601 609.0172 610.5056 622.4282 599.1431 592.5422 592.7851 624.5787 663.5583 691.1088 763.5073 517.1666 516.1037 448.2978 407.6189 412.4961 392.4088 355.243 339.6811 338.3909 338.8019 346.9418 359.2097 386.5398 357.5622 324.3647

Electrode (#) Asy 1 Asy 2 Asy 3 Asy 4 Asy 5 Asy 6 Asy 7 Asy 8 Asy 9 Asy 10 Asy 11 Asy 12 Asy 13 Asy 14 Asy 15 Asy 16 Asy 17 Asy 18 Asy 19 Asy 20 Asy 21 Asy 22 Asy 23 Asy 24 Asy 25 Asy 26 Asy 27 Asy 28 Asy 29 Asy 30 Asy 31

1/3

64.75 68.75 72.75 76.75 80.75 84.75 89.5 87.125 89.5 0 89.5 0 89.5 8.75 80.75 80.75 8.75 2.375 30.75 26.75 58.75 62.75 18.75 70.75 14.75 74.75 30.75 26.75 58.75 62.75 18.75 70.75 14.75 74.75

0 0 0 0 0 0 50.5 0 2 53 53 0 0 0 0 53 53 0 48 48 48 48 48 48 48 48 0 0 0 0 0 0 0 0

0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75

64.75 68.75 72.75 76.75 80.75 84.75 0 87.125 0 8.75 80.75 8.75 80.75 0 89.5 89.5 0 2.375 30.75 26.75 58.75 62.75 18.75 70.75 14.75 74.75 30.75 26.75 58.75 62.75 18.75 70.75 14.75 74.75

53 53 53 53 53 53 50.5 53 2 44 44 8 8 8 8 44 44 53 53 53 53 53 53 53 53 53 4 4 4 4 4 4 4 4

0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6

Total Length Of Primary Conductors 0 89.5 89.5 0 0 0 0 0 89.5 89.5 89.5 89.5 4.75 4.75 84.75 84.75 0 0 89.5 89.5 18.2338 26.2795

0 0 53 53 4 8 48 44 4 8 48 44 0 53 0 53 15.5 30.5 15.5 30.5 12 5.7714

10/29/12 16:56:02

0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75

0 89.5 89.5 0 0 0 0 0 89.5 89.5 89.5 89.5 4.75 4.75 84.75 84.75 0 0 89.5 89.5 18.2338 26.2795

53.0002 53.0002 53.0002 53.0002 53.0002 53.0002 89.5001 53.0002 89.5001 12.5533 12.5533 11.8569 11.8569 11.8569 11.8569 12.5533 12.5533 53.0002 5.0022 5.0022 5.0022 5.0022 5.0022 5.0022 5.0022 5.0022 4.0028 4.0028 4.0028 4.0028 4.0028 4.0028 4.0028 4.0028

9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8

361.196 371.1382 412.0159 470.6927 497.1722 479.9251 1009.4945 594.5449 963.6107 70.5904 68.4306 8.7561 38.8665 27.7502 49.3133 68.0692 68.5695 600.269 57.2039 60.3583 53.8135 50.7014 66.3736 54.0569 67.7882 59.6579 39.9271 36.2835 41.1381 45.1334 40.354 47.3117 35.6786 42.7058

Asy 32 Asy 33 Asy 34 Asy 35 Asy 36 Asy 37 Asy 38 Asy 39 Asy 40 Asy 41 Asy 42 Asy 43 Asy 44 Asy 45 Asy 46 Asy 47 Asy 48 Asy 49 Asy 50 Asy 51 Asy 52 Asy 53 Asy 54 Asy 55 Asy 56 Asy 57 Asy 58 Asy 59 Asy 60 Asy 61 Asy 62 Asy 63 Asy 64 Asy 65

269.1686 278.9472 288.3705 290.3565 198.493 202.3112 221.0217 220.0513 211.6189 204.5027 219.2928 217.673 187.2169 211.8309 200.5663 208.4215 217.3369 230.2225 215.4884 224.6139 98.6189 126.3899

Asy 1 Asy 2 Asy 3 Asy 4 Asy 5 Asy 6 Asy 7 Asy 8 Asy 9 Asy 10 Asy 11 Asy 12 Asy 13 Asy 14 Asy 15 Asy 16 Asy 17 Asy 18 Asy 19 Asy 20 Asy 21 Asy 22

2926.69 meters 0 0 53 53 4 8 48 44 4 8 48 44 0 53 0 53 15.5 30.5 15.5 30.5 12 5.7714

6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75

6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8

2/3

33.5001 38.763 46.6162 59.2939 70.3557 77.9408 70.4116 66.5551 59.4504 66.6764 38.8855 31.466 10.448 11.4451 12.8 82.679 83.1814 60.505 47.205 46.5001 38.7857 17.524 2.5 87 87 2.5 2.5

10.2839 6.2767 10.399 5.3671 10.6381 6.0516 42.2919 46.5887 42.3883 37.3198 37.4064 42.4 4 8.15 18.2921 10.5516 25.0493 33.9996 33.9996 42.2839 46.4816 25.2581 0 53 0 53 2.5

