Master of Science (MS)


Electrical and Computer Engineering

Document Type



The object of the study is a double-sided axial flux permanent magnet brushless dc (AFPM BLDC) motor with salient pole stator. Its winding can be connected either in single-phase or in two-phase system, which results in different operation of the motor.

The objective of the thesis is to analyze and compare the performances of the AFPM BLDC motor with single-phase winding and two-phase winding. To study the motor operation, a mathematical dynamic model has been proposed for each of the motor with different winding, which became the basis for simulations that were performed using MATLAB/SIMULINK software package.

The calculations were done for the particular motor which was designed as a water pump with the wet rotor. The results of simulations were presented in form of the waveforms of selected quantities and the electromechanical characteristics performed by the motor in steady-state conditions. The later were the basis for developing a simple mathematical model of the motors which allow to analyze their performance only in steady-state conditions.

The calculation results show that the two-phase motor version develops more smooth torque and reaches higher efficiency than the single-phase version. However the advantage of using a single-phase version is simpler and cheaper converter which the motor is supplied from. This implicates of using this type of motor for fans and pumps where torque ripple is not the subject, while the two-phase motor can be applied where more smooth torque is required.

Both motors are supplied from inverter whose structure depends on the type of winding. Since there were voltage type inverters, the switching angle of transistors had significance on the motor performance. This influence was studied for both motors.

A study on the influence of switching angle on motor performance shows that the motors operate better when advance switching angle β = -30°, where the motors operate with the highest efficiency.



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Committee Chair

Ernest A. Mendrela