Motorola M68HC08 Reference Manual page 139

6.5.4.3 Alignment Current and Current Regulator Setting
NOTE:
DRM028 — Rev 0
MOTOROLA
Freescale Semiconductor, Inc.
CURR_MAX_FAULT_A should be changed for a motor with maximal
allowable current lower than the board.
Initial value for OVer-Current Counter [-]:
/* CAN_CHANGE_5: */
#define I_CNTR_OVC
Range: <0,255>
I_CNTR_OVC determines the number of current samples with current
value > CURR_MAX_FAULT_A needed before entering the drive
fault state. The current sampling period is PER_CS_T1_US = 128 s
at default software and PWM frequency setting. I_CNTR_OVC should
normally not be changed. Lower value of I_CNTR_OVC secures a
fast, safer over-current switch-off. High value of I_CNTR_OVC
secures an unexpected over-current switch-off.
The current during alignment state (before motor starts) [ ]:
/* MUST_CHANGE_1_EXPER: */
#define CURR_ALIGN_A 0.55
Range: <0,CURRENT_RANGE_MAX_A>
It is recommended that nominal motor current value be set. Sometimes
when power source is not able to deliver the required current, it is
necessary to set a lower value then nominal motor current.
CURR_ALIGN_A can be evaluated with PC master software tuning file
tuning_bldc.pmp.
It might also be necessary to set the current PI regulator constants:
/* MUST_CHANGE_2_EXPER: */
#define CURR_PIREG_P_GAINSCALELEFT 0
Range: <0,8>
/* MUST_CHANGE_3_EXPER: */
#define CURR_PIREG_P_GAIN
Range: <0,255>
where the current regulator proportional gain is:
KP = CUR_PIREG_P_GAIN*2
/* MUST_CHANGE_4_EXPER: */
User Guide
For More Information On This Product,
Go to: www.freescale.com
Tuning for Customer Motor
0x04
128
CURR_OUREG_P_GAINSCALELEFT
Designer Reference Manual
User Guide
(EQ 6-4.)
139