AN1913D Freescale Semiconductor / Motorola, AN1913D Datasheet - Page 54

• Manufacturer Part Number: AN1913D
• Description: 3-phase BLDC Motor Control with Sensorless Back-EMF ADC Zero Crossing Detection using DSP 56F80x
• Manufacturer: Freescale Semiconductor / Motorola

Setting of Software Parameters for Other Motors
Coef_HlfCmt
Coef_Toff
10.3 Speed setting
10.3.1 Maximal and Minimal Speed and Speed Regulator Setting
#define x_MOTOR_COMMUTATION_PREV
#define x_SPEED_ROTOR_MAX_RPM
#define x_OMEGA_MIN_SYSU
Notes: Remember that minimal angular speed is not in radians, but in system units! Where 32768 is the
#define PER_SPEED_SAMPLE_S 0.001
#define x_SPEED_PI_PROPORTIONAL_GAIN
#define x_SPEED_PI_PROPORTIONAL_GAIN_SCALE 19 /* speed proportional gain scale*/
#define x_SPEED_PI_INTEGRAL_GAIN
#define x_SPEED_PI_INTEGRAL_GAIN_SCALE
Notes: If the motor has problems when requested speed is changed, then it is recommended to slow down
54
this final Coef_CmtPrecomp determines the interval between motor commutations when no
Back-EMF
Coef_CmtPrecomp with commutation period.
determines Commutation advancing (retardation) - the interval between Back-EMF Zero Crossing and
motor commutation
The application software multiplies fractional Coef_HlfCmt with commutation period.
determines the interval between Back-EMF Zero Crossing and motor commutation
The application software multiplies fractional Coef_Toff with commutation period
All these section settings are in bldcadczcdefines.h.
In order to compute the speed setting, it is important to set number of BLDC motor commutations per
motor mechanical revolution:
Maximal required speed in rpm is set by:
If you also request to change the minimal motor speed, then you need to set minimal angular speed
The speed PI regulator constants can be tuned as described below. All settings can be found in
bldcadczcdefines.h.
The execution period of the speed controller is set by:
Both proportional and integral gain has two coefficients: portion and scale!
Speed Proportional gain:
Speed Integral gain:
The PI controller proportional and integral constants can be set experimentally.
There
x_SPEED_PI_INTEGRAL_TI_REAL), which are not directly used for regulator setting, but can be
maximal speed done by
the regulator. If the yy_GAIN_SCALE is increased, the gain is decreased!
are
Zero
also
Crossing
the
BLDC control with BEMF Zero Crossing using ADC
Freescale Semiconductor, Inc.
For More Information On This Product,
x_SPEED_ROTOR_MAX_RPM
coefficients
is
Go to: www.freescale.com
captured.
3000
4096 /* angular frequency minimal [system unit] */
18
/* Sampling Period of the Speed Controller [s] */
x_SPEED_PI_PROPORTIONAL_GAIN_REAL
/* Motor Commutations Per Revolution */
/* maximal rotor speed [rpm] */
22000 /* speed proportional gain portion*/
27500 /* speed integral gain portion */
The
23 /* speed integral gain gain scale */
application
software
multiplies
fractional
(resp.