WEG CFW-09 User Manual page 203

CHAPTER 6 - DETAILED PARAMETER DESCRIPTION
[Factory Setting]
Parameter
P331
Voltage Ramp
P332
Dead Time
These
parameters ( P331
and P332) are only
displayed when
P202 = 0, 1, 2 or 5
(V/F / VVW Control)
204
Range
Unit Description / Notes
The Flying Start function allows the inverter to start a motor that is running
0.2 to 60.0
freely. This function takes the motor from its actual speed to the speed
[ 2.0 ]
reference set at the inverter.
0.1 s
In order to enable the Flying Start function set P320 = 1 or 2.
0.1 to 10.0
If the Flying Start function is not needed at some moments, a digital
[ 1.0 ]
input may be set to disable the Flying Start (set only one of the parameters
0.1 s
between P265 and P270 to 17).
Flying Start for V/F/VVW Control Mode:
To do that it has a voltage ramp (adjusted in P331) and the motor
frequency is fixed and defined by the speed setpoint. The Flying Start
will always work when a start or run command is given, after the time
adjusted in P332 (to allow for the motor demagnetization).
Parameter P331 sets the time required for the output voltage reaching
the rated voltage.
Flying Start (FS) function for the Sensorless Vector Control (P202 = 3)
The Flying Start function takes place after the START command. At this
moment, the inverter senses the motor speed, and once the motor speed
is found, which may be in the forward or reverse direction, the motor is
accelerated to the speed reference indicated in P001.
Parameters P135, P331 and P332 are not used by the Flying Start
function when P202 = 3.
Settings:
It is recommended to adjust P151 to the value in table 6.8 and P150 to
1.
Ride-Through for V/F Control Mode or VVW:
The Ride-Through function for the V/F and VVW Control Modes works in
a different manner than in the Vector Control Mode. As soon as the line
supply falls to a value lower than the undervoltage (E02) Trip level (refer
to item 7.1), the IGBT inverter is disabled (no voltage pulses at the motor).
There is no tripping due to undervoltage, and the DC Link voltage will
slowly fall until the line supply comes back.
If the line supply takes too long to come back (more than 2 s) the inverter
may trip by E02 or E70. If it comes back before, the inverter will start
the motor with a voltage ramp like in the Flying Start function. The voltage
ramp time is defined also in P331. Refer to figures 6.44 a) and b).
The parameter P332, used for the Ride-Through function, sets the
minimum time which the inverter will wait to restart the motor after voltage
re-establishment. This time is computed from the line loss and is required
for the motor demagnetization. Set this time at two times the motor
rotor constant, refer to table in P412.
The Ride-Through function allows recovering the inverter without E02 trip
(under voltage) during a momentary power supply interruption.