AN1931D Freescale Semiconductor / Motorola, AN1931D Datasheet - Page 23

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

MOTOROLA
4.3.1.3 Position Reset with Rotor Alignment
After reset, the rotor position is unknown, because a quadrature encoder does not give an absolute
position until the index pulse arrives. As shown in
the d axis of the d-q coordinate system before a motor begins running. The alignment algorithm is
shown in
value of the quadrature encoder does not affect this setting). Then the I
current. The rotor is now aligned to the required position. After rotor stabilization, the encoder is reset
to the zero position, then the I
executed only once during the first transition from the Stop to Run state of the Run/Stop switch.
Figure
4-6. First, the position is set to zero, independent of the actual rotor position. (The
q
Freescale Semiconductor, Inc.
3-Phase PM Synchronous Motor Vector Control
Figure 4-6. Rotor Alignment Flow Chart
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Tr‡Ãsv‘rq†v‡v‚
d
Xhv‡Ãs‚…Ã…‚‡‚…
current is set back to zero, and alignment is finished. The alignment is
†‡hivyv“h‡v‚
Figure 4-5. Rotor Alignment
$OLJQPHQW
D
G
2D
D
ƒ
$OLJQPHQW
T
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unknown rotor position
(not aligned)
2
M
Figure
zero rotor position
(aligned)
Tr‡Ãƒ‚†v‡v‚Ãs…‚€
Sr†r‡Ãrp‚qr…
d
Field
rp‚qr…
ƒ‚†v‡v‚
4-5, the rotor position must be aligned with
D
D
(QG
T
G
2
2
0
d
current is set to alignment
System Concept
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