Permanent magnet brushless direct-current motor with closed windings

Abstract

The invention relates to a permanent magnet brushless direct-current motor with closed windings, wherein the windings are in closed connection like the direct-current motor, and permanent magnet excitation and electronic reversing are adopted. An armature winding is placed on a stator, a permanent magnet is placed on a rotor, each coil is connected with a pair of power electronic switches, and the other ends of the power electronic switches are respectively connected with an anode and a cathode of a power source. Current directions of the coils located under an N pole or S pole are identical and keep unchanged by means of electronic reversing, and the running principle of the coils is identical to that of the direct-current motor. As the permanent magnet excitation and the electronic reversing are adopted, the number of poles of the motor can be increased, the number of grooves of each pole of the motor is reduced, and dimensions of a yoke of the motor and ends of the coils are reduced. In addition, as the windings are in closed connection, the number of the grooves does not need to meet symmetric conditions of three phases (or multiple phases). Accordingly, a mechanical characteristic, an adjustment characteristic and a current-torque characteristic of the direct-current motor are kept, furthermore, efficiency and power density are improved, and the design is more flexible.

Description

technical field [0001] The invention relates to a direct current motor, in particular to a closed winding permanent magnet brushless direct current motor which not only uses the same winding closed link as the direct current motor, but also uses permanent magnet excitation and electronic commutation. Background technique [0002] Traditional DC motors have the advantages of wide speed regulation range, smooth speed regulation characteristics, high overload capacity, large starting and braking torque, etc. However, its application is limited by mechanical commutators, brushes, and excitation coils, making DC reliability, efficiency, and power density poor. [0003] With the development of permanent magnet materials and power electronics technology, there has been a permanent magnet brushless motor that uses permanent magnets to establish a magnetic field and uses power electronic devices to commutate permanent magnet brushless motors. It has the advantages of high efficiency,...

AI Technical Summary

Problems solved by technology

[0005] However, whether it is a permanent magnet brushless motor with a general structure or a special structure, the windings of each phase (three-phase or multi-phase) of the motor are open-circuit connected, not closed-connected like the traditional DC motor windings, so its operating principle is different from that of DC motors. The operating characteristics of DC motors cannot be achieved

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