the evolution & development of medium voltage switchgear designed for special wind farm applications
A worldwide increase in energy demands and supportive renewable energy policies have been key factors in the growth of renewables over the last decade. Between 1998 and 2007, wind power's installed capacity has grown by 30.4 per cent each year, and international organisations are expecting similar figures until the year 2030.
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.
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