AN1931D Freescale Semiconductor / Motorola, AN1931D Datasheet - Page 9

• Manufacturer Part Number: AN1931D
• Description: 3-Phase PM Synchronous Motor Vector Control
• Manufacturer: Freescale Semiconductor / Motorola

MOTOROLA
3.3 Digital Control of PM Synchronous Motor
stator flux-linkage space vector, the rotor flux-linkage space vector or the magnetizing space vector.
The most popular reference frame is the reference frame attached to the rotor flux linkage space vector,
with direct axis (d) and quadrature axis (q).
After transformation into d-q coordinates, the motor model as follows:
By considering that below base speed i
form:
From the equation
by the current i
In adjustable-speed applications, the PM synchronous motors are powered by inverters. The inverter
converts DC power to AC power at the required frequency and amplitude. The typical 3-phase inverter
is illustrated in
U
DCB
GND
sq
Figure
only.
C1
PWM_Q1
PWM_Q2
(EQ
3-4.
d
t d
3-21.), it can be seen that the torque is dependent and can be directly controlled
Freescale Semiconductor, Inc.
3-Phase PM Synchronous Motor Vector Control
u
u
For More Information On This Product,
Sd
Sq
=
d
t d
p
-- -
J
=
=
Figure 3-4. 3- Phase Inverter
=
3
-- - p
2
R
R
Sd
Q1
Q2
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S
S
p
-- -
J
i
i
Sq
Sd
Sq
Phase_A
=
3
-- - p
2
sd
Sd
+
+
=0, the equation
L
=
i
t d
t d
S
d
Sq
d
PWM_Q3
PWM_Q4
i
L
Sd
M
–
S
i
Sq
i
Sd
+
Sq
Sq
+
Sq
–
–
M
i
Sd
T
F
F
L
–
Sq
Sd
(EQ 3-20.)
T
Q3
Q4
L
Phase_B
PWM_Q5
PWM_Q6
can be reduced to the following
Target Motor Theory
Q5
Q6
Phase_C
(EQ 3-16.)
(EQ 3-17.)
(EQ 3-18.)
(EQ 3-19.)
(EQ 3-20.)
(EQ 3-21.)
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