Wind turbines disconnected from the grid: proactive measures to preserve wind turbine components

It is usually accepted that electrical components and water generally don’t play nice together. When a wind turbine is stopped due to local grid maintenance or disconnected from the network for periods of time, measures may be needed to be taken to ensure moisture levels within the wind turbine do not develop to a level that puts the wind turbine electrical systems at risk. Certain levels of moisture within the wind turbine can cause problems, all of which are avoidable if certain proactive measures are taken. The amount of time a wind turbine can remain offline / disconnected from the grid before the moisture levels become a risk to the wind turbine differs from between manufactures. The time of year and external conditions also plays a significant role in determining when / if additional measures should be considered in terms of grid maintenance.

In most cases, an external generator or dehumidifiers may be required. If generators are the chosen method, then there are various configurations at which generators can be deployed. Greensolver in collaboration with our partners generally deploy generators at each wind turbine, however site configuration and the anticipated length of time offline will determine the best method for addressing possible moisture. Moisture mitigation measure need to be considered in cases of delayed connection to the grid for a new wind farm, as well as for grid outage and disconnection from the wind farm network, on an operational wind farm.

• Moisture absorbing bags can also be used. They are placed in controller cabinets in order to avoid moisture and corrosion on electrical parts. The openings of a controller cabinets must be sealed.
• Measures should be employed pertaining the position of the wind turbine in relation to the wind direction, this is to prevent blades and other component damage.  Different measures are needed for different manufactures / models. In some cases the use of the generator will allow the wind turbine systems to continue to manage the positioning of the wind turbine safely.

When the wind turbine can be reconnected to the grid, inspections must be performed on various components. The recommendations made above should always be carried out by suitably qualified and experienced persons.

Read more about various electrical protection strategies for onshore wind in this article. Do not hesitate to get in touch with our experts to discuss your onshore wind needs.