AN1911 Freescale Semiconductor / Motorola, AN1911 Datasheet - Page 8

• Manufacturer Part Number: AN1911
• Description: 3-Phase AC Motor Control with V/Hz Speed Open Loop Using DSP56F80X
• Manufacturer: Freescale Semiconductor / Motorola

System Design Concept
8
The control process is as follows:
When the Start command is accepted (using the Start/Stop Switch), the state of the inputs is
periodically scanned. According to the state of the control signals (Start/Stop switch, speed up/down
buttons or PC Master set speed) the speed command is calculated using an acceleration/deceleration
ramp. With the use of the V/Hz ramp the corresponding voltage is calculated and then DC-Bus Ripple
Cancellation function eliminates the influence of the DC Bus voltage ripples to the generated phase
voltage amplitude. The PWM generation process calculates a three phase voltage system at required
amplitude and frequency which includes dead time. Finally, the 3-phase PWM Motor Control signals
are generated.
Indirect Power Factor Correction Using DSP56F80X
Freescale Semiconductor, Inc.
For More Information On This Product,
Figure 4-1. System Concept
Go to: www.freescale.com