Study on unit combination type direct-driven submersible permanent magnet motor

Conventional submersible motor manufacturing process, operation and repair difficult technology, puts forward a submersible direct drive the super thin unit combination type permanent magnet motor. This paper introduces the composition and structure characteristic of the motor. Through establishing 2D finite-element analysis model of the submersible motor and curve fitting by parameter calculations, the relationship curve between the air magnetic bridge width and the leakage flux coefficient is given out. The waveform of the air-gap magnetic field and the harmonic content are analyzed with the finite element method to obtain the waveform deviation factor-pole eccentricity curve and the optimal eccentricity. Then get the curve between the no-load back-EMF with the groove depth of stator yoke based on a series of finite element calculations. At last, the 3D finite element calculation results verify the motor stator, rotor structure optimization design effectiveness. The structure of the unit combination type permanent magnet synchronous motor is feasible, and can be widely applied to the submersible screw pump system.