AN1857 Freescale Semiconductor / Motorola, AN1857 Datasheet - Page 47

• Manufacturer Part Number: AN1857
• Description: A 3-Phase ac Induction Motor Control System Based on the MC68HC908MR32
• Manufacturer: Freescale Semiconductor / Motorola

AN1857
MOTOROLA
PI_CONST is accessed from the main software timer in PI_CONST rate.
The rate defines the time constant of the PI controller. The following
sequence is performed (see
The corresponding voltage amplitude is calculated according to the volt-
per-hertz profile. Thus, both parameters for PWM generation are
available (Table_inc, Amplitude).
1. During deceleration, the dc-bus voltage is checked, and, in case
2. When no deceleration overvoltage is measured, the
3. The actual motor speed is calculated. It is based on the time
4. The PI speed controller is performed and the corrected motor
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of overvoltage, the deceleration is interrupted until the capacitor is
discharged.
acceleration/deceleration speed profile is calculated.
measurement between two subsequent rising edges of the input
capture.
frequency calculated.
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Figure
26):
Application Note
Software
47