初级绕组分段永磁直线同步电机端部效应研究

发布时间：2018-04-05 00:40

本文选题：永磁直线同步电机　切入点：绕组分段　出处：《哈尔滨工业大学》2014年博士论文

【摘要】：长初级永磁直线同步电机具有动子质量小、可靠性好等优点，并可综合考虑效率、可控性及安全生命周期等因素，采用模块化和标准化设计，在高速及长行程运动场合具有广阔的应用前景。模块组合电机能够灵活实现多种拓扑类型的匹配，本文以连续定子型初级绕组分段永磁直线同步电机为研究对象。由于次级与绕组分段的初级模块均为有限长，双“开断”的纵向端部令初级绕组分段永磁直线同步电机具有与传统直线电机不同的电磁特性。本文通过分析两类端部效应的影响机理和作用规律，探索计及端部效应的磁场解析与磁路模型修正计算方法，开展双端部效应影响下的电磁参数及电磁力波动问题的研究，总结电机设计及运行中的规律性特征，实现对电机数学模型的准确描述和应用拓展研究。首先结合运动及驱动方式分析初级模块化、分段长度及极槽配合等电磁方案的配合准则与适用范围。在此基础上，针对长初级电机损耗大的问题，开展以最大电机常数为优化目标的电磁负荷配比研究，获得不同极槽配合电机的最优配比计算方法，为电机主要设计尺寸的确定提供参考；随后开展分段永磁直线样机的电机常数测试研究，并指出该常数可作为电机磁饱和状态的灵敏性表征量。通过异型磁极磁场的细分逼近分析、半开域磁场边界确定等求解问题的处理，进行初级模块区域磁场储能的计算,获得段间过渡时磁场动态行为的数学描述。上述分析为后续电机两类端部效应问题的深入探究奠定理论基础。在次级有限长所引起的端部效应研究中，首先建立次级纵向端部效应的数学模型，基于区域边界条件法解析获得计及该端部效应的磁场计算修正因子，并总结出端部效应对气隙磁场的影响规律。研究表明，，次级端部效应引起了不均匀分布的气隙磁场和局部饱和现象，选择合理的端部磁极尺寸比及次级轭板延伸长度可抑制其影响。继而开展计及次级端部效应的电机空载磁路模型简化等效研究，并在此基础上深入分析电机的空载漏磁系数及永磁磁链参数特征，通过反电势测试及磁链计算验证了分析结论。在绕组分段的初级模块端部效应研究中，主要分析了端部未通电铁心对模块端部磁场的影响，获得不同边界条件下初级模块的电感不平衡规律。研究结果表明，齿槽类直线电机的端部漏磁场沿铁心的延伸路径受制，端部铁心长度的变化对端部磁场的影响微弱；集中绕组电机首段和尾段的端部绕组自感要低于中间区域绕组。通过初级模块的不对称特性实验进行验证，同时获得影响电流不对称状态的关联与非关联因素。进而基于解析及有限元法分析电机的段间电感及其不平衡特性，探究组合尺寸与段间电感的关系。计算结果表明，基于区域磁场储能函数化及端部储能等效补偿的能量摄动法可较准确地对段间相电感进行参数化分析。对考虑两类端部效应的磁场计算、磁路等效方法以及关联电磁参数的研究实现了电机电磁关系的准确表达，是探索更为便捷的电机静、动态特性分析方法的重要环节和基础，同时分析过程中所确立的设计准则对电机精细化设计具有重要的指导意义。基于区域及端部效应磁场特征，开展电机关键参数的计算及测试方法研究。首先由自、互感波形的谐波系数得到交、直轴电感及其耦合电感的电流与位移特性，并提出正弦激励结合微分计算的方法进行耦合电感电流特性的实验研究。计算结果表明，集中绕组电机首段、中间段与尾段的耦合电感波形在相位和幅值上具有差异性，首段初级的耦合电感波形峰峰值最大，中间段的峰峰值最小。随后提出分区域的计算方法开展电机铁耗的速度与负载特性研究，进而得到不同组合状态中初级模块铁耗的变化规律。提出分段直线电机参数拓展研究的思路，在各类参数分析中，构建其与基本组合尺寸的关系，扩展现有电机数学模型的适用范围，并在此基础上了搭建考虑铁耗的初级绕组分段永磁直线同步电机的动态仿真模型。两类纵向端部效应是初级绕组分段永磁直线同步电机电磁力波动的重要来源。首先提出永磁直线同步电机定位力的统一解析模型，获得电机定位力的频率特性，并结合电势电流法分析电机的推力波动特征，随后提出了端部分裂磁极、端部和中间极面不等极弧系数等端部磁场优化方法，实现了电机中特有波动力的有效抑制。针对分段电机中不一致的机械气隙状态，以及段间过渡时相邻两段初级绕组电流存在的误差量等非理想电磁状态，开展电磁力波动特性的研究。研究结果表明，在发生气隙或电流偏差时，推力波动中的2p次及其倍数次谐波显著；段间电流幅值偏差会引起推力平均值和波动量均发生变化，而相位偏差仅引起波动量变化。这些分析将为新型高可靠性直接驱动系统的开发及其应用范围的拓展奠定理论和技术基础。
[Abstract]:This paper analyzes the influence mechanism of two kinds of end effects and the calculation method of magnetic circuit model , and studies the electromagnetic parameters and electromagnetic force fluctuation problem under the influence of double - end effect .

