Design And Optimization Of Permanent Magnet Tubular Linear Generator

With the deepening of the global energy crisis, wind power generation, photovoltaic power generation,wave energy power generation, solar thermal power generation and other renewable energy power generation have become research hotspot at home and abroad. The main contents of this thesis are to study a type of permanent magnet tubular linear generator that is used in solar thermal power generation system.In the dish Stirling solar thermal power generation system,permanent magnet linear generator as the electromechanical energy conversion device,has important influence on generation efficiency and output power quality.In this thesis,the related analysis,design,optimization about permanent magnet tubular linear generation have been carried on.This thesis has set forth the status of research and development about permanent magnet tubular linear generator,also the structure,classification and work-principle are illustrated simply.The model's establishment and electromagnetic analysis of this generator have been done by the finite element software Ansoft Maxwell.By changing the size and ratio of permanent magnet,also changing the stator's tooth width,the relationship between EMF and parameters above is obtained and analyzed.Due to the analysis above does not take the main parameters' mutual change into account,so in order to minimize the total harmonics distortion,parameters above are futher optimized by orthogonal design,and the best sizes are acquired.According to this optimized generator,its with-load output characteristic is analyzed,the output voltage and power's curves are obtained.This study is an important foundation for the next step about power conversion.Accurate permanent magnet motor steady-state parameters such as armature reactance inductance and permanent magnet flux are essentially necessary for many performance simulations and motor design's rationality and control strategies based on d-q coordinate system.The parameters are difficult to be calculated by regular approach because they are seriously affected by the cross saturation effects.To overcome this problem,taking the finite element method as a powerful tool,a freeze element permeability method is proposed to linearization of the nonlinear field problem,and the steady-state parameters varying with d-axis and q-axis current are worked out.The d-axis and q-axis inductances are analyzed and obtained.This thesis also has analyzed the detent force that exist in generator,discussed the cause of detent force,deduced the expressions of cogging force and edge-side force,also discussed the measures to reduce the edge-side force and the cogging force.The optimal design of this generator has performed by changing the length of stator's axial and the height of side-end tooth,optimal size of axial length and tooth height were obtained.