0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75

33.5001 38.763 46.6162 59.2939 70.3557 77.9408 70.4116 66.5551 59.4504 66.6764 38.8855 31.466 10.448 11.4451 12.8 82.679 83.1814 60.505 47.205 46.5001 38.7857 17.524 2.5 87 87 2.5 2.5

Total Length Of Primary Rods Total Number Of Elements

10/29/12 16:56:02

10.2839 6.2767 10.399 5.3671 10.6381 6.0516 42.2919 46.5887 42.3883 37.3198 37.4064 42.4 4 8.15 18.2921 10.5516 25.0493 33.9996 33.9996 42.2839 46.4816 25.2581 0 53 0 53 2.5

6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75 6.75

6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8

103.0204 128.5067 110.6656 138.974 117.1085 134.086 103.1555 118.8133 96.0011 85.3077 81.8778 105.7262 134.5481 112.2497 101.0655 129.5212 138.9217 77.681 74.3604 97.0962 123.99 94.4669 191.0269 213.7886 206.1457 216.6275 138.8092

Asy 23 Asy 24 Asy 25 Asy 26 Asy 27 Asy 28 Asy 29 Asy 30 Asy 31 Asy 32 Asy 33 Asy 34 Asy 35 Asy 36 Asy 37 Asy 38 Asy 39 Asy 40 Asy 41 Asy 42 Asy 43 Asy 44 Asy 45 Asy 46 Asy 47 Asy 48 Asy 49

294 meters 114

3/3

Potential contour report

Monday, October 29, 2012, 16:31:58

Station Name

KDL

Project Study

KDL-150KV SUBSTATION KDL

Parameters Title

Potential contour plot #01

Bus ID LG Fault Current Remote Contribution Return Electrode Current Parallel Z Upper Layer Thickness Upper Layer Resistivity Lower Layer Resistivity Equal Potentials (Distinct)

150kV SS 50000 amps 100 % 0 amps 1 ohms 100 meters 39.91 ohm-m 39.91 ohm-m Yes

X1 Y1 X2 Y2

0 meters 0 meters 89.5 meters 53 meters

X Intervals Y Intervals

10 10

Potential Thresholds Maximum Permissible Touch

0 (0%)

768.48 volts

192.12 (25%)

384.24 (50%)

576.36 (75%)

768.48 (100%)

Maximum Touch Potential At Point(s) X (meters) 0

10/29/12 16:34:28

990.625 volts

Allowable LG Current

38787.3 amps

Y (meters) 37.1

1/1

Potential profile plot #06 10000 9500 9000 8500 8000 7500 7000 6500

Voltage (volts)

6000 5500 5000 4500 4000 3500 3000 2500 2000 1500 1000 500 0 0

5

10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95

Length (meters) Surface Potentials Touch Potentials Maximum Permissible Step = 2581.78 volts

Step Potentials Ground Potential Rise = 8599.16 volts Maximum Permissible Touch = 768.48 volts

105

Potential profile report

Monday, October 29, 2012, 16:48:01

Station Name

KDL

Project Study

KDL-150KV SUBSTATION KDL

Parameters Title

Potential profile plot #06

Bus ID LG Fault Current Remote Contribution Return Electrode Current Parallel Z Upper Layer Thickness Upper Layer Resistivity Lower Layer Resistivity Equal Potentials (Distinct)

150kV SS 50000 amps 100 % 0 amps 1 ohms 100 meters 39.91 ohm-m 39.91 ohm-m Yes

X1 Y1 X2 Y2

88 meters 0 meters 0 meters 51.5 meters

Step Interval

1 meters

Potential Thresholds Ground Potential Rise Maximum Permissible Step Maximum Permissible Touch

8599.16 volts 2581.78 volts 768.48 volts

Maximum Surface Potentials Step Potentials Touch Potentials

10/29/12 16:52:43

8411.79 volts 430.54 volts 741.32 volts

1/1

Potential profile plot #07 10000 9500 9000 8500 8000 7500 7000 6500

Voltage (volts)

6000 5500 5000 4500 4000 3500 3000 2500 2000 1500 1000 500 0 0

5

10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95

Length (meters) Surface Potentials Touch Potentials Maximum Permissible Step = 2581.78 volts

Step Potentials Ground Potential Rise = 8599.16 volts Maximum Permissible Touch = 768.48 volts

105

Potential profile report

Monday, October 29, 2012, 16:49:13

Station Name

KDL

Project Study

KDL-150KV SUBSTATION KDL

Parameters Title

Potential profile plot #07

Bus ID LG Fault Current Remote Contribution Return Electrode Current Parallel Z Upper Layer Thickness Upper Layer Resistivity Lower Layer Resistivity Equal Potentials (Distinct)

150kV SS 50000 amps 100 % 0 amps 1 ohms 100 meters 39.91 ohm-m 39.91 ohm-m Yes

X1 Y1 X2 Y2

0 meters 51.5 meters 88 meters 0 meters

Step Interval

1 meters

Potential Thresholds Ground Potential Rise Maximum Permissible Step Maximum Permissible Touch

8599.16 volts 2581.78 volts 768.48 volts

Maximum Surface Potentials Step Potentials Touch Potentials

10/29/12 16:53:47

8414.44 volts 318.46 volts 741.32 volts

1/1

Value is 0.5