AN1857 Freescale Semiconductor / Motorola, AN1857 Datasheet - Page 28

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

Application Note
Power Factor
Correction
3-Phase Motor
Control System
Configuration
28
Power factor correction control (PFC) circuitry provides control of the
PFC switch and handles the necessary feedback to provide a sinusoidal
power line current. The capability of PFC can be enabled or disabled by
changing a jumper configuration on the power module. The jumper can
be found in proximity to the dc bus capacitor. The objective of the PFC
hardware and software is to draw sinusoidal current from the ac main
supply power in an attempt to approach as close as possible a unity
power factor. The circuitry on the power board is a boost power supply,
controlled by the MR32 on the control board. Without PFC, the current
from the ac main supply tends to draw current at the peak of the ac sine
wave.
Describing the control of the PFC circuity exceeds the scope of this
application note. A forthcoming application note will describe PFC
control in detail.
Figure 19
system configuration with an MMDS05/08 emulation system and PC
workstation. An optional PC, connected to the MR32 control board, is
shown. The optional PC can be used to communicate control system
parameters to the system via software running on the control board. The
system may be exercised in standalone mode, without the MMDS05/08
emulator and PC workstation, by placing a programmed MR32 into the
daughter board and plugging it into the control board in place of the
MMDS05/08 emulator system.
Freescale Semiconductor, Inc.
For More Information On This Product,
is a block diagram of the complete 3-phase motor control
Go to: www.freescale.com
MOTOROLA
AN1857