Motorola M68HC08 manual Alignment Current and Current Regulator Setting, Range 0,8

Freescale Semiconductor, Inc.

Freescale Semiconductor, Inc.

User Guide

Tuning for Customer Motor

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 ∝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.

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*2CURR_OUREG_P_GAINSCALELEFT(EQ 6-4.)

	/* MUST_CHANGE_4_EXPER: */
DRM028 — Rev 0		Designer Reference Manual
MOTOROLA	User Guide	139

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