In this paper , the matching criterion and the applicable scope of the electromagnetic schemes such as the primary modularization , the sectional length and the pole slot matching are analyzed in combination with the motion and the driving mode . On the basis of this , the optimal matching calculation method is carried out with the maximum motor constant as the optimization target aiming at the problem of large loss of the long primary motor , and the reference is provided for the determination of the main design size of the motor ;
This paper studies the motor constant test of the segmented permanent magnet linear prototype , and points out that the constant can be used as the sensitive characterization of the magnetic saturation state of the motor . Through the subdivision approximation analysis of the special - shaped magnetic pole magnetic field and the determination of the magnetic field boundary of the semi - open field , the mathematical description of the magnetic field dynamic behavior at the time of transition between segments is obtained .

In the research of the end effect caused by the secondary finite length , the mathematical model of the secondary longitudinal end effect is first established , and the influence law of the end effect on the air gap magnetic field is analyzed based on the regional boundary condition method .

In the study of the end effect of the primary module of the winding section , the influence of the non - energized iron core on the magnetic field of the end part of the module is mainly analyzed , and the unbalance law of the inductance of the primary module under different boundary conditions is obtained . The results show that the leakage magnetic field of the end part of the tooth slot linear motor is restrained along the extension path of the iron core , and the influence of the change of the length of the core iron core on the magnetic field of the end part is weak ;
Based on the analysis and the finite element method , the relationship between the size of the motor and the inter - section inductance is obtained . The calculation results show that the energy perturbation method based on the analysis and finite element method can accurately express the inductance between the segments . The calculation results show that the magnetic field calculation , the equivalent method of the magnetic circuit and the correlative electromagnetic parameters have realized the accurate representation of the electromagnetic relationship of the motor .

Based on the characteristics of region and end effect magnetic field , the calculation and test methods of key parameters of the motor are studied . First , the harmonic coefficients of the self - inductance and mutual inductance are obtained , the current and displacement characteristics of the coupling inductance of the direct - axis inductance and the coupling inductance are studied . The calculation results show that the coupling inductance waveform of the first segment , middle segment and tail section of the concentrated winding motor is different in phase and amplitude .

Two kinds of longitudinal end effects are the important sources of electromagnetic force fluctuation of the permanent magnet linear synchronous motor of the primary winding . Firstly , a unified analytical model of the positioning force of the permanent magnet linear synchronous motor is put forward to obtain the frequency characteristic of the motor positioning force .
These analyses will provide a theoretical and technical basis for the development of a new high reliability direct drive system and its application range .

【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TM341

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