Abstract
The brushless de (BLDC) motor is becoming widely used and popular in the small horsepower motor applications. Factors such as simplicity in control, low cost, high efficiency, low frame size, high torque per inertia, high power density and, most importantly, being br-ushless are the reasons that make the BLDC motor very attractive in motor drive applications. In this research a systematic approach to synchronous operation of the brushless DC (BLDC) motor has been investigated and implemented. This thesis establishes principles of synchronous operation of the BLDC motor, develops stable operating conditions, derives the required implementation formulas and introduces some new definitions. The synchronous system follows, open loop, a speed command. The system has been provided by two input references: current and speed. The current reference throughout the operation has been kept constant at the maximum applicable continuous current to obtain maximum torque. Current regulation has been achieved by hysteresis current control. The speed reference has been varied from zero speed to the desired speed linearly. Once speed reaches to the desired speed, it is kept constant at the desired speed. Since the motor operates synchronously and no position information has been used, the motor has to follow exactly the reference speed, otherwise pull out occurs. By this implementation, three operating points of the BLDC motor with synchronous operational system has been presented. One of the three operating points at maximum speed corresponds to maximum load operation.
Guzelgunler, Yilcan (1998). Synchronous operation of the BLDC motor. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1998 -THESIS -G89.