AN1913D Freescale Semiconductor / Motorola, AN1913D Datasheet - Page 51

• 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

10.1 Current and Voltage Settings
10.1.1 DC-Bus Voltage, Maximal and Minimal Voltage and Current Limit Settings
#define x_VOLT_DC_BUS
#define x_DCB_UNDERVOLTAGE
#define x_DCB_OVERVOLTAGE
#define x_DCB_OVERCURRENT
Notes: Note the hardware protection with setting of pots R116, R71 for DSP56805EVM or R40, R45 for
10.1.2 Alignment Current and Current Regulator Setting
#define x_CURR_PI_PROPORTIONAL_GAIN 30000
#define x_CURR_PI_PROPORTIONAL_GAIN_SCALE 24
#define x_CURR_PI_INTEGRAL_GAIN
#define x_CURR_PI_INTEGRAL_GAIN_SCALE 23
Notes: If the overcurrent fault is experienced during the Alignment state, then it is recommended to slow
Notes: The coefficients x_CURR_PI_PROPORTIONAL_GAIN_REAL (resp.
10.2 Commutation Control Settings
For the right regulator settings, it is required to set the expected DC-Bus voltage in bldcadczcdefines.h:
The current voltage limits for software protection are:
All settings in this section are in bldcadczcdefines.h.
The current during the Alignment state (before the motor starts) is recommended to be set to the
current nominal motor value:a
#define x_CURR_ALIGN_DESIRED_A 17.0
Usually it is necessary to set the PI regulator constants. (The PI regulator is described in algorithm
controllerPItype1 description in SDK doc).
The current controller works with a constant execution (sampling) period determined by the PWM
frequency:
Current Controller period = 1/pwm frequency.
Both proportional and integral gain have two coefficients: gain portion and scale.
Current Proportional gain:
Current Integral gain:
The PI controller proportional and integral constants can be set experimentally.
In order to get the motor reliably started, the commutation control constants must be properly set.
DSP56803EVM (see EVM manuals for details)
down the regulator. If the yy_GAIN_SCALE is increased, the gain is decreased.
x_CURR_PI_INTEGRAL_TI_REAL) are not directly used for regulator setting, but can be used
to calculate the
(resp.
the comments.
x_CURR_PI_INTEGRAL_GAIN, x_CURR_PI_INTEGRAL_GAIN_SCALE
x_CURR_PI_PROPORTIONAL_GAIN, x_CURR_PI_PROPORTIONAL_GAIN_SCALE
BLDC control with BEMF Zero Crossing using ADC
Freescale Semiconductor, Inc.
For More Information On This Product,
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15.8
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3.0
19000
/* DC-Bus expected voltage */
/* Undervoltage limit [V] */
/* Overvoltage limit [V] */
/* Overcurrent limit [A] */
/* Alignment Current Desired [A] */
/* integral gain portion */
/* integral gain gain scale */
Setting of Software Parameters for Other Motors
/* proportional gain portion */
/* proportional gain scale*/
) using the formulae in
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