Ice detection method and system for wind turbine blades

摘要

The invention provides a method and system of detecting ice or other foreign matter on a wind turbine blade or damage to a wind turbine blade. The method in one aspect comprises: measuring twisting torque on the blade about its longitudinal axis to provide a detected torque signal; comparing a value based on the detected torque signal with a comparison value, the comparison value derived from one or more measured parameters having a predetermined relationship with the twisting torque about the longitudinal axis of the blade when the blade is operating under normal operating conditions; and determining that ice or other foreign matter is on the blade or that the blade is damaged if the value based on the detected torque signal differs from the comparison value by more than a predetermined amount. Wind turbine blades are designed such that any change in the shape of the blade reduces twisting torque on the blades significantly. Torque about the longitudinal axis of the blade can therefore be used as a sensitive indicator of ice on the blade and of damage to the blade.

主权项

1. A method of detecting ice or other foreign matter on a windturbine blade or damage to a wind turbine blade, the wind turbine blade mounted to a hub and having a longitudinal axis extending away from the hub, comprising:
measuring twisting torque on the blade about its longitudinal axis to provide a detected torque signal; comparing the detected torque signal with a comparison value, the comparison value derived from one or more measured parameters having a predetermined relationship with the twisting torque about the longitudinal axis of the blade when the blade is operating under normal operating conditions, wherein the one or more measured parameters comprise bending moments on the blade; and determining that ice or other foreign matter is on the blade or that the blade is damaged if the detected torque signal differs from the comparison value by more than a predetermined amount.