AN1905 ST Microelectronics, Inc., AN1905 Datasheet - Page 71

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

■
Depending on the application and/or the speed range, it might be necessary, as seen in the
previous sections, to use different values of K
quency.
These values will have to be reported in the code to feed the regulation loop algorithm. A func-
t i o n
(Set_Target_Electrical_Frequency) is provided as an example in the software library and can
be used in most of the cases, as long as the coefficient values can be linearized (see
7
look-up table may be necessary.
When running the starter kit in standalone mode, the RS232 communication interface might
be used using the ‘tty_7.exe’ windows program; this will allow the K
directly on a PC; it is also possible to get the motor speed, the rising and the falling Bemf
delay.
To enter the four set-points, some defines in the mtc.h file must be edited according to the col-
lected parameters: (See 'Mtc_Settings_Sensorless.h' or 'Mtc_Settings_Sensor.h' for Min and
Max frequency values)
//Fmin
#define Ki_Fmin
#define Kp_Fmin
..
//F_1
#define F_1
#define Ki_F_1
#define Kp_F_1
..
//F_2
#define F_2
#define Ki_F_2
#define Kp_F_2
..
//Fmax
#define Ki_Fmax
#define Kp_Fmax
on page 17 for details). On the contrary, a function with a larger number of set-points or a
Adjusting Ki and Kp vs the motor frequency
p e r f o r m i n g
ST7MC THREE-PHASE BLDC MOTOR CONTROL SOFTWARE LIBRARY
20
10
50
40
10
30
13
18
1000
2000
l i n e a r
// 100 Hz
// 200 Hz
i n t e r p o l a t i o n
p
and K
i
parameters depending on motor fre-
b e t w e e n
p
and K
f o u r
i
values to be read
s e t - p o i n t s
Figure
71/77