CONCO has undertaken a R47-m substation upgrade for the City of Tshwane. The requirement came about when the City of Tshwane prioritised the Pretoria North and Akasia areas as one of their zones of choice for development, thereby necessitating the need to upgrade the Wolmer 132/11kV Substation.

“The objective of this project,” says Pieter Steyn, CONCO Principal Project Engineer, “was to establish new infrastructure for a bulk electrical supply point next to the existing Wolmer 132/11kV Substation where electricity is transformed from 132kV to a distribution voltage of 11kV. This infrastructure comprises new equipment that replaces not only the existing equipment on 132kV and 11kV voltages, but also increases the firm capacity from 35MVA to 120MVA. The substation is designed to create more flexibility from an operational perspective and to ensure safe and reliable power in the supply area.

“The scope of the project also included the transfer of the 11kV load from the existing 132/11kV substation to the new 132/11kV substation, as well as the complete decommissioning of the two existing 35MVA transformers, including the transporting, relocating and commissioning of these transformers at another existing City of Tshwane 132/11kV Substation (Gomsand).

“The City of Tshwane has standardised on their primary substations, inter alia, with 120MVA firm capacity, ARBC transformer configuration and a 132kV double busbar system.  In order to comply with these requirements we had to optimise our design for the 132kV outdoor equipment because of space limitations on site.  As a result we installed Pantograth-type 132kV disconnectors instead of the conventional type and made temporary alterations on the existing 132kV connection to make space available for the installation of some of the new 132kV outdoor equipment.  This all had to be done without any power failures to the consumers.

“The project’s greatest benefit will be a more reliable supply of electricity to existing consumers and with the increased capacity, opportunities will be created for potential developers to enhance development in the City of Tshwane’s zones of choice,” says Steyn.

For more information email pieter.steyn@conco.co.za