SMA WB 3000-US - Manual (Page 5)

SMA America, LLC Turbine operation
Addendum operating requirements DBWB30-40US-UUS113610 5/12
3.1 Polynomial characteristic curve
The operation mode "Turbine" of the inverter uses a programmable output characteristic curve (output
and voltage curve) to regulate the input current depending on the generator voltage.
The polynomial characteristic curve is a programmable power curve depending on the DC input
voltage. By adapting the default polynomial characteristic curve to the small wind turbine system
being used, you can optimize the energy output of the small wind turbine system.
To optimally adapt the polynomial characteristic curve of the inverter to the wind turbine system being
used, you can change the following parameters on the PC with the Windy Boy Setup Tool
version 1.0.6 or Sunny Data Control (www.SMA-America.com). Before changing the curve
parameters, consult the manufacturer of the wind turbine system for its typical characteristics:
Parameter Description
Vpv-Start This value defines the grid connection voltage. As soon as the DC input
voltage of the inverter reaches the voltage set here, the grid monitoring of
the inverter starts up. When this occurs, the inverter carries out various
self‑tests, measurement processes and grid synchronization. When the tests
are successfully completed and the DC input voltage for the time "T-Start"
rises above "Vpv-Start", the inverter connects to the grid.
VdcWindStart This value defines the starting point of the output characteristic curve. When
the DC input voltage reaches this value after grid synchronization, the
inverter using the output characteristic curve, starts with the load of the wind
turbine and feeds into the grid.
Wind_a
0
This value serves to internally calculate the output characteristic curve. By
the following formula: P(U)= a
0
+ a
1
⨯ U + a
2
⨯ U
2
+ a
3
⨯ U
3
Wind_a
1
Wind_a
2
Wind_a
3
Pmax This value defines the maximum AC output power of the inverter. The
inverter feeds the maximum power that has been set here into the grid.
Should the wind turbine system however produce more power than
"Pmax", this surplus power must be purged accordingly. Otherwise, there
is a risk that the inverter will be damaged by overvoltage.
P-Wind-Ramp This value defines the target startup of the wind turbine system. Only after
connecting the inverter to the grid, the wind turbine system is not rapidly
charged but using a configurable ramp.
KP-Wind-Ramp This value defines the control speed of the power characteristic curve. The
inverter reacts to changes in the DC input voltage by adjusting its output
power using the power characteristic curve. The higher this parameter is
set, the larger the power jump in response to the changes in the DC input
voltage. Values that are too high lead to vacillations and instability in the
system. Values that are too low delay the optimal load of the turbine and
thereby reduce the yield.