ElmoMC SimplIQ Digital Servo Drives-Bell Command Reference - Manual (Page 298)

LPF, 1
st
order d/dt limiter
PF[13] PF[7,8,14]
2
Effective
current
demand
Σ
I
q
Σ
I
d
-
-
KP[1],KI[1]
XA[6]
Q - Current
controller
Σ
Speed
correction
KP[1],KI[1]
PF[9]
Q - Current
controller
Σ
Speed
correction
0
Output
Trans-
formation
and
saturation
V
q
V
d
Field angle WS[20]
Input
Trans-
formation
Ia
Ib
Ic
Phase
currents
Va
Vb
Vc
LPF, 1
st
order
PF[12]
DC voltage
3-phase
motors
only
Σ
Cogging correction
lookup table
PN[2]
Current cmd prefilter
Figure 20: Block diagram of the current controller
9.1.1 Input Transformation: Calculating Iq and Id
When the motor winding is sinusoidal, the Iq and the Id are calculated as follows:
( )
( )
2
cos( cos( cos(
3
2
sin( sin(
) 120 ) 240 )
) 120 ) 2 si 40 ) n(
3
q a c
d a c
o o
b
o o
b
I I
I I I
I I
I
θ θ θ
θ θ θ
+ + + +
+ = + + +
=
(Three phase case,
CA[28]=0)
Or
cos( cos( ) 90 )
) sin( sin( 90 )
o
b
o
q a
d a b
I I
I
I
I I
θ θ
θ θ
+
+ + =
+ =
(Two phase case, CA[28]=0)
This means that when Iq=1, Id=0 the current through each of the motor windings is
sinusoidal, and its peak value is 1 Amp, and its RMS value is 0.707Amp.
SimplIQ for Steppers Application Note The Current Controller
MAN-STECR (Ver. 1.1)
99