UNIFREM v.3.41x
10 May 2017
Page 72 from 180
Name [ID]
Description
Def.
Flying start
[374]
Turning on the converter flying start to the rotating motor for control modes without
speed feedback. In closed vector or V/f control (if the IRC functional feedback is
working), the flying start is performed automatically, ignoring this parameter.
Turned
off
Turned off
Flying start function for rotating motor is turned off. Every drive start begins from zero
frequency. If START would be applied in this mode to rotating motor, fault E11-Overcurrent
(page 32)" or E4-Overvoltage (page 32)" can occur.
Accelerated
Direction and zero speed detection is performed on every start, which is followed by an
eventual rotor speed search and flying start. This mode is suitable for drives with high moment
of inertia and transportation vehicles drives.
Normal
Rotor speed search and flying start to the rotating motor is performed on every start. This
mode is suitable for drives with high moment of inertia and transportation vehicles drives.
F. start time
[375]
Frequency search period during the flying start process.
1,5 s
0,1 s ÷ 100,0
s
Affects the speed and the accuracy of the frequency search. If the search time is too short, it
can cause the frequency to have a high deviaton from the real frequency, or it will not be
found at all.
Inaf/I0 Ratio
[778]
Defines the current value for the direction detection and the frequency search when
phasing a spinning motor as a multiple of the magnetizing flux Magnetizing current
[355] (page 45).
1,000
0,100 ÷ 3,000
Better flying-start reliability is assured at a high search current, but a bigger brake force is
applied to the rotor. Correct value is found as a compromise between excessive braking and
an inaccurate detection of the rotor frequency.
7.5.7 VOLTAGE CONTROLLER (VC)
Group of parameters number [747]
Parameters of the voltage controller (VR) that includes both the KINETIC BACKUP controller and the
DYNAMIC DECELERATION controller.
MENU \ SETTINGS \ CONTROL AND REGULATION \ VOLTAGE CONTROLLER (VC)
Name [ID]
Description
Def.
Kinetic backup
(KB) [748]
Turning on of the kinetic backup (KB) controller, which maintains the voltage on a
setpoint value KB setpoint [753] (page 72) during supply outage or voltage drop
in the DC link by decreasing the output frequency, to keep the drive in operation.
It is used to bypass short time power supply outage, e.g. on traction vehicles, but
also on pumps and fans. Success condition is a sufficient moment of inertia of the
load, whose kinetic energy is used to charge the DC link.
Turned
off
Turned off
Kinetic backup is turned off.
Turned on
Kinetic backup is turned on.
KB
setpoint
[753]
Voltage setpoint of the kinetic backup controller.
450,0 V
Undervoltage
1
÷
Overvoltage
2
Voltage value of the DC link, which is kept when kinetic backup is active.
1
Refer to chapter 3.1
(str. 14) by product type.
2
Refer to chapter 3.1
(str. 14) by product type.
Flux during KB
[1178]
Coefficient of magnetic flux drop during kinetic backup activity.
0,60
0,30 ÷ 1,00
By decreasing the flux level it is possible to extend the time of backup during input voltage
outage. Value of 1.00 means no flux decrease.
Dynamic
deceleration
(DD) [749]
Turning on the dynamic deceleration (DD) controller, which maintains the voltage
on a setpoint value DD setpoint [754] (page 73) during excessive voltage in the
DC link by increasing the output frequency, to keep the drive in operation.
It is used to brake or stop drives with high moment of inertia, where the brake
resistor is not available. It can be used to support other methods of braking (BM,
flux braking). It is necessary to keep in mind that this function can, when wrongly
configured and with an excess of energy on the motor shaft, cause an extension
of the deceleration ramp at the STOP, or an increase of frequency to maximum.
Turned
off
Turned off
Dynamic deceleration is turned off.
Turned on
Dynamic deceleration is turned on.
Turned on - accel. Dynamic deceleration is turned on and also the acceleration up to Fmax is allowed.
