Component 143: wind turbine

Specifications

Line connections
1	Power outlet

General User Input Values Results Displays Example

General

Component 143 represents a wind turbine. Based on the power curve provided by the manufacturer of the wind turbine, the generated electrical output is determined depending on the mean wind speed at hub height.

The relation between the power output P of a wind turbine, the undisturbed wind speed v₁ at hub height, and the power coefficient c_P is as follows:

Here applies: R – rotor radius, ρ – air density.

The power coefficient c_P is a measure of the aerodynamic efficiency of the wind turbine. The higher the value of c_P the higher the portion of the wind kinetic energy converted to the power output. The typical values of c_P can reach for modern wind turbine airfoil profiles up to 0.5 at optimal conditions (no blade pitching).

Depending on whether the wind turbine is in the planning stage or already in operation and equipped with measurements, the wind speed at hub height can be used either from the result of the calculation of the values from Component 142 (Wind data) or as a direct specification value in Component 143. Various algorithms are used in the case of a calculation of the wind speed from Component 142 to the actual hub height (cf. the specification of Component 142).

As the power characteristic of the manufacturer refers to the wind speed normalized according to IEC 61400-12-1, it is necessary to know the current air temperature and the air pressure to convert the current wind speed to the wind speed at the ISO reference density of 1.225 kg/m³. The values for the current air temperature and the air pressure are the same for all wind turbines of the wind farm and are therefore specified in one Component 142.

Also, when the individual wind turbines of a wind farm are located too close to each other, a wake flow generated by a wind turbine may influence another wind turbine, depending on the wind direction. Also the orology of the location (the surface irregularities of the area) has an influence on the spatial wind distribution. For instance, the wind turbines of a wind farm that are installed at different ground levels may be exposed to different wind speeds. For such effects, a power correction factor FW is provided in Component 143, which depends on two parameters in a specification value matrix, the undisturbed wind speed and the wind direction. FW=1 means no correction, i.e. the wind turbine converts the undisturbed wind speed at hub height into the electrical output precisely according to the specified power characteristic. With values FW<1 e.g. the wake flow effects due to other wind turbines can be represented. Values FW>1 are conceivable as well if e.g. the airflow is accelerated by a rise of ground.

Specification of voltage, frequency and type of current in the component:

It is possible to specify the voltage (VOLT), frequency (FREQ) and type of current (NPHAS) as the default value in the component.

The flags FVOLT and FFREQ are used to set whether the specification is to be made by the new specification values VOLT and FREQ respectively (0) or externally as a measured values on the electrical line (-1).

Warning!: A warning will be output if the minimum hub height is fallen below.

Default value database

Data from various manufacturers have been stored in the default value database for this component.

User Input Values

TYPENAME	Wind turbine type name
FFU	Turbine switched Like in Parent Profile (Sub profile option only) Expression =0: OFF =1: ON
IWDATA	Index for comp.142, to use wind parameters
FIDENT	Calculation mode Like in Parent Profile (Sub profile option only) Expression =0: Simulation - wind speed given, output power computed ,using power curve =1: Identification - wind speed and output power given, power coefficient computed
ROTDIAM	Rotor diameter
HH	Hub height
HHMIN	Minimum hub height
Z0	Roughness length
FVWHH	Handling of the wind speed at hub height Like in Parent Profile (Sub profile option only) Expression =0: use directly the value of VWHH =1: recompute the value of VWIND from comp. 142 to the hub height using logarithmic vertical velocity profile ( Algorithm 1 of comp. 142) =2: recompute the value of VWIND from comp. 142 to the hub height using logarithmic vertical velocity profile and Monin-Obukhov length acc. to TA Luft, VDI 3783-8 Bl. 1 and VDI 3783 Bl. 8 ( Algorithm 2 of comp. 142)
VWHH	Wind speed at hub height
FFW	Use power correction factor FW Like in Parent Profile (Sub profile option only) Expression =0: OFF =1: ON
FVOLT	Flag for the method for specification of voltage Like in Parent Profile (Sub profile option only) Expression =0: Defined by specification value VOLT =-1: Voltage given externally on electrical outlet
VOLT	Voltage (on electric lines)
FFREQ	Flag for the method for specification of frequency Like in Parent Profile (Sub profile option only) Expression =0: Use specification value FREQ =-1: Frequency given externally on electrical outlet
FREQ	Generator frequency
NPHAS	Type of current Like in Parent Profile (Sub profile option only) Expression =0: Direct current =1: One-phase alternating current =3: Three-phase alternating current

Result Values

AS	Swept area
RVWHH	Computed wind speed at hub height without normalization acc. to IEC-61400-12-1
RVWHHIEC	Computed wind speed at hub height normalized acc. to IEC 61400-12-1
CP	Overall power coefficient

Characteristic line

Char.line 1: Power produced Q1 = f (VWHHIEC) (Wind speed at hub height normalized acc. to IEC)

     X-Axis           1         VWHHIEC            1. Point
                         2         VWHHIEC            2. Point
                        .
                       N         VWHHIEC             last Point

     Y-Axis          1          Q1                    1. Point
                         2          Q1                    2. Point
                       .
                        N         Q1                    last Point

Input matrix

MXFW : Power correction factor FW depending on the wind speed at hub height normalized acc. to IEC 61400-12-1 and wind direction

Component displays

Display option 1

Example

Click here >> Component 143 Demo << to load an example.

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