Design And Analysis Of The Outer Rotor Permanent Magnet Synchronous Motor For Elevator

As a vertical transport vehicle, the elevator has become increasingly indispensable in people's daily life and economic production activities, and the research and development of high-performance motor has accordingly become an urgent matter.Permanent magnet synchronous motor has gradually drawn people's attention for its high performance, flexible control and stable operation, while in the elevator industry, the direct-drive permanent magnet synchronous motor traction system has become a favorite in elevator system research. Based on the technical indicators, the paper has designed a 4.1 KW permanent magnet synchronous elevator motor and analyzed it by the finite element methodology.This paper first studied the inherent problem of the permanent magnet synchronous motor(PMSM)- the cogging torque, and then deduced the causes and analytic formula of the cogging torque, from which and the perspective of the structure of elevator with permanent magnet synchronous motor the paper analyzed several feasible methods to weaken the cogging torque and verified them by the finite element simulation. At the same time, calculated by the parameter Nc and CT, the size of the cogging torque in several alternative plans can be judged during the preliminary process motor design.Secondly, this paper analyzed the magnetic flux leakage in the addendum produced by the common slot structure near the pole of the elevator motor. Then, the paper studied the causes of the leakage, its analytic formula and the methods to weaken the leakage.It is concluded that the size of the tip leakage can be changed accordingly due to the differences in the extreme slot combination, arc coefficient, crown height and so on, then combined with the finite element method(fem), the paper has carried on the simulation analysis on the effects of various parameters change.Finally, according to the special structure in the elevator outer rotor polar slot of the permanent magnet synchronous motor and considering the prominent problems that affect its performance in the tip leakage and the cogging torque, a set of suitable equivalent magnetic circuit model is deduced, and a 4.1 k W elevator motor was designed by utilizing the model. Targeted on suppressing the cogging torque and addendum magnetic flux leakage,the paper proposed a variety of solutions on changing motor parameters and conducted simulation comparison respectively with the finite element method(fem), and finally the scheme of the motor was established.