Download DRM020 Reference Manual

Freescale Semiconductor, Inc.
Designer Reference Manual — 3-Phase ACIM Drive with Tachogenerator
Section 2. System Description
Freescale Semiconductor, Inc...
2.1 Contents
2.2
System Concept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.3
Volt-per-Hertz Control Technique . . . . . . . . . . . . . . . . . . . . . . . 17
2.2 System Concept
The system is designed to drive a 3-phase AC induction motor. The
microcontroller runs the main control algorithm. According to the user
interface input and feedback signals, it generates 3-phase PWM output
signals for the motor inverter.
For the drive, a standard system concept is chosen (see Figure 2-1).
The system incorporates the following hardware parts:
•
power supply rectifier,
•
three-phase inverter,
•
optoisolation
•
feedback sensors: DC-Bus voltage, DC-Bus current,
tachogenerator for motor speed measurement,
•
microcontroller MC68HC908MR32.
The drive can basically be controlled in two different ways (or operating
modes) that can be set by an on-board jumper.
•
In the Manual Operating Mode, the required speed is set by
Start/Stop switch, Forward/Reverse switch and speed
potentiometer.
DRM020 — Rev 0
MOTOROLA
Designer Reference Manual
System Description
For More Information On This Product,
Go to: www.freescale.com
15