II F 3-4
3.4
Speed Control
The speed controller is located in the AMC Board.
Speed reference
The source of the reference is depending on the
operating mode.
Advant control,
Field bus interface
➔
remote mode, DDCS
on AMC Board
DrivesWindow
➔
local mode, DDCS
on AMC Board
Panel CDP312
➔
local mode, connec-
tor on CON-2
Analogue inputs
➔
local I/O mode
Speed reference features:
Speed reference limiter
Speed ramp with emergency stop
Variable slope rate
Speed correction
Reference for inching before the ramp
2 different references for inching behind the
ramp
Speed measurement
The actual speed may be calculated from arma-
ture voltage and flux (field current) or measured
with analogue tacho or pulse encoder.
Controller part features
PID controller
2 first order low pass filters
Window control
Acceleration compensation
Speed and torque adaptation
Droop
Additional torque references
Torque limitation and gear backlash function
(the integral part of the controller is set to a
suitable value on limitation)
Oscillation damping (band rejection filter for
speed error)
The diagram Fig. 3.7/2 shows the functionality of
the speed reference chain as well as of the speed
controller.
3.5
Torque Control
Flux and Torque Calculation
These are generally open loop. The flux is
adjusted by the field current. The reference of the
field current is generated by the superimposed
armature voltage control.
The torque is adjusted by the armature current.
The conversion from torque to current reference
is done by means of the calculated flux (based on
the field current and saturation characteristic).
Torque reference features:
Torque reference A with 1st order filter and
load share
Torque reference B with torque ramp
Torque reference limiter
Torque correction and torque step
Torque correction by means of analogue in-
put 1
A good behaviour in the field weakening re-
quires speed measurement by tacho or encoder.
A simplified scheme of the torque reference
chain is given in diagram fig. 3.7/2.
