Program features 37
Limitation based on grid frequency
Power limitation based on grid frequency can be set to operate in either incremental P(f) or
free-running P(f) mode. The P(f) limitation type can be selected with parameter 130.62 P(f)
limit type.
Incremental P(f) limitation curve
The frequency that starts power limitation is defined by parameter 130.63 P(f) corner
frequency. When this frequency is surpassed, the current power value is saved and the
power limit is calculated in relation to this power level. The limit stays in effect until the
frequency drops below the value defined by parameter 130.65 P(f) release frequency.
After the time defined in parameter 130.66 P(f) release time has expired, the power limit is
ramped up with the parameter 130.67 P(f) release ramp in relation to nominal power.
Figure 17. Incremental P(f) limitation curve
Free running P(f) limitation curve
When the value in parameter 130.63 P(f) corner frequency is surpassed, the current power
level is saved and the power limit is calculated in relation to this power level. The limit is
set to change freely according to the frequency above the corner frequency. When the
frequency drops below the value specified by parameter 130.63, the power limit is ramped
up using parameter 130.67 P(f) release ramp in relation to the power reference type
specified by 130.68 P(f) release ramp ref.
Figure 18. Free running P(f) limitation curve
P
lim
/%
Hz
P/f limit type = Incremental
Release ramp
Limit gradient
Release
time
Release
frequency
Corner
frequency
Power at the time of
exceeding corner point
P/f limit type = Free running
P
lim
/%
Power at the time of
exceeding corner point
Release ramp
Limit gradient
Corner release
frequency
Hz
To Next Page
Loading...
Need help?
General