On Wednesday,14 September 2016 local media had post unit 5 synchronisation discussion with Medupi Project Director Phillip Dukashe.
Dukashe,who obtained Bachelor of Science Degree in Engineering at University of Cape Town has been with Eskom for 22 years. He started at Majuba Power Station during its construction in 1994 and there he got into Contract Supervision & Contract Management before going into the Production side in 1998, where he was eventually appointed as Maintenance Manager. He later joined Tutuka Power Station as Engineering Manager and in 2001 he was appointed Power Station Manager.
In 2005 he joined Koeberg Power Station as General Manager in charge of Koeberg and Pebble Bed Modular Reactor(PBMR) before joining Group Capital in 2010, where he was responsible for capital projects within Eskom. His first job was involved in (RTS) Return To Service, bringing older stations that were decommissioned back to operational.
He was also responsible for Majuba Silo recovery, refurbishments projects at coal powered stations and Duvha recovery. He handled major projects and whenever there were issues at those power stations the Group Capital Team would get involved.
Dukashe, who started at Medupi in February 2016 says he did Project Management in his studies this helps him execute the responsibilities he is tasked with at Medupi.
“I started my work in a similar position to this and this helps me understand power station technology better,having worked as manager in Engineering, Maintenance and Power Station. I also would grab information from my predecessor, Roman Crookes whenever we had executive meetings.”
Dukashe gave local media a well detailed background on Medupi Unit 5 synchronisation that happened on Thursday, 08 September 2016 at 15h32.”Unit 5 was synchronised to the grid and that is a very exciting time for us. When you synchronise a unit it means all the construction activities including commissioning come together, electrical systems, mechanical, instrumentation,coal, water,boiler, turbine and generator among others. On Thursday the unit was loaded and it is still been commissioned. It will be synchronised before taken off for cleaning and more commissioning. So far 380 megawatts was achieved from Thursday 08 September to Wednesday 14 September.
On Tuesday, 13 September 2016 the unit ran through the night for the first time”; said Dukashe, who emphasises this milestone was as a result of team effort and not just Eskom’s hard work.
The next step is to take the unit commercial and all they are left with is to do a lot tests between now and then as they want the unit to operate on auto without requiring manual intervention. Eskom will do optimisation along the tests to reach full load before going commercial in March 2018.
Dukashe says this synchronisation happened before the targeted date and with this they are certain to achieve the same when going commercial.
What is the difference between commissioning and synchronisation?
Dukashe says; “When you build a power station, you will have a number of contractors, boilers, turbines, controlling instrumentation, civil and electrical among things that drive a power station to operate.
All have to work together, for example you get coal fed into a boiler, a conveying system that has to take coal from where it’s stored to the boiler, and the boiler which is a major structure that separates units is 130 metres tall and has a technology on its own. What it does is heats up water to temperature in excess of 500 decree celsius, where water turns into steam that is sent into the turbine. The turbine is then spun at 3000 revolutions per minute,or 50 revolutions per second. The pressure to pump the steam is too strong and the turbine is connected to a generator which spins in a magnet and through that electricity is produced.
Before you commission,your control instrumentation system(CNI) has to talk through what is expected of it. When a boiler requires coal you need to press a button for the coal to come through a conveyor system into a boiler.
Also once steam is produced you need to be able to send it to the turbine,all these have to be automated. Part of commissioning is connecting all this to ensure it works. You ensure when you press a button it does as expected. If you don’t want coal anymore you can trip a conveyor belt,and it should trip,if there is any mulfucntion ensure it fails safely. Rather trip it than create an explosion.
Synchronisation is when all energy that’s created at power station is taken through transmission line and send electricity to national grid. A very crude example is when a car is build,all mechanical and manufactured items, should work together and when you switch it on it,it has to go”, said Dukashe
When completed, Medupi Power Station is to have six boilers each powering an 800
Megawatts turbine, producing 4800 Megawatts ofpower. It is expected to become the largest
dry-cooled coal-fired power station in the world, with a megawatt feeding about 650 homes, the amount of power produced on unit 5 by last Wednesday could feed 20 000 homes and this was well before it reached half load, at about 380 megawatts.
Medupi Project currently has approximately 14 500 employees and Dukashe says not more than 800 employees, unless when there are outages will be in a running power plant once the station is operational.