EXTERNAL POWER REFERENCE SUPERVISION IN WIND TURBINES
Publication Date: 2015-Mar-10
The IP.com Prior Art Database
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EXTERNAL POWER REFERENCE SUPERVISION IN WIND TURBINES BACKGROUND
 A method is described of evaluating power reference signals from an external control system or a supervisory system in a wind turbine power plant.
Description of the Related Art
 External control systems (e.g., a Supervisory Control and Data Acquisition (SCADA) system) are typically connected to a wind turbine and used to transmit power reference signals that instruct the wind turbine to output a specific power desired by the utility grid. The output power of the wind turbine can be deliberately lowered by the power reference signals in order to protect the wind turbine or the power grid from damage. Currently, wind turbines may include an input ramp filter that either ignores or decreases the rate of change of power reference signals so that the output power required by the grid does not ramp up or down at a rate that could damage the wind turbine. Grid operators, however, continue to pressure wind turbine operators to change output power of the wind turbine at faster rates in response to the needs of the power grid. Very fast power changes may have the risk of imposing high level of structural stresses on the tower, the drive-train, and other load-caring components, and of imparting high fatigue loads.
BRIEF DESCRIPTION OF THE DRAWINGS
 Figure 1 is a schematic illustration of a wind power plant which includes a plurality of wind turbines according to one embodiment.
 Figure 2 is a flowchart illustrating an exemplary method for evaluating power reference signals from an external control system according to one embodiment.
 Figure 3 depicts an exemplary graph showing the extracted power reference signals according to one embodiment.
 Figure 4 depicts a graph illustrating a supervision metric based on the graph of Figure 3.
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ATTORNEY DOCKET NO.: VEST/0224 (061643)
 Figure 5 is a flowchart illustrating an exemplary method for evaluating power reference signals from an external control system according to another embodiment.
 To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one embodiment may be beneficially utilized on other embodiments without specific recitation.
 Embodiments of the concept generally relate to methods of evaluating power reference signals from an external control system or a supervisory system to determine if a power reference signal may potentially damage a wind turbine. In one exemplary embodiment, the wind turbine evaluates all incoming power reference signals against a metric that determines whether one or more power reference signals are harmful. The metric may represent a deviation of the rate of change of the power reference signal over a specified time period. If the rate of change of the power reference s...