Design of a High Reliability and High Performance Permanent Magnet Synchronous Motor Used in Oil-Submersible Electric Pump System

Submersible permanent magnet synchronous motors (SPMSM) operate in harsh and complex environments, so reliability is the basis of motor design. However, the diameter limitations of the oil pipe and the limitation of slot fill factor make the performance of SPMSMs lower than the conventional PMSMs. This paper analyzed the design limitations in SPMSMs, pointing out the necessity of saturated magnetic circuit design, and gives a high-reliability and high-performance scheme based on the finite element method (FEM). The single-layer winding and parallel slots are adopted in stator to improve the empirical slot fill factor, and the double-layer “1+V” type permanent magnets (PMs) are adopted in rotor to improve the saliency ratio and torque. Furthermore, the maximum rotor stress, the anti-demagnetization performance of the PMs and the steady-state temperature rise of the motor were also calculated in this paper. Finally, the proposed SPMSM is fabricated and tested to confirm its feasibility.