Pulse width variable control of rotor position detection signal for BLDC motor driving control

In general, in order to control the stator current and angle, high-precision rotor position information is required due to the characteristics of the BLDC motor. Since this information is used by connecting a position sensor such as an encoder or resolver to the rotating shaft of the motor, it is a factor that increases the size of the device, the cost of the driving system, and the inertia of the rotor. Another method for obtaining the rotor position information is to detect the position by the Hall-sensor and attach it to the part corresponding to the magnetic axis of the stator winding, and the rotor position information corresponding to the electric angle of 60∘ is in 6 steps. Can be obtained by stator exciting. It is difficult to maintain the motor at a constant speed because this method generates torque ripple and cannot be precisely controlled by feedback. Therefore, based on these problems of the position sensors, many methods of driving the BLDC motor by sensorless have been studied, but basically, the initial driving and the driving at low speed of the motor act as a big problem. Therefore, in this paper, we aim to improve the low-resolution problem by constructing a circuit that can replace a high-speed sensor such as an existing encoder or resolver using a low-cost Hall sensor. In this process, in the case of a BLDC motor with a low-speed specification, 1) the existing 6-pulse signal cannot be recognized, 2) the required time for the pulse-width of the 6-pulse signal, and 3) since the problems such as the required time for the pulse width of the signal and 3) since problems such as the complexity of a circuit composed of hardware are considered, we will study the method of driving a BLDC motor through variable control of the pulse width of the proposed rotor position detection signal. Copyright © The Korean Institute of Electrical Engineers