SPE-Reconductoring Case Studies

RE-CONDUCTORING CASE STUDIES FOR VARIOUS UTILITIES AND PRIVATE COMPANIES

PRESENTED BY:Er. S. M. TAKALKAR (MD)

TAKALKAR POWER ENGINEERS & CONSULTANTS PVT. LTD. (TPECPL)

FOR, THE SOCEITY OF POWER ENGINEERS (INDIA), VADODARA CHAPTER NATIONAL ANNUAL GENERAL MEETING

Case Studies of HPCs Employed By Utilities & Private Companies

Takalkar Power Engineers and Consultants Pvt. Ltd. (TPEC)

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RE-CONDUCTORING CASE STUDIES FOR VARIOUS UTILITIES AND PRIVATE COMPANIES

1. R AJ A ST H AN R AJ Y A VI J P R AS ARA N NI GAM LI MI TE D

Rajasthan Rajya Vij Prasaran Nigam Ltd. (RRVPNL) has its transmission line network of 132 kV in Jaipur City. Some of the lines which were laid between 1960 to 1980 are now covered by the expanded city. There is a great deal of encroachment along, across and below the lines, which were once in open field. There are number of interconnected transmission line network connecting their 132 kV Grid Sub Stations (GSS). Due to increase in population & industrialization, demand of electricity has also increased and this is a biggest issue Rajasthan Rajya Vij Prasaran Nigam Limited (RRVPNL) is facing now a days. Installation of new power lines is very costly and there is not enough time to build new lines. It is very difficult to acquire tower sites and right-of-way for construction of high voltage overhead lines in urban and suburban areas. The best solution of increasing the capacity of the line is Up-rating or Up- gradation of the existing lines. Up-rating of existing lines can be achieved by increasing the thermal rating of the line. This can be done by changing the existing conductor with a new High Performance Conductor (HPC) having higher operating temperature, same mechanical properties and low sag values as compared to that of existing conductor. Up-gradation can be achieved by increasing the voltage level of the lines and thus augmenting the power supply. The most important aspect is Right of Way (ROW)

RRVPNL had identified some of the critical lines from the point of Up-rating. The lines are as follows:

1) 132kV Chomu to 132kV Govindgarh (Combination of H pole and Tower)2) 132kV Chambal to 132kV Mansarovar3) 132kV Mansarovar to 132kV Sawai Mansingh stadium4) 132kV Puranaghat to 132kV Kunda Ki Dhani (KKD) ( Combination of H pole and

Tower)5) 132kV VKIA to 220kV VKIA6) 132kV VKIA - 132kV Vaishali- 132kV Hirapura7) 132kV Hirapura – Rampura Dabadi – Chomu (Combination of H pole and Tower)

Most of transmission lines stated above, connecting important 132 kV Grid Sub Station (GSS) are already strung with ACSR Panther and ACSR Wolf Conductors. These

conductors are operating at their maximum operating temperature of 85 0c thus providing current of 464 Amp. Due to load growth, RRVPNL wants to increase their transmission line capacity to twice as thatof their conventional ACSR Conductors.


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Technical Comparison for ACSR Panther & its equivalent HPC Conductors

Properties ACSR Panther ACCC CasablancaCross Sectional Area (mm2) 262.00 303.90

Conductor Diameter (mm) 21.00 20.50

Modulus Of Elasticity (kg/cm2) 816000.00

1182466.87 above Thermal Knee point and 636085.6 below Thermal knee point

Co-efficient of Linear Expansion (/⁰C) 17.8*10-6

1.61*10-6 above Thermal Knee point (65 0c) & 18.9*10-6 below Thermal knee

Point

Weight (kg/km) 974.00 790.00

UTS (kgf) 8826.00 10408.77

DC Resistance @ 20° C Temp (ohms/km) 0.13900 0.10250

Maximum Operating Temperature (˚C) 85 175

Voltage Level (kV) 132 132

Nos. of conductor per phase 1 1

Nos. of Circuits 1 1

Line length (km) 1 1

Span in Mtrs. 325 325

Calculations are for Single Conductor Configuration & Single Circuit Arrangement

Case 1 : Maintaining same Current as that of ACSR Panther at its maximum operating temperature in all proposed conductors

The following calculations are carried out at temp stated besides: 85 77.49

Current to be maintained: 464 464

AC Resistance (ohms/km) 0.1756 0.1267Line losses in kW/ckt 113 82Power Factor 0.85 0.85

Power Transferred in MW/ckt 87 87

Sag at above mentioned temp & 0% wind 7.81 6.24

Tension to be maintained at 32 0C & 100%wind 2855.15 2854.99

Electrical design parameters for transmission line length of 10 kM for Single ckt.

Sending end power in MW 87.00 87.00


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Receiving end power in MW 85.93 86.23Total Induction of Line in H/Phase 5.53E-03 5.55E-03Total Capacitance of Line in µF/Phase 2.11E-01 2.10E-01Voltage regulation (%) 1.43 1.18Efficiency (%) 98.69 99.05

Case-2 : Current in Amp at maximum continuous operating temperature in all proposedHPC conductors

The following calculations are carried out at temp stated besides: 85 175

Current to be maintained: 464 981AC Resistance (ohms/km) 0.1756 0.1666Line losses in kW/ckt 113 481Power Factor 0.85 0.85




Saving per single circuit as in case-1 for duration of one year:Cost of power loss in INR 4/- per kW 3959520 2873280Cost of Power transferred without losses inINR 4/- per kW 3048480000 3048480000Revenue generated in INR 4/- 3044520480 3045606720Additional Revenue generated as compared to ACSR in INR ----------------- 1086240Additional Revenue generated as compared to ACSR in INR (Crore) ----------------- 0.11

Technical Comparison for ACSR Wolf & its equivalent HPC Conductors

Properties ACSR Wolf ACCC CopenhagenCross Sectional Area (mm2) 195.00 251.00



1208970.438 above Thermal Knee point

and 648318.04 below Thermal knee point


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1.61*10-6 above Thermal Knee point (65 0c) & 18.6*10-6 below Thermal knee

Point

Weight (kg/km) 726.00 669.70

UTS (kgf) 6864.00 7431.19








Calculations are for Single Conductor Configuration & Single Circuit Arrangement

Case 1 : Maintaining same Current as that of ACSR Wolf at its maximum operating temperature in all proposed conductors

The following calculations are carried out at temp stated besides:

85 75.41






Electrical design parameters for transmission line length of 10 kM for Single ckt.

Sending end power in MW 73.00 73.00Receiving end power in MW 71.99 72.33Voltage regulation (%) 1.47 1.13Efficiency (%) 98.54 99.03

Case-2 : Current in Amp at maximum continuous operating temperature in all proposedHPC conductors


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Current to be maintained: 387 848AC Resistance (ohms/km) 0.2361 0.2076Line losses in kW/ckt 106 448Power Factor 0.85 0.85Power Transferred in MW/ckt 73 160



Saving per single circuit as in case-1 for duration of one year:Cost of power loss in INR 4/- per kW 3714240 2452800Cost of Power transferred without losses inINR 4/- per kW 2557920000 2557920000Revenue generated in INR 4/- 2554205760 2555467200Additional Revenue generated as compared to ACSR in INR ----------------- 1261440Additional Revenue generated as compared to ACSR in INR (Crore) ----------------- 0.13

The following points can be inferred from above attached Technical Comparison Table:

1. Weight of ACCC Copenhagen conductor (kg/km) is 8% less as compared to ACSR.2. DC Resistance at 20 0c of ACCC Copenhagen conductor is 32% lower as compared to

ACSR thus boosting up ampacity and simultaneously decreasing losses.3. Power Transferred (MW) of ACCC conductor at its maximum operating temperature is

120% higher as compared to that of ACSR.4. Maintaining tension of ACSR at 32 0c & full wind as starting condition in ACCC

conductor as in the case of Re-conductoring, we obtain reduction of 6% in the values of sag at maximum operating temperature as compared to conventional ACSR conductor.

2. O DI S H A P O WE R T R AN SMI SSI O N C O RP OR AT I O N LI MI TE D

Odisha Power Transmission Corporation Limited (OPTCL) is having 132 kV lines running from Chandaka to Mancheswar (circuit-2) of 5.88 km, Chandaka to Ranasingpur of 24.25 km, Chandaka to Nimapura of 57.25 km and Tarkera to Chhend of (2X6.16 km) length and are strung with ACSR Panther Conductor. ACSR Panther Conductor is having maximum current rating of327 Amp at maximum continuous operating temperature (750c).


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ACSR Panther Conductor is capable of catering maximum of 65 MW Power through its Single Circuit Arrangement. OPTCL wants to cater additional power (160 MW per Single Circuit) through its 132 kV Transmission Line Corridor. Lines are going to be overloaded so change in the conductor by higher size is necessary. This will require strengthening of tower and foundation. OPTCL may transfer its additional power by dismantling its existing towers and upgrading the existing voltage level to some higher voltage level but it would ask for a larger shutdown period. Construction of new transmission line would require right of way and approvals from the various authorities and the procedure may ask for a larger project completion time period.

Considering above facts, it is advisable to cater the additional power requirement through same ROW and using same Towers by Re-conductoring of existing lines with new generation High Performance Conductor (HPC) conductors.

An proven method of increasing transmission line thermal rating (up rating) involves replacing the original (typically) steel-reinforced aluminum conductor (ACSR) with a HPC conductor with approximately same diameter as that of the original conductor. Therefore, OPTCL has approached M/s. Sterlite Technologies, to give appropriate solution related to the conductor design for augmenting the capacity with minimum changes and thus affording very little shutdown.

These conductors can carry higher amperes without much variation in the mechanical properties of the conductor compared to one which is presently in service. This aspect makes it possible to string high ampacity conductor on the existing structures with little change or no change in the support structures and foundations.

For this particular application it is proposed to deploy ACCC Casablanca conductor instead of existing ACSR Panther Conductor. Since the mechanical properties of ACCC Casablanca and ACSR Panther conductor are nearly same, it will be possible to string them on the existing transmission line structures without any modification and their foundations also need not be changed. The maximum span is considered as 320M.

