任意缸体旋叶式压缩机的叶片型线设计理论研究及应用

与缸体内壁相接触的叶片头部形状是旋叶式压缩机设计的关键之一。应用微分几何理论,研究出与各设计基本参数紧密相关、与缸体型线相匹配的叶片型线设计方法,从理论上保证旋叶式压缩机的运行可靠性,为实现高效压缩的旋叶式压缩机设计提供计算依据,拓宽设计理论。计算机仿真与试验表明,由设计理论获得的叶片具有很好的啮合特性,完全消除了尖点滑移和局部磨损现象,具有均匀相对滑动;型线的形状保证叶片头部与缸体内壁的运行可靠性;叶片头部具有最简单的型线形状,易于机械加工制造;与主型线光滑连接的前、后过渡修正圆弧,使叶片与缸体内壁啮合时,不成刀刃状,且利于形成油膜,改进润滑状况,同时降低缸体、转子及转子叶片和叶片槽的加工和装配精度要求。     

发电机运行状态对定转子径向振动特性的影响分析

分析隐极同步发电机定转子径向振动随发电机运行状态的变化规律。首先通过分析不同运行状态时发电机电磁关系、电枢反应特性,以及正常运行时作用于定子的脉振电磁力特性和作用于转子的不平衡电磁力特性,分别得到定子径向倍频振动和转子径向工频振动在励磁电流一定时随发电机有功功率的变化特征,以及有功功率一定时随励磁电流的变化特征。实测了SDF-9型隐极同步发电机定转子振动信号,与理论分析结果基本吻合。另一方面也揭示基于振动特征诊断发电机故障时,必须考虑发电机的运行参数和运行状态,否则其诊断结果在实际应用中是不完整的。     

跟踪-微分器在感应电动机定子磁链估计中的应用

针对传统微分器的噪声放大问题及低通滤波器代替纯积分器带来的固有误差问题,对跟踪－微分器在感应电动机定子磁链估计中的应用进行研究。首先,引入跟踪－微分器对检测的定子电流进行了预处理来抑制噪声,再利用跟踪—微分器提取定子电流角频率信息。在此基础上,进一步提出一种利用定子电流角频率信息进行增益及相位补偿的可编程级联低通滤波器代替纯积分器的定子磁链估计方案。仿真与试验结果验证了改进方案的实用性和优越性。     

Hilbert versus Concordia transform for three-phase machine stator current time-frequency monitoring

This paper deals with mechanical fault diagnosis in three-phase induction machines from stator current measurements. According to machine models, mechanical faults lead to amplitude and/or phase modulations of the measured stator current with possibly time varying carrier frequency. The modulation diagnosis requires a univocal definition of the instantaneous phase and amplitude. This is performed by associating a complex signal to the real measured one. For a convenient separate modulation diagnosis, the complex signal instantaneous phase and amplitude are expected to carry, respectively, information about the phase and amplitude modulations. The complex signal is classically obtained through the Hilbert transform. Under Bedrosian conditions, the so-called analytic signal allows a separate modulation diagnosis. However, mechanical faults may also produce fast modulations violating the Bedrosian conditions. This study proposes an alternative complex signal representation which takes advantage of the three stator current measurements available in a three-phase machine. From two stator current measurements, the Concordia transform builds a complex vector, the so-called space vector, which unconditionally allows separate modulation diagnosis. This paper applies and compares the Hilbert and Concordia transforms, theoretically and in case of simulated and experimental signals with various modulation frequency ranges.     

定子铁心精加工胎具设计

电机的定子冲片是外圆开口冲片,装压用销钉在靠近里孔处外铆接成的。这种装压方式,容易造成铁心外圆松散、容易变形。设计精加工内圆面,车胎过程,介绍车胎的制作和特点。     

发电机定子接地微机保护装置的研制及其动模试验

介绍了自调整式的发电机定子接地微机保护装置的硬件结构和软件结构及其主要功能，以及保护装置的可靠性和抗干扰性能，动模试验证明了该装置的优良性能。     

转向叶片泵定子参数化设计方法研究

定子是转向叶片泵的关键零件之一,其内轮廓曲线复杂,运动特性多变,设计困难。为了解决定子零件高质高效设计问题,研究了基于Pro/Engineer平台的转向叶片泵定子参数化设计方法,并利用运动仿真模块对定子的运动特性进行了分析。该方法有效提高了定子的设计效率,为定子曲线的优化设计奠定了基础。     

圆柱-球体多自由度超声电机定子驱动端面的运动分析与仿真

对圆柱 球体多自由度超声电机定子的驱动端面的运动形式作出了基本假设 ,在已知一个特定驱动点振幅的前提条件下 ,建立起定子上一般驱动点的运动方程。结合在MATLAB环境下对驱动点的运动仿真结果 ,分析了驱动点运动的规律和特点。由于这个特定驱动点的振幅是可计算的和可测量的 ,因而本文提出的电机定子驱动端面的运动分析、仿真方法是定量的 ,这为进一步弄清该种电机的驱动机理、改进和提高电机的性能、实现电机输出性能的仿真设计等提供了有效的依据。     

平衡式径向柱塞泵的设计

进行了平衡式柱塞泵的理论分析,针对柱塞泵的运动情况,阐述了为实现柱塞泵的无流量脉动的柱塞的运动速度曲线所必须具备的特征,导出了几种常见的无流量脉动特征速度曲线,并设计了平衡式径向柱塞泵。     

Improvements in ground-fault protection of unit-connected generator stator winding using laboratory test environment

This paper describes an idea of realization of a software–hardware laboratory environment enabling to run research and implementation in the area of ground-fault protection of modern unit-connected generators. There are three basic elements in this environment: simulation model of a unit-connected generator for investigating intermittent arc ground-faults in generator stator winding, PC-based system for ground-fault waveforms synthesis and microprocessor-based hardware for implementation of a new protection algorithm developed by authors.