AN1914 Freescale Semiconductor / Motorola, AN1914 Datasheet - Page 29

• Manufacturer Part Number: AN1914
• Description: 3-Phase BLDC Motor Control with Sensorless Back EMF Zero Crossing Detection Using DSP56F80x
• Manufacturer: Freescale Semiconductor / Motorola

5.5 Speed Control
6.
6.1 System Outline
Notes:
The speed close loop control is provided by a well known PI regulator as shown in
actual speed (Omega_Actual) is computed from average of two BEMF Zero Crossing periods (time
intervals) received from the sensorless commutation control block.
The speed controller works with constant execution (sampling) period PER_SPEED_SAMPLE_S
(request from timer interrupt).
The motor control system is designed to drive the 3-phase BLDC motor in a speed closed loop.
There are more software versions targeted for a concrete DSP and Evaluation Module (DSP/EVM):
The hardware setup of the system for a particular DSP varies only by the EVM Board used. The
application software is identical for all DSPs; the EVM and chip differences are handled by SDK
drivers for the particular DSP EVM board.
Automatic board identification allows one software program runs on each of three hardware and motor
platforms without any change of parameters:
The hardware setup is shown in
be found in
•
•
•
•
•
•
Hardware
DSP56F803
DSP56F805
DSP56F807
Low Voltage Evaluation Motor Hardware Set
Low Voltage Hardware Set
High Voltage Hardware Set
The detailed description of individual boards can be found in comprehensive user’s manuals
belonging to each board. The user’s manual incorporates the schematic of the board,
description of individual function blocks and bill of materials. The individual boards can be
ordered from Motorola as a standard product.
Section
DSP56F80x MC PWM Module in Motor Control Applications
12.1.
Freescale Semiconductor, Inc.
For More Information On This Product,
Figure
Go to: www.freescale.com
6-12,
Figure 6-13
and
Figure
6-14. More information can also
Section
7.2.4. The
Hardware
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