Sensorless Control of Commutation Winding Low-Power Brushless DC Motor Based on the Use of Back-EMF
Enin, V., Stepanov, A.
Article language: English
Abstract. The method of sensorless control of switching of windings of three-section BLDC motor with permanent magnets based on calculation of back-EMF of rotation is proposed. After converting the equations of the three-section BLDC motor to a two-phase system, the switching moments of the windings are determined. Switching moments are calculated using a function representing the ratio of back-EMF rotations computed for a two-phase system. In these moments back-EMF of the turned off and turned on sections are equal. Using this function, signals are generated to control the transistors of inverter. We consider a BLDC motor with a trapezoidal back-EMF of rotation, which is approximated by a piecewise linear function and an inscribed ellipse. Modeling of three-section BLDC using the proposed method of sensorless control of switching windings confirmed the effectiveness of the method and the possibility of its use in a wide range of rotor speeds.
Keywords: brushless DC motor, sensorless control, back–EMF, approximation, simulation
Pages: 23–32Total pages: 10
Year of publication: 2019