Alternating pole brushless permanent magnet motor and electronic power steering system based on the motor

Abstract

The invention discloses an alternating pole brushless permanent magnet motor, which is used in an electronic power steering system. The motor includes: a stator core in the shape of a hollow cylinder, the inner wall of which has slots, and the stator windings are placed in the corresponding stator slots. Inside; the rotor core in the shape of a hollow cylinder is coaxially sleeved in the central through hole of the stator cylinder, and its outer surface is provided with a plurality of slots, and the number of slots is half of the number of poles in the operating magnetic field of the motor; and a plurality of Magnetic steel, which is placed in each slot of the rotor core in one-to-one correspondence, and the polarity of the magnetic steel in adjacent slots is the same, so that the rotor magnetic steel only has a single polarity, forming a salient pole structure, thereby reducing the amount of permanent magnets while maintaining the output torque of the motor. The invention also discloses a corresponding electronic power steering system. The device of the invention optimizes and improves the rotor structure of the permanent magnet motor, reduces the permanent magnet consumption of the motor rotor and can save the position sensor of the power steering system.

Description

technical field [0001] The invention belongs to the technical field of power steering systems, and more particularly relates to a brushless permanent magnet motor used in a power steering system and an electronic power steering system based on the motor. Background technique [0002] The power steering system is an important part of modern automobiles. Its main function is that when the driver steers the steering wheel, the torque sensor detects the steering wheel's steering and the magnitude of the torque. The motor controller issues instructions to control the motor to output steering assist torque of corresponding magnitude and direction, thereby generating auxiliary power. [0003] At present, the power steering system of automobiles generally adopts the hydraulic power steering system. It can be said that after more than ten years of development, the hydraulic steering technology is relatively mature. However, from the development trend of the entire steering system, as...

AI Technical Summary

Problems solved by technology

[0009] Although the existing brushless permanent magnet motors used in electronic power steering systems can realize electronic commutation through external circuits, the brushes and commutators required by brushed DC motors are omitted, thereby avoiding commutation sparks and carbon brushes. However, since the N pole and S pole of the rotor magnetic field are composed of permanent magnets, the amount of permanent magnets is relatively large, especially the amount of rare earth permanent magnets is large, resulting in high cost and environmental impact.

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