IF08CZ9 September, 2019
- 39 -
CIRCUIT OPERATION (cont’d)
Vector Control D-Q Axis Current Control
The figure on the following page shows the block diagram of the D-Q axis current control.
This system controls the current of an induction motor by separating it into a magnetic flux (Field)
component and a torque component. This drive controls the current on the D-Q coordinates. It can control
the current to an AC motor as a DC value, achieving high performance control irrespective of output
frequencies.
(1) ID (Field current) control
A magnetic flux reference is generated based upon the speed reference. This and the field current
setting (MI_ID_BASE) are used to generate an ID reference. This ID reference and the ID feedback signal
are input into a PI controller. The output of this controller is the ED_R (Field voltage reference). Optional
Inductance (L) compensation can also be used (ACR_WL). If used, these signals are combined with the PI
controller output to create the ED_R.
(2) IQ (Torque current) control
The torque reference, which is the result of the previously mentioned speed control, is input and
divided by magnetic flux to obtain an IQ reference. This IQ reference and IQ feedback signal are input into a
PI controller. The output of this controller is the EQ_R (Torque voltage reference). An induction voltage
compensation (ACR_E2) and L compensation (ACR_WL) may also be used. If used, these values are
combined with the output of the PI controller to create the EQ_R.
L Compensation
Induction voltage compensation
+
-
SFC
SFC_DATA
(option)
Torque
Reference
T_R
+
-
+
-
+
+
<Current Control>
ACR_A: Anti-overshoot
ACR_P: P gain
ACR_W1: Response
<Anti-overshoot>
<Integral>
<Proportional>
Limit
Calc.
<IQ Limit>
IQ_R
1.0/100%
Modulation
rate
Rated Current
Adjustment
CS_MOTOR_CURR
CS_EQUIP_CURR
IQ_FBK
<Integral>
<Proportional>
ID_FBK
ACR_WL
ID_REF
IQ_REF
Frequency
F0
EQ_R
Flux
Reference
FL_R
Frequency F0
ACR_E2
ED_R
Rated Current
Adjustment
CS_MOTOR_CURR
CS_EQUIP_CURR
LMT_E
÷
+ +
+
+
+
-
+
-
+ +
+ -
ID_R
MI_ID_BASE
ID_R
FL_R
MA_FLUXFUNC
00 - 20
ID_FUNC
Modulation
rate
D-Q Axis Current Control
Toshiba Reference File #328