The High Performance Conductor (HPC), ACCC Casablanca conductor can carry 970 Amp at its maximum continuous operating temperature (1750C). Mechanical sag of this conductor is also less than that of the sag of existing ACSR Panther conductor

Technical Comparison of ACSR Panther & ACCC Casablanca conductor

Properties ACSR Panther ACCC Casablanca

Cross Sectional Area (mm2) 262.00 316.50


Weight (kg/km) 974.00 840.00

UTS (kg) 8826.00 10306.00



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Ruling Span (M) 320 320

Maintaining Ampacity of 800 Amp in proposed ACCC conductor



AC Resistance (ohms/km) 0.1701 0.1498

Power Factor 0.9 0.9

Power Transferred in MW/circuit 65 160

FOS at 32°C Temperature, 0% wind 4.00 5.14

FOS at 05°C Temperature, 2/3rd wind 2.97 4.15

FOS at 32°C Temperature, 100% wind 3.10 3.62Sag at maximum operating temp & 0% wind in M 7.25 5.78

Tension at 32 0c & 100% wind in kg 2843.12 2843.66Ampacity at maximum operating temperature in proposed conductors







FOS at 32°C Temperature, 100% wind 3.10 3.62Sag at maximum operating temp & 0% wind in M 7.25 5.96Tension at 32 0c & 100% wind in kg 2843.12 2843.66

Assumptions: Coefficient of Emissivity=0.45, Wind Velocity=0.6 m/s, Solar absorption Coefficient=0.8, Constant of mass temperature coefficient of

resistance of conductor per ºC = 0.004, Solar Radiation=1045 W/mm2, Ambient

Temperature=50 0c.


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Requirement as per OPTCL Tender documents:

1. Overall diameter of complete conductor should not exceed 21 mm and 5% variation(+ &-), Approximate mass of complete conductor should be less than or equal to 974 kg/km.Ampacity shall be calculated as per IEEE 738 standard.

2. Minimum required Factor ofSafety (FOS) at 32°C& 0% wind for the proposed HPCconductor is 4.57, while the obtained FOS from ACCC Casablanca conductor comes out to be 5.14.

3. Minimum required Factor of Safety (FOS) at 32°C&100% wind for the proposed HPC conductor is 2.00, while the obtained FOS from ACCC Casablanca conductor comes out to be 3.62.

4. Minimum required Factor of Safety (FOS) at 05°C&66% wind for the proposed HPCconductor is 2.00, while the obtained FOS from ACCC Casablanca conductor comes out to be 4.15.

5. Minimum values of Sag at maximum operating temperature and 0% wind should be strictly limited to 6.14 M, while ACCC Casablanca conductor gives maximum sag of just5.96 M.

6. Design Tension of 132 kV towers should be strictly limited below 2918 kg at 32 0c &100% wind during Re-conductoring, while restringing ACCC Casablanca conductor over the existing towers offers a tension of 2843.66 kg at 32 0c & 100% wind.


5. Weight of ACCC Casablanca conductor (kg/km) is 14% less as compared to ACSR.6. DC Resistance at 20 0c of ACCC Casablanca conductor is 26% lower as compared to

ACSR thus boosting up ampacity and simultaneously decreasing losses.7. Maintaining Ampacity of 800 Amp in ACCC Casablanca which is 144% higher as

compared to maximum operating temperature of ACSR conductor, the power transferred (MW) in case of ACCC Conductor boosts up by 145%.

8. Power Transferred (MW) of ACCC conductor at its maximum operating temperature is196% higher as compared to that of ACSR.

9. Maintaining tension of ACSR at 32 0c & full wind as starting condition in ACCCconductor as in the case of Re-conductoring, we obtain reduction of 18% in the values of sag at maximum operating temperature as compared to conventional ACSR conductor.

Technical Comparison of ACSR Panther & its equivalent HPC conductors

Properties ACSR Panther STACIR/TW




614000 below Thermal knee point (40 0c) and1549439.348 aboveThermal knee point


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18*10-6 below Thermal knee point (40 0c) and3.6*10-6 above Thermalknee point

Weight (kg/km) 974.00 974

UTS (kgf) 8826.00 9281.99





Nos. of Ckts 1 1



Maintaining current of 800 Amp in all proposed conductors


75 119.60



Ohmic losses in kW/ckt (considering loss factor = 0.53) 29 149

Cost of Ohmic Loss in Rs. (Considering Rs.165110/kW) 4788190 24601390






Sag at maximum operating temp & 0% wind in M 7.25 6.40

Tension at 32 0c & 100% wind in kg 2843.12 2890.00

Tension at 32 0c & 0% wind in kg(For Stringing purpose) 2206.98 2317.46Tension at 5 0c & 66% wind in kg 2972.23 3050.55

Current at maximum operating temperature in all proposed conductors



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Ohmic losses in kW/ckt (considering loss factor = 0.53) 29 380

Cost of Ohmic Loss in Rs. (Considering Rs.165110/kW) 4788190 62741800



Assumptions: Coefficient of Emissivity=0.45, Wind Velocity=0.6 m/s, Solar absorption Coefficient=0.8, Constant of mass temperature coefficient of resistance of conductor per ºC = 0.004, Solar Radiation=1045 W/mm2, Ambient Temperature=50 0c.

Requirement as per OPTCL Tender documents:

1. Overall diameter of complete conductor should not exceed 21 mm and 5% variation (+ &-), Approximate mass of complete conductor should be less than or equal to 974 kg/km. Ampacity shall be calculated as per IEEE 738 standard.

2. Minimum required Factor of Safety (FOS) at 32°C&100% wind for the proposed HPCconductor is 2.00, while the obtained FOS of STACIR conductor comes out to be 3.26.

3. Minimum required Factor of Safety (FOS) at 05°C&66% wind for the proposed HPCconductor is 2.00, while the obtained FOS of STACIR conductor comes out to be 3.11.

4. Minimum values of Sag at maximum operating temperature and 0% wind should be strictly limited to 6.4 M, while STACIR conductor gives sag of 6.40 Mcatering 800 Amp at a temperature of 119.60 0c.

5. Design Tension of 132 kV towers should be strictly limited below 2918 kg at 32 0c &100% wind during Re-conductoring, while restringing ACCC Casablanca conductor over the existing towers offers a tension of 2890 kg at 32 0c & 100% wind.


1. Weight of STACIR conductor (kg/km) is same as that to ACSR.2. DC Resistance at 20 0c of STACIR conductor is 25.17% lower as compared to ACSR

thus boosting up ampacity and simultaneously decreasing losses.3. Maintaining Ampacity of 800 Amp in STACIR which is 144.64% higher as compared to

maximum operating temperature of ACSR conductor, the power transferred (MW) in case of STACIR boosts up by 146.15%.

4. Power Transferred (MW) of STACIR at its maximum operating temperature is 250.76%higher as compared to that of ACSR.

5. Maintaining tension of ACSR at 32 0c & full wind as starting condition in STACIR as in the case of Re-conductoring, we obtain same values of sag at aoperating temperature of119.60 0c as compared to conventional ACSR conductor.


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3. D AM OD AR V AL LE Y C O RP OR AT I O N , DV C

Damodar Valley Corporation has its 110 kV lines strung with ACSR Lark and AAAC conductors on their 110 kV towers. ACSR Lark & AAAC Conductor are having maximum current rating of 512 Amp & 616 Amp at maximum continuous operating temperature (750c) for ACSR Lark and 90 0c for AAAC. ACSR Lark & AAAC Conductors are capable of catering maximum of 85 MW & 102 MW Power through its Single Circuit Arrangements. DVC wants to cater additional power (153 MW per Single Circuit) through its 110 kV Transmission Line Corridor. This will require strengthening of tower and foundation. DVC may transfer its additional power by dismantling its existing towers and upgrading the existing voltage level to some higher voltage level but it would ask for a larger shutdown period. Construction of newtransmission line would require right of way and approvals from the various authorities and the procedure may ask for a larger project completion time period.



For this particular application it is proposed to deploy ACCC Reykjavik conductor instead of existing ACSR Lark Conductor. Since the mechanical properties of ACCC Reykjavik and ACSR Lark conductor are nearly same, it will be possible to string them on the existing transmission line structures without any modification and their foundations also need not be changed. The maximum span is considered as 325M.

The High Performance Conductor (HPC),ACCC Reykjavik conductor can carry 959 Amp at1750C. Here the sag of this conductor is also less than that of the sag of existing ACSR Lark conductor. Hence, existing tower and foundation need not be changed.

Technical Comparisons for ACSR Lark & ACCC Reykjavik Conductor

Properties ACSR Lark ACCC Reykjavik



Total Weight (kg/km) of the conductor 923.30 702.40

UTS (kg) 9060.00 10040.77

DC Resistance @ 20° C Temp(ohms/km) 0.14350 0.12630


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Nos. of Circuit 1 1

Line length in km 1 1

Span in M 325 325

Ampacity to maintain power of 153 MW in ACCC conductor


75.00 160.24

Current obtained at above mentioned temp: 512 917

Ac Resistance in ohm/km 0.175553 0.197566

Line losses in kW/circuit 138.06 498.39



Tension maintained at 32deg C & 100%wind

5051.04 5050.83

Sag in M at temp stated above & 0%wind 7.00 5.87

Ampacity at maximum operating temperature in all proposed conductors

The following calculations are carried out at temp stated besides: 75.00 175.00

Current obtained at above mentionedtemp:

512 959





Tension maintained at 32deg C & 100%wind

5051.04 5050.83

Sag in M at temp stated above & 0%wind

7.00 5.94


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Technical Comparisons for AAAC & its ACCC equivalents

Properties AAAC(37/2.88) ACCC Reykjavik



Modulus Of Elasticity (kg/cm2) 693407.00 1208970.44

Co-efficient of Linear Expansion (/⁰C) 23*10^-6 1.61*10^-6

Total Weight (kg/km) of theconductor

664.00 702.40

UTS (kg) 6761.80 10040.77

DC Resistance @ 20° C Temp(ohms/km)

0.13921 0.12630

Maximum Operating Temperature(˚C)

95 175



Nos. of Circuit 1 1

Line length in KM 1 1

Span in M 325 325

Ampacity to maintain power of 153 MW in ACCC conductor


90.00 160.24


616 917





Tension maintained at 32deg C &100% wind

4585.89 4585.68



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Ampacity at maximum operating temperature in ACCC conductor


90.00 175.00


616 959





Tension maintained at 32deg C &100% wind

4585.89 4585.68


Assumptions: Coefficient of Emissivity=0.6, Wind Velocity=0.6 m/s, Solar absorption Coefficient=0.5, Constant of mass

temperature coefficient of resistance of conductor per ºC = 0.004, Solar

Radiation=1200 W/mm2, Ambient Temperature=36 0c.

