DC Motor with Salient Poles Rotor and All Coils Placed on the Stator 2016-01-0001
DC motors are the most controllable electrical machines but more complicated for fabrication, in comparison with induction motors having simplified design but more complicated for control. Regular DC motor contain excitation (field) coil on the stator and armature coil on the rotor. Armature coil connected with external voltage source by a mechanical commutator with brushes. This arrangement complicates fabrication of DC machine, increases its cost, lowered reliability, and demands regular maintenance. Electromagnets inside of the stator increase dimensions of DC motor. In DC motor with salient pole rotor, there are no coils on the rotor, and mechanical commutator with brushes is eliminated, and eliminated all disadvantages connected with this arrangement. In this paper, we consider the new version of DC machine with DC stator excitation in compare with presented earlier. The difference is in using individual coil excitation for each armature coil, placed on the stator. In this case, /we can design one, two, three or multiple phase machines. The reason for design two and three phase machine is for improvement of start condition and increase power of the DC motor. In the paper, we discuss theoretical bases design of motor with salient poles rotor and all coils placed on the stator. As in a regular DC motor, we consider series and parallel connection armature and field coils. In the considered motor, the power transistors commutator and the reflective optical sensor of rotor position are used instead mechanical commutator in regular DC machines. We consider design configuration of power transistor commutator and the reflective optical sensor of rotor position which depend from number of phases realized in particular version of the machine. Prototype DC motors with salient rotor poles and all coils placed on the stator where fabricated and tested. Tests results confirm theoretical bases of design brushless DC machines with DC stator excitation, and its properties.