The goal of this thesis was to examine the type commutation process of the electrical motors mentioned in the title, also to give solutions about the problems caused by this commutation process.
Chapter 1.1 describes the electrical motors with permanent magnet rotor, and square waved fluxdensity. The chapter contains description about various types of these kind of motors.
Next chapter explains the control strategies of these Brushless DC motors, including the conventional current control variants, and a direct torque control variation.
The third part is about the transient processes during the commutation and the problems it causes. It also describes theoretically the reason of the problems, such as torque ripple, and speed restriction.
Fourth chapter gives few possible solutions for the problems.
The fitfth and sixth chapter describes the simulation modells and, the results on one of the modells. Lot of examination was done and the most interesting results were choosen for demonstration.
The last chapter is a short assumption.