Suppression method of air gap winding parallel branch circulating current

Abstract

The invention relates to a suppression method of the air gap winding parallel branch circulating current. A winding is formed by nesting at least two sets of outer and inner windings which are wound by the single-strand wires, through the different connection modes of the outer and inner windings and the different structural forms of the outer and inner windings, the situation that the nested outer and inner windings are same as or similar to the phase of a reverse electromotive force and are equal to or close to the amplitude of the reverse electromotive force, is guaranteed, and the situation that the inphase resistance and inductance of the nested outer and inner windings are both same or get close is guaranteed. The inphase windings having the above characteristics are connected in parallel, and the three-phase windings are in delta or Y-shaped connection according to the actual application. Compared with the prior art, and according to the invention, the circulating current of theparallel branched can be effectively reduced or even eliminated, thereby reducing the circulating current loss of the windings, reducing the no-load and the load loss of a motor, improving the motorefficiency and reducing the temperature rise of the motor. The method is suitable for the application of a coreless high-speed motor.

Description

technical field [0001] The invention relates to motor windings, in particular to a method for suppressing circulation in parallel branches of air gap windings. Background technique [0002] For the non-cogging permanent magnet motor, the main components of the motor include stator core, stator winding, rotor magnet and shaft, and the winding is the core component of the non-cogging permanent magnet motor. [0003] The traditional coreless motor (such as US.4,5543,507) will induce a large eddy current loss in the high-speed rotating magnetic field because the winding is directly exposed to the air gap magnetic field. Therefore, when designing the coreless winding, it is necessary to use Coils are wound with thinner copper wires. Based on this requirement, in order to make full use of the stator and rotor space of the motor, it is necessary to use a multi-strand parallel winding scheme to wind the coils. There will be a phase difference between the coils. If the two coils are...

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Problems solved by technology

[0003] The traditional coreless motor (such as US.4,5543,507) will induce a large eddy current loss in the high-speed rotating magnetic field because the winding is directly exposed to the air gap magnetic field. Therefore, when designing the coreless winding, it is necessary to use Coils are wound with thinner copper wires. Based on this requirement, in order to make full use of the stator and rotor space of the motor, it is necessary to use a multi-strand parallel winding scheme to wind the coils. There will be a phase difference between the coils. If the two coils are connected in parallel, the phase difference will cause internal circulation, which will cause loss;

[0004] Patent CN200810065047.0 proposes to use multi-strand insulated thin wires twisted into a spiral shape, which is beneficial to the circulation of different wires due to phase difference and increases copper loss. Due to the manufacturing process of the strand helical winding, it is easy to cause inter-turn damage of the winding

[0005] Patents US20090315427, US20070103025 and CN200610136515.X solve the problem of concentric windings reducing eddy currents and circulating currents in cogless motors to a certain extent, but the patents are only suitable for concentric structures, not suitable for stacked windings and oblique windings, and cannot solve the problem of stacked windings and Eddy Current and Circulating Current Problems Encountered in Slant Windings in Coggingless Motors

[0006] In patents US20070103025 and CN200610136515.X, several windings need to be assembled and rounded during the winding production process, which is difficult to process. At the same time, a single coil can only be wound into a rhombus structure, which is not suitable for a hexagonal winding structure; patent CN201310021865.1 and CN201310188734.2 proposed the winding mode of cogging-free windings and the combination of different windings, but these two patents still did not solve the technical problem of cogging-free motors at high power and high speed caused by parallel connection between phases.

[0007] Patent CN201710646697.3 proposes a nested winding for high-speed hollow cup motors. This patent is suitable for stacked windings, wave windings and concentric windings. This patent can reduce the eddy current phenomenon of air gap windings. At the same time, the patent mentions nested inner and outer The ring is wound by multiple strands, and the circulation between the multiple strands is reduced through a reasonable connection between the nested inner and outer rings, but the patent does not specifically propose that the nested inner and outer coils use single-strand winding due to the radial magnetic field distribution Phase-to-phase circulation caused by unevenness (for example, the circulation produced by the parallel connection of the nested outer coil phase A1 and the inner coil phase A2, the circulation produced by the parallel connection of the outer coil phase B1 and the inner coil phase B2, the circulation produced by the parallel connection of the outer coil phase C1 and the inner coil phase C2 circulation)

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