Powertech Transformers, a subsidiary of Powertech and the JSE listed Altron Group recently completed manufacture of two 315MVA 400kV power transformers for City of Tshwane which are the largest for this municipality.  These transformers are for the new Wildebees Infeed-Station which is situated on the eastern side of the City. This is the first 400kV substation for City of Tshwane. The largest transformers that the company has manufactured for City of Tshwane previously were 300MVA 275kV transformers. The above 315MVA 400kV transformers were designed, reviewed (by PTT’s Technology Department), manufactured and successfully tested in PTT’s test department in their Pretoria West factory with only local engineers involved.

Some details of the components and material are as follows:
• At least 60% of local copper was used on this design which was sourced from PTT’s sister company Aberdare Cables.
• Locally manufactured Zenox/Varistors.
• Insulation material from Powertech Insulation (another sister company).
• The units without oil weigh 186 tons each and a total mass of 314 tons once oil-filled.  The length measure 17 meters, width 7.4 meters and height of 9.45 meters.
These transformers will be transported by Rotran’s (part of ESKOM) specialised vehicle which is able to transport large transformers.  Rotran operate a large flotilla of vehicles unique to South Africa which deal with specialised loads.  This specialised equipment is supplied by Nicolas Industries, who have built all the new equipment purchased by Rotran since 2005.

The above two 315MVA transformers are of strategic importance to the City of Tshwane as they are  part of the first phase of the new Wildebees 400/132kV Infeed-Station which is required to supply electricity to the Tshwane bulk electricity network because of the rising demand due to the increasing growth of the city.  Kungwini was also recently incorporated into the City of Tshwane’s municipal area which has resulted in a further increase in electricity demand that the City has to cater for.   The Wildebees Infeed-Station will form part of the major Infeed-Stations Kwagga, Njala and Rietvlei where electricity is supplied directly from Eskom.  A further interesting fact is that the Wildebees Infeed-Station is the first 400kV supply voltage that Eskom will distribute to City of Tshwane (CoT) where the existing voltages are 275kV and 132kV. 
  
This infrastructure spend is part of Tshwane’s development plan as mentioned by the mayor of Tshwane, Councillor Kgosientso Ramokgopa in his state of the city address recently. Bernard Meyer, CEO Powertech Transformers says “apart from Eskom there is only a small number of customers buying transformers at this voltage range in Africa.  PTT has been a supplier to City of Tshwane for many years supplying transformers to all their major substations within their municipal boundaries.  The on-time and high quality supply of the two units backed up by local after sales service will ensure total piece of mind to City of Tshwane”. PTT supplies a full range of transformers, from generator step-up to transmission and distribution transformers in their three factories. The range includes three-phase and single-phase units, auto-transformers, arc-furnace, locomotive and traction transformers, miniature sub-stations, NECRT’s as well as LNER’s and shunt reactors.