无刷双馈电机的建模与仿真

无刷双馈电机（BDFM）作为一种新型电机,兼有绕线式转子异步电机和同步电机的优良特性,尤其适合于变速恒频发电领域,通过分析无刷双馈电机的结构及工作原理,建立了基于转子速坐标系的d-q轴无刷双馈电机数学模型,根据所得的数学模型,对无刷双馈电机的各种运行方式进行了仿真分析,采用MATLAB/Simulink进行了计算机仿真研究,得出了各种运行方式下的仿真波形,仿真结果验证了数学模型的正确性和可行性,并得到了一些有益的结论.     

无刷双馈电机的开环仿真研究

通过以无刷双馈电机的转子侧dq0坐标系状态方程为电机模型,在MATLAB/SIMULINK的仿真集成环境下完成了对无刷双馈电机开环六拍阶梯波逆变器供电下的性能仿真.结果表明,无刷双馈电机的数学模型是正确的,为以后的闭环控制提供了依据.     

无刷双馈风力发电机在供暖系统中的应用

无刷双馈电机是一种新型特殊感应电机,在分析了无刷双馈电机的运行机理的基础上,设计一个功率5kW、6/2极的磁障转子无刷双馈风力发电取暖系统,基于场路耦合有限元法,仿真分析了在负荷相同情况下,不同转速下的磁障转子无刷双馈风力发电取暖系统运行状况.仿真结果表明:该电机在风电供暖系统是可行的,为无刷双馈风力发电机在供暖应用方面提供理论依据.     

提高无刷双馈电机效率的方法和途径

无刷双馈电机是一种新型的感应电机,可以降低调速系统的容量,对电网的谐波污染小,因而具有很好的发展前景。从无刷双馈电机的原理出发,分析定子和转子的损耗,进一步对定子绕组极数的选择、定子绕组的设计形式、转子绕组极数的选择以及转子绕组的设计等方面进行详尽说明和分析,总结出提高该类电机效率的方法和途径。     

基于高频信号注入双馈电机无传感器控制技术

针对控制系统中机械传感器存在的安装困难、易发生故障等一系列的问题,提出基于高频信号注入的无传感器检测法。分析了双馈电机使用高频注入法检测转子转速及位置的原理,即通过在双馈电机的转子侧注入高频信号,并提取在定子侧感应出的高频信号,经过锁相环检测算法,计算得出转子的位置及转速信号。建立了基于高频注入的双馈电机矢量控制模型,通过仿真和样机实验验证了双馈电机高频信号注入无传感器控制技术的可行性,为双馈电机的无传感器控制技术的实际应用奠定了良好的理论基础。     

综述无刷双馈电机的结构和运行原理

1．引言 无刷双馈电机（BmshlessDoubly—FedMachines,简称：BDFM）是由Hunt于20世纪初提出的．但是由于当时控制技术的限制,一直未能得到实际应用。随着电力电子技术和控制技术的发展,使得对双馈电机的控制成为可能。1980年初,Wallace等人在无刷双馈电机的控制绕组上加上频率和电压均可调的交流电源,将该电机与控制系统组成无刷双馈电机调速系统．实现了高效无级调速。而且可以实现变速恒频发电．     

无刷双馈磁阻发电机的设计与优化

为了合理引入磁障,抑制电枢反应磁势的交轴分量,提高并网时无刷双馈磁阻发电机发电能力,基于场路耦合有限元法对比研究了磁阻转子在不同极弧系数、不同磁障宽度、不同磁障形状、 不同磁障深度以及有、无磁障对发电机性能的影响.并在此基础上,提出一比较合理的无刷双馈磁阻发电机的并网设计方案.研究表明:在电机结构尺寸相同情况下,磁障的宽度和形状对电磁转矩影响不大,而极弧系数对输出电磁转矩影响较大.     

无位置传感器无刷直流电机的控制系统研究

本文主要介绍了一种无位置传感器无刷直流电机控制系统的硬件结构和软件系统,分析了无刷直流电机转子位置检测方法。该系统以PLC为核心监测转速的变化,采用3段式起动方法,并利用PLC串口和上位机进行通信。     

电磁阻尼对低速电机转子横向非线性振动的影响

对交流电机转子横振时电磁阻尼及考虑电磁阻尼时转子横振进行了研究.首先应用磁场理论求得了电机三相不对称运行时电磁阻尼力,并对三相对称时的电磁阻尼进行了计算.接着用拉格朗日-麦克斯韦方程求得了转子横向振动的方程,画出了三相对称时转子强迫振动的幅频曲线,并与实验进行了对照,实验结果与理论结果吻合的很好.     

