考虑发电机约束条件的潮流计算方法

由于当发电机满足励磁电流限制时,并不能保证发电机定子电流不越限,当发电机满足定子电流限制时,也不能保证发电机励磁电流不越限,因此,本文将受发电机定子和转子电流约束下的节点定义为ＰＩ节点,同时,基于凸极式同步发电机定子电流和转了电流约束方程组,采用牛顿法分别推导了极坐标和直角坐标系统下的功率偏并型潮流方程,并给出ＰＩ节点的潮流雅可比矩阵元素修正公式,当考虑了定子电流和转子电流约束条件后,潮流计算的计     

基于定子电流小波变换的感应电机速度估计算法的研究

提出一种基于齿槽谐波检测的转速估计算法。首先对感应电机定子电流进行小波变换,得到谱后再利用脊线检测算法提取瞬时频率,然后根据齿槽谐波频率估计转速。将该算法在感应电机无速度传感器直接转矩控制系统中进行了仿真,仿真结果表明,使用小波变换的估计算法不受电机参数的影响,明显提高了电机的转速估计精度,并且在整个转速范围内有效,从而也解决的了在低速范围内,转速估计精度低的问题。     

发电机停机电气制动控制的优化设计

阐述了隔河岩水电厂发电机停机电制动的工作原理,分析了励磁系统改造后灭磁开关运行方式变化,引起电制动投运后退出运行时转子绕组过压的原因,提出了电制动控制优化改进方案,经过试验检验,证明此方案可行。     

亭子口水利枢纽电站水轮发电机组选型设计及主要技术问题探讨

根据亭子口水利枢纽电站的具体运行特点,参考国内外同类电站资料及机组制造商的设计制造水平,针对亭子口水利枢纽电站水头较低、机组尺寸较大等特点,对水轮发电机组参数、水轮机运行稳定性、定子、转子和推力轴承等机组选型和结构设计中的主要问题进行了分析,并提出了相应的对策.     

龚嘴水电站水轮发电机转子 绝缘处理

龚嘴水电站1号水轮发电机转子绝缘为B级绝缘,运行至今已三十多年。由于运行环境湿度大等因数,转子绝缘性能降低,严重影响机组正常的安全运行。2003年11月该厂改造了1号发电机组的定子线圈、铁心和水涡轮,通过采用新型通风系统改善了转子绝缘性能,实现了定子、转子温升分布均匀,温升较低,提高了发电机转子绝缘性能,达到了机组增容10 MW的目的。     

一种新型多旋翼飞行器的建模与反演控制

针对目前多旋翼飞行器存在的不足之处,提出一种外形布局新颖、内部结构简洁、具有硬件冗余且易于工程实现的新型多旋翼飞行器,并提出一种反演控制策略.首先,给出了飞行器的运动学模型和动力学模型,随后,设计了飞行器的姿态和位置控制器.其中,姿态控制器设计中将一阶滤波器和线性跟踪微分器用于其中,以实现系统对控制指令的快速响应;位置控制器用于解算跟踪期望轨迹所需要的姿态角信息.最后,通过仿真验证实验,验证了本文所提控制策略的正确性.     

Bearing loads of dual rotor-bearing system under stationary and transient conditions

Aimed at aeroengine vibration failure, bearing loads of dual rotor-bearing system caused by unbalance are calculated under stationary and transient conditions. The three-dimensional (3-D) finite element method (FEM) model of dual rotor-bearing system was established. Applying the rotor dynamics function of Ansys 12.0, bearing loads were calculated under various unbalance force in stationary condition, and the transient vibration characteristics and the effect of acceleration on bearing loads were discussed. On the basis of simulation results, the influence disciplines of unbalance on bearing loads and theoretic reference for reducing bearing loads during start-up were obtained.     

汽轮机寿命监测系统

将汽轮机转子作为监测对象,确定其基本信息和热应力分布情况.从转子疲劳寿命损耗和高温蠕变寿命损耗两个方面给出转子寿命损耗的计算方法,设计并实现了汽轮机寿命监测系统,以实现汽轮机寿命监测与管理的任务.     

Intelligent fault inference for rotating flexible rotors using Bayesian belief network

Flexible rotor is a crucial mechanical component of a diverse range of rotating machineries and its condition monitoring and fault diagnosis are of particular importance to the modern industry. In this paper, Bayesian belief network (BBN) is applied to the fault inference for rotating flexible rotors with attempt to enhance the reasoning capacity under conditions of uncertainty. A generalized three-layer configuration of BBN for the fault inference of rotating machinery is developed by fully incorporating human experts’ knowledge, machine faults and fault symptoms as well as machine running conditions. Compared with the Naive diagnosis network, the proposed topological structure of causalities takes account of more practical and complete diagnostic information in fault diagnosis. The network tallies well with the practical thinking of field experts in the whole processes of machine fault diagnosis. The applications of the proposed BBN network in the uncertainty inference of rotating flexible rotors show good agreements with our knowledge and practical experience of diagnosis.