Quality checking at Zest WEG
A locally manufactured main power transformer was recently delivered to a wind farm project near Swellendam in the Western Cape.
The local manufacture of the transformers gives project developers the opportunity to increase the local content of renewable power projects, in line with the Department of Trade, Industry and Competition’s local content requirements. In addition, manufacturer Zest WEG asserts that its broad-based black economic empowerment level 1 status allows renewable energy developers and contractors to align projects with South Africa’s transformation goal.
The transformer was built at the company’s Heidelberg facility in Gauteng, in consultation with parent-company WEG group. The company explains that comprehensive testing was conducted at its laboratory and included lightning impulse withstand tests and temperature-rise tests, especially relevant to simulate the potentially high temperatures where transformers are located.
The 45 MVA transformer will receive 33 kV from the wind turbines and step this up to 132 kV for the main power grid.
The unit measures 5.7 m in height and 7 m in length, with a total assembled weight of 70 t. The transformer could not be transported in one piece but was delivered and assembled on site, where further testing and cold commissioning was undertaken.