Mark Turvey, Territory Sales Manager
The Baltic 2 wind farm, formerly known as Kriegers Flak, is the second German offshore wind farm to be built in the Baltic Sea. It will ultimately incorporate 80 wind turbines with a total generating capacity of 288 MW. Baltic 2 is, at the time of writing still under construction but when it is complete, there will be around 85 km of 33 kV cables linking the individual turbines to a transformer platform where the voltage will be stepped up to 150 kV for transmission to an onshore substation at Bentwisch in the Rostock district of Germany.
To prepare themselves for working on submarine cables associated with the Baltic 2 project, a team of six jointer technicians from Balfour Beatty’s cabling division recently came to Megger’s UK site in Dover for training on offshore HV cable testing. Their specific aim was to gain initial experience of the test equipment that they would be using on the project.
Most of the cable testing for the Baltic 2 project will be carried out offshore; the jointers and the test equipment will be taken by crew on a boat to the turbine pillars and other test locations where access to the installed submarine cable is possible.
The Balfour Beatty team had requested intensive training on the use of the test equipment, and during their time in Dover they were taken from basic understanding to full competence with the equipment, and were also given an insight into European and UK cable test standards. The training included methods and practical work using high-voltage VLF (very low frequency) test equipment, high-performance TDRs (time-domain reflectometers), sheath testers, and DC insulation resistance test sets.
All of the instruments used feature on-board storage of results and the ability to download and save data permanently on computer. This is an important benefit, as it allows the contractors to provide their clients with a complete and permanent record of the work carried out. The clients will therefore have reliable reference data available for the lifetime of the cable system. Should any damage or failure occur, this will help with the speedy location of the problem. The TDR “fingerprint” results for each cable will be particularly useful in this respect.
Their training completed, the Balfour Beatty jointers were well equipped to perform their crucial role in the Baltic 2 project, and were eager to get to grips with its challenges.