Section 6. User Guide; Contents; Application Suitability Guide - Motorola M68HC08 Reference Manual

Designer Reference Manual — Sensorless BLDC Motor Control

6.1 Contents

6.2 Application Suitability Guide

6.2.1 Minimal Application Speed
NOTE:
DRM028 — Rev 0
MOTOROLA
Freescale Semiconductor, Inc.
6.2 Application Suitability Guide . . . . . . . . . . . . . . . . . . . . . . . . . . 109
6.3 Warning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
6.4 Application Hardware and Software Configuration . . . . . . . . . 113
6.5 Software Parameters Setting and Tuning
for Customer Motor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
This application suitability guide deals with issues which may be
encountered when tailoring application using customer motor.
As it is known, the back-EMF voltage is proportionally dependent on
motor speed. Since the sensorless back-EMF zero crossing sensing
technique is based on back-EMF voltage, it has some minimal speed
limitations! The motor start-up is solved by starting (back-EMF
acquisition) state, but minimal operation speed is limited.
The minimal speed depends on many factors of the motor and hardware
design, and differs for any application. This is because the back-EMF
zero crossing is disturbed and effected by the zero crossing comparator
threshold as explained below and in the sections
Mutual Inductance and
Usually, the minimal speed for reliable operation is from 7% to 20% of
the motor's nominal speed.
User Guide
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Section 6. User Guide

6.2.4.1 Effect of Mutual Phase Capacitance
6.2.4.2 Effect of
Designer Reference Manual
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