Research On The Driving Characteristics Theory Of Permanent Magnet Linear Motor & It's Optimal Design Of Force Ripple

With the support of the key project of Zhejiang province science and technology Program, this dissertation studies the electromagnetic field model and characteristics analysis in details. The dissertation can be divided into eight chapters.In chapter 1, the value and aim of the dissertation are stated. At first, the application and research actuality of the linear motors direct-driving technology in the machining tools and electronic industry-specific equipments at home and abroad are reviewed. Then the main content of the dissertation is presented.In chapter 2, a novel general space harmonics field analysis model is developed to determine the magnetic field distribution in various permanent magnet linear motors. In this model, the spatial distribution of current and PM is replaced by the Equivalent Magnetizing Current(EMC). And the EMC model was employed to solve the magnetic field distribution of air cored and slotless Permanent Magnet Linear Synchronous Motor (PMLSM), the computed results by the proposed model are compared with those generated from finite element method, which show in good agreements.In chapter 3, based on the equivalent magnetometive function, the slot effect model of air gap magnetic field in iron-cored slotted PMLSM was presented by Schwarz-Christoffel Transformation. Combined with the above EMC model, the air gap magnetic field distribution of iron-cored slotted PMLSM was analyzed with the slot effect taken into account, and computed results by the proposed model are compared with those generated from finite element method, which show in good agreements.In chapter 4, combined the magnetic field distribution generated from above model with equivalent magnetic circuit, electromagnetic parameters such as synchronous reactance, reaction reactance, leakage reactance and back electromotive force constant etc. were concluded, and the steady-state operation characteristics were disclosed. Further the steady-state operation performance analysis were completed, including the phase voltage and frequency impact on thrust and power, thrust—power angle characteristic, thrust constant, power equation etc.In chapter 5, finite element method was employed; the thrust and normal force were computed under the conditions of different currents virtual values with fixed...