Lust CDA3000 - Page 151

3-68
Engineering Guide CDA3000
3 Selection of inverter module
Positioning accuracy with Start/Stop operation as a function of
motor control method
ϕ
F
= ω
..
t
RF
ϕ
F
= Positioning error
in °
ω = Velocity
in mm/s
tRF = Response error
(terminal
scan cycle) in s
(1) Scan cycle of control terminals (CDA3000 = 1 ms) on inverter
(t
RF
=response error)
(2) Destination position 1 (stop signal comes together with read-in
of control signals on inverter)
(3) Destination position 2 (Stop signal comes directly after read-in of
control signals on inverter)
(4) Slip range (depending on control mode the braking ramp
is slip-dependent)
Figure 3.30 Start/stop positioning
Property
VFC
Voltage
Frequency
Control
SFC
Sensorless Flux
Control
FOR
Field-Oriented
Regulation
Braking time 100 ms, external moment of inertia = motor moment of inertia
Standard motor (U
N
= 400 V)
1500 rpm to 0 rpm
10° 9° 9°
Standard motor (U
N
= 400 V)
1500 rpm to 0 rpm
4° 4° 3°
Servomotor (U
N
= 330 V)
1500 rpm to 0 rpm
12° 10° 8°
Servomotor (U
N
= 330 V)
1500 rpm to 0 rpm
6° 5° 4°
Braking time 500 ms, external moment of inertia = motor moment of inertia
Table 3.33 Typical positioning errors referred to the motor shaft in °
(1)
(2)
(3)
(4)
t