Wind Turbine Slip Rings
The hub slip ring in large wind turbines has proved to be a difficult application for a lot of slip ring manufacturers.
There are 2 types of hub slip rings for large wind turbines; one used for powering the electric pitch motors and the other for controlling the hydraulic pitch system. They are both used for the same reason, powering/controlling the pitch of the blades to control the speed of the gearbox/generator. For the most part each presents the same challenges in designing a slip ring. However, the slip rings for controlling the hydraulic systems are much smaller since there is no need for power circuits.
The main challenge with these slip rings is the environment. Depending on the type of turbine and location the environmental conditions can be very wide spread. The design of the slip ring must take into account rain, salt air, oil from other components and a lot of vibrations. The one condition that nearly all wind turbine slip rings must handle is cold air. Depending on the style of ring a heater may be require to withstand these below zero conditions.
Another challenge is the fact there are so many different wind turbine designs. It’s hard to relate data from a slip ring in one manufacture to another because of the difference in the overall turbine design. The pitch system determines the need of circuits within the slip ring which intern determines the overall size. The larger the slip ring the more rugged it needs to be to handle its own weight. Other differences between turbines range from vibrations, leaking gear box oil and size limitations.
UEA has a long history of supplying to very rugged applications such as rough terrain cranes and boom trucks. These applications deal with the weather of all four seasons, dirt, oil, road salt, and vibrations much the same as a wind turbine. These challenging conditions are why UEA has been a good fit as a wind turbine slip ring supplier.