6.3.2 Wind measurement and nacelle alignment
After completing the start lead-up, status 0:2 - Turbine operational is displayed.
If the control system is in automatic mode, the average wind speed is above 1.8 m/s and the wind
direction deviation is sufficient for yawing, the WEC starts alignment with the prevailing wind direc‐
tion. 60 seconds after completing the start lead-up the WEC goes into idle mode. The rotor blades
are slowly pitched in as a check is performed on the emergency pitching capacitors.
If the WEC is equipped with load control sensors, the rotor blades stop at an angle of 70° and ad‐
just the load measurement points, which might take several minutes. During this time, status 0:5
- Calibration of load control is displayed.
If the average wind speed during the wind measurement and alignment phase of 150 seconds is
above the current start wind speed (about 2.0 m/s), the start-up procedure is initiated (status 0:1).
Otherwise, the wind energy converter remains in idle mode (status 2:1 - Lack of wind :
Wind speed too low).
Power consumption
As the wind energy converter is not supplying any active power at that moment, the electrical ener‐
gy consumed by the WEC is taken from the grid.
6.3.3
Generator excitation
Once the rotor reaches a certain rotational speed that depends on the WEC type (for instance, ap‐
prox. 3 rpm with the E-82), generator excitation is initiated. The electricity required for this purpose
is temporarily taken from the grid. Once the generator reaches a sufficient speed the WEC sup‐
plies itself with power. The electricity for self-excitation is then taken from the DC link; the energy
taken from the grid is reduced to zero.
6.3.4 Power feed
As soon as the DC link voltage is sufficient and the excitation controller is no longer connected to
the grid, power feed is initiated. After the rotational speed has increased due to sufficient wind and
with a power setpoint P
set
> 0, the line contactors on the low-voltage side are closed and the WEC
starts feeding power into the grid.
The number of activated inverters is gradually increased, depending on the number necessary for
the power generated by the generator. Power control regulates the excitation current so that power
is fed according to the required power curve.
The power increase gradient (dP/dt) after a grid fault or a regular start-up can be defined within a
certain range in the control system. For more detailed information, see the
Grid Performance
data
sheet for the particular ENERCON WEC type.
Control system
D0376616-2 / DA 14 of 21
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