Given the challenges of building a wind farm offshore, and the ongoing difficulties posed by maintaining turbines in the tough marine environments, PES looks at how medium voltage equipment is being adapted and developed to meet increasingly high requirements.
Growth of installed wind power capacity by year (figure1)
The expected expansion of wind power, along with the development of bigger turbines, has allowed us to build wind power farms not only on land, but now also out at sea. In such cases, requirements of medium voltage (MV) equipment are even higher. As access is more limited in water, turbine reliability and its safety features become more vital to operation. Guaranteeing maximum and continuous supply during operation and personnel safety when inside an offshore turbine are serious considerations during construction.
As a consequence of this new reality, MV switchgears have undergone developmental changes. A switchgear now must accomplish higher insulating levels and operate under much harder salinity corrosion, humidity, and temperature conditions than those established by international standards. The following describes the main developments with MV switchgear, as well as the particular type tests performed, which reproduce sea transportation conditions and the environmental conditions of offshore wind turbines. This was done by means of accelerated aging tests in salinity chambers, which has allowed certification of MV switchgears for use in offshore wind turbines, as well as on wind farms with extreme climate conditions.
CGM.3-V unit installed inside wind turbine tower (figure2)
Environmental impacts
Driving mechanisms are the devices responsible for opening and closing a turbine’s three-position switch-disconnector and circuit breaker. It would only be opened when a fault occurs within the wind farm’s MV grid, or during maintenance or operation checks. Of course, the reliability of this device is vital from a safety and performance point of view, especially if you’re the wind farm operator.
In geographical places like the US and Canada, temperatures at a wind farm can be as low as -22° F (-30° C) during operation and -40° F (-40° C) while equipment is being stored. In these conditions, operation of the driving mechanisms must be
