To Next Page

To Previous Page

Parameter

structure

Keypad and

display

Parameter

x.00

Parameter

description format

Advanced parameter

descriptions

Macros

Serial comms

protocol

Electronic

nameplate

Performance RFC mode

Menu 3

Regen

Unidrive SP Advanced User Guide 87

Issue Number: 10 www.controltechniques.com

When regen mode is selected Pr 3.08 is the destination from digital I/O2 (T25) with the I/O set up as an input as default. This input, or an alternative

input, should be connected to an auxiliary contact on the contactor so that it follows the state of the contactor..

When the unit has been enabled and successfully synchronized this bit will become active. If the regen unit attempts to re-synchronize or trips, this bit

becomes inactive. When regen mode is selected this bit is routed to a digital I/O1 (T24) with the I/O set up as an output as default. The output, or an

alternative output, should be used to enable the motor drive(s) connected to the DC Bus link of the regen unit.

Power feed-forward compensation can be used to reduce the transient DC Bus link voltage produced when a fast load transient occurs on drives

connected to the Regen unit. 100.0% power feed-forward is equivalent to an active current of Kc / 0.45 (i.e. over current trip level) and an AC terminal

peak phase voltage equal to DC_VOLTAGE_MAX / 2. This scaling is the same as the power output from Pr 5.03 when high speed output mode is

used (see Menu 7). Therefore an analog output of the drive supply the load and analog input 2 or 3 of the drive acting as the supply Regen unit can

be connected together to give power feed-forward compensation without further scaling if the two drives are of equal rating. If the ratings are different

the analog input scaling must be used to give the correct power feed-forwards, where the scaling is given by Load drive Kc / Regen unit Kc.

This parameter defines the strategy used for current trimming in regen mode. If Pr 3.11 = 0 then current trimming is only carried out once after power-

up. If Pr 3.11 = 1 current trimming is carried out after power-up and then before the drive runs each time it is enabled.

3.08

Contactor closed

Drive modes Regen