Overspeed protection system and method

Abstract

An overspeed protection system for a wind turbine having a hub and at least one rotor blade mounted to the hub includes a rotation sensor adapted for measuring a rotor speed of said wind turbine; a comparator connected to the rotation sensor and adapted for comparing the measured rotor speed with a predetermined threshold value of the rotor speed wherein the comparator outputs a signal indicative of the comparison; and an auxiliary pitch drive controller connected to the comparator and adapted to receive the signal indicative of the comparison, the auxiliary pitch drive controller being further adapted for controlling a pitch drive unit of the wind turbine independently of a main turbine controller and, if the threshold value is exceeded, to adjust a pitch angle of the rotor blade of the wind turbine so that aerodynamic braking of the wind turbine is effected.

Description

BACKGROUND OF THE INVENTION[0001]The subject matter described herein relates generally to methods and systems for controlling the operation of a wind turbine, and more particularly, to methods and systems for preventing an overspeed condition of a wind turbine.[0002]Generally, a wind turbine includes a turbine that has a rotor that includes a rotatable hub assembly having multiple blades. The blades transform wind energy into a mechanical rotational torque that drives one or more generators via the rotor. The generators are sometimes, but not always, rotationally coupled to the rotor through a gearbox. The gearbox steps up the inherently low rotational speed of the rotor for the generator to efficiently convert the rotational mechanical energy to electrical energy, which is fed into a utility grid via at least one electrical connection. Gearless direct drive wind turbines also exist. The rotor, generator, gearbox and other components are typically mounted within a housing, or nacell...

AI Technical Summary

Benefits of technology

[0009]According to a further embodiment, a wind turbine includes a rotatable hub and at least one rotor blade mounted to the hub, wherein a pitch angle of the rotor blade can be adjusted by a pitch drive system; a speed sensor adapted for measuring a rotational speed of the wind turbine; a detection unit connected to the speed sensor and adapted for detecting if the measured rotational speed exceeds a predetermined threshold value; and, an auxiliary pitch drive controller adapted to adjust a pitch angle of the rotor blade to effect aerodynamic braking of the wind turbine if the threshold value is exceeded, the auxiliary pitch drive contro

Problems solved by technology

Each electrical and/or mechanical component may have independent or different operating limitations, such as current, voltage, power, and/or temperature limits, than other components.

Moreover, known wind turbines typically are designed and/or assembled with predefined rated power limits.

Such operation may result in inefficient wind turbine operation, and a power generation capability of the w

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