THREE PHASE SENSOERLESS BRUSHLESS DIRECT CURRENT MOTOR AND SYSTEM FOR CONTROLLING DRIVING THEREOF

摘要

The present invention is a system for controlling the driving of a three phase sensorless BLDC motor which includes a driving circuit in which multiple driving switches for driving of stators, and a detection resistance for detecting a driving current applied to the stator. A driving control system of the three phase sensorless BLDC motor comprises; a counter electromotive force composition circuit part which detects a code change point of three phase counter electromotive force from a three phase output voltage and produces a function generation (FG) signal in which the code change point is reflected; a phase locked loop (PLL) circuit part for fixating the phase of the FG signal; an output composition circuit part which produces driving control signals of the driving circuit based on an output signal of the PLL circuit part and outputs the driving control signals to the driving circuit; a torque ripple removal and pulse width modulation (PWM) control part which computes a value of current ripples generated in the detection resistance in the commutation of the driving circuit and produces first and second ripple signals by adding and subtracting the value of the current ripples in an average current signal of the motor and controls a duty ratio of driving control signals based on the first and second current ripple signals. [Reference numerals] (10) Driving circuit;(110) BEMF comparison circuit;(120) Function generation circuit;(210) PFD charge pump circuit;(240) Frequency demultiplier;(310) Shift resistor;(320) Output controller;(410) Current ripple detection circuit;(420) Obliquity signal producing circuit;(430) PWM generation circuit;(440) Commutation selection circuit;(500) clock selection circuit