Бесконтактные двигатели постоянного тока с трехсекционной обмоткой и двумя индукторами

Abstract

Two brushless DC motors (BLDC) with a three-section armature windiщ and two cylindrical inductors-magnets are considered. One motor has an ordinary drum-type armature windiщ, and numbers of radial poles in its two inductors differ from each other by a factor of three. The other motor has a toroidal armature winding, and the numbers of radial poles in its two inductors differ from each other by a factor of two. An expression for the distribution of the resulting armature winding magnetic induction over the air gap circumference is given. The optimal relationships between the parameters of two inductors are determined. Expressions are obtained for the ratios of the electromagnetic torques of the considered motors and for the known BLDC motor with a conventional three-section armature winding and a composite inductor consisting of an inner magnetically soft bushing and external poles formed by magnets. The compared machines have the same number of power transistors and are made with the same dimensions of their electromechanical parts, and their armature windings consume the same power from the power source. It has been found that the electromagnetic torque in the considered motor with the ordinary armature winding is approximately a factor of 1.37 greater than in the known motor with a three-section armature winding, whereas in the motor with a toroidal armature winding it is smaller by about a factor of 1.1, i.e., insignificantly. However, the electromagnetic torque pulsation in the motor with a toroidal winding and three power transistors is approximately 3%, whereas in the known motor with three and six power transistors its values are approximately equal to 8 and 4.5%, respectively. The considered motors with simpler cylindrical inductors can compete with the known BLDC motors.