Requirements as per DVC specification:1. Power to be catered by HPC conductor should be 1.5 times the maximum power

transferred by ACSR Lark or AAAC Panther conductor.

2. Maximum vertical sag of the new proposed HPC conductor at its maximum operating temperature should be less than existing ACSR Lark and AAAC Panther conductor at their individual maximum continuous operating temperature.

The following point can be inferred from the above Technical comparison sheet:1. Weight of ACCC conductor is 24% less as compared to ACSR Lark and 5% higher as

compared to AAAC Panther conductor.

2. DC Resistance of ACCC is 12% and 9% less as compared to ACSR Lark and AAAC Panther conductors respectively.

3. As per DVC specification, power to be transferred through the proposed HPC conductor should be 1.5 times to that existing ACSR Lark and AAAC Panther conductor whichever is maximum. Transferring 153 MW at 917 Amp through the ACCC conductor which is79% and 48% higher as compared to existing ACSR Lark and AAAC Panther conductors respectively.


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4. Power Transferred of ACCC conductor at its maximum operating temperature is 88% and56% higher as compared to ACSR Lark and AAAC Panther conductors respectively.

5. Maintaining Tension of ACSR Lark and AAAC Panther conductors at 32 0c & 100% wind in ACCC Conductor as in the case of Re-conductoring, vertical sag in case of ACCC conductor decreases by 15% and 11% as compared to ACSR Lark and AAAC Panther conductors respectively.

4. M A H A R A S H T R A S T A T E T R A N S M I S S I O N C O R P O R A T IO N L T D . ( M S TC L )

CASE STUDY NO: 4.1

The existing Parli-II (Girwali) 220/132/33 kV substation of MSTCL is having 220 kV Main Bus of Twin 0.4 ACSR Zebra and 220 kV Auxiliary Bus of Single 0.4 ACSR Zebra. The Main Bus gantry structures and column foundations are designed to take the mechanical load of twin conductor only. This Main bus bar can be loaded for about 1300 Amps. With additional demand, the bus bar current will go to 2800 Amps. For catering this load, it is necessary to augment the bus bar capacity either by changing twin Zebra configuration to quad Moose or by replacing existing ACSR Zebra with a HPC (High Temperature Low Sag) conductor of Twin per Bundle configuration. Opting for quad Moose configuration will need change in the Bus gantry structures and column foundations. This is extremely difficult from the outage point of view. Therefore, MSTCL has approached M/s. Sterlite Technologies, Pune to give suitable solution related with the conductor design for augmenting the capacity of the bus bar with minimum changes and thus affording very little shutdown.

The HPC (High Temperature Low Sag) conductors can carry higher amperes without much variation in the mechanical properties of the conductor compared to one which is presently in service. This aspect makes it possible to string high ampacity conductor on the existing structures with little change or no change. For this particular application it is proposed to use Twin ACCC Kolkata conductor instead of existing Twin ACSR Zebra Conductor. Since the mechanical properties of ACCC Kolkata and ACSR Zebra conductor are nearly same, it will be possible to string them on the existing gantry structures without any modification and their foundations also need no change. The maximum span of the bus between two gantries is 36M.

Sag tension calculation with existing span of 36M for ACSR Zebra conductor & ACCC Kolkata conductor is enclosed herewith. The comparison of the mechanical properties and current carrying capacities of ACSR Zebra & ACCC Kolkata conductor is given here under.


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Technical Comparison of ACSR Zebra & ACCC Kolkata conductor

Properties ACSR Zebra ACCC KolkataCross Sectional Area (Sq mm) 484.50 603.28


Modulus Of Elasticity (kg/cm2) 703400.00 1144750.25

Co-efficient of Linear Expansion (/0C) 19.30*10-6 1.61*10-6

Weight (kg/km) 1621.00 1606.00

UTS (kg) 13284.40 17614.68


Emergency temperature (˚C) 105 200




Nos. of Circuit 1 1

Bus length (km) 1 1

Span in M 36 36

Maximum Current to be transferred in Amp for Twin per Bundle Configuration

1346 3254

Maximum Power to be transferred in MW forTwin per Bundle Configuration 895 2165

Maintaining same Ampacity of ACSR Zebra in ACCC Kolkata conductor

The following calculations are carried out at temp stated besides in 0c 75 70.39

Current in Amp: 673 673

AC Resistance (ohms/km) 0.0848 0.0660Line losses in kW/circuit 230 179Power Factor 0.9 0.9


Sag in M at above mentioned temp & 0% wind 0.27 0.09Tension in kg worked out at 32 0C & 100%wind 3347.65 3347.60Tension in kg worked out at 0 0C & 66% wind 5403.14 3654.61

Maintaining Ampacity of 2800 Amp in the proposed ACCC Kolkata Conductor for Twin PerBundle configuration


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Current of 1400 Amp to be transferred forTwin per Bundle Configuration

---------- 2800

Power to be transferred in MW for Twin perBundle Configuration

---------- 1863

Ampacity equivalent to 1400 Amp to be transferred in proposed ACCC Kolkata Conductor

The following calculations are carried out at temp stated besides in 0c 75 137.59


AC Resistance (ohms/km) 0.0848 0.0803Line losses in kW/circuit 230 944Power Factor 0.9 0.9



Ampacity at maximum continuous operating temperature in both ACSR Zebra and ACCC Kolkata conductors

The following calculations are carried out at temp stated besides in 0c 75 175

Current in Amp: 673 1627AC Resistance (ohms/km) 0.0848 0.0883Line losses in kW/circuit 230 1402Power Factor 0.9 0.9Power Transferred in MW/circuit 448 1082


Assumptions : Coefficient of Emissivity=0.6, Wind velocity=0.6m/s, Solar AbsorptionCoefficient=0.5, Constant of mass temperature coefficient of resistance of conductor perºC = 0.004 for all conductors, Solar Radiation = 1200 Wt / sq m, Average ambient temp= 45 deg C, Wind Pressure=45 kg/ sq m.


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The following can be observed from above table:

1. The ACCC Kolkata conductor is able to deliver 3254 Amps at its maximum operating temperature of 1750C with Twin per Bundle configuration. At this temp the sag of ACCC Kolkata conductor is 0.14M which is less as compared to existing ACSR Zebra conductor at 750 C temperatures.

2. The tension of ACCC Kolkata conductor at 320C and 100% wind is equivalent to that ofACSR Zebra conductor with same parameters.

3. The weight of ACCC Kolkata conductor is less than that of ACSR Zebra conductor.Similarly, UTS of ACCC Kolkata conductor is almost 32 % higher than that of ACSRZebra conductor.

TemperatureChange (

0c)

ACSR Zebra ACCC Kolkata

AmpacityAC

ResistanceLine

Losses AmpacityAC

ResistanceLine

Losses70.39 673 0.06604 179

75 673 0.0848 230 757 0.06702 23085 NA NA NA 908 0.06912 34295 NA NA NA 1031 0.07124 454

105 NA NA NA 1135 0.07336 567115 NA NA NA 1227 0.07548 682125 NA NA NA 1308 0.07763 797135 NA NA NA 1382 0.07976 914145 NA NA NA 1450 0.08188 1033155 NA NA NA 1513 0.08399 1154165 NA NA NA 1572 0.08614 1277175 NA NA NA 1627 0.08825 1402


1. Maintaining Ampacity of ACSR Zebra in ACCC Kolkata conductor, AC Resistance andLine losses in case of ACCC Conductor reduces by 22%.

2. Line losses depends upon Ampacity & AC Resistance of conductor at varying temperature, as the ampacity increases with increase in temperature line losses also increases simultaneously.

MSTCL may operate ACCC Kolkata conductor at its maximum operating temperature for a short duration during maximum peak hours and moreover line length is small so practically line losses shall not be taken in account.

CASE STUDY NO: 4.2

The existing 100kV Padgha - Bhivandi Ckt-1 & Ckt-2 D/C transmission line of MSTCL is strung with ACSR Goat conductor. ACSR Goat conductor is capable to cater 82 MW power per circuit at its continuous maximum operating temperature. MSTCL wants to cater additional


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power through existing 100 kV D/C transmission line corridor. To cater the additional power Installation using new line is very costly and time consuming. It is also difficult to acquire right- of-way& approvals from the various authorities for construction of new transmission line. Considering above facts, it is advisable to cater the additional power requirement through same ROW and using same Towers by Re-conductoring of existing lines with new generation High Performance Conductor (HPC) conductors.

An proven method of increasing transmission line thermal rating (up rating) involves replacing the original (typically) steel-reinforced aluminum conductor (ACSR) with a HPC conductor with approximately same diameter as that of the original conductor. Therefore, MSTCL has approached M/s. Sterlite Technologies, to give appropriate solution related to the conductor design for augmenting the capacity with minimum changes and thus affording very little shutdown.

These conductors can carry higher amperes without much variation in the mechanical properties of the conductor compared to one which is presently in service. This aspect makes it possible to string high ampacity conductor on the existing structures with little change or no change in the support structures and foundatioins. For this particular application it is proposed to deploy ACCC Brussels conductor instead of existing ACSR Goat Conductor. Since the mechanical properties of ACCC Brussels and ACSR Goat conductor are nearly same, it will be possible to string them on the existing transmission line structures without any modification and their foundations also need not be changed. The maximum span is considered as 325M.

