AN1905 ST Microelectronics, Inc., AN1905 Datasheet - Page 31

• Manufacturer Part Number: AN1905
• Description: St7mc Three-phase BLDC Motor Control Software Library
• Manufacturer: ST Microelectronics, Inc.

Set_Target_Electrical_Frequency
Synopsis
Description
Input
Caution
Functions called
See also
Code example
ST7MC THREE-PHASE BLDC MOTOR CONTROL SOFTWARE LIBRARY
#include "mtc.h"
void Set_Target_Electrical_Frequency(u16 target_freq)
This function is used to refresh the MCPUH/L register contents
(MCPVH/L in current mode). The output of the PI regulation loop routine
is used to do so.
The ‘target_freq’ is a u16 variable, and has to be set according to the de-
sired target frequency (0.1Hz resolution).
The target electrical frequency is given by:
target_freq = desired electrical frequency x 10 (0.1 Hz resolution)
Frequency is given with 0.1Hz resolution.
regul_PI
ST7MC Datasheet: MTC chapter.
desired electrical frequency : 100 Hz:
target_freq = 100 Hz x 10 = 1000;
-> Set_Target_Electrical_Frequency(1000)
Reminder:
Electrical frequency = number of pair poles x mechanical frequency
RPM speed = 60 x Mechanical frequency (RPM: revolutions per minute)
example: electrical frequency = 100 Hz, motor with 8 pair poles:
100Hz electrical <-> 100/8 =12.5Hz mechanical <-> 12.5 x 60=750 RPM
31/77