such as reliability, corrosion and maintainability.
However, most of these technologies are based on traditional
onshore turbines that have been modified to the offshore conditions.
In the mechanical transmission system of the conventional
turbine, variable ratio gearbox is used to provide energy for the
shaft connected with a generator. Because the large scale gearbox
is more apt to fail [2], regular repairs are required, which can considerably
increase operation and maintenance costs. Although it
also happens to onshore turbines, such maintenance in the offshore
environment is more complex and expensive. Another point
of concern in the existing transmission system is the use of vast
amounts of copper. Nevertheless, copper price is very unstable