Sag tension calculation with ruling span of 325M for ACSR conductor &ACCC Brussels conductor is enclosed herewith. The comparison of the mechanical properties and current carrying capacities of ACSR Goat & ACCC Brussels conductor is given here under.

Technical Comparison of ACSR Goat & equivalent ACCC Conductor

Properties ACSR Goat ACCC Brussels

Cross Sectional Area (mm2) 399.6 477


Modulus Of Elasticity (kg/cm2) 703400

1121305 aboveThermal knee point (900C) & 636085.6 belowThermal knee point.

Co-efficient of Linear Expansion (/⁰C) 19.3*10^-6

1.61*10-6 aboveThermal knee point(900C ) & 18.9*10-6 belowThermal knee point

Weight (kg/km) 1491.30 1275.00

UTS (kg) 13765.00 13873.60


Page 20






Nos. of Circuit 1 1


Span in M 325 325

The following calculations are carried out at temp °C as stated below Case-1 :Maintaining same Current in ACCC Conductor

Temp °C 75.00 69.83


AC Resistance (ohms/km) 0.1098 0.0817Line losses in kW/ckt 2303 1714Power Factor 0.85 0.85Power Transferred in MW/ckt 82 82

Tension to be maintained at 32 0C &100% wind 5640.59 5644.58Sag at above mentioned temp & 0%wind 7.39 6.68

Case-2 :Current at maximum operating temperature of ACCC conductor

Temp 0c 75.00 175.00

Current in Amp: 577 1396AC Resistance (ohms/km) 0.1098 0.1098Line losses in kW/ckt 2303 13481Power Factor 0.85 0.85Power Transferred in MW/ckt 82 199

Tension to be maintained at 32 0C &100% wind 5640.59 5396.83Sag at above mentioned temp & 0%wind 7.39 7.01

Assumptions: Coefficient of Emissivity = 0.6, Wind velocity = 0.6 m/s, Solar absorption coefficient = 0.5, Constant of mass temperature coefficient of resistance of conductor per

ºC= 0.004 for other conductors, Solar Radiation = 1200 Wt / sq m, Average ambient temp=

45 deg C, Wind Pressure=117.96 kg/m^2, Wind zone=3.


Page 21



1. The ACCC Brussels conductor is able to deliver 1396 Amps at its maximum operating temperature of 1750C with single configuration. At this temp the sag of ACCC Brussels conductor is 7.01M which is 380mm less as compared to existing ACSR Goat conductor at its maximum operating temperature 750C .

2. It can also seen from the calculation that ACCC Brussels is capable to transmit the199MW power at its maximum continuous operating temperature of 1750C whereasACSR Goat is transmitting 84MW power at its maximum operating temperature of 750C.

3. The tension of ACCC Brussels conductor at 320C and 100% wind is equivalent to that ofACSR Goat conductor with same parameters.

4. The weight of ACCC Brussels conductor is 15% less than that of ACSR Goat conductor.

TemperatureChange (

0c)

ACSR Goat ACCC Brussels

AmpacityAC

Resistance

LineLosses(kW/ckt) Ampacity

AC Resistance

Line Losses(kW/ckt)

69.83 ------- ------- ------- 577 0.0817 1714

75 577 0.1098 2303 658 0.08312 226780 NA NA NA 726 0.08445 280490 NA NA NA 841 0.08710 3881

100 NA NA NA 936 0.08978 4807110 NA NA NA 1019 0.09247 6049120 NA NA NA 1092 0.09512 7146130 NA NA NA 1158 0.09777 8260140 NA NA NA 1218 0.10046 9389150 NA NA NA 1273 0.10310 10526160 NA NA NA 1324 0.10578 11682170 NA NA NA 1373 0.10844 12879175 NA NA NA 1396 0.10980 13481

The following can be observed from above table:1. Maintaining Ampacity of ACSR Goat (at 750C) in ACCC Brussels conductor (at

69.830C), AC Resistance and Line losses in case of ACCC Conductor reduces by 25%.2. Line losses depends upon Ampacity & AC Resistance of conductor at varying

temperature, as the ampacity increases with increase in temperature line losses also increases simultaneously. However, considering the critical ROW issue & need to transmit more power there is no alternative but to go for HPC. Besides, the losses are worked out at continuous maximum current and temperature of 175°C. This may not be a reality. Therefore the losses may not be very high.

CASE STUDY NO: 4.3The existing MSETCL (200/100kV) Receiving substation at Magthane, Borivali is having 220kV Main Bus of Twin 0.4 ACSR Moose. The Main Bus gantry structures and column foundations are designed to take the mechanical load of twin conductor only. This Main bus bar


Page 22


can be loaded for about 1500 Amps. With additional demand, the bus bar current will go to 3100Amps.

This has become necessary to allow the additional power evacuation from the existing bus to the proposed GIS of R-Infra in the substation of MSETCL. The existing bus gantries of the substations cannot withstand the load of Quad Moose and replacing them would need a very long shut down. The metropolitan city of Mumbai cannot afford long shut down.

Therefore, MSETCL has approached M/s. Sterlite Technologies, Pune to give suitable solution related with the conductor design for augmenting the capacity of the bus bar with minimum changes and thus affording very little shutdown. For this particular application it is proposed to use Twin ACSS Curlew conductor instead of existing Twin ACSR Moose Conductor. Since the mechanical properties of ACSS Curlew and ACSR Moose conductor are nearly same, it will be possible to string them on the existing gantry structures without any modification and their foundations also need no change. The maximum span of the bus between two gantries is 39M.

The comparison of the mechanical properties and current carrying capacities of ACSR Moose& ACSS Curlew conductor is given here under.

Technical Comparison of ACSR Moose & ACSS Curlew conductor

Properties ACSR Moose ACSS Curlew

Typical Factors ACSR 54/7/3.53mm 54/7/3.513 mm

Ref Spec. IS 398 Part V ASTM B586

AL/Steel Area AL 528.21 / St 68.78 591

Conductive Wire Al 1350 H19Al1350 O (Fully AnnealedAl wires)

Core Wire Galvanized SteelGalfan Coated STC 6Steel


Modulus Of Elasticity (Kg/cm2) 704000 704000

Linear Co-efficient 19.3*10-6 11.5*10-6

Conductivity of Conductor 52% 53.24%

Weight (Kg/Km) 2004 1983

Emergency temperature 105 310Maximum Operating

Temperature (˚C)85 210

Current Carrying Capacity (Amp)at 85˚ C

880 -


- 1075


Page 23



- 1180


- 1275


- 1360


- 1438


- 1511


- 1582

Conductor Sag in Mtrs (Span =40m) at 85° C

1.16 -

Conductor Sag in Mtrs (Span =40m) at 160° C

- 1.26

Conductor Tension in kg (Span =40m) at 85° C

335.30 -

Conductor Tension in kg (Span =40m) at 160° C

- 312.64

Conductor FOS (Span = 40m) at85° C

46.92 -

Conductor FOS (Span = 40m) at160° C

- 45.65

Strength (Kgf) 16200.00 14271DC Resistance (ohms/Km) @ 20°C Temp

0.05596 0.05477

DC Resistance (ohms/Km) @ 75°C Temp

0.06827 0.06682

DC Resistance (ohms/Km) @ 85°C Temp

0.07050 0.06901

DC Resistance (ohms/Km) @100° C Temp

- 0.07230


- 0.07449


- 0.07668


- 0.07887


- 0.08106


- 0.08325


- 0.08544


Page 24



1. The ACSS Curlew conductor is able to deliver 1703 Amps at its maximum operating temperature of 2100C with single configuration. At this temp the sag of ACSS Curlew conductor is 1.26M which is 100mm more as compared to existing ACSR Moose conductor at its maximum operating temperature 850C .

2. It can also seen from the calculation that ACSS Curlew is capable to transmit the 536MW power with single configuration at its maximum continuous operating temperatureof 2100C whereas ACSR Moose is transmitting 251 MW power at its maximum operating temperature of 850C.

3. The tension of ACSS Curlew conductor at 320C and 100% wind is equivalent to that ofACSR Moose conductor with same parameters.

4. The weight of ACSS Curlew conductor is 1.04% less than that of ACSR Moose conductor.

5. T R A N S M I S S I O N C O R P O R A T I O N O F A ND R A P R AD E S H L I M I TE D (APTRANSCO)

Transmisssion Corporation of Andra Pradesh Limited (APTRANSCO) is having 132 KV line running from Shapurnagar – IDPL – Chinthal DC feeder & Ghanapur-Bandlaguda. The line is continuously loaded to its full capacity. The existing line is strung with ACSR Panther & ACSR Wolf conductor strung mainly on PRS type Structures.

ACSR Panther Conductor is having maximum current rating of 254 Amp at maximum continuous operating temperature (750c).

ACSR Panther Conductor is capable of catering maximum of 48 MW Power through its Single Circuit Arrangement. APTRANSCO wants to cater additional power (170 MW per Single Circuit) through its 132 kV Transmission Line Corridor. Lines are going to be overloaded so change in the conductor by higher size is necessary. This will require strengthening of tower and foundation. APTRANSCO may transfer its additional power by dismantling its existing towers and upgrading the existing voltage level to some higher voltage level but it would ask for a larger shutdown period. Construction of new transmission line would require right of way and approvals from the various authorities and the procedure may ask for a larger project completion time period.

Considering above facts, it is advisable to cater the additional power requirement through same ROW and using same Towers by Re-conductoring existing lines with new generation High Performance Conductor (HPC) conductors.

An proven method of increasing transmission line thermal rating (up rating) involves replacing the original (typically) steel-reinforced aluminum conductor (ACSR) with a HPC conductor with approximately same diameter as that of the original conductor. Therefore, APTRANSCO has approached M/s. Sterlite Technologies, to give appropriate solution related to the conductor design for augmenting the capacity with minimum changes and thus affording very little shutdown.


Page 25



For this particular application it is proposed to deploy INVAR Conductor size30/7/3mm(Invariable to temperature) conductor equivalent to size of ACSR/AAAC Panther conductor on existing towers without their re-modeling / strengthening. Since the mechanical properties of STACIR and ACSR Panther conductor are nearly same, it will be possible to string them on the existing transmission line structures without any modification and their foundations also need not be changed. The maximum span is considered as 320M.

