METHOD FOR SMOOTHER STARTING ELECTRIC MOTOR WITHOUT A HALL ELEMENT

摘要

A method of smoothly starting a Hall-less motor includes the steps of applying voltage to two items of a three-phase motor, determining positioning duty and positioning time so that duty cycle progressively increases from zero to prevent jitter during positioning, using fixed duty cycle so that dragging duty cycle equals to positioning duty cycle, setting initial phase-changing time and phase-changing time when dragging is ended, changing phase after timer is interrupted, generating logic signal by three-phase signal generated by three-phase motor, and transmitting to central processor simultaneously using external interruption method. The method adopts low cost hardware circuit structure, optimizes starting algorithm, and simplifies product design. Algorithm optimization is carried out in every step, and it has the advantages of smooth starting process, short starting time, and almost zero starting failure rate.