Motorola M68HC08 - Manual (Page 139)

User Guide
Tuning for Customer Motor
DRM028 — Rev 0 Designer Reference Manual
MOTOROLA User Guide 139
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 0x04
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
µs
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.
6.5.4.3 Alignment Current and Current Regulator Setting
The current during alignment state (before motor starts) [
Α]:
/* 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.
NOTE: 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 128
Range: <0,255>
where the current regulator proportional gain is:
KP = CUR_PIREG_P_GAIN*2
CURR_OUREG_P_GAINSCALELEFT
(EQ 6-4.)
/* MUST_CHANGE_4_EXPER: */
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Freescale Semiconductor, Inc.
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