In South Africa, over the past 18 months, Marthinusen & Coutts and ACTOM Turbo Machines have performed a comprehensive range of repairs and refurbishments to boost the generation capacity of privately owned coal fired plant Kelvin Power Station.
According to a company statement, the repair work to the aging station, which uses old technology – making sourcing replacement parts difficult – has now contributed towards boosting the station’s generating capacity from 120MW to 300MW.
The repair work carried out consisted of Marthinusen & Coutts covering the repair of one of the station’s 60MW synchronous alternators, while ACTOM Turbo Machines performed general overhauls on five 60MW turbine generator sets.
Extent of the damage
In December last year, Kelvin Power awarded a 30-month contract to ACTOM Turbo Machines to provide ongoing maintenance service for the station’s turbine generator sets.
The stator of the 60MW synchronous alternator was damaged when the unit suffered a breakdown in March last year. Tests conducted on site established that three stator bars had been damaged, whereupon it was decided to replace a total of six stator bars.
Rob Melaia, engineering and technical executive at Marthinusen & Coutts explained: “Due to the fact that the winding is of a special single-layer type in which the strands in each stator bar are individually brazed onto the associated strands of the bar next to it, the replacement of the stator bars was a prolonged process lasting several months.”
Ownership of Kelvin
The coal-fired Kelvin Power Station, currently owned by Nedbank Group Ltd and Investec Ltd, is supplying Johannesburg’s City Power, through a 20-year power purchase agreement signed in 2001, with approximately 7% of the city’s energy needs.
However, in 2013 the co-owners made an undertaking to the Competition Commission that the power station would be owned and operated by an entity with the necessary expertise.