Behavior and functional modeling methods of doubly salient electromagnetic generators for aircraft electrical power system applications

The Doubly Salient Electromagnetic Generator(DSEG) is a promising candidate in aircraft generator application due to the simplicity, robustness and reliability. However, the field windings and the armature windings are strongly coupled, which makes the inductance characteristics non-linear and too complex to model. The complex model with low precision also leads to difficulties in modeling and analysis of the entire aircraft Electrical Power System(EPS). A behavior level modeling method based on modified inductance Support Vector Machine(SVM) is proposed. The Finite Element Analysis(FEA) inductance data are modified based on the experiment results to improve the precision. A functional level modeling method based on input–output characteristics SVM is also proposed. The two modeling methods are applied to a 9 kW DSEG prototype. The steady state and transient process precision of the proposed methods are proved by comparing with the experiment results. Meanwhile, the modeling time consumption, the application time consumption and the calculation resource demand are compared. The DSEG behavior and functional modeling methods provide precious results with high efficiency, which accelerates theoretical analysis and expands the application foreground of the DSEG in the aircraft EPS.     

Mathematical modeling of an armature assembly in pilot stage of a hydraulic servo valve based on distributed parameters

The dynamic performance of a nozzle-flapper servo valve can be affected by several factors such as the disturbance of the input signal, the motion of the armature assembly and the oscillation of the jet force. As the part of vibrating at high frequency, the armature assembly plays a vital role during the operation of the servo valve. In order to accurately predict the transient response of the armature assembly during the vibration, a mathematical model of armature assembly is established based on the distributed parameters method (DPM) and Hamilton principle. The new mathematical model is composed of three main parts, the modal eigenfunction, modal mechanical response expressions of the spring tube and the motion equation of the other armature assembly. After programing, the purpose of using the DPM to predict the dynamic response of different positions located on the armature assembly is achieved. For verifying the validity of the mathematical model, the finite element method (FEM) and classic model (CM) of armature assembly are applicated by commercial software under the same condition. The comparison results prove that the DPM can effectively predict the axial and tangential deflection of the armature assembly different positions which the CM can’t duing to its over-simplification. A certain error is generated when predicting the axial deformation at different heights by DPM, which is caused by an approximate method to simulate the torsion of the spring tube. The comparison results of the spring tube deflection at different vibration frequencies shows that the adaptability of DPM is significantly higher than the classic model, which verify the model is more adaptable for predicting the dynamic response of the armature assembly.     

超磁致伸缩电静液作动器磁场分析与优化

提出一种超磁致伸缩电静液作动器（GMEHA）结构,采用永磁体与控制线圈组合提供驱动磁场.首先建立了该组合磁路数学模型,并给出了超磁致伸缩棒内磁感应强度计算解析式;其次,对以上结构进行了有限元分析（FEA）,得出了磁路主要结构参数与磁场分布均匀性之间映射规律;最后进行了作动器磁场试验研究并与有限元分析结果进行了对比,验证了理论与有限元模型的可预测性,给出了该电静液作动器结构设计方法.结果表明:该电静液作动器的最佳驱动频率为250Hz,最大无负载体积流量为0.85L/min,最大阻断力达到了120N.      

A multi-parameter model of heat treatment process for soft magnetic materials on performance of HSERs

Material properties play an important role in the performance of electromagnetic mechanism. For an aeronautic Hermetically-Sealed Electromagnetic Relay (HSER), more than 50% parts are made of soft magnetic materials. Therefore, the performance of soft magnetic materials directly determines the static and dynamic characteristics of the HSER. Based on the theory of crystal recrystallization, this paper analyzes cold extrusion and heat treatment in the processing of soft magnetic materials, simulates the grain change process of an armature at different heat treatment temperatures, establishes a correlation model of temperature, grain size, and magnetic energy, and verifies results by scanning electron microscopy. Results of heat treatment temperatures from 800 °C to 920 °C are obtained and compared. A sample soft magnetic material after heat treatment at different temperatures has the largest difference in the initial magnetization range, up to 22%. In order to verify the fluctuation of the overall output characteristics of an HSER caused by the difference between soft magnetic materials, a static and dynamic analysis model of a typical HSER is established, and the accuracy of the model is verified by a set of actual test system. The difference of dynamic characteristics under different heat treatment temperatures is nearly 3%.     

A fault-tolerant triple-redundant voice coil motor for direct drive valves: Design, optimization, and experiment

A direct drive actuator (DDA) with direct drive valves (DDVs) as the control device is an ideal solution for a flight actuation system. This paper presents a novel triple-redundant voice coil motor (TRVCM) used for redundant DDVs. The TRVCM features electrical/mechanical hybrid triple-redundancy by securing three stators along with three moving coils in the same frame. A permanent magnet (PM) Halbach array is employed in each redundant VCM to simplify the system structure. A back-to-back design between neighborly redundancies is adopted to decouple the magnetic flux linkage. The particle swarm optimization (PSO) method is implemented to optimize design parameters based on the analytical magnetic circuit model. The optimization objective function is defined as the acceleration capacity of the motor to achieve high dynamic performance. The optimal geometric parameters are verified with 3D magnetic field finite element analysis (FEA). A research prototype has been developed for experimental purpose. The experimental results of magnetic field density and force output show that the proposed TRVCM has great potential of applications in DDA systems.     

