ABB ACS 800 Series, Firmware Manual

Page: 72 / 340

Program features
72
Speed control performance figures
The table below shows typical performance figures for speed control when Direct
torque control is used.
Torque control performance figures
The drive can perform precise torque control without any speed feedback from the
motor shaft. The table below shows typical performance figures for torque control
when Direct torque control is used.
100
t (s)
T
T
N
(%)
T
load
n
act
-n
ref
n
N
0.1 - 0.4%s
T
N
= rated motor torque
n
N
= rated motor speed
n
act
= actual speed
n
ref
= speed reference
*Dynamic speed error depends on speed controller tuning.
Speed control No pulse
encoder
With pulse
encoder
Static speed error,
% of
n
N
+ 0.1 to 0.5%
(10% of nominal
slip) + 0.01%
Dynamic speed
error 0.4%s* 0.1%s*
*When operated around zero frequency, the error may be
greater.
Torque control No pulse
encoder With pulse
encoder
Linearity error + 4%* + 3%
Repeatability
error + 3%* + 1%
Torque rise time 1 to 5 ms 1 to 5 ms
100
t (s)
T
T
N
< 5 ms
90
10
(%)
T
ref
T
act
T
N
= rated motor torque
T
ref
= torque reference
T
act
= actual torque