3-Phase BLDC Motor Sensorless Control Using MC56F8013

TuningTable 7-6. Run Parameters SummaryName Description Units Range DefaultFreeMasterLocationPER_RUN_PROCCMT_USMinimum value for periodToff.µs50.0–30000.0170.0 Control > RunCOEF_RUN_CMT_PRECOMP_FRACCoefficient for calculatingpreset commutationperiodFractionFRAC16(0.1)–FRAC16(0.9)FRAC16(0.5)Control > RunCOEF_RUN_CMT_PRECOMP_LSHFTCoefficient for calculatingpreset commutationperiodN/A 1–4 2 Control > RunCOEF_RUN_HLFCMTCoefficient for calculatingcommutation period, afterzero crossing is detectedFractionFRAC16(0.1)–FRAC16(0.9)FRAC16(0.5)Control > RunCOEF_RUN_TOFFCoefficient for calculatingperiod ToffFractionFRAC16(0.1)–FRAC16(0.5)FRAC16(0.250)Control > RunMAX_ZCROSERRMaximum commutationperiod counts with no zerocrossing detection, to stopthe commutationN/A 2–30 4 Control > RunChanging these parameters in the FreeMaster environment does not affect the application until the motoris stopped and restarted.7.5.3.2 PER_RUN_PROCCMT_USMinimum value for the period Toff.This value is used for limit the period Toff to a minimum. Therefore, the period Toff applied after everycommutation can be a minimum of PER_RUN_PROCCMT_US.7.5.3.3 COEF_RUN_CMT_PRECOMP_FRACCoefficient for calculating the commutation preset period.This coefficient is used with COEF_RUN_CMT_PRECOMP_LSHFT to buildCOEF_RUN_CMT_PRECOMP as follows.CoefRunCmtPrecomp = CoefRunCmtPrecpFrac « CoefRunCmtPreCompLshftThe preset period is calculated after every commutation, as a default commutation period in case no zerocrossing is detected in the next commutation period. If no zero crossing is detected before the presetcommutation period expires, commutation is performed. If zero crossing is detected before the presetcommutation time expires, the next commutation time is updated and the preset commutation time is notused.3-Phase BLDC Motor Sensorless Control using MC56F8013, Rev. 082 Freescale Semiconductor