Technical Comparison for ACSR Panther & STACIR ConductorsProperties ACSR Panther STACIR

Typical Features:30/3mm

Al+7/3mm Steel30/3.00 + 7/3.00

mmRef Specification IS 398 Part II IEC 62004




747706.42 above thermal knee point (50 0C) and454536.18 below thermal knee point


3.7*10-6 for temperature above thermal knee point (50 0C) and 15.43*10-6

below thermal knee point

Weight (kg/km) 974.00 939.00

UTS (kgf) 9140.67 8766.56







Span in Mtrs. 320 320Case 1 : Maintaining same Current as that of ACSR Panther in STACIR conductor


Page 26





Line losses in kW/ckt 33 31Power Factor 0.85 0.85


Sag at above mentioned temp & 0%wind 7.06 4.51

Tension to be maintained at 32 0C &100% wind 4847.09 4848.71

Tension to be maintained at 32 0C & 0%wind 2285.72 3007.68Case 2 : Current in Amp at maximum continuous operating temperature in ACSR Panther & STACIR conductors


75 210




Tension to be maintained at 32 0C & 0%wind 2285.72 3007.68Saving in Case 1:

Cost of power loss in INR 4/- per kW for1 year 1156320 1086240Cost of Power transferred in INR 4/- per kW for 1 year 1681920000 1681920000Revenue generated in INR 4/- 1680763680 1680833760Additional Revenue generated as compared to ACSR in INR for 1 year ----------------- 70080


Page 27


Additional Revenue generated as compared to ACSR in INR (Crore) ----------------- 0.01Saving in Case 2:

Cost of power loss in INR 4/- per kW for1 year 1156320 21724800Cost of Power transferred without losses in INR 4/- per kW for 1 year 1681920000 6237120000Revenue generated in INR 4/- 1680763680 6215395200Additional Revenue generated as compared to ACSR in INR for 1 year ----------------- 4534631520Additional Revenue generated as compared to ACSR in INR (Crore) ----------------- 453.46Assumptions:(1) Coefficient of Emissivity = 0.45 (2) Wind velocity = 0.6 m/s(3) Solar absorption co-efficient = 0.8(4) Constant of mass temperature coefficient of resistance of conductor per ºC =0.004 for all conductors.

(5) Solar Radiation = 1045 Wt / sq m(6) Average ambient temp= 55 0C(7) Wind Pressure=150 kg/m2

Requirement as per APTRANSCO Tender documents:

1. Overall diameter of complete conductor should not exceed 21 mm and 5% variation (+ &-), Approximate mass of complete conductor should be less than or equal to 974 kg/km. Ampacity shall be calculated as per IEC 1597 standard.

2. Minimum values of Sag at maximum operating temperature and 0% wind should be strictly limited to 6.5 M, while STACIR conductor gives sag of 5.49 M at maximum operating temperature of 210 degC

3. Design Tension of 132 kV towers should be strictly limited below 4847.09 kg at 32 0c &100% wind during Re-conductoring, while restringing STACIR conductor over the existing towers offers a tension of 4848.71 kg at 32 0c & 100% wind.


1. Weight of STACIR conductor (kg/km) is 3.59% as compared to ACSR.2. DC Resistance at 20 0c of STACIR conductor is 5.61% lower as compared to ACSR thus

boosting up ampacity and simultaneously decreasing losses.3. Ampacity in STACIR at maximum operating temperature (210 0c) is 271.92% higher as

compared to maximum operating temperature of ACSR conductor, the power transferred(MW) in case of STACIR boosts up by 270.83%.


Page 28


4. Maintaining tension of ACSR at 32 0c & full wind as starting condition in STACIR as in the case of Re-conductoring, we obtain a reduction of 22.15% sag at anoperating temperature of 2100c as compared to conventional ACSR conductor.

ACSR Wolf Conductor is having maximum current rating of 218 Amp at maximum continuous operating temperature (750c).

ACSR Wolf Conductor is capable of catering maximum of 41 MW Power through its Single Circuit Arrangement. APTRANSCO wants to cater additional power (146 MW per Single Circuit) through its 132 kV Transmission Line Corridor. Lines are going to be overloaded so change in the conductor by higher size is necessary. This will require strengthening of tower and foundation. APTRANSCO may transfer its additional power by dismantling its existing towers and upgrading the existing voltage level to some higher voltage level but it would ask for a larger shutdown period. Construction of new transmission line would require right of way and approvals from the various authorities and the procedure may ask for a larger project completion time period.

Considering above facts, it is advisable to cater the additional power requirement through same ROW and using same Towers by Re-conductoring existing lines with new generation High Performance Conductor (HPC) conductors.

An proven method of increasing transmission line thermal rating (up rating) involves replacing the original (typically) steel-reinforced aluminum conductor (ACSR) with a HPC conductor with approximately same diameter as that of the original conductor. Therefore, APTRANSCO has approached M/s. Sterlite Technologies, to give appropriate solution related to the conductor design for augmenting the capacity with minimum changes and thus affording very little shutdown.


For this particular application it is proposed to deploy INVAR Conductor size 30/7/2.59 mm (Invariable to temperature) conductor equivalent to size of ACSR Wolf conductor on existing towers without their re-modeling / strengthening. Since the mechanical properties of STACIR and ACSR Wolf conductor are nearly same, it will be possible to string them on the existing transmission line structures without any modification and their foundations also need not be changed. The maximum span is considered as 320M.


Page 29


Technical Comparison for ACSR Wolf & STACIR ConductorsProperties ACSR Wolf STACIRTypical Features: ------------ 30/7/2.59 mmRef Specification ------------- IEC 61089




838532.11 below thermal knee point (50 0C) and1549031.6 above thermal knee point


3.7*10-6 for temperature above thermal knee point (50 0C) and 14.9*10-6

below thermal knee point

Weight (kg/km) 726.00 699.00

UTS (kgf) 6864.00 6612.64







Span in Mtrs. 320 320Case 1 : Maintaining same Current as that of ACSR Wolf in STACIR conductor







Page 30




Case 2 : Current in Amp at maximum continuous operating temperature in ACSR Wolf & STACIR conductors





Tension to be maintained at 32 0C & 0%wind 1715.67 1682.34Saving in Case 1:

Cost of power loss in INR 4/- per kW for1 year 1156320 1086240Cost of Power transferred in INR 4/- per kW for 1 year 1436640000 1436640000Revenue generated in INR 4/- 1435483680 1435553760Additional Revenue generated as compared to ACSR in INR for 1 year ----------------- 70080Additional Revenue generated as compared to ACSR in INR (Crore) ----------------- 0.01Saving in Case 2:

Cost of power loss in INR 4/- per kW for1 year 1156320 19692480Cost of Power transferred without losses in INR 4/- per kW for 1 year 1436640000 5115840000Revenue generated in INR 4/- 1435483680 5096147520Additional Revenue generated as compared to ACSR in INR for 1 year ----------------- 3660663840


Page 31


Additional Revenue generated as compared to ACSR in INR (Crore) ----------------- 366.07Assumptions:(1) Coefficient of Emissivity = 0.45 (2) Wind velocity = 0.6 m/s(3) Solar absorption co-efficient = 0.8(4) Constant of mass temperature coefficient of resistance of conductor per ºC =0.004 for all conductors.

(5) Solar Radiation = 1045 Wt / sq m(6) Average ambient temp= 55 0C (7) Wind Pressure=150 kg/m2

Requirement as per APTRANSCO Tender documents:

1. Overall diameter of complete conductor should not exceed 18.13 mm and 5% variation (+& -), Approximate mass of complete conductor should be less than or equal to 974kg/km. Ampacity shall be calculated as per IEC 1597 standard.

2. Design Tension of 132 kV towers should be strictly limited below 3723.21 kg at 32 0c &100% wind during Re-conductoring, while restringing STACIR conductor over the existing towers offers a tension of 3723.39 kg at 32 0c & 100% wind.


1. Weight of STACIR conductor (kg/km) is 3.71% as compared to ACSR.2. DC Resistance at 20 0c of STACIR conductor is 5.55% lower as compared to ACSR thus

boosting up ampacity and simultaneously decreasing losses.3. Ampacity in STACIR at maximum operating temperature (210 0c) is 255.96% higher as

compared to maximum operating temperature of ACSR conductor, the power transferred (MW) in case of STACIR boosts up by 256.09%.

4. Maintaining tension of ACSR at 32 0c & full wind as starting condition in STACIR as in the case of Re-conductoring, we obtain a slight increase of 3.40% sag at an operating temperature of 210 0c as compared to conventional ACSR conductor.

6. G U J A R A T E N ER G Y TR A N S M I S S S I O N C O R P O R A T I O N L T D . (GETCO)

Due to rapid Industrial growth around Rajkot in Gujarat the following transmission lines under the jurisdiction of transmission division Rajkot, are getting over loaded.

1. 66 kV Vikram – Punitnagar H-Frame Line of length 5 km.2. 66 kV Vikram – Punitnagar D/C Line of length 5 km.3. 66 kV Shapar – Sidheshwar D/C Line of length 3.5 km.4. 66 kV Vikram – Shapar D/C Line of length 4 km.


Page 32


The above lines are strung with ACSR Dog Conductor which can carry about 300 Amp only. It has therefore become necessary to augment the capacity of above line to extent of above 500Amps. An attractive method of increasing transmission line thermal rating (up rating) involves replacing the original (typically) steel-reinforced aluminum conductor (ACSR) with a High Performance Conductor (HPC) conductor with approximately the same diameter as the original ACSR but being capable of operation at temperatures as high as 150⁰C with less thermal elongation than ACSR.So the best solution is Re-conductoring of existing lines with High Performance Conductor (HPC) Conductor. Ideally, these special HPC conductors can be installed and operated without the need for extensive modification of the existing structures and foundations.

The High Performance Conductor (HPC),TACIR Dog (Thermal Alloy Conductor steel Reinforced) conductor is having almost the same mechanical properties of ACSR Dog conductor. Here the sag of this conductor is also less than that of the sag of existing ACSR Dog conductor. Hence, existing tower and foundation need not be changed.

