ABSTRACT
In spite of intensive development of solid-state converter-fed electromechanical drives with induction and synchronous motors, the DC brush motors are still in use. This is due to the simple and cost-effective speed control and very good performance characteristics of DC motors. The basic function of DC brush machines is conversion of the DC current energy into mechanical energy with controlled parameters, variable speed or variable torque, or vice versa, mechanical energy into DC energy. The rectangular coil can pass this position due to its moment of inertia. When the semi-rings turn more than 90°, the current in the coil flows in the opposite direction and the polarity of the magnetic field generated by the rectangular coil is also in the opposite direction. In motors subject to heavy duties, the quadrature armature reaction is neutralized by means of a compensating winding embedded in the pole-shoe slots of the main poles.
