AN2357 Freescale Semiconductor / Motorola, AN2357 Datasheet - Page 10

• Manufacturer Part Number: AN2357
• Description: Sine Voltage Powered 3-Phase Permanent Magnet Motor with Hall Sensor
• Manufacturer: Freescale Semiconductor / Motorola

AN2357/D
Power Stage
PM Motor
Parameters
Software Design
Data Flow
PC Master
Process
Sensor Edge
Detection
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Sine Voltage Powered 3-Phase Permanent Magnet Motor with Hall Sensor
Motorola’s embedded motion control series low-voltage (LV) BLDC power
stage is designed to run 3-phase BLDC and PM synchronous motors. It
operates from a nominal 12-volt motor supply. It delivers up to 30 A of rms
motor current from a dc bus that can deliver peak currents of up to 46 A. In
combination with one of Motorola’s embedded motion control series control
boards, it provides a development platform that allows algorithms to be written
and tested, without the need to design and build a power stage. It supports a
wide variety of algorithms for controlling BLDC and PM synchronous motors.
The control algorithm was tested on a motor with the following basic
parameters:
This section describes the control algorithm design process and the software
blocks implemented in the drive.
The closed loop drive control algorithm for the sine voltage powered 3-phase
PM motor with Hall sensor is described in
omega from speed pot (manual control) (or from external control (SCI)),
maximal torque (torque_limit), and Hall sensor signal (Hall sensor). The output
is a 3-phase PWM signal (PWM generation).
The PC master process controls data exchange between the application and
the SCI. The module enables reading and writing to the CPU RAM and reading
the whole CPU memory.
Each incoming edge on the signal from Hall sensor causes the saving of the
actual timer value and setting of the capture flag. The flag is recognized in the
following PWM reload, and it starts a task which is divided between two PWM
reload interrupts. In the first interrupt the sine wave is synchronized, and the
period of the hall sensor signal is calculated. In the following PWM reload
interrupt, the “phase_increment” is calculated.
Freescale Semiconductor, Inc.
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For More Information On This Product,
Nominal voltage, 12 V
Three pole pairs
Three phases
One Hall sensor in phase A, so the number of pulses per revolution is
equal to the number of rotor pole pairs.
Go to: www.freescale.com
Figure
8. The inputs are desired
MOTOROLA