M/s Sterlite has made submission to M/s Gujarat Energy Transmission Corporation (GETCO), which indicates that it is possible to change the existing ACSR DOG conductor by TACSR DOG Conductor for raising the load ability of the existing 66kV S/C or D/C Lines. This can be done without any change in the existing Tower Structures. GETCO has many lines in their Power system, which are getting over loaded and it is not possible to change the Towers or add more Towers to the Lines.

Technical Comparison of ACSR Dog & TACSR Dog conductor

Properties ACSR Dog TACSR DogCross sectional Area (mm²) 118.5 118.5Conductor Diameter (mm) 14.15 14.15Modulus Of Elasticity (Kg/cm2) 775000 775000

Linear Co-efficient 19.8x10-6 11.5x10-6

Weight (Kg/Km) 394 394Strength (Kgf) 3305 3666

DC Resistance (ohms/Km) @ 20° C Temp 0.279200 0.27800DC Resistance (ohms/Km) @ 67° C Temp 0.331690 0.33026DC Resistance (ohms/Km) @ 112° C Temp NA 0.38030

DC Resistance (ohms/Km) @ 150° C Temp NA 0.42256

Maximum Operating Temperature 75 150


Page 33


Current Carrying Capacity (Amp) at 67˚ C 268 269Current Carrying Capacity (Amp) at 112˚ C NA 480Current Carrying Capacity (Amp) at 150˚ C NA 577

Conductor Sag in Meters(Span = 260m) at 67° C & no wind

5.32 4.37


NA 5.33


NA 6.11

Conductor Tension in Kg(Span = 260m) at 0° C & 66% wind 1315.58 1291.05

Conductor Tension in Kg(Span = 260m) at 67° C & no wind

626.26 761.61


NA 624.38


NA 545.03

Conductor FOS(Span = 260m) at 32° C & no wind 4.00 4.00

Conductor FOS(Span = 260m) at 67° C & no wind

5.28 4.81


NA 6.05


NA 6.73

AC Resistance (ohm) @ 67°C 0.331950 0.33052AC Resistance (ohm) @ 112°C NA 0.38053AC Resistance (ohm) @ 150°C NA 0.42277

Power Loss in kW/km @ 67°C (3 phaseDouble Circuit) =I2*AC Resistance

143 144

Power Loss in kW/km @ 112°C(3 phaseDouble Circuit) =I2*AC Resistance

NA 526

Power Loss in kW/km @ 150°C (3 phaseDouble Circuit) =I2*AC Resistance NA 845


Page 34


Here calculated value of sag is 5.32 m against the maximum allowable sag is8.23 m (27' - 0'')


1. Ampacity in TACIR at maximum operating temperature (1500c) is 115.29% higher as compared to maximum operating temperature of ACSR conductor.

2. Maintaining tension of ACSR at 32 0c & full wind as starting condition in TACIR as inthe case of Re-conductoring, we obtain a increase of 68.23% sag at an operating temperature of 150 0c as compared to conventional ACSR conductor.

COMPARATIVE STATEMENT FOR ACSR DOG & TACSR DOG CONDUCTOR AS PER IS:802,1978

BASIC INPUTS CONSIDERED

UNITSACSR DOG

TACSR DOG

Normal Span M 185.00 185.00

Cross section area M² 1.19E-04 1.19E-04

U.T.S. Kg 3305 3785

Weight Kg/M 0.394 0.394

Modulus of Elasticity E Kg/M² 7.75E+09 7.75E+09

Α C 1.98E-05 1.15E-05

Wind pressure Kg/M² 45.00 45.00

Overall Diameter M1.415E-

021.415E-

02

SAG-(M) TENSION-(Kg) F.O.S.LOADING

CONDITIONACSR DOG

TACSR DOG

ACSR DOG

TACSR DOG

ACSR DOG

TACSR DOG

0 C◌ No wind 1.36 1.36 1243.87 1243.38 2.66 3.04

0 C◌ 66% wind 1.25 1.25 1350.41 1350.22 2.45 2.80

0 C◌ Full wind 1.16 1.16 1458.25 1457.42 2.27 2.60

32 C◌ No wind 2.04 1.71 826.75 984.07 4.00 3.85

32 C◌ 66% wind 1.72 1.50 980.41 1120.29 3.37 3.38

32 ◌C Full wind 1.51 1.35 1117.54 1246.44 2.96 3.04

67 C◌ No wind 3.04 2.22 554.35 758.36 5.96 4.99

67 C◌ 66% wind 2.33 1.83 722.53 919.07 4.57 4.12

67 C◌ Full wind 1.94 1.59 867.58 1059.01 3.81 3.57

113 C◌ No wind 4.32 3.00 390.55 562.46 8.46 6.73


Page 35


113 C◌ 66% wind 3.12 2.30 540.31 731.44 6.12 5.17

113 C◌ Full wind 2.50 1.92 673.49 875.85 4.91 4.32

Comparison of Sag and Tension between ACSR Dog & TACSR Dog Conductor as under:

1. It will be worthwhile to indicate that the tower design is governed basically by the two important parameter related with the conductor. There are as under:

2. Sag of conductor at maximum temperature and no wind condition - This condition determines the height of bottom cross arm above the ground level.

3. The tension of conductor at 0 deg. C with 66% wind or at 32 deg. C with 100% wind whichever is higher – This condition relates to the strength of the tower and also has a direct effect on the weight of the tower/s as well as foundation quantities.

4. If 1 - a and b are satisfied by any alternate conductor, the intermediate values of sag andtension are in significant.

5. It can be seen from the sag tension calculation that the sag of TACSR Dog Conductor at113 deg. C. is comparable to that of ACSR Dog at 67 deg. C. In addition to this, the tension of ACSR Dog & TACSR Dog are comparable at 0 deg. C & 66% wind.

6. The GETCO officials have an apprehension that the values of sag and tension at intermediate loading (intermediate temperature between 67 deg. C & 113 deg. C), the values of sag and tension of both the conductors will vary. This cannot be denied but so far as the transmission line tower design practice in the country is concerned, whatever is indicated 1 a & b above is valid. The intermediate values of sag and tension of proposed TACSR Dog Conductor have no significance what so ever be, in the critical aspects of the tower design.

It can be further stated that the replacement can be done easily without any change in hardware. This is obvious from the point of view that the Ferrous and Aluminum components of hardware and clamps/connectors deform at much higher temperature (250 deg. C and above).

7. T O RRE NT P O WE R LI MI TE D

Due to rapid Industrial growth in Ahmadabad in Gujarat the existing 132 kV D/C Torrent power line from New Pirana to Vinzol under the jurisdiction of transmission division Ahmadabad, is getting over loaded.

The line is strung with ACSR Panther Conductor which can carry about 440 Amps only. It has therefore become necessary to augment the capacity of above line to extent of above 1058 Amps.


Page 36


An attractive method of increasing transmission line thermal rating (up rating) involves replacing the original (typically) steel-reinforced aluminum conductor (ACSR) with a High Performance Conductor (HPC) conductor with approximately the same diameter as the original ACSR butbeing capable of operation at temperatures as high as 2000c with less thermal elongation thanACSR. So the best solution is Re-conductoring of existing lines with High Performance Conductor (HPC) Conductor. Ideally, these special HPC conductors can be installed and operated without the need for extensive modification of the existing structures and foundations.

The High Performance Conductor (HPC), ACCC Lisbon (Aluminum Conductor Composite Core) conductor is having almost the same mechanical properties of ACSR Panther conductor. Here the sag of this conductor is also less than that of the sag of existing ACSR Panther conductor. Hence, existing tower and foundation need not be changed.

M/s Sterlite has made submission to M/s Torrent Power Limited, which indicates that it is possible to change the existing ACSR Panther conductor by ACCC Lisbon Conductor for raising the load ability of the existing 132 kV D/C Lines. This can be done without any change in the existing Tower Structures.

Technical comparison of ACSR Panther & ACCC Lisbon Conductors

Properties ACSR PANTHER ACCC LISBONCross Sectional Area (mm2) 262.00 358.4Conductor Diameter(mm) 21.00 21.78


1144750.25 above Thermal Knee point and 640163.10 below Thermal knee point.


1.61*10-6 aboveThermal Knee point and 18.76*10-6

below Thermal knee point

Weight (kg/km) 976.00 956.60UTS (kgf) 9128.00 10570.84DC Resistance @ 20° C Temp (ohms/km) 0.13900 0.09000Emergency temperature (˚C) 105 200Maximum Operating Temperature (˚C) 75 175Voltage Level (kV) 132 132Normal Span, m 325 325Nos. of conductor per phase 1 1Nos. of Ckts 1 1


Page 37


Line length (km) 1 1FOS @ 0 °C, 36% wind 2.75 4.37FOS @ 32 °C, 0% wind 4.00 6.07FOS @ 32 °C, 100% wind 2.07 2.40Conductor Tension, kg @ 32 °C, 100% wind 4404.67 4404.63Following calculations are at temp, (˚C)(If not mentioned)

75.00 110.50

Current Carrying Capacity (Amps) 440 850AC Resistance (ohms/km) 0.170070 0.122727Sag , 0% wind (m) 7.23 7.55Line losses in kW 98.78 266.01Power Factor 0.9 0.9MW Transferred (MW) 88 170Cost of power per kW in Rs. 4 4Cost of Powerloss for 1 year (Rs.) 3461129 9321010Cost of Power for 1 year (Rs.) 3083520000 5956800000Revenue Generated for 1 year (Rs.) 3080058871 5947478990

Additional Revenue Generated for 1 year (Rs.) --- 2867420119


1. Weight of ACCC Lisbon conductor (kg/km) is 1.98% less as compared to ACSR Panther.2. DC Resistance at 20 0c of ACCC Lisbon conductor is 35.25% lower as compared to

ACSR thus boosting up ampacity and simultaneously decreasing losses.3. Ampacity in ACCC Lisbon conductor at maximum operating temperature (1750c) is

154.43% higher as compared to maximum operating temperature of ACSR conductor, the power transferred (MW) in case of ACCC Lisbon conductor boosts up by 154.32%.

