盘式对转永磁风力发电机设计与分析

针对现有风力发电系统普遍存在的工作风速范围较窄、风能利用率较低等问题,设计了一种盘式双转子对转永磁风力发电机,双转子对转运行。在介绍该电机的结构与运行原理的基础上,推导了电机功率尺寸方程,给出了该电机的初步设计方法。利用有限元软件对电机进行了三维建模和动态仿真分析,得到其磁路特点和电磁性能,验证了所提设计方法的有效性。     

Online condition diagnosis for a two-stage gearbox machinery of an aerospace utilization system using an ensemble multi-fault features indexing approach

China manned space station is designed to operate for over ten years. Long-term and sustainable research on space science and technology will be conducted during its operation. The application payloads must meet the ‘‘long life and high reliability" mission requirement. Gearbox machinery is one of the essential devices in an aerospace utilization system, failure of which may lead to downtime loss even during some disastrous catastrophes. A fault diagnosis of gearbox has attracted attentions for its significance in preventing catastrophic accidents and guaranteeing sufficient maintenance. A novel fault diagnosis method based on the Ensemble Multi-Fault Features Indexing(EMFFI) approach is proposed for the condition monitoring of gearboxes. Different from traditional methods of signal analysis in the one-dimensional space, this study employs a supervised learning method to determine the faults of a gearbox in a two-dimensional space using the classification model established by training the features extracted automatically from diagnostic vibration signals captured. The proposed method mainly includes the following steps. First, the vibration signals are transformed into a bi-spectrum contour map utilizing bi-spectrum technology,which provides a basis for the following image-based feature extraction. Then, Speeded-Up Robustness Feature(SURF) is applied to automatically extract the image feature points of the bi-spectrum contour map using a multi-fault features indexing theory, and the feature dimension is reduced by Linear Discriminant Analysis(LDA). Finally, Random Forest(RF) is introduced to identify the fault types of the gearbox. The test results verify that the proposed method based on the multi-fault features indexing approach achieves the target of high diagnostic accuracy and can serve as a highly effective technique to discover faults in a gearbox machinery such as a two-stage one.     

Aircraft engine fault detection based on grouped convolutional denoising autoencoders

Many existing aircraft engine fault detection methods are highly dependent on performance deviation data that are provided by the original equipment manufacturer. To improve the independent engine fault detection ability, Aircraft Communications Addressing and Reporting System (ACARS) data can be used. However, owing to the characteristics of high dimension, complex correlations between parameters, and large noise content, it is difficult for existing methods to detect faults effectively by using ACARS data. To solve this problem, a novel engine fault detection method based on original ACARS data is proposed. First, inspired by computer vision methods, all variables were divided into separated groups according to their correlations. Then, an improved convolutional denoising autoencoder was used to extract the features of each group. Finally, all of the extracted features were fused to form feature vectors. Thereby, fault samples could be identified based on these feature vectors. Experiments were conducted to validate the effectiveness and efficiency of our method and other competing methods by considering real ACARS data as the data source. The results reveal the good performance of our method with regard to comprehensive fault detection and robustness. Additionally, the computational and time costs of our method are shown to be relatively low.     

大型载人空间基础设施商业化运营模式初探

为提高以空间站为代表的大型载人空间基础设施运行效率和运营效益,本文在研究国际空间站(ISS)在轨运营模式及商业化做法的基础上,针对我国现有空间基础设施的在轨运营特点、国家战略和社会商业化需求,提出了引入社会资本建立商业化运营模式和建立商业成果转化基金等建议,成立专门的商业化运营管理机构,进行统筹管理和商业化运营,探索形成一套职责清晰、高质高效、效益突出的商业化运营管理体系,既保证空间基础设施在轨健康运行,高效开展各类空间应用,又降低建设和运营成本。在孕育商业模式和创新项目促进经济社会发展的同时,也具有重要的现实意义和深远的社会效益。     

基于高功率因数控制的永磁同步电机无电解电容驱动系统控制策略

永磁同步电机无电解电容驱动系统因其成本与寿命的优势,在白色家电领域逐步得到广泛的应用。然而,由于使用小容量的薄膜电容取代大容量的电解电容,母线电压会以两倍工频波动,在母线电压处于波谷时,逆变器输出电压容易饱和,导致控制性能恶化,网侧电流畸变。因此,提出了一种基于高功率因数控制的转矩控制环和电压矢量修正策略,能够有效提升网侧功率因数,抑制网侧电流谐波并符合IEC 6100032标准。该算法的有效性通过仿真得以验证。     

电动汽车轮毂电机技术的发展现状与发展趋势

轮毂电机具有结构紧凑、传动效率高、控制和转向灵活等优点。由轮毂电机驱动的电动汽车是新能源汽车重要的发展方向。通过各种电机的对比,认为永磁同步电机效率高、功率密度高、可靠性好,是轮毂驱动电机一个较好的选择。总结了电动汽车轮毂电机国内外的应用概况,介绍了轮毂电机电磁设计优化、控制策略及散热方式和结构方面进行的研究和工作,最后探讨了我国电动汽车轮毂电机研究中存在的问题,展望了轮毂电机未来的发展方向。     

电动汽车用永磁同步电机控制器设计

电动汽车逐渐成为人们出行的交通工具之一,对技术可靠性和安全性的要求较高。电机控制器是实现电池直流电源向三相交流电源转换的装置,驱动永磁同步电机(PMSM)输出力能。设计了一款基于瑞萨单片机的PMSM控制器,从元器件选型、硬件保护电路原理、PCB布局、控制算法、结构强度和热分析方面展开分析。最后生产控制器样机并搭建试验平台,对PMSM控制器进行了效率特性测试、发电测试和温升测试。试验结果验证了设计方案的合理性。     

某型超精密机床液体静压导轨温控设计与仿真方法研究

针对某型超精密机床液体静压导轨温度控制进行深入研究,提出多种不同的温度控制方法,并应用ANSYS仿真软件分别对液体静压导轨热变形进行了仿真,得出了不同温度控制方法下导轨的热变形大小。仿真结果显示,针对不同使用环境,通过不同的温度控制方法,对液体静压导轨进行热变形控制,从而满足超精密机床的使用要求,提高超精密机床的加工精度。。     

一种星载微波接收机应用的全集成厚膜电源设计

应新一代小型化、轻量化星载微波接收机需求,借鉴引进的国外微波接收机全集成厚膜电源设计理念,采用轻质化硅铝材料和LTCC厚膜集成技术的新方案设计了一种应用于星载微波接收机的全集成厚膜电源.该厚膜电源模块为全集成设计,除了实现DC-DC基本功能,还集成了EMI滤波器以及多个功能电路单元,模块可直接和卫星平台配电系统对接.本...     

带倾角合成射流激励器对低速主流矢量控制研究

基于全流场计算模型——X-L,对带倾角合成射流激励器控制宏观低速主流流动进行了数值分率的情况下,可使主流流动方向发生大幅度析和机理研究。结果显示,激励器出口倾角对主流矢量角控制影响很大,在不增加输入功偏转。在激励器存在出口倾角情况下,各状态参数和激励器布置位置对主流矢量影响按规律变化且存在最佳值。压强梯度的存在和旋涡的卷吸作用是合成射流激励器控制宏观低速流流动方向的主要因素。