Patent attributes
Disclosed herein is a control method of a sensorless brushless direct current (BLDC) motor, and more particularly, a drive control method of a concentrated winding BLDC motor which prevents shutdown due to failures of detection of zero cross points (ZCPs). A reference voltage inputted to comparators is altered to set new reference points. ZCPs are detected using the new reference points to avoid uneven detection of the ZCPs. Phase commutation is corrected corresponding to the ZCPs detected using the new reference points to reduce current ripple, thereby leading to stable control of the sensorless BLDC motor. To this end, the control method adds or subtracts a preset certain value to/from a reference voltage to produce a new reference voltage, and detects ZCPs with respect to the new reference voltage to control drive of the sensorless concentrated winding BLDC motor.