同步电机参数在线小扰动辨识技术研究

针对目前同步电机参数辨识方法存在的对输入扰动信号要求严、不能计及非线性因素等缺陷，对同步电机参数在线小扰动辨识技术进行了研究．构建了同步电机参数在线采集系统，建立了同步电机的恰当电路模型和状态方程，采用最大似然估计法在轻载和低励磁状态下辨识电机的线性参数，然后在磁路饱和状态下对饱和参数进行辨识修正，最后在大扰动的情况下，对参数和模型进行检验、修正．仿真计算结果与实测数据吻合较好，证明了文中所提出的同步电机参数辨识技术的有效性．     

Identification of Heffron-Phillips model parameters for synchronous generators operating in closed loop

Heffron-Phillips model of a synchronous machine is commonly used in small signal stability analysis and for off-line design of power system stabilisers. The data used to determine the parameters of this model are either hard to measure or require the machine to be taken off-line to take the measurements which, in general, is inconvenient. identifying these parameters from online data measurements is important since it does not require any a priori knowledge of the machine data. the problem of closed-loop identification of the Heffron-Phillips model parameters is of practical importance since the data used for identification can be gathered when the machine is normally connected to the power system. the use of open-loop identification techniques using data gathered during closed-loop operation of synchronous generators leads to bias errors in the estimated parameters. motivated by the fact that the synchronous machine model is multivariable and is well defined in a state space structure, a closed-loop subspace parameter identification technique is proposed. consistency of the proposed approach is illustrated using Monte Carlo analysis. comparison of the proposed method with open-loop identification technique shows the superiority of this approach.     

双盘转子系统轴向－径向碰摩非线性动力学特性分析

动静碰摩是透平机械常见的故障之一,其动力学行为较为复杂,表现为在机器运行的过程中碰摩故障产生的故障征兆丰富多样。建立了双盘转子-轴承系统在轴向碰摩、径向碰摩以及两种碰摩共同冲击下的有限元法连续模型,采用计及了回转效应和剪切效应的梁单元,对转子系统在不同碰摩情况下的非线性动力学行为进行了数值模拟,研究了转子转速、转子系统上的不平衡量的分布以及碰摩刚度对系统的影响。研究结果表明：相对于径向碰摩故障的动力学特征,轴向碰摩产生的非线性特征不明显,与工程中观察的现象基本一致的;但当两种碰摩均考虑时,系统的非线性动力学特征与仅考虑径向碰摩时有显著的不同。所得计算结果可为大型高速旋转机械系统的故障诊断和碰摩故障的振动控制提供理论指导,从而保证系统的安全运行。     

Four-quadrant instantaneous torque control of switched reluctance machine at low speed based on co-energy control

An instantaneous torque control scheme of switched reluctance machines for four-quadrant operation at low speed based on co-energy considerations is presented. The co-energy is estimated online with a co-energy estimator, which only requires easily obtainable parameters such as the machine terminal quantities and the machine characteristics at low current. By regulating the co-energy while tracking a one-dimensional co-energy profile, the torque contribution of each phase of the switched reluctance machine can be controlled and optimised. Thus, the requirement of pre-measured data is reduced when compared to current-profiling methods. The closed-loop control system is analysed and then designed based on internal model control. The excitation sequence and torque sharing function for four-quadrant operation to produce smooth torque output are also presented. The operation limits of the scheme are examined. Computer simulation and experimental results confirm that the proposed scheme can be exploited to reduce the high-frequency torque ripples significantly.     

基于虚拟总轴的制袋机多轴同步控制系统设计

目的为了提高制袋产品质量及同步控制精度,实现产品技术升级,设计一种基于虚拟总轴的多轴同步控制系统。方法以三边封制袋机为研究对象,介绍其工艺流程及工作原理,搭建其运动控制系统拓扑结构,基于虚拟总轴同步控制策略,详细分析制袋机多轴同步控制基本原理,设计一种浮辊补偿算法,给出软件设计方法,并通过实际运行采集实验数据进行验证。结果该控制系统可以满足制袋机的运动控制要求,补偿相邻两轴间的同步误差,使得制袋系统两牵引轴间同步误差控制在0.3%左右。结论引入该策略的同步控制系统具有良好的同步性与稳定性,提高了制袋质量、精度和效率,降低次品率,较好地满足了制袋机裁切精度要求。     

新型双馈变速凸极同步电机

提出一种新型双馈变速凸极同步电机,阐述了它的基本原理和结构,电机的转子采用分裂磁极和正交绕组, 结构简单、可靠。转子绕组由低频交流变频电源供电,使电机具有变速恒频的特性。通过原型样机的试验,验证了该项发明的正确性和实用性,它将在大型水电、风电中得到广泛应用。     

载波注入的无传感器PMSM转子自测角研究

提出一种基于载波电压信号注入的新型无传感器永磁电机转子自测角原理,将电机本体作为旋变器,向电机绕组中注入载波电压激励信号．在分析载波电压信号激励下永磁同步电机数学模型的基础上,研究了基于凸极跟踪转子位置的自测角方法．讨论了载波信号的注入、提取以及包含转子位置信息的高频负序电流的外差处理技术．采用仿真结果进行了分析,通过旋变器的实测结果验证了其正确性．仿真结果表明,以此机理实现的永磁同步电机无传感器控制具有很好的鲁棒性,同时具有良好的静、动态性能．     

Semi-analytical method for determining d-axis synchronous generator parameters using the dc step voltage test

The DC step voltage experiment is an alternative and non-destructive time-domain test to extract parameters from electrical machines that follows the standstill frequency response test procedure described in IEEE standard 115A. This work presents a new method for semi-analytically determining the characteristic parameters of the d-axis synchronous machine model. The test is carried out when the machine is at rest and the rotor's position is at d-axis; a DC-controlled power source is applied suddenly at two of the three terminals of the stator machine and the field circuit is short-circuited. Test measurements of d-axis stator voltage excitation and field and d-axis stator current responses were used. Both stator and field current patterns are simultaneously fitted to exponential functions which coefficients are analytically related to the d-axis characteristic parameters of the equivalent circuit. These characteristic parameters come from the conventional two transfer functions: direct-axis operational inductance L_d(s) and the armature to field transfer function sG(s). To validate the proposed methodology, test data is used in the d-axis parameter determination of a 7 kