Vonsch Quatrofrem Series, Конфигурация и диагностика

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UNIFREM v.3.41x
10 May 2017 Page 144 from 180
Example: Activity of flux braking on the real device
Flux braking at lower gain Flux braking at higher gain
During flux braking, bigger motor overheating occurs, so it is necessary to provide sufficient
thermal protection, thermistor or PT100, possibly forced cooling.
8.8 Flying start
During the operation of electric drives there is often a situation, when you need to start control,
even if the motor is rotating. For example: flue fan is rotating due to pressure difference, traction
vehicle is in motion or generator of small hydropower plant is rotating. The most accurate and
fastest process to do this is by using the speed sensor (encoder-IRC). Encoder gives precise
information about the frequency of the machine and the converter is able to automatically adapt
and phase-on. It is not necessary to use the sensor when using the function "Flying start" in the
frequency converter UNIFREM 400 XXX. Flying start can be turned on by parameter:
Parameter ID: 374
SETTINGS
– > CONTROL AND REGULATION – > FLYING START -> Flying start
It is a fully automatic function which carries out the process off flying start to the rotating motor (or
generator) always after the START command activating. Flying start takes place in several stages
and its duration may be variable from rotational speed, motor power as well as parameter settings.
Frequency
Motor
current
U
DC
voltage
Frequency
Motor
current
U
DC
voltage