4. Maintaining tension of ACSR at 32 0c & full wind as starting condition in ACCC Lisbon as in the case of Re-conductoring, we obtain a slight increase of 4.426% sag at anoperating temperature of 175 0c as compared to conventional ACSR conductor.

8. T AT A P O WE R C O MP AN Y LI MI TE D

CASE STUDY NO: 8.1

Existing 220 kV Double Circuit Transmission line from Kalwa to Salsette of M/s Tata Power Company Limited is strung with Twin ACSR Panther & Single ACSR Moose conductor. The Route length of the double circuit line is 8 kms. The double Circuit line is strung with twin ACSR Panther for about 7.5 km and remaining 0.5 km with ACSR Moose conductor. Due to increase in power demand the existing line is getting loaded.


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ACSR Panther conductor can cater maximum current of 546 Amp at its maximum continuous operating temperature and with twin per bundle configuration max of 1064 amp. With increase in power demand, current to be catered is about 1800 Amp per bundle conductor configuration.

In order to cater the increase in power demand, twin ACSR Panther shall be replaced with twin Moose conductor or with High Performance Conductor (HPC) Panther equivalent conductor as these new generation conductors are having same overall diameter and mechanical strength as that of conventional ACSR conductors.

As the existing tower structure are designed with twin ACSR Panther conductor and replacing them with twin ACSR Moose, tower foundations need to be re-designed to take the load of twin ACSR Moose conductor and would also need a longer shut down. The metropolitan city of Mumbai cannot afford such long shut down.

Therefore, M/s Tata Power Company Limited has approached M/s. Sterlite Technologies, Pune to give suitable solution related with the conductor design for augmenting the capacity of the line with minimum changes and thus affording very little shutdown.

For this particular application it is proposed to use Twin ACCC Casablanca conductor instead of existing Twin ACSR Panther Conductor. Since the mechanical properties of ACCC Casablanca and ACSR Panther conductor are nearly same, it will be possible to string them on the existing tower structures without any modification and their foundations also need no change.

The comparison of the mechanical properties and current carrying capacities of ACSR Panther& ACCC Casablanca conductor is given here under.

Technical Comparison of ACSR Panther & equivalent Conductors


Typical Factors: 30/7/2.99 mm -----------

Cross Sectional Area (mm2) 262 316.50



1182466.87 aboveThermal knee point (90 0c) and 636085.6 below Thermal knee point


18.9*10-6 below Thermal knee point (90 0c) and 1.61*10-6

above Thermal knee point



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UTS (kg) 9095 10409





Nos. of Ckts 1 1



Case 1 : Maintaining Current of 900 Amp per Subconductor for TwinBundle Configuration per Single Circuit


Current to be maintained in Amp: 550 900AC Resistance (ohms/km) 0.1732 0.1510Line losses in kW/ckt 2515 5870Power Factor 0.85 0.85Power Transferred in MW/ckt 346 566

Sag at above mentioned temp & 0% wind 8.74 8.44Tension to be maintained at 32 degC& 100%wind 4431.81 4431.16Tension to be maintained at 32 degC& 0%wind(For Stringing) 2273.32 2113.84

Case 2 : Current at maximum operating temperature per Subconductor for Twin Bundle Configuration per single Circuit

The following calculations are carried out at temp stated besides: 85.00 175


Sag at above mentioned temp & 0% wind 8.77 8.59Tension to be maintained at 32 deg C& 100%wind 4431.81 4431.16Cost Capitalization for Case 1


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Cost of power loss at a tariff of INR 4/- forACSR Panther and ACCC 88,125,600.00 205,684,800.00

Revenue without Power Loss (@ Rs 4/- per kWh) for ACSR Panther & ACCC per year 12,123,840,000.00 19,832,640,000.00

Revenue generation (INR) @ for ACSR Panther& for ACCC per year 12,035,714,400.00 19,626,955,200.00

Additional Revenue Generation compared toACSR for 1 year INR for ACCC per year

------------7,591,240,800.00

Additional Revenue Generation compared to ACSR for 1 year INR for ACSR Panther & ACCC in Crore

------------759.12

Assumptions:(1) Coefficient of Emissivity = 0.45(2) Wind velocity = 0.6 m/s(3) Solar absorption co-efficient = 0.6(4) Constant of mass temperature coefficient of resistance of conductor per ºC = 0.004 for all conductors.(5) Solar Radiation = 1045 Wt / sq m(6) Average ambient temp= 40 deg C(7)Wind Pressure=124.87 kg/m2, Wind zone=3


1. Weight of ACCC Casablanca conductor (kg/km) is 18.97% less as compared to ACSR Panther.

2. DC Resistance at 20 0c of ACCC Casablanca conductor is 25.07% lower as compared toACSR thus boosting up ampacity and simultaneously decreasing losses.

3. Ampacity in ACCC Casablanca conductor at maximum operating temperature (1750c) is88.46 % higher as compared to maximum operating temperature of ACSR conductor, the power transferred (MW) in case of ACCC Casablanca conductor boosts up by 88.62 %.

4. Maintaining tension of ACSR at 32 0c & full wind as starting condition in ACCC Casablanca as in the case of Re-conductoring, we obtain a slight increase of 2.05 % sag at an operating temperature of 175 0c as compared to conventional ACSR conductor.


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Current Carrying Capacity per Subconductor as per IEC-1597 (1995)

Temp in0c

ACSR Panther ACCC CasablancaAmpacity AC Resistance Ampacity AC Resistance

50 93 0.153764 113 0.11553355 234 0.156482 270 0.11756860 315 0.159207 362 0.11960265 377 0.161932 432 0.12163670 428 0.164676 490 0.12366875 472 0.167399 540 0.12572980 511 0.170122 584 0.12776085 546 0.172866 624 0.12979790 NA NA 660 0.13183495 NA NA 694 0.133870

100 NA NA 724 0.135930105 NA NA 753 0.137965110 NA NA 780 0.139999115 NA NA 805 0.142058120 NA NA 829 0.144091

125 NA NA 851 0.146123130 NA NA 872 0.148181135 NA NA 893 0.150212140 NA NA 912 0.152243145 NA NA 931 0.154300150 NA NA 949 0.156330155 NA NA 966 0.158366160 NA NA 982 0.160423165 NA NA 998 0.162459170 NA NA 1014 0.164516175 NA NA 1029 0.166551200 NA NA 1098 0.176787

CASE STUDY NO: 8.2

Existing 110 kV Double Circuit Transmission line from Arkay Switchyard 110 kV to Valuthur110/220 kV Swithchyard of M/s Tata Power Company Limited is strung with single ACSRPanther conductor. The Route length of the double circuit line is 4.311kms. Due to increase in power demand the existing line is getting loaded.

ACSR Panther conductor can cater maximum current of 476 Amp at its maximum continuous operating temperature. With increase in power demand, current to be catered is about 900 Amp. In order to cater this increase in power demand, ACSR Panther shall be replaced with Moose conductor or with High Performance Conductor (HPC) Panther equivalent conductor as these new generation conductors are having almost same overall diameter and mechanical strength as


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that of conventional ACSR conductors. As the existing tower structure are designed with ACSR Panther conductor and replacing them with ACSR Moose, tower foundations need to be re- designed to take the load of ACSR Moose conductor and would also need a very long shut down.

Therefore, M/s Tata Power Company Limited has approached M/s. Sterlite Technologies, Pune to give suitable solution related with the conductor design for augmenting the capacity of the line with minimum changes and thus affording very little shutdown.For this particular application it is proposed to use ACCC Casablanca conductor instead of existing ACSR Panther Conductor. Since the mechanical properties of ACCC Casablanca and ACSR Panther conductor are nearly same, it will be possible to string them on the existing tower structures without any modification and their foundations also need no change. The comparison of the mechanical properties and current carrying capacities of ACSR Panther& ACCC Casablanca conductor is given here under.

Technical Comparison of ACSR Panther & ACCC Conductor


Typical Factors: -------------- 10 TW/6 TW/1/7.11 mmCross Sectional Area (Sqmm) 262 303.90

Conductor Dia (mm) 21.00 20.50


1182466.87 aboveThermal knee point (700c) and 636085.6 belowThermal knee point


18.9*10-6 below Thermal knee point (70 0c) and1.61*10-6 above Thermal knee point


UTS (kgf) 8826.0 10408.77


Maxiumum Operating Temperature (˚C) 85 175



Line length (km) 4.311 4.311


Case 1 : Maintaining Current of ACSR Panther in ACCC Casablanca Conductor per Single Circuit


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Tension to be maintained at 32 degC& 100%wind 4742.72 4744.70Tension to be maintained at 32 degC& 0%wind(For Stringing) 2206.77 2192.24

Case 2 : Current at maximum operating temperature in both Conductors perSingle Circuit



Sag at above mentioned temp & 0% wind 7.81 6.75Tension to be maintained at 32 degC& 100%wind 4742.72 4744.70

Case 3 : Maintaining Current of ACSR Panther in ACCC Casablanca Conductor per Double Circuit





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Tension to be maintained at 32 degC& 100%wind 4742.72 4744.70Tension to be maintained at 32 degC& 0%wind(For Stringing) 2206.77 2192.24

Case 4 : Current at maximum operating temperature in both Conductors perDouble Circuit



Sag at above mentioned temp & 0% wind 7.81 6.75Tension to be maintained at 32 degC& 100%wind 4742.72 4744.70

Assumptions:(1) Coefficient of Emissivity = 0.45 (2) Wind velocity = 0.6 m/s(3) Solar absorption co-efficient = 0.6(4) Constant of mass temperature coefficient of resistance of conductor per ºC = 0.004 forall conductors.(5) Solar Radiation = 1045 Wt / sq m(6) Average ambient temp= 45 deg C(7)Wind Pressure=146.71 kg/m2Wind zone=6, Terrain Category=3,Relaibility Level=1.


1. Weight of ACCC Casablanca conductor (kg/km) is 18.97% less as compared to ACSR Panther.


3. Ampacity in ACCC Casablanca conductor at maximum operating temperature (1750c) is88.46 % higher as compared to maximum operating temperature of ACSR conductor, the power transferred (MW) in case of ACCC Casablanca conductor boosts up by 88.62 %.

