电动汽车车载永磁同步电动机转子位置自检测算法

永磁同步电动机由于其自身的众多优点,在现代电动汽车上得到了越来越广泛的应用.文章介绍了一种采用增量式码盘和转子磁极初始位置辨识算法相结合的方法来实现永磁同步电动机转子位置的自检测.这种方法可以应用在隐极式同步电动机上,实现在无位置传感器的条件下确定电动机转子的绝对位置,并且简单、有效,受电动机参数变化的影响比较小,在电动机静止、低速和高速运行时都可以正常使用.利用MATLAB/Simulink软件建立了这种方法的仿真模型,仿真结果证明了该方法的可行性和有效性.     

烧结主风机改造

介绍了天铁冶金集团二烧车间主烧结 1 2 0 0 0 m3/min风机的改造 ,通过技术改造 ,在不改变风机机壳及主体基础和电机基础的前提下 ,改变风机转子直径和叶片数量等参数 ,使风机全压由1 0 0 0 0 Pa提高到 1 4 0 0 0 Pa,流量由 1 2 0 0 0 m3/min提高到 1 4 5 0 0 m3/min,满足了烧结机的需要 ,取得了显著的经济效益     

螺杆钻具中定子和转子的中频感应热处理生产线

介绍了石油、天然气钻井用螺杆钻具中的定子、转子和类似工件的中频感应调质热处理生产线的工艺要求、设计思路和生产线结构。与传统的调质工艺相比，采用感应调质生产线提高了工件的综合力学性能，减少了热处理畸变，提高了经济效益。     

发电机退电制动时转子过电压的分析

分析了隔河岩电厂发电机在退电制动时转子过电压的原因,提出了在制动变压器之前增加一个接触器以解决转子过电压的方法,结果表明,所用方法是可行的。建议将电厂目前的制动方式(恒流方式)改造成柔性制动方式,以便进一步提高机组运行效率。     

超导发电机转子模态分析

应用ANSYS分别对某超导发电机内转子、外转子和转子整体进行模态分析.考虑内转子中挠性支撑结构,将外转子轴承约束简化为弹性约束.考虑该弹性约束刚度的影响,获得内、外转子的前10阶固有频率和振型图;针对双层转子结构整体,对比分析结构中内、外转子的振动形式,获得转子的固有振动特性.     

Annular ring slot antenna design with reconfigurable polarization

A microstrip‐fed conventional annular ring slot (ARS) antenna with linear polarization (LP) is initially studied. To generate two orthogonal degenerate modes for circular polarization (CP) radiations, two identical meandering perturbation slots (MPS) are symmetrically loaded into the ARS. By further incorporating a PIN diode switch across each MPS, the proposed antenna can switch between left‐hand CP (LHCP), right‐hand CP (RHCP), and LP. All three polarizations have shown good impedance bandwidth and broad CP bandwidth that can satisfy the wireless local area network (WLAN) 2.4‐GHz operating band (2400–2480 MHz). Furthermore, desirable gains of 1.8–2.0 dBi and 2.40–2.84 dBic are also exhibited at LP and LHCP/RHCP, respectively. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 26:110–120, 2016.     

Millimeter‐wave planar high gain SIW antenna using half elliptic radiation slots

This article reports a high gain millimeter‐wave substrate integrated waveguide (SIW) antenna using low cost printed circuit board technology. The half elliptic slots which can provide small shunt admittance, low cross polarization level and low mutual coupling are etched on the board surface of SIW as radiation slots for large array application. Design procedure for analyzing the characteristics of proposed radiation slot, the beam‐forming structure and the array antenna are presented. As examples, an 8 × 8 and a 32 × 32 SIW slot array antennas are designed and verified by experiments. Good agreements between simulation and measured results are achieved, which shows the 8 × 8 SIW slot array antenna has a gain of 20.8 dBi at 42.5 GHz, the maximum sidelobe level of 42.5 GHz E‐plane and H‐plane radiation patterns are 22.3 dB and 22.1 dB, respectively. The 32 × 32 SIW slot array antenna has a maximum measured gain of 30.05 dBi at 42.5 GHz. At 42.3 GHz, the measured antenna has a gain of 29.6 dBi and a maximum sidelobe level of 19.89 dB and 15.0 dB for the E‐plane and H‐plane radiation patterns. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:709–718, 2015.     

浅析卧式水轮发电机组转子动平衡试验方法

引起水轮发电机组振动的原因是多方面的,而转子质量不平衡所产生的不平衡力是引起机组振动的主要原因之一。转子动平衡试验就是通过在对应的位置配加重块,从而抵消不平衡力,达到减小振动的目的。文章以A电站为例,通过三元平衡法找出转子质量的不平衡点,通过加载平衡块,使其振动值符合国家标准的有关规定。     

Nonlinear centrifugal effects on a prestressed laminated rotor

Electrical rotors are usually used in rotating machinery such as in ship engine pods. Designing such rotors in bending requires careful modeling of a laminated stack prestressed by tie rods. Theoretically, steel sheets, varnish layers and prestressing make it difficult to homogenize the constitutive properties of a stack both at rest and under operating conditions. Moreover, it is noteworthy that tie rods subjected to centrifugal forces bend until reaching annular clearance. Their nonlinear bending tends to increase their stiffening effects and the axial lamination load, therefore it affects the homogenized constitutive properties of a stack modeled with Timoshenko beams. By combining a fixed-point algorithm and penalty method at each speed of rotation, it is possible to plot the Campbell diagram and unbalance responses by considering updated properties and the axial load of the tie rods generated by centrifugal effects. An industrial application is used to show that centrifugal effects have a slight influence on rotor dynamics.     

带导流墙的门槽结构在闸门全开工况下的应用

从空穴特性、流态特征方面出发,分析了带导流墙的门槽结构在闸门全开泄洪情况下改善流态、降低门槽受冲刷和空蚀危险性方面的作用,认为其在深孔泄水道闸门及其他高水头平面闸门中有很好的推广应用价值。