交流圆弧磁悬浮感应电机机制研究

磁悬浮（无轴承）电机利用磁场力使转子悬浮并驱动其实现高速或超高速旋转．基于传统电机技术提出一种交流圆弧电机原理,并按电磁轴承悬浮技术,水平方向对称于转子布置2个圆弧电机,垂直方向对称于转子布置2个圆弧电机,构成交流磁悬浮感应电机;建立电机在干扰作用下转子与定子间的间隙（气隙长度）变化规律,基于电磁理论建立了气隙磁感应强度的分布规律,利用虚位移原理建立电机电磁悬浮力和电磁转矩数学模型;通过有限元分析对磁感应强度、电磁悬浮力和电磁转矩等分布特性进行了仿真研究．     

旋片式真空泵转子的有限元分析

利用ANSYS对旋片式真空泵的转子进行静力和模态分析,其结果为旋片式真空泵的设计提供了科学的参考数据,为进一步的有限元分析和优化设计提供了理论依据,从而提高了真空泵的设计质量。     

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In Experiment 1, boid and colubrid snakes defecated with shorter latencies after their home cages were cleaned than did control snakes that received equivalent handling without cage cleaning. Experiment 2 replicated this finding and also showed that snakes exposed to clean cages emit more tongue flicks after reintroduction to the clean home cage than do control snakes. Experiment 3 demonstrated that cage cleaning has similar effects in two species of crotalid snakes. The increase in tongue flicking after cage cleaning is interpreted as investigatory behavior and reflects the fact that snakes respond to the absence of familiar odors. Experiment 4 showed that a clean cage containing odors derived from snake feces produces less tone-flick exploration and fewer defecation responses in rattlesnakes than does a clean cage without such odors.     

Investigatory behavior in snakes,II: Cage cleaning and the induction of defecation in snakes

In Experiment 1, boid and colubrid snakes defecated with shorter latencies after their home cages were cleaned than did control snakes that received equivalent handling without cage cleaning. Experiment 2 replicated this finding and also showed that snakes exposed to clean cages emit more tongue flicks after reintroduction to the clean home cage than do control snakes. Experiment 3 demonstrated that cage cleaning has similar effects in two species of crotalid snakes. The increase in tongue flicking after cage cleaning is interpreted as investigatory behavior and reflects the fact that snakes respond to the absence of familiar odors. Experiment 4 showed that a clean cage containing odors derived from snake feces produces less tone-flick exploration and fewer defecation responses in rattlesnakes than does a clean cage without such odors.     

Modelling and verification of a new Roots blower profile based on analysis of performance of different leaf contour

The rotor of a Roots blower is the key component relating to its capability, so the profile design of the rotor in a Roots blower is extremely important. We focused on the modelling and verification for a novel Roots blower tooth profile based on the performance analysis. By comparing the area utilization coefficient and the ratio of several traditional rotor profiles, we proposed a new rotor profile. Then, we further accomplished the mathematical modelling of the proposed rotor profile and the computational fluid dynamics (CFD) simulation, and obtained the Roots blower outlet flow monitoring curves. Finally, we verified the characteristics by a physical experiment.     

Dynamic Stability Analysis of Cages in High-Speed Oil-Lubricated Angular Contact Ball Bearings

To investigate the cage stability of high-speed oil-lubricated angular contact ball bearings, a dynamic model of cages is developed on the basis of Gupta’s and Meeks’ work. The model can simulate the cage motion under oil lubrication with all six degrees of freedom. Particularly, the model introduces oil-film damping and hysteresis damping, and deals with the collision contact as imperfect elastic contact. In addition, the effects of inner ring rotational speed, the ratio of pocket clearance to guiding clearance and applied load on the cage stability are investigated by simulating the cage motion with the model. The results can provide a theoretical basis for the design of ball bearing parameters.     

波浪作用下单体与双体深水网箱水动力特性研究

本文运用刚体运动学原理及集中质量方法,建立了单体和双体深水网箱在波浪作用下的数学模型,并利用物理模型试验结果对数学模型进行验证。在此基础上,比较了单体网箱和双体网箱的水动力特性。由数值模拟结果可知,在相同波况条件下,双体网箱各类锚绳受力特征值均大于单体网箱对应工况各类锚绳的受力特征值,考虑双体网箱锚绳受力增加情况,其中锚碇锚绳受力平均增幅为65%,连接锚绳受力平均增幅为262.2%,网格锚绳受力平均增幅为95.6%;双体网箱浮架中心点的水平方向运动幅度总体上小于单体网箱对应情况,两种形式网箱的浮架中心点竖直方向运动幅度和倾角大小几乎相等,而两类网箱的网衣体积损失率总体上比较相近。     

基于LabVIEW的航空发动机转子故障诊断系统设计

以LabVIEW为开发平台,针对航空发动机转子系统的常见故障,利用数据采集卡采集故障信号,结合信号处理中的时频分析方法,设计了航空发动机转子故障诊断系统,并利用转子故障模拟实验器的实验数据验证了该系统的有效性.