Research On Rotor Topology And Strength Of Megawatt High-Speed Permanent Synchronous Magnet Motor

High-speed permanent magnet motors are widely used in industry due to their high power density,small size,light weight and high efficiency.The rotor structure of the permanent magnet motor,especially the permanent magnet structure,has a great influence on the performance of the motor,and its design has strong flexibility,so it is of great significance to study the influence of the rotor topology on the performance of the motor.High-power high-speed motors limit their maximum power and speed due to their heat generation and rotor mechanical strength.Therefore,for the megawatt high-speed permanent magnet motor,the rotor strength problem is more prominent,and the precise calculation of the rotor strength is an important step in the design of the high-speed permanent magnet motor.In this thesis,the electromagnetic design,permanent magnet pole structure and rotor stress of megawatt high-speed permanent magnet generator will be studied.In order to match the characteristics of small size and high speed of high-speed permanent magnet motor generator,this thesis designs and determines the rotor topology structure scheme of high-speed permanent magnet motor generator,analyzes the electromagnetic characteristics of the motor,and gives a preliminary electromagnetic design scheme.Several different permanent magnet pole structures are compared,and the effects of different magnetization methods of permanent magnets on the performance of the motor are comparatively studied.The influence of the eccentric distance of the eccentric magnetic pole of the inner arc and the eccentric magnetic pole of the outer arc on the air-gap flux density under different magnetization methods,an optimization scheme is proposed,and the simulation results show that the optimization effect is obvious.Aiming at the problem that the megawatt high-speed permanent magnet motor is greatly affected by the cogging effect,an appropriate magnetic slot wedge is designed,and the influence of the magnetic permeability characteristics of the magnetic slot wedge on the motor performance is proposed and analyzed.In order to verify the feasibility of the rotor structure scheme,the mechanical strength of the rotor of the megawatt high-speed permanent magnet motor is analyzed,the stress on the rotor is theoretically and numerically analyzed,the stress on different rotor structures is discussed,and a comparative analysis is made.For the safety of different rotor structures,the influence law of the inter-pole filling material,sheath thickness,temperature,speed and other factors on the stress of each part of the rotor is given.The research results of this thesis provide a reference for the comprehensive design of megawatt high-speed permanent magnet generators.