Danaher Motion SuperDrive ACS24 Series, Руководство пользователя

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26.04.2005
Configuration & control of the AC SuperDrive
6.11 T
UNING OF CURRENT CONTROL
In order to tune the Current Control some motor data are required, namely the
•
Stator and rotor leakage inductance (L
s
λ
and L
r
λ
)
•
Stator and rotor resistance @ 100
°
C (R
s
and R
r
)
Normally these values are supported by Danaher Motion and the default Current Control
parameters can be used (Table 22). However, from the impedance data of the motor the Pgain,
Igain and Lsigma can be computed (checked) as follows.
The Pgain and Igain in the current PI controller can be calculated as:
256
4 I
3 U
) L L ( f 2
Pgain
base
dc
r s c
⋅
⋅
+ ⋅ ⋅ π ⋅
=
λ λ
3 256
f
1
4 I
3 U
) R R ( f 2
Igain
s
base
dc
r s c
⋅ ⋅ ⋅
⋅
+ ⋅ ⋅ π ⋅
=
where:
f
c
= Current control bandwidth (200 Hz)
f
s
= Sampling (execution) frequency of the current control (4000 Hz)
L
s
λ
, L
r
λ
= Stator and rotor leakage inductance
R
s
, R
r
= Stator and rotor resistance @ 100
°
C
U
dc
= 24, 36, 48 or 80 V (corresponds to 16384
⋅√
3 DSP units)
I
base
= 410 A (corresponds to 4096 DSP units)
The factor 3 in the computation of the Igain is introduced in order to improve the performance of
the current control when the back emf inside the motor changes quickly. That happens when the
derivative of the motor speed is high since the back emf is proportional to the motor speed.
The value of the decoupling factor Lsigma is calculated as
4096
4 I
3 U
) L L ( f 2
Lsigma
base
dc
r s base
⋅
⋅
+ ⋅ ⋅ π ⋅
=
λ λ
where f
base
= 50 Hz
User's Guide 1.0 Item No.
89Y05120A
61