2012-10-01 - Polish ABB Transformer Service headquartered in Lodz has recently accomplished a first-ever offshore surge-arresters installation project on the biggest offshore windfarm in the world.
Walney Offshore Windfarm is located on Irish Sea and comprises above 100 turbines with rotor diameters between 107 and 120 meters. Each turbine delivers 3.6 MW of power and the energy is gathered by two offshore substations transforming it between 33 kV and 132 kV with the help of four 120 MVA power transformers originally manufactured by ABB Power Transformer Factory in Lodz.
ABB Transformer Service team approaching a Walney Offshore Windfarm substation in a transit boat. Photo courtesy of Miroslaw Owczarek, ABB in Poland.
Dong Energy was the leading company behind the Walney Offshore Windfarm project in both the construction and operational phase. It was already in the operational phase of the project, when ABB, having delivered the four 120 MVA transformers, was approached to propose a tailored engineering solution concerning an on-site substation upgrade. The customer’s intention was to increase the operational safety of the windfarm by introducing surge arresters at the transformers terminals.
At this stage Polish ABB Transformer Service was given a challenge which could not have been met without their engineers’ craftsmanship and the R&D support of the local ABB Transformer Factory in Lodz. It was the above virtues as well as legal and project management support from Danish ABB and perfect cooperation with the customer, which rendered possible the ultimate success of the operation.
ABB engineers installing modified cable boxes with surge arresters: the bottom section is being lowered onto the cable socket. Final stage of surge arresters installation on one of four 120 MVA ABB transformers. Both photos courtesy of Miroslaw Owczarek, ABB in Poland.
The complexity of the project could be elaborated upon from different perspectives. One of the major concerns was the threat of serious seawater contamination which could result from reckless conduct or human error. Nevertheless, a potential serious risk of ecological catastrophe was significantly mitigated owing to the servicemen experience, diligence and very strict ABB OHS rules followed throughout the whole project. As one can imagine, an offshore substation platform is a limited-access location requiring specific certification such as confined-space, high-voltage, climbing, sea-survival or boat-transfer training among others. Additionally, there is a very tight time slot for windfarm shutdown due to evident cost of energy production outage. To make things more difficult, even during the scheduled work time, Polish engineers could be asked to leave the platform at short notice due to deteriorating weather conditions.
All the above obstacles, however, would have been of little significance without the on-site installation solution invented by Polish Transformer Service engineers. Namely, from the technical point of view, twelve 300 kg surge arresters along with modified cable boxes had to be hoisted and carried carefully through a maze of passageways up to the final location, where old 450 kg cable boxes had to be dismantled, safely manipulated and lowered to the floor level.
ABB engineers leaving the quay prior to transition towards WOW substation. Photo courtesy of Miroslaw Owczarek, ABB in Poland.
After three months of hard work, the project was successfully completed in July proving outstanding competences of Polish ABB engineers in the field of offshore transformer service. No doubt it also opened the door to future orders in this very promising renewable energy sector, where customers may significantly benefit from the professionalism and experience of Polish ABB.