Research on Starting Methods for Sensorless Brushless DC Motors

The working principle of sensorless brushless DC motors was briefly analyzed.The principles,advantages and disadvantages of rotor pre-setting starting method,three-step starting method,increasing frequency and increasing voltage synchronous starting method increasing frequency and current regulation control starting method,short time measuring pulse rotor orientation starting method,voltage interpolation starting method were been analyzed.According to the defects of the several starting methods,improvement measures proposed by related scholars were analyzed.Last in the paper,to shortcomings of existing research of sensorless brushless DC motor starting method,several urgent-depth research problem were proposed:more accurate,lower-cost positioning method study of initial rotor position;the study of multidimensional voltage interpolation starting method;Closed loop starting methods.