In a company statement prior to the energisation of the Helios substation, the permanent grid connection; South Africa’s Loeriesfontein Wind Farm in the Northern Cape Province has been making use of a mobile transformer to enable early connection to the grid for commissioning of the turbines.
Kevin Foster, the Country construction manager for Mainstream Renewable Power, explained that the mobile transformer is set for two major purposes.
First, it will provide a temporary supply to the project, to mitigate the risk that Eskom transmission is delayed with energisation of Helios.
It will also allow for early grid code testing of Loeriesfontein Wind Farm, which will eventually increase the chances of early operations, ahead of the Commercial Operations Date.
Foster said that they have worked very closely with Eskom to supply and operate the mobile transformer, which is typically used by the Utility to temporarily connect to substations during maintenance or unplanned shutdowns so as to allow continued use of the substations. These Mobile transformers are not normally used to connect Wind Farms to the distribution system.
The company said that the Helios substation energisation is on track for 15 August 2017. At this point the Loeriesfontein Wind Farm will be able to kick off with final grid code testing prior to the commercial operations.
Every wind turbine is connected to a step-up transformer which is meant to boost the generating output of the wind turbine generator from 690 V to 33KV. These transformers are located at the base of the wind turbine.
The cables throughout the wind farm bring the 33kV current from the step-up transformers to convene at the substation where the main transformer is situated.
At the substation, the main transformer increases the voltage further from 33kV up to 132kV, the voltage required to transfer the power to Eskom.
The Loeriesfontein Wind Farm Wind Farm forms part of the South African government’s Round 3 Renewable Energy Independent Power Producer Procurement Programme and is expected to begin operations by December 2017.