BRUSHLESS DIRECT CURRENT MOTOR WITHOUT POSITION SENSOR

摘要

The present invention relates to a device for operating a brushless direct current motor without a position sensor comprising a driving control unit, a current detector, a counter electromotive force estimation unit, an electrical degree estimation unit, an angular error correction unit, and a motor driving unit. The driving control unit outputs a current command value and a voltage command value for driving the brushless direct current motor. The current detector detects the largest current value among currents of each phase driving the brushless direct current motor and outputs the same as a real current. The counter electromotive force estimation unit calculates counter electromotive force by using the voltage command value and the real current. The electrical degree estimation unit calculates an electrical degree and an electrical degree speed by using the counter electromotive force. The angular error correction unit outputs an angular error component for reducing an angular error by using the current command value and the real current. The motor driving unit drives the brushless direct current motor according to the electrical degree and the angular error component. [Reference numerals] (14) Speed controller; (18) Current controller; (32) DC estimation unit; (36) Counter electromotive force estimation unit; (42) Electrical degree estimation unit; (44) Electrical degree speed estimation unit; (54) Error polarity converter; (56) Angular error correction unit; (62) Conversion point determination unit; (64) PWM circuit unit; (66) Driving inverter