Vary Parameters
0
User Label NL1 base NL1.1 NL1.2 NL1.3
Run Number 1 2 3 4
Shore to Grid
TRUE or FALSE OH line FALSE FALSE FALSE FALSE
TRUE or FALSE DC connection
Park to Shore
TRUE or FALSE OH Line
TRUE or FALSE DC Connection FALSE FALSE FALSE FALSE
Turbine to Cluster
TRUE or FALSE OH Line FALSE FALSE FALSE FALSE
TRUE or FALSE DC Connection FALSE FALSE FALSE FALSE
1=star, 2=chain, 3=circuit Design type 3 3 3 3
1=power, 2=load break, 3=isolating link Switch type 2 2 2 2
Figure 5.1-5: Details of the ’GridConParams’ worksheet. 5.2 Variables that remain constant from run to run
All the sheets examined in this section allow specification of values that remain constant for any particular invocation of the model, These values can be changed by the user, and will remain at the values specified for all calculations subsequently undertaken.
Cp-L curves.
The model can deal with turbines having complex modes of operation such that more than one Cp-lambda curve is necessary to fully describe their performance. Details of particular Cp-lambda curves are placed into worksheet ‘PowerCurves’ using a normalised format, and here it is only necessary to specify the reference number of the curves to be used. The reference numbers of each power curve should be inserted in the rows marked ‘Operation regime 1’, ‘Operation regime 2’ and ‘Operation regime 3’, with ‘Operation regime 1’ specifying the curve for use at the lowest wind speeds and ‘Operation regime 3’ that for the highest wind speeds. The rows marked ‘Cp_max’ and ‘Lambda at Cp_max’ should contain the maximum absolute co-efficient of performance in each operation regime and the tip speed ratio at which that performance is achieved.
Values in the next sub-section specify wind speeds at which the operating regime of the turbine changes and have the following significance.
Limiting speed: The wind speed beyond which further increases in wind speed do not produce increases in the electrical power produced. This is usually equal to the rated speed.
Rated speed: The wind speed at which the turbine produced its rated power output. Cut-in speed: The minimum wind speed at which the turbine operates.
Transition speed 1: The wind speed above which the turbine operates according the first Cp-lambda curve. This is usually equal to the cut in speed.
Transition speed 2: The wind speed at which turbine operation switches from the first Cp-lambda curve to the second. If only one Cp-lambda curve is used then this value should be set to the cut-out speed.
Transition speed 3: The wind speed at which turbine operation switches from the second Cp-lambda curve to the third. If only one Cp-lambda curve is used then this value my be ignored. If two Cp-lambda curves are used then this value should be set to the cut out speed.
Transition speed 4: This value should be set to the cut out speed of the turbine.
Physical dimensions
Height of nacelle: The vertical dimension of the nacelle.
Area of nacelle: The frontal area presented by the nacelle to the wind. Nacelle Cd: The drag co-efficient for the nacelle.
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Turbine Design Input Sheet
Unlike the master and the structural input sheets, which require inputs for each calculation, this sheet is used to define particular turbine types which are referred to in the ’turbine type’ parameter of the master sheet
NOTE: Cp-lambda curves are dealt with separately in sheet ’PowerCurves’ NOTE 2: Not all options work correctly - caution is advised
Reference Number 1 2 3 4 5 6 7 8
Description WTS-80 1.5MW KT 4-90 KT 4-100 KT KT KT KT to finish to finish
Units Basic Information
kW Rated power output 3000 1500 4000 4000 3000 3000 3000 3000
No of regimes 1 1 1 1 1 1 1 1
ECU Unit cost 1.70E+06 1.00E+06 1.90E+06 1.93E+06 1.50E+06 1.80E+06 2.50E+06 3.00E+06
m Blade diameter 80 64 90 100 80 80 80 80 Cp-L Curves Operation regime 1 6 8 6 6 7 7 7 7 Cp_max 0.494 0.487 0.494 0.494 0.423 0.423 0.423 0.423 Lambda at Cp_max 9.22 8.5 9.22 9.22 7.36 7.36 7.36 7.36 Operation regime 2 - - - - Cp_max - - - - Lambda at Cp_max - - - - Operation regime 3 - - - - Cp_max - - - - Lambda at Cp_max - - - -
Misc wind speeds m/s Limiting speed 14 18 16 16 16 16 16 16 m/s Rated speed 14 18 16 16 16 16 16 16 m/s Cut in speed 2.5 3 2.5 2.5 2.5 2.5 2.5 2.5 m/s Transition speed 1 2.5 3 2.5 2.5 2.5 2.5 2.5 2.5 m/s Transition speed 2 25 25 25 25 25 25 25 25 m/s Transition speed 3 - - - - m/s Transition speed 4 Physical dimensions m Height of nacelle 10 8 11.25 12.5 10 10 10 10 sq. m Area of nacelle 35 22.4 44.3 54.6 35 35 35 35 Nacelle Cd 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 kg Nacelle mass 130000 75000 141000 152000 130000 130000 130000 130000
Nacelle mass: The total mass of the nacelle and equipment, including the rotor. Structure blade area: The effective area presented by the blades to the wind. This values is used in computing the axial wind force on the blades.
Misc. Information.
Power control system: This parameter is essentially obsolete, but has been left in place as it may be re-activated in a future release of the model. It should be left set to ‘pitch’.
Drive type: This value contains the (assumed constant) efficiency of the turbine power transmission mechanism.
Generator type: This value contains the (assumed constant) efficiency of the turbine generator.
Safety factor: This parameter is obsolete and should be left set at ‘1’.
Scaling controls
If the turbine rated power scaling facility discussed in section 5 and volume 2 [5.2-1] is used, these values control which of the turbines features are scaled. Setting a value to ‘1’ means that a feature will be scaled with the rated power, while setting it to 0 means that the feature is not scaled.
Fatigue data set
This parameter specifies the reference number of the data set to be used for the effective load method of calculating the fatigue loads exerted by the turbine on the support structure.
5.2.2 PowerCurves
Details of the Cp-lambda curves used in the energy production calculations are contained within this sheet (figure 5.2-2) . The columns labelled L/LP contain values of the tip speed ratio normalised by the tip speed ratio at which the maximum co- efficient of performance is achieved; while the columns labelled Cp/CpM contain the corresponding co-efficients of performance normalised by the maximum co-efficient of performance. Data must be order from the lowest tip speed ratio to the highest. The final entry for each performance curve should specify a normalised tip speed ratio of 999 and a normalised co-efficient of performance of 0.
The data in the sheet may be modified by the user. Unfortunately, it is not possible to add extra performance curves to the sheet. Implementation of a new curve can only be accomplished by replacement of one of the existing data sets.
JOR3-CT95-0087 Opti-OWECS