4. Maintaining tension of ACSR at 32 0c & full wind as starting condition in ACCC Casablanca as in the case of Re-conductoring, we obtain a slight increase of 2.05 % sag at an operating temperature of 175 0c as compared to conventional ACSR conductor.


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Current Carrying Capacity as per IEC-1597 (1995)

Temp in0c

ACSR Panther ACCC CasablancaAmpacity AC Resistance Ampacity AC Resistance

60 159 0.161210 187 0.11960265 262 0.163908 304 0.12163670 332 0.166606 384 0.12366875 387 0.169325 448 0.12572980 435 0.172021 502 0.12776085 476 0.174717 549 0.12979790 NA NA 591 0.13183495 NA NA 629 0.133870

100 NA NA 664 0.135930105 NA NA 696 0.137965110 NA NA 725 0.139999115 NA NA 753 0.142058120 NA NA 779 0.144091125 NA NA 804 0.146123130 NA NA 827 0.148181135 NA NA 849 0.150212140 NA NA 870 0.152243145 NA NA 890 0.154300150 NA NA 910 0.156330155 NA NA 928 0.158366160 NA NA 946 0.160423165 NA NA 963 0.162459170 NA NA 979 0.164516175 NA NA 995 0.166551200 NA NA 1069 0.176787

CASE STUDY NO: 8.3

Existing 22 kV Double Circuit Transmission line No. 5& 6 running from Saki Receiving Station to IIT of M/s Tata Power Company Limited is strung with single ACSR Dogconductor. The Route length of the double circuit line is 3.50kms. Due to increase in power demand the existing line is getting loaded. ACSR Dog conductor can cater maximum current of 300 Amp at its maximum continuous operating temperature.

With increase in power demand, current to be catered is about 670 Amp. In order to cater this increase in power demand, ACSR Dog shall be replaced with Panther conductor or with High Performance Conductor (HPC) Dog equivalent conductor as these new generation conductors are having almost same overall diameter and mechanical strength as that of conventional ACSR conductors. As the existing tower structure are designed with ACSR Dog conductor and replacing them with ACSR Panther, tower foundations need to be re-designed to take the load of ACSR Panther conductor and would also need a very long shut down.


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Therefore, M/s Tata Power Company Limited has approached M/s. Sterlite Technologies, Pune to give suitable solution related with the conductor design for augmenting the capacity of the line with minimum changes and thus affording very little shutdown.For this particular application it is proposed to use ACCC Helsinki conductor instead of existing ACSR Dog Conductor.

Since the mechanical properties of ACCC Helsinki and ACSR Dog conductor are nearly same, it will be possible to string them on the existing tower structures without any modification and their foundations also need no change. The comparison of the mechanical properties and current carrying capacities of ACSR Dog& ACCC Helsinki conductor is given here under.

Technical Details of ACSR Dog & ACCC Helsinki Conductor

Properties ACSR Dog ACCC Helsinki

Typical Features:6/4.72 mm + 7/1.57

mm -------------




1188989 above Thermal knee point (55 0C) &655453.61 below Thermal knee point.


1.61*10-6 above Thermal knee point(55 0C ) &18.7*10-6 belowThermal knee point

Weight (kg/km) 394 479.70

UTS (kgf) 3265.00 7034.00


Emergency temperature 105 200

Maximum Operating Temperature (˚C) which canbe withstand

85 175


Normal Span, m 225 225


Nos. of Ckts 1 1


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Line length (km) 1.000 1.000

Conductor Tension @ 32 °C, 100% wind in kg 1235.33 1235.09

Conductor Tension @ 32 °C, 0% wind in kg 816.54 761.92Sag at 0% wind ,85°c for ACSR Dog and at0%wind,175°c for ACCC Helsinki

4.79 5.05

Current Carrying Capacity (Amps) 300 670

Temp at which 300 Amp for ACSR Dog & 670 Amp for ACCC Helsinki conductor is carried through 85.00 175.00

AC Resistance (ohms/km) at 85°c for ACSR Zebra and at 175°c for ACCC Kolkata 0.352028 0.301770

Line losses (kW) per conductor 95.05 406.39


MW Transferred (MW) per circuit 10 21

Assumptions:(1) Coefficient of Emissivity = 0.45 (2) Wind velocity = 0.56 m/s(3) Solar absorption co-efficient = 0.8(4) Constant of mass temperature coefficient of resistance of conductor per ºC = 0.004 for all conductors.(5) Solar Radiation = 1045 Wt / sq m (6) Average ambient temp= 45 deg C (7)Wind Pressure=52 kg/m2


1. DC Resistance at 20 0c of ACCC Helsinki conductor is 33.34% lower as compared toACSR thus boosting up ampacity and simultaneously decreasing losses.

2. Ampacity in ACCC Helsinki conductor at maximum operating temperature (1750c) is123.33% higher as compared to maximum operating temperature of ACSR conductor, thepower transferred (MW) in case of ACCC Helsinki conductor boosts up by 110 %.

3. Maintaining tension of ACSR at 32 0c & full wind as starting condition in ACCC Helsinki as in the case of Re-conductoring, we obtain a slight increase of 5.42 % sag atan operating temperature of 175 0c as compared to conventional ACSR conductor.


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9. UP P o wer T r ans miss io n Co r po r ati on Li mi ted ( UPP TC L)

UP Power Transmission Corporation Limited (UPPTCL) is having 132 kV lines running from Muradnagar to B.S. Road in the district of Ghaziabad and is strung with AAAC Panther Conductor on the towers designed with ACSR Panther of 18 km length. ACSR Panther Conductor is having maximum current rating of 408 Amp at maximum continuous operatingtemperature (750c).

ACSR Panther Conductor is capable of catering maximum of 81MW Power through its Single Circuit Arrangement. UPPTCL wants to cater additional power (212 MW per Single Circuit) through its 132 kV Transmission Line Corridor. Lines are going to be overloaded so change in the conductor by higher size is necessary. This will require strengthening of tower and foundation. UPPTCL may transfer its additional power by dismantling its existing towers and upgrading the existing voltage level to some higher voltage level but it would ask for a larger shutdown period. Construction of new transmission line would require right of way and approvals from the various authorities and the procedure may ask for a larger project completion time period.


An proven method of increasing transmission line thermal rating (up rating) involves replacing the original (typically) steel-reinforced aluminum conductor (ACSR) with a HPC conductor with approximately same diameter as that of the original conductor. Therefore, UPPTCL has approached M/s. Sterlite Technologies, to give appropriate solution related to the conductor design for augmenting the capacity with minimum changes and thus affording very little shutdown.


For this particular application it is proposed to deploy ACCC Casablanca conductor instead of existing ACSR Panther Conductor. Since the mechanical properties of ACCC Casablanca and ACSR Panther conductor are nearly same, it will be possible to string them on the existing transmission line structures without any modification and their foundations also need not be changed. The maximum span is considered as 325M.

The High Performance Conductor (HPC), ACCC Casablanca conductor can carry 970 Amp at its maximum continuous operating temperature (1750C). Mechanical sag of this conductor is also less than that of the sag of existing ACSR Panther conductor


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Technical Comparison of ACSR Panther & ACCC Casablanca Conductor


Typical Factors 30/7/3.00 mm

6/4.6 +10/4.58 mm (equivalent round wire)

Ref Spec. IS 398 Part II ASTM B 857Cross sectional Area(mm²)

262 303.9

Conductive Wire Al 1350 H191350 O-

Temper TW Al Wire

Core Wire Galvanized SteelComposite

CoreConductor Diameter(mm) 21 20.5

Modulus Of Elasticity(Kg/cm2)

767000 1182870

Linear Co-efficient 17.8x10-6 1.61*10-6

Weight (Kg/Km) 976 790Strength (Kgf) 9128.00 10408No of circuit 1 1No of Conductors per phase

1 1

Voltage Level(kV) 132 132DC Resistance (ohms/Km)@ 20° C Temp

0.139 0.1025

Emergency temperature 105 200Maximum Operating

Temperature75 180

Current Carrying Capacity:

Current Carrying Capacity(Amp) at 75˚ C 408 472

Current Carrying Capacity(Amp) at 180˚ C

NA 1062

Current Carrying Capacity(Amp) at 210˚ C

NA NA

Conductor sag in Mtrs:


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Conductor Sag in Mtrs(Span = 325m) at 75° C

8.83 6.58

Conductor Sag in Mtrs(Span = 325m) at 180° C NA 7.06

Conductor Sag in Mtrs(Span = 325m) at 210° C NA NA

AC Resistance:

AC Resistance (ohms/Km)@ 75° C Temp

0.1701 0.1257

AC Resistance (ohms/Km)@ 180° C Temp NA 0.1686

AC Resistance (ohms/Km)@ 210° C Temp NA NA

Line Losses:

I2R Losses (kW/Km) @75° C Temp

84.93 84.03


NA 570.49


NA NA

MW Transferred:MW transferred (MW) @75° C Temp 81 94

MW transferred (MW) @180° C Temp

NA 212

MW transferred (MW) @210° C Temp

NA NA

Losses per Power Transferred:

I2R Losses / MW @ 75° C Temp

0.105% 0.089%


NA 0.269%


NA NA

NOTE-It is to be noted that Line losses and Power Transferred are calculated for single circuit line. So values of line losses would be kW/single circuit & that of Power Transferred would ne MW/single circuit. The length of line is considered as 1 kM.


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1. Weight of ACCC Casablanca conductor is 19.05% less as compared to ACSR Panther conductor.


3. Ampacity in ACCC Casablanca conductor at maximum operating temperature (1750c) is160.29% higher as compared to maximum operating temperature of ACSR conductor, thepower transferred (MW) in case of ACCC Casablanca conductor boosts up by 161.73 %.

4. Maintaining tension of ACSR at 32 0c & full wind as starting condition in ACCC Casablanca as in the case of Re-conductoring, we obtain a slight increase of 20.04 % sagat an operating temperature of 175 0c as compared to conventional ACSR conductor.

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