考虑磁场饱和的双定子永磁同步发电机的磁路模型

双定子永磁同步发电机(DSPMSG)包括内外两个定子和中间的转子,一般的电磁场计算软件计算比较困难。建立DSPMSG的磁路计算模型,利用铁磁材料的磁化特性曲线考虑磁场饱和,并同时考虑内、外两套绕组电枢反应对永磁磁场的影响,可对电机的性能参数进行计算,便于设计变量的及时快速调整。通过对1台3.3 kW样机的磁路计算和有限元计算的比较,证明了该模型的有效性和实用性。     

Generalized model of brushless DC generator

A generalized model is described for a brushless DC machine consisting of a multiphase synchronous machine with a full-wave bridge rectifier connected to its output terminals. The state-variable equations for the machine are suitable for numerical integration on a digital computer, and are assembled in a form which permits investigations to be made on the effects of different numbers of armature phase windings and different winding connections. The model has been used in both steady-state and transient studies on a number of generating units, with the detailed information which is provided being beneficial to design engineers. Comparisons presented between predicted and measured results illustrate the validity of the model and the mathematical techniques adopted, and confirm that accurate information on the performance of a brushless generator may be obtained prior to manufacture     

基于ABAQUS的混杂纤维增强复合材料固化变形模拟

针对混杂纤维增强复合材料固化变形问题,以两种纤维增强双马树脂基复合材料为研究对象,建立了一种基于ABAQUS的混杂纤维增强复合材料固化变形预测模型。大尺寸(500 mm×500 mm)平板固化变形实验结果表明,建立的有限元数值模拟计算方法能够较准确的预测混杂纤维增强复合材料固化变形的变形趋势和最大变形量,最大变形量测算误差约为10%~15%。     

锪窝孔边扇形角裂纹应力强度因子的三维有限元分析

 根据航空等领域内锪窝铆接及锪窝锣接构件的典型结构特征,采用三维的十节点四面体等参有限单元模型,分别对无裂纹及孔边含裂纹锪窝孔 /直通孔结构进行了模拟分析;得到了锪窝孔构件的危险部位及90°,120°锪窝孔边扇形角裂纹的应力强度因子,给出了覆盖面广的计算曲线;通过对计算结果的分析,讨论了裂纹长度、孔径以及板厚等因素对应力强度因子的影响。和已有的文献比较表明,本文数值结果精确,方法可靠。     

高速开关阀非定常磁场的有限元计算

高速开关阀滞后的主要原因是电感元件存在滞后,这很容易通过加一个高电压产生过电流而去磁得到补偿。由于磁场存在涡电流,因此限制了阀的快速性的提高,而且阻碍磁力线渗入电磁铁。采用先进的有限元方法,得到了电流和磁通量的瞬态特性,以及磁力线渗入电磁铁的瞬态过程,从而得到涡电流对高速开关阀的影响。通过过电流去磁和使用低导电材料可以降低高速开关阀的滞后。     

某型民用运输机主起落架连接区结构静力试验

飞机静力试验是飞机试验的重要内容之一,是验证飞机结构强度和静力分析正确性的重要手段。为验证某型民用运输机主起落架连接区结构满足静强度要求,以及有限元计算分析的正确性,在静力试验飞机上进行了主起落架连接区结构静力试验。通过全机有限元模型和细节有限元模型分析计算,进行加载、应力\应变、位移试验数据与有限元计算值的分析对比,计算值与试验数据符合较好。     

Interleaved boost converter with zero diode reverse-recovery loss

A three-phase interleaved continuous-inductor-current-mode (CICM) boost converter with zero diode reverse-recovery loss is proposed. In the converter, the di/dt of the output rectifiers is controlled by an integrated magnetic component. All the output rectifiers can be turned off softly and a very high efficiency is obtained. The equivalent-circuit model of the integrated inductors, the operation principle of the converter, and the design issues are discussed. Simulation and experimental results are presented.     

超磁致伸缩电静液作动器的试验研究与特性分析

超磁致伸缩材料驱动的电静液作动器具有结构高度集成、性能影响因素多以及理论分析复杂等特点,为寻求超磁致伸缩电静液作动器可靠的理论分析方法以提高其输出性能,首先搭建了超磁致伸缩执行器与作动器试验测试平台,完成了执行器与作动器动态特性对比试验,在准确测试与观察试验现象的基础上,对超磁致伸缩电静液作动器进行结构分解,以各环节固有频率为理论分析切入点,采用试验、理论与有限元分析相结合的方法,分析了悬臂梁阀片、管路、液压缸以及蓄能器等动态特性对作动器输出性能的影响规律,总结出符合试验结果的理论分析方法并确定了影响与制约作动器输出性能的关键环节,最后提出了超磁致伸缩电静液作动器优化改进方案,优化后作动器试验结果显示：在200 Hz左右、0.6 MPa 的偏压作用下,选取 0.15 mm 厚度的阀片,作动器的输出性能达到最佳,其输出流量最大可达1.2 L/min。     

