Parameter Descriptions: Regen; Menu 3 Regen Logic Diagram - Emerson unidrive sp User Manual

Menu 3 Parameter Keypad and
Regen structure display

Parameter descriptions: Regen

Figure 5-5 Menu 3 Regen logic diagram
25
Enable
31
input
Power
3.10
feed-forward
compensation
Voltage
3.05
set-point
DC bus
5.05 2.01
voltage
Key
Input
X
X
terminals
X
Output
X
terminals
The parameters are all shown at their default settings
In Regen mode some form of charging system must be used to limit the current taken from the supply to charge the d.c. link capacitors when the
supply is first connected to the drive inverter terminals (i.e. UVW). Either an external soft start resistor or the charging system in the drive may be
used. See Unidrive SP Regen Installation Guide for details. When the d.c. link capacitors are charged a contactor, controlled by the drive, is closed to
either short out the external charging resistor, or to disconnect the charging system and connect the drive inverter terminals directly to the supply. This
contactor is controlled by Pr 3.07 which is normally used as the source for the drive relay. An auxiliary contact on this contactor is monitored in Pr 3.08
which normally follows the state of digital I/O 2.
A current feedback trimming routine runs before the drive is enabled to minimize offsets in the current feedback. Unnecessary offsets can be caused
by the current taken from the supply to power the drive control electronics or by current pulses due to noise on the supply during the current trimming
period. If an external charging resistor is used and the shorting contactor is open the additional supply resistance can reduce the peak level of these
currents. If the charge system in the drive is used and the contactor is open the drive inverter terminals are not connected to the supply, and so there
is no current flowing into the drive inverter terminals. Therefore the drive will always ensure that the contactor is open while the current trimming
system is active. Two alternative strategies can be selected with Pr 3.11:
1. The first strategy (Pr 3.11=0) activates current trimming immediately after the supply is applied to the drive before the contactor is closed. Current
trimming is not carried out again unless the drive is powered down and powered up again.
2. The second strategy (Pr 3.11=1) activates current trimming after power up before the contactor is closed and again each time just before the drive
is enabled. Because the contactor must be open during current trimming the contactor is opened when the drive enable is applied, the current
trimming is performed, the contactor is closed and then the drive is enabled. If the enable is active during power-up with this strategy, current
trimming is only carried out once before the contactor is closed.
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Parameter Parameter
x.00 description format
Softstart
contactor
closed
Regen
3.08
sequencer
Regen
restart
3.04
mode
Power to
current
conversion
Voltage
controller
kp gain
+
3.06
_
Read-write (RW)
0.XX
parameter
Read-only (RO)
0.XX
parameter
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Advanced parameter
Macros
descriptions
start contactor
motor drive
3.03 2.01
+
Current
+
control
(Menu 4)
Output
5.02 2.01
voltage
Output
5.03 2.01
power
Reactive
3.01 2.01
power
Output
5.01 2.01
frequency
Input
3.02 2.01
inductance
Serial comms Electronic
Performance RFC mode
protocol nameplate
Close soft
3.07
Enable
3.09
Regen
status
Modulator
and power
circuit
Unidrive SP Advanced User Guide
41
42
24
Mains
supply
Issue Number: 10