Page 58 - Energize April 2022

TECHNICAL

Both field tests confirmed that reduced operating temperatures
and higher ampacity can be achieved by applying SSC to standard
overhead conductors. This increases the cost of the conductor but
payback periods of 1 to 2 years through energy savings have been
estimated. 2

References
1. P Imminger, et al: “Preliminary Report on Oak Ridge National
Laboratory Testing of Drake/ACSS/MA2/E3X”, ORNL/TM-
2015/549
2. J Coffey: “High Temperature Overhead Conductor Rating
Figure 10: Temperature difference between coated and uncoated Considerations”, Prysmian Group/General Cable Littleton,
conductors 4
Colorado
3. CS Taylor and HE House: “Emissivity and Its Effect on the
The test run of 4 x 10 m long Rabbit (50 mm2) ACSR conductors were Current- Carrying Capacity of Stranded Aluminium Conductors”,
used: Two coated with Assettcool SSC (as the ‘test conductor’); and Transactions of the American Institute of Electrical Engineers.
two used uncoated, as received (as the ‘control conductor’) Part III: Power Apparatus and Systems (Volume 75, Issue 3,
• Conductors connected electrically in series to ensure that the January 1956)
same current was carried by all conductors 4. N Coogan: “A 12 Month Field Trial of Novel Conductor Coatings
• 8 K-type thermocouples were inserted into the core for Increased Ampacity: Performance and Durability”, Cigre
• Power supply: 3 x 1500 W DC power supplies (450 A, 30V DC) Southern Africa 10th regional conference, 2021
5. J Eglesias, et al: “Guide for thermal rating calculations of
Results showed an improved performance of either increased overhead lines”, Cigre TB 601 December 2014
ampacity at a fixed temperature or reduced temperature at a fixed
current level. Send your comments to rogerl@nowmedia.co.za

Date Uncoated Temp SSC Temp Cooling %
January 2021 71,5 76,4 10,3
February 2021 65,4 58,6 10,1
March 2021 72,2 64,9 9,6
April 2021 74,1 65,4 11,5
May 2021 73,4 63,6 12,9
June 2021 70,3 63,6 13,1
Table 3: Average monthly cooling for months 11 to 16 of the field trial 4

Date and time Uncoated Temp SSC Temp Cooling %
23January 22h55 121,0 94,7 21,8%
28 February 02h15 100,2 80,1 20,1
03 March 04h00 102,9 78,8 23,5
23 April 12h05 70,4 53,9 23,4
15 May 18h42 110,2 83,8 24,0
22 June 08h25 96,5 74,2 23,1
Table 4: Peak cooling for months 11 to 16 of the field trial4

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