背绕式有槽永磁同步电机的电磁场解析模型

以1台5 kW背绕式高速永磁同步电机为研究对象,建立其电磁场解析模型。将电磁场求解域划分为气隙子域、永磁体子域、槽口子域和槽子域,求解相应的拉普拉斯方程或泊松方程,解析模型计及电枢反应场、永磁场和定子开槽的影响。计算了该电机的气隙磁密、绕组磁链、绕组反电动势、齿槽转矩和电磁转矩,并将结果与二维有限元法计算结果和试验数据比较,比较结果说明了解析模型的准确性。最后以槽口开度为变量,研究其对气隙磁密分布和齿槽转矩的影响。     

基于磁链重构的永磁同步电机分布参数模型

针对基于电感的永磁同步电机(PMSM)线性集中参数模型无法描述电机磁路饱和、反电动势非正弦等非理想特性的问题,提出一种基于磁链重构的PMSM分布参数模型,并进行了仿真和试验验证。首先通过有限元分析(FEA)获取电机不同工作点下的磁链,其次利用傅里叶级数展开和多项式拟合方法对磁链进行重构,再根据重构的磁链建立起PMSM分布参数模型,并进行了仿真和试验验证。仿真和试验结果表明,模型能准确描述PMSM在不同工况下的非线性特性。     

Neural Network aided PMSM multi-objective design and optimization for more-electric aircraft applications

This study uses the Neural Network(NN) technique to optimize design of surfacemounted Permanent Magnet Synchronous Motors(PMSMs) for More-Electric Aircraft(MEA)applications. The key role of NN is to provide dedicated correction factors for the analytical PMSM mass and loss estimation within the entire design space. Based on that, a globally optimal design can be quickly obtained. Matching the analytical estimation with Finite-Element Analysis(FEA) is the main research target of training the NN. ...     

同步感应线圈发射器电磁场研究

同步感应线圈发射器(Synchronous Induction Coil launcher,SICL)具有驱动线圈与发射载荷无机械接触、推力大,适合发射大质量物体等特点,具有良好的军事应用前景。在电磁发射过程中,SICL的驱动线圈将产生脉冲强电磁场,当磁场强度超过某一阈值时,会干扰发射载荷及周围的电子设备的正常工作,甚至使其损坏。文章分析了 SICL的工作原理,建立了其电磁场的数学模型;编制仿真程序分析了 SICL的电磁发射过程,得到了放电回路的电流波形、SICL电磁场的强度及分布规律;利用搭建的电磁发射系统,进行了电磁发射实验,测量了 SICL的磁场分布,对比仿真结果与实验数据,结果表明:仿真结果正确可信,研究结论对 SICL的结构设计和工程发展具有一定的理论指导意义和参考使用价值。     

镍基单晶合金气冷叶片模拟试样的蠕变性能研究

对带孔和不带孔的某第二代镍基单晶合金平板试样进行了蠕变性能试验研究与有限元对比计算.高温蠕变试验表明, 平板试样的晶体取向和是否开孔对蠕变寿命有明显的影响.气膜孔导致蠕变寿命的降低, 对[001]取向的影响大于[111]取向.在高温低应力条件下, [001]取向的蠕变性能要优于[111]取向.有限元分析结果表明, 气膜孔改变了试样中的应力分布, 在孔附近产生了高应力, 导致模拟试验蠕变寿命的降低.有限元计算蠕变持久寿命与试验结果吻合, 说明采用基于分切应力的蠕变持久寿命计算模型是合理的.      

高锁螺栓干涉配合安装工艺参数对凸瘤的影响分析

 干涉配合螺栓连接是提高飞机结构疲劳寿命的一种有效方法,干涉安装中产生的凸瘤对结构强度极为不利。分析了凸瘤产生的原因,对M8钛合金高锁螺栓进行了静态压入试验,同时建立了有限元模型进行数值模拟,通过对比压入力和凸瘤大小,验证了有限元模型。对影响凸瘤产生的工艺参数进行了分析。有限元模拟结果表明:最佳干涉量为1.5%,顶铁中孔直径略小于螺栓2倍时产生的凸瘤较小,钉孔间摩擦因数须小于0.15,孔出口0.2×120°倒角可减小凸瘤和降低此处的应力集中效应。     

A seventh-order model for dynamic response of an electro-hydraulic servo valve

In this paper, taking two degrees of freedom on the armature–flapper assembly into account, a seventh-order model is deduced and proposed for the dynamic response of a two-stage electro-hydraulic servo valve from nonlinear equations. These deductions are based on fundamental laws of electromagnetism, fluid, and general mechanics. The coefficients of the proposed seventhorder model are derived in terms of servo valve physical parameters and fluid properties explicitly.For validating the results of the proposed model, an AMESim simulation model based on physical laws and the existing low-order models validated by other researchers through experiments are used to compare with the seventh-order model. The results show that the seventh-order model can reflect the physical behavior of the servo valve more explicitly than the existing low-order models and it could provide guidance more easily for a linear control design approach and sensitivity analysis than the AMESim simulation model.