Environmental Engineering Reference
In-Depth Information
and Fig.
14.20
a, this section presents the experimental power curves for the 6-
blade rotor wind turbine.
The study applies the optimum MPPT control strategy presented in Eqs. (
14.44
)
and (
14.45
), considering the generator losses—Eq. (
14.46
)- and with
K
a
= 8.8453 9 10
-6
. All the experiments maintain the pitch angle in Region 1 at
b = 0. Figure
14.26
a shows the power curve (P
g
vs. v
1
) for Regions 1, 2, and 3
(see also Fig.
14.10
) of three scenarios: using a 100, 90 and 80 % of the maximum
power coefficient C
pmax
. Figure
14.26
b shows the rotor speed X
r
of the wind
turbine at the operating wind speeds v
1
for the three cases.
The rated (nominal) power for the 6-blade wind turbine is P
g_rated
= 150 m-
Watts. For the 100 % C
pmax
case the rated power is achieved at a wind speed
v
1_rated
= 4.2 m/s with a rated rotor speed X
r_rated
= 324 rpm, the cut-in (wind
turbine connection) is at v
1
= 2 m/s and X
r
= 180 rpm, the cut-off (wind turbine
disconnection) is at v
1
= 5.0 m/s and X
r
= 324 rpm, Region 1 is between 2 m/
s B v
1
\ 3.6 m/s,
Region
2
between
3.6 m/s B v
1
\ 4.2 m/s,
and
Region
3
between 4.2 m/s B v
1
\ 5.0 m/s.
For the 90 % case, the rated power is achieved at a wind speed v
1_rated
= 4.2 m/s
with a rated rotor speed X
r_rated
= 333 rpm, the cut-in is at v
1
= 2 m/s and
X
r
= 180 rpm, the cut-off is at v
1
= 5.0 m/s and X
r
= 333 rpm, Region 1 is
between 2 m/s B v
1
\ 3.7 m/s, Region 2 between 3.7 m/s B v
1
\ 4.2 m/s, and
Region 3 between 4.2 m/s B v
1
\ 5.0 m/s.
For the 80 % case, the rated power is achieved at a wind speed v
1_rated
= 4.2 m/s
with a rated rotor speed X
r_rated
= 344 rpm, the cut-in is at v
1
= 2 m/s and
X
r
= 180 rpm, the cut-off is at v
1
= 5.0 m/s and X
r
= 344 rpm, Region 1 is
between 2 m/s B v
1
\ 3.8 m/s, Region 2 between 3.8 m/s B v
1
\ 4.2 m/s, and
Region 3 between 4.2 m/s B v
1
\ 5.0 m/s.
14.6.6 Wind Farm Topology Configurations and Effect
on Power Efficiency
Topology configuration is critical to the efficiency and effective power generation
of a wind farm system. The aerodynamic effects of each wind turbine on the wind
profile around them are profound. In commercial wind farms, wind turbines are
most often placed far enough apart that their effects are negligible (typically about
9 rotor diameters apart in the predominant wind direction and 5 rotor diameters
apart in the perpendicular direction).
However, with an appropriate advanced controller it may be possible to place
individual wind turbines closer together and compensate for the effects on the wind
profile to maximize energy production in a fixed area. In order to accomplish this,
these effects must first be observed and modeled. This section shows the conve-
nience of the test bench for this analysis.
