Posters

Abstract

Yaw misalignments cause considerable revenue losses and unnecessary loads on wind turbines, leading to increased maintenance costs and reduced turbine lifetime. The key reason of this annual energy production loss is that the standard equipment on wind turbines today cannot detect the yaw misalignments. When mounted on the nacelle, the anemometer sits behind the rotor blades, which is affected by the turbulence induced by the rotor. To avoid this error, the iSpin sensor sits in front of the rotor and can measure the free wind that is actually hitting the wind turbine. When measuring directly at the spinner, iSpin sensor can very accurately measure if the wind turbine is correctly aligned with the wind (yaw misalignment detection). In addition, by adding the iSpin Yaw module, it can not only detect, but also correct the yaw misalignment of the turbine by entering a yaw offset in the turbine controller. The intended use for the iSpin Yaw is basically to connect to a specific turbine controller and overwrite the signals coming from the pre-installed anemometer. This gives opportunity for the iSpin Yaw to directly control how the wind turbine is corrected for Yaw Misalignment. The iSpin Yaw is connected to the pre-installed iSpin system in the hub by Wi-Fi and uses generated data from there to correct the measured Yaw Misalignment. The idea behind iSpin Yaw is to use the iSpin wind measurements, while the wind turbine is rotating faster than cut in speed, to feed the wind turbine controller (WTC) with more accurate wind direction signals for the WTC to align the wind turbine better in the wind. In order to do this, iSpin Yaw must emulate the same signal as the wind turbine would normally receive from the wind direction sensor. iSpin Yaw is designed to take two simultaneous wind direction inputs. These can be a mix of digital, analog, and serial communication inputs. If the wind direction sensor signals are valid and the turbine is in operation, yaw misalignment correction can take place. The yaw misalignment correction can be carried out in two ways: 1. Static yaw misalignment correction: When making a static yaw misalignment correction, the iSpin Yaw will receive the wind direction signals from the wind turbine's anemometer and adjust the signal by xxx.x° (fixed parameter) before sending the adjusted signal to the WTC. The static yaw misalignment offset will always be applied to the wind sensor signal regardless of the wind conditions. 2. Dynamic yaw misalignment correction: In order to do the dynamic yaw misalignment correction, wind speed measurements coming directly from the iSpin system are used. Instead of “adding” a fixed offset to the wind turbine's existing wind direction signal(s), the iSpin Yaw will apply different offsets depending on the wind speed detected (which iSpin detects with much higher accuracy than the nacelle anemometer).