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题名	直线感应电机磁场定向与效率优化控制研究; 直线感应电机磁场定向与效率优化控制研究
作者	1任晋旗,电工研究所
学位类别	博士
答辩日期	2008-06-06
授予单位	中国科学院电工研究所
导师	1李耀华,电工研究所
关键词	直线感应电机 磁场定向控制 在线参数辨识 效率优化控制 模型法 黄金分割搜索法 linear induction motors field oriented control on line parameter identification efficiency optimization control the loss model method the golden section search method
其他题名	直线感应电机磁场定向与效率优化控制研究
中文摘要	直线感应电动机结构简单、坚固耐用，能够直接产生直线机械运动，不需要中间传动转换装置，因此在工业生产、交通运输等部门应用广泛。直线感应电动机用于轨道交通具有非黏着牵引、噪音低、初期投资较小、经济适用性好等优点，是一种具有良好前景的城市交通方式。由于直线电机气隙较大，效率一般较低，采用效率优化控制能够减少其运行能耗，因此具有重要的意义。 直线电机结构特殊，存在边端效应，对电机特性影响很大，相比旋转电机，电机的数学模型更为复杂。本文在建立直线感应电机动态数学模型的基础上，推导了间接磁场定向控制方程，实现了直线感应电机的磁场定向控制，动态补偿励磁电流分量，该方法能够保持电磁推力恒定，实现较快的电机动态响应速度。 直线电机运行时存在动态边端效应，对气隙磁通和励磁电感等影响很大。本文提出了基于模型参考自适应系统的励磁电感参数辨识算法，能够计算电机动态励磁电感参数，辨识结果符合电机动态特性，调整模型能够准确计算电机的初级电流和次级磁链，为电机的特性分析和控制提供准确的数学模型。 本文研究了基于模型法的直线感应电机效率优化控制策略。指出直线电机初级漏感较大，如果忽略其影响，将造成较大的损耗计算误差。提出了包含初级漏感铁损的损耗模型，根据该损耗公式推导效率优化控制算法，得到初级励磁、推力电流分量比值的最优关系，能够提高不同速度和负载工况下电机的稳态运行效率，特别能够提高轻负载工况下的电机效率，而且采用优化算法没有明显影响电机运行的动态特性。 本文提出基于搜索法的效率优化算法，在线测量电机输入功率，以损耗最小为优化目标，采用黄金分割算法搜索初级励磁、推力电流分量的最优比值，实现了直线感应电机的效率最优控制。提出的算法不依赖电机的模型和参数，能够提高轻负载工况下的电机效率。当负载、推力变化时，保持最优效率点运行，不需要重新启动搜索算法，具有较快的搜索速度。 本文比较了模型法和搜索法两种效率优化控制方法在轨道交通直线牵引电机中的应用，由于城市轨道交通的运行区间较短，稳速运行区间也较短，采用搜索法进行效率优化控制的寻优时间较长，采用模型法进行效率优化控制又受到实际工况和电机参数变化的影响。因此，提出两者相结合的控制策略，利用搜索法寻找运行工况的最优电流比值，在实际运行时按照已经搜索的结果进行优化控制，是一种较为实用的效率优化控制策略。 Linear induction motor is durable and simple in structure, able to direct drive and needs no intermediate mechanical drive gear, thus it is widely used in industrial and transportation applications. Linear induction motor for rail transportation has many merits such as non-mount traction, low noise, smaller initial investment and good economic applicability and is a promising urban transport means. Since the air gap of the linear induction motor is larger which results in low efficiency, it is of great significance to introduce the efficiency optimization control and reduce the operation energy consumption. Linear induction motor has special structure with end or edge effects which influence the electrical characteristics greatly. Compared with that of rotary motor, the model of linear induction motor is more complicated. Based on the establishment of linear induction motor dynamic model, the indirect field-oriented control scheme is derived in the paper. Dynamic magnetizing compensation method is applied to achieve good dynamic response and keep almost constant electromagnetic thrust. The dynamic end effects existing in the operation process affect the air-gap flux and magnetizing inductance greatly. This paper presents a magnetizing inductance identification algorithm based on model reference adaptive system, the dynamic magnetizing inductance can be calculated, and the experimental results are in accordance with the property of linear induction motor influenced by dynamic end effects. The proposed adjustment model can accurately calculate the primary currents and secondary fluxes, and provide mathematical model for control and motor performance analysis. In this paper, loss model based efficiency optimization control strategy is proposed. As well known, the primary leakage inductance of linear induction motor is larger, thus it can not be neglected in the motor loss model. The loss model including the iron loss of primary leakage inductance is presented and the efficiency optimization control algorithm is derived, the optimal ratio between primary magnetizing and thrust current components can then be determined. By maintaining the optimal ratio of current components, the motor efficiency can be improved in all of the speed and load conditions of the steady-state operation, especially in light load range, and the dynamic response is not degraded too much. This paper presents search method based efficiency optimization scheme for linear induction motor also. Golden section search algorithm is used to find the optimal ratio between primary magnetizing and thrust current components by on-line measuring the electrical input power and optimize to the smallest loss and improve the operation efficiency. The algorithm does not rely on the motor model and parameters and can improve the efficiency under light load working condition. When the load or the thrust changes during operating, it can keep to running while maintaining optimal efficiency and does not need to restart the search algorithm, thus it is a comparatively fast optimization method. This paper compares the application of two efficiency optimization methods proposed above in the linear induction motor traction transit line. Usually, the interval of urban rail transport in operation is short and the steady speed operation period is also short, on the other hand, the hunting time for optimal is long as for the search efficiency optimization method while the loss model method is subject to the change of motor parameters. The paper proposes combination of the two control strategy, in which search method is used to find the optimal ratio, and during the real operation process, it is force to track the optimal search results obtained beforehand. The combination method proposed is practical by validation.
语种	中文
公开日期	2010-10-18
页码	106
分类号	TM1;TM921
内容类型	学位论文
源URL	[http://ir.iee.ac.cn/handle/311042/6762]
专题	电工研究所_其他部门_其他部门_博士学位论文
推荐引用方式 GB/T 7714	1任晋旗,电工研究所. 直线感应电机磁场定向与效率优化控制研究, 直线感应电机磁场定向与效率优化控制研究[D]. 中国科学院电工研究所. 2008.

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