Electricity + Control August 2015

STANDBY + BACK-UP TRANSFORMERS + SUBSTATIONS

ROUND UP

KougaWind Farm project – challenges

The ACTOM group’s medium voltage switchgear business unit, AC- TOMMV Switchgear, has frequently demonstrated its adaptability and technical capability of developing and producing cutting-edge equipment to best suit new applications as they arise. Its develop- ment of a medium voltage compact substation for use in wind farm power generation is no exception. Within a relatively short period it successfully developed and produced 36 kV compact substations – also known as pad-mounted transformer kiosks (PTKs) – for use at the Kouga Wind Farm at Oyster Bay in the Eastern Cape. The 80 MW Kouga Wind Farm, comprising 32 wind turbine generators (WTGs), was completed late last year and is now op- erational. It was one of the major renewable energy projects in the ‘Window 1’ first phase of SouthAfrica’s national renewable energy programme launched two years ago. ACTOM Power Systems, the group’s substation project manage- ment business unit, was awarded the R150 M electrical balance of plant contract for Kouga, comprising building a 33 kV/132 kV substation to link the wind farm to the Eskom power grid, provid- ing and installing the 660 V/33 kV PTKs at the bases of each of theWTGs and installing the collector network linking them to the main substation. ACTOM MV Switchgear was subcontracted to develop and pro- duce the PTKs, whileACTOMPowerTransformers was assigned the task of designing andmanufacturing the transformers for the PTKs. “The project was a new challenge for all three of us,” commented John McClure, ACTOM Power Systems general manager. “Being our first balance of plant contract for a wind farm, for our busi- ness unit it chiefly involved getting to grips with the complex grid compliance requirements, in addition to designing the cabling clusters in the collector network.”

The project posed unusual technical challenges for bothACTOM MV Switchgear and ACTOM Power Transformers, which had to develop substantially different forms of equipment in their respec- tive fields than they had previously been called upon to devise for new applications. Furthermore, they had to achieve their respec- tive goals within tight time constraints. Greg Whyte, ACTOM MV Switchgear’s design and development manager, explained: “With renewable energy, particularly wind farms, the transformer power and voltage ratings exceed the scope of traditional miniature substations, where the maximum power rating is 1 000 kVA and the rated voltage is up to 24 kV. So for the Kouga project we were clearly venturing into unchartered territory, where the required rated power for the PTKs was 2 800 kVA and the rated voltage 36 kV.” Enquiries: John McClure, ACTOM Power Systems.Tel. 011 430 8700 or email john.mcclure@actom.co.za

A schematic drawing of the pad-mounted transformer kiosk (PTK) developed by ACTOM MV Switchgear for the Kouga Wind Farm’s wind turbine generators.

Integration of wind farms in southern Brazil

Alstom has been awarded a turnkey contract worth approximately €100 million from Eletrosul Centrais Electricas S/A (Eletrosul) to integrate wind farms located at Rio Grande do Sul State, all situated at the southern- most tip of Brazil, into the country’s transmission grid. This project is scheduled for commercial operation in March 2018.To complete this project, Alstomwill lead a consortium to provide a turnkey solution, including the supply of two new substations and the extension of six existing substations, which will connect the power from the wind farms substations.This project, known as Lots A1 &A4 from the Brazilian Electricity RegulatoryAgency (ANEEL) auction, opens the door to further integration of renewable energies, empowering the country to better

forecast its wind energy capacity for the next six years, playing a key role in strengthening Brazil’s transmission system. Alstomwill supply its products, software and automation technologies with equipment produced locally at Canoas and Itajuba sites, in Brazil. “The southern region of Brazil has huge wind energy potential and will now be able to fully optimise this alternative energy, ultimately creating diversity in the overall energy mix for over 30 million people. This contract reinforces Alstom’s leadership in

supplying customer-centered solutions and an expert, local engi- neering team on the ground to bring innovative technologies to optimize grid performance”, says Sérgio Gomes, Vice President of AlstomGrid in LatinAmerica. Alstom has been present in Brazil for 60 years and has completed over 30 transmission turnkey projects in the country in the 230 kV and 500 kV market. Enquiries: Email virginie.hourdin-bremond@chq.alstom.com

Electricity+Control August ‘15

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