User Guide

DS70640A-page 6  2010 Microchip Technology Inc.
• End Speed
End speed value setup is a trade-off between the efficiency of the control and the
estimator’s minimum speed limit to accurately estimate speed and position.
Normally, the user would want to set the open loop end speed value as low as
possible so that the transitions to closed loop functioning occur as soon as
possible from the startup. Keeping in mind the compromise stated above,
consider an end speed of one third of nominal speed of the motor under tuning
for the beginning.
userparms.h
Figure 1-3 illustrates the parameters that were previously chosen. The image
represents the capture of an oscilloscope current probe attached to one of the motor’s
phases.
FIGURE 1-3: