For Propulsion Applications It Is Possible to Utilize Both the Torque Output of the Rotor and the Reactional Torque Acting on the Stator of the Driving Electric Motor by Linearizing the Stator

This paper presents a novel idea of utilizing the reactional torque of the conventional electric motor as a linear output for propulsion in addition to the conventional torque output of the rotor. The idea is demonstrated by a theoretical proposal of linearizing the stator of one of the most used motors in Electrical Vehicles and Hybrid Vehicles. The proposed Linear Stator Motor is a simple modification without involving any functional change of the conventional motor. Though theoretical, the indicated possible input energy saving of more than 75% as compared to the conventional motor is no surprise, as by linearizing the stator, an almost equal linear propulsion output is added to the conventional rotor output. In addition to this remarkable saving in input energy, the proposed Linear Stator Motor that suits all types of vehicles, can maintain propulsion without the need for a mechanical transmission system. Also, in the case of watercraft and aircraft vehicles, no external mechanical propulsion drive system is required. It is just an internal force that can push the vehicle forward, backward, or laterally, while the conventional rotor output can be utilized for energy recovery by driving a DC generator.

The Low-Frequency Oscillation Restrain Method Research of Converter-Fed Multi-Phase Induction Motor Propulsion system

The inverter-fed induction motor drive system may become unstable at low frequencies and light load, and phase current and speed of the induction motor may oscillate periodically, which will threaten safety and reliability of the system. This paper chooses nine-phase induction motor simulated propulsion system as the research object, small disturbance model of three-phase induction motor is built, and average equivalent model of the converter is built by introducing switch function. On the basis above, small disturbance mathematic model of the whole system is obtained. As for the limitation of parameters adjustment method of restrain low-frequency oscillation, the restrain method combining current close-loop with dead-time compensation is put forward. Finally, the proposed restrain method is verified respectively on the built simulation and experimental analogue platform. And the simulation and experimental results indicate that the proposed method can not only satisfy the requirement of low-frequency oscillation restraining, but also be expanded widely, and the stability of the system can get improved greatly.

Steady-State Performance Analysis of Brushless DC Propulsion Motor

The brushless DC motor can be used in the marine electric propulsion system for its excellent control characteristics and large thrust. In order to estimate the operating performances of the brushless DC motor for the high-power shipping during the design stage, the steady-state analysis is as important as the dynamic analysis generally. A mathematical model of the brushless DC propulsion motor is established according to the state-space method for the dynamic and steady-state performance analysis. The state-space mathematical model is a set of linear differential equations, so the steady-state currents of the armature windings can be gained directly by the symmetrical boundary conditions and the eigenvalues of the system matrix. The steady-state simulation results are compared with the dynamic ones to validate the correctness of this eigenvector method.

Self-contained Capsubot Propulsion Mechanism

In this paper, a self contained capsubot （capsule robot） propulsion mechanism is investigated. The proposed capsubot works on the principle of internal force-static friction. A modified linear DC motor is used to drive the capsubot. A novel acceleration profile is proposed for the moving part （linear cylinder） based on the principle. A significant feature of the proposed capsubot is that it is legless, wheelless, and trackless. The developed capsubot with a proposed propulsion mechanism demonstrates a very good average velocity. The propulsion mechanism has the potential to be used for the propulsion of a wireless-controlled self-propelling capsule endoscope. Simulation and experimental results demonstrate the performance of the self-contained capsubot with the proposed acceleration profile.

UAQ4 Magnetic Levitating Train： Propulsion System for Urban Transportation

This paper discusses the design of the propulsion system of the UAQ4 （University of L＇Aquila, model 4） magnetic levitating train which is used for transportation applications in urban environments. UAQ4 is the only magnetic levitating vehicle with resistance motion, except for aerodynamic drag and with energy consumption near zero at low speed. The feasibility of the system has been successfully verified and tested in the laboratory. Propulsion and braking are provided by a novel direct-current linear stepper motor, with the primary formed by permanent magnets distributed on central beam of the track, and the secondary by coils on board the vehicle, instead of the present alternate current linear motors that have well-known disadvantages. The motor working principles are described, and its performances are analyzed, by a finite element numerical model which allows modifying the most important parameters of the system. The main components of a full scale motor for urban transportation are measured and discussed.

航空电推进电机多层波浪形拓扑及散热设计方法

针对航空电推进电机的散热问题,提出一种基于多层波浪形散热拓扑的航空电推进电机高效散热设计方法。航空电推进电机采用多层波浪形散热拓扑,建立电机等效热网络模型,确定等效热阻、对流换热系数等重要参数,完成电机温度精确计算,并通过CFD仿真验证所建立电机等效热网络模型的准确性和有效性。以此为基础,对比分析传统散热翅和多层波浪形散热拓扑对电机功率密度的影响。基于多层波浪形散热拓扑的等效热网络模型,采用遗传学习粒子群优化(GL-PSO)算法,完成航空电推进电机高效散热优化设计。优化结果表明:相比于原始方案,优化方案的机壳质量减轻15.1%,整个电机的功率密度提升0.06 kW/kg。

舰船电力推进系统的分析与仿真研究

以最大程度保障舰船稳定运行为目标,展开舰船电力推进系统的分析与仿真研究,依据舰船电力推进系统结构组成,构建多种组成部分的数学模型,基于Matlab-Simulink仿真分析软件进行舰船电力推进系统模拟和计算,分析其在不同工况下的性能表现。仿真分析结果显示,直接正车启动表现出较快的响应速度,但螺旋桨转矩过载严重。相比之下,分级正车启动虽然启动过程相对较长,但螺旋桨转矩和舰船速度的变化更为平稳。突加负载工况下,本文方法表现出较好的性能,能够快速适应负载变化,调节时间短,且电机电流波动小,有利于保障电力推进系统的稳定运行。航速变化工况下,波动幅度和稳态误差均较小,具有较高的稳定性和控制精度。

飞机电推进系统高效能电机及其驱动控制技术

飞机动力系统的电气化是继机载二次能源逐步统一为电能之后航空电气化发展的重要方向和高级阶段,能够大幅提升飞机动力系统能量利用效率,是航空业绿色发展的重要途径。电机系统是飞机电推进系统的核心机电能量变换环节,高效能电机、电力电子变换及其驱动控制技术是电推进飞机发展的基础支撑。该文从电推进飞机动力系统架构出发,分析电推进飞机电机系统的特征与要求。总结永磁同步电机、异步电机、电励磁无刷同步电机和超导电机4种类型电机在电推进飞机上的研究和应用现状,系统讨论电推进系统中不同类型电机和电机驱动器的关键技术。最后,展望新材料、新器件、新工艺、人工智能和综合热管理等技术对电推进飞机电机及其驱动控制技术发展的推动作用。

径轴向聚磁型永磁推进电机优化设计与分析

为了进一步实现永磁电机磁负荷和转矩密度的提升,提出了一种径轴向聚磁型永磁推进电机结构,转子永磁体在Halbach径向聚磁结构基础上进一步结合轴向延伸永磁体,实现了永磁磁场的径轴向聚磁。针对该种新型电机,本文详细研究了其结构特点,利用有限元分析了所提电机结构的电磁性能。首先对比分析了定转子等长结构、定转子不等长(overhang)结构输出性能,并对对称型overhang结构进行了参数化优化,有效提升了电机转矩密度。最后,利用三维有限元模型对比分析了径向overhang和径轴向overhang电机的电磁性能,结果发现径轴向overhang电机空载磁密提升了6%、输出转矩增大了1.3%、转矩脉动减少了0.4%,进一步验证了电机性能的优越性。

Dynamic neighborhood genetic learning particle swarm optimization for high-power-density electric propulsion motor

To maximize the power density of the electric propulsion motor in aerospace application,this paper proposes a novel Dynamic Neighborhood Genetic Learning Particle Swarm Optimization(DNGL-PSO)for the motor design,which can deal with the insufficient population diversity and non-global optimal solution issues.The DNGL-PSO framework is composed of the dynamic neighborhood module and the particle update module.To improve the population diversity,the dynamic neighborhood strategy is first proposed,which combines the local neighborhood exemplar generation mechanism and the shuffling mechanism.The local neighborhood exemplar generation mechanism enlarges the search range of the algorithm in the solution space,thus obtaining highquality exemplars.Meanwhile,when the global optimal solution cannot update its fitness value,the shuffling mechanism module is triggered to dynamically change the local neighborhood members.The roulette wheel selection operator is introduced into the shuffling mechanism to ensure that particles with larger fitness value are selected with a higher probability and remain in the local neighborhood.Then,the global learning based particle update approach is proposed,which can achieve a good balance between the expansion of the search range in the early stage and the acceleration of local convergence in the later stage.Finally,the optimization design of the electric propulsion motor is conducted to verify the effectiveness of the proposed DNGL-PSO.The simulation results show that the proposed DNGL-PSO has excellent adaptability,optimization efficiency and global optimization capability,while the optimized electric propulsion motor has a high power density of 5.207 kW/kg with the efficiency of 96.12%.

基于多通道数据融合及CNN的电机故障诊断方法

为解决因电机结构复杂、信号非平稳等因素导致电机故障诊断困难问题及传统故障诊断算法对专家经验的依赖,提出一种基于多通道数据融合与卷积神经网络(CNN)相结合的电机故障诊断方法。该方法首先采集电机驱动端的振动信号和定子电流信号并对其进行时频域转换,再将两者频域信号进行归一化处理并转变为二维图谱数据,最后构建CNN网络模型,确定网络层数、学习率等超参数,并将样本输入模型进行故障特征提取和分类诊断。结果表明,在合适的参数下采用该方法的电机故障诊断准确率为100%,对比单独采用振动信号或电流信号的传统故障诊断方法和1D-CNN模型,该方法能够更有效地对电机各类故障进行诊断。

支撑刚度对水下航行器电机-推进轴系振动特性的影响规律分析及优化

针对水下航行器电机-推进轴系动力学响应的影响及其优化问题,建立了水下航行器电机-推进轴系的动力学模型,模型考虑了推进电机隔振器刚度参数、推进电机内部电磁激励力、滚动轴承非线性特性、推进器动态激励力以及弹性联轴器的影响,分析了隔振器刚度特性对电机-推进轴系动力学响应特性的影响规律,提出了推进电机隔振器刚度参数优化流程,以推进电机振动响应为指标,建立了隔振器刚度优化目标函数,实现了隔振器刚度参数优化设计。结果表明,隔振器刚度参数优化能减少电机不平衡磁拉力引发的低频振动,使推进电机定子及转子振幅降低25.6%~65.7%。

基于紧格式动态线性化的吊舱推进电机滑模矢量控制

针对复杂海况下吊舱推进电机存在的模型建立困难以及负载扰动问题,提出了基于紧格式动态线性化的滑模矢量控制方法。首先,考虑船舶实际工况建立包含船舶运动模型和螺旋桨负载特性的船-桨数学模型,并通过紧格式动态线性化方法,建立带时变参数和负载扰动项的吊舱推进电机数据模型;然后,设计基于最小转速跟踪误差指标的滑模控制器,同时设计神经网络观测器对控制律中的未知负载扰动项进行估计,并将估计值反馈到控制器中进行扰动补偿。仿真结果表明,所设计的控制器减小了推进电机的转速超调、转矩脉动,提高了吊舱推进电机系统的控制性能。

船舶推进电机预测磁链控制研究

为解决船舶推进电机传统预测控制中涉及的权重系数的整定和优化问题,以及推进电机在预测控制下的无速度传感器问题,提出使用自适应预测磁链控制。首先分析预测转矩控制的控制性能和原理,并将改控制方式中的以控制磁链和转矩为目的转化为对等效定子磁链的控制,从而形成预测磁链控制;同时引入自适应控制算法以实现电机的无速度传感器控制;最后对推进电机的传统控制方式和自适应预测磁链控制进行仿真对比研究。预测磁链控制可以成功消除对权重系数的整定工作及其影响,且有着很好的启动性能、减少了谐波分量、降低了磁链和转矩脉动。同时,自适应控制算法对各个工况的转速观测精度都很高。自适应预测磁链控制对异步电机有着优良的控制效果,且具有很好的稳态特性和鲁棒性,可提高船舶推进电机的控制性能。

电推进飞机定子励磁型无刷电机应用研究

基于电推进飞机的发展需求,结合航空背景,研究一种定子励磁型无刷电机应用于飞机电驱动系统的性能指标。分析了该电机的拓扑结构特点,采用参数化建模方法,在ANSYS Maxwell中建立了电机的仿真模型。运用有限元分析,以转矩特性为主要参数,对该电机进行了仿真优化,得到了适合于电推进飞机场合的电机最优模型。对优化后的电机电磁特性进一步分析,包括转矩特性、电机效率、输出功率和磁场分布等。结果表明:优化后的电机永磁体用量减少了0.18 dm^(3),输出转矩提高了7.7%,转矩脉动系数下降了8.1%,输出功率密度达4.8 kW/kg,效率达96.1%。该电机具有结构简单、功率密度高、电机效率高的优点。

电动飞机电推进用永磁同步电机无传感器控制技术综述

随着绿色航空的发展和新能源技术的不断进步,电动飞机也得到了快速发展。作为电动飞机的核心,电推进系统也受到越来越多的关注。永磁同步电机(PMSM)凭借其功率密度大、效率高等优势成为电动飞机电推进系统的理想解决方案。由于不依赖位置传感器,永磁同步电机无传感器控制技术能够更好地满足电动飞机对高空复杂环境下高可靠性的要求。首先,对当前电动飞机推进用永磁同步电机无位置传感器控制的主要方法进行了总结和比较。其次,针对转子起始位置检测、低速起动以及中高速运行中的关键技术和难点进行了分析。最后,对目前研究中存在的问题进行了归纳,并对未来的发展进行了展望。

基于无位置变载波频率的深海矢量推进电机控制方法

为了提高矢量推进电机在深海探索中的稳定性与隐身性,文中以表贴式永磁同步电机为基础,结合周期扩频调制技术和改进型滑模观测器无位置控制技术,提出了基于无位置变载波频率的深海矢量推进电机控制方法。通过电机变载波频率、电机起动变速和负载突变仿真实验,验证所提控制方法的控制效果,结果表明所研究控制方法转速估算准确,对转速有良好的动态跟踪性能,额定转速工况下转速估算误差率仅为0.32%,0.5倍额定转速工况下转速估算误差率仅为0.09%,且具有明显的高频谐波扩频抑制效果和良好的动态抗干扰性能。结合减少位置传感器带来的电机结构简化效果,文中提出的控制方法可有效降低深海矢量推进电机作业时的故障率,减少易被探测的高次固定频率谐波,提高了深海矢量推进电机的可靠性与隐身性,为深海UUV提供高效可靠的动力保障。

基于拓扑优化的大型推进电机支撑结构轻量化设计

为解决某大型推进电机陆上试验支撑结构质量大、制造及运输成本高的问题,首先将依据经验设计的支撑结构建立三维模型,采用ANSYS Workbench进行静力学分析和模态分析,确认原设计的可靠性。然后基于ANSYS Workbench拓扑优化模块,通过去除优化区域中对整体结构影响最小的部分进行优化,根据优化结果重新设计并建立三维模型,最后进行静力学分析及模态分析,确保经优化后仍能满足推进电机运行要求,从而在保证安全运行的条件下实现支撑结构的轻量化。经过优化设计,支撑结构整体质量减小了26.4%,达到了轻量化设计的目的。本次优化设计表明拓扑优化可以有效指导大型设备支撑结构的设计工作,能够优化支撑结构的构成,降低制造、运输成本,避免材料的浪费。

涵道风扇电机强迫风冷散热结构设计与实验

针对涵道风扇电机的轻量化高效散热需求,提出基于涵道风扇内部流场的强迫风冷散热方法,设计了肋片高度为3 mm、6 mm、9 mm和12 mm的四种风冷散热结构,应用工程估算和CFD方法对不同风速下散热效果进行对比分析,搭建实验平台开展地面试验验证。结果表明,在桨毂上增加散热肋片能够有效提高散热效率,壁面温升可降低至无肋片模型的74%、55%、44%、35%;对于轴向风冷,肋片能显著强化散热,但是存在温度不均的问题。工程估算和CFD方法对电机的带肋表面风冷散热分析有较好的精度,可用于涵道风扇电机的温升预示,为涵道风扇推进系统的使用提供依据。根据分析结果提出了高功率密度电机强化散热的研究方向。

电力推进永磁同步电机的无传感器控制研究

为提高电力推进无传感器永磁同步电机的稳定性,基于两相旋转坐标系和电机矢量模型,提出一种改进的电机滑模观测器。为增强滑模观测器的抗干扰性能和控制精度,采用sigmoid函数作为滑模观测器开关函数,并引入模糊控制策略改进开关增益;然后采用ACO算法优化滑模观测器的可调参数。仿真结果表明,该改进滑模观测器可提高电力推进无传感器永磁同步电机对转速和转矩控制的稳定性,使d、q轴电流更平稳,提高永磁同步电机的转子位置估计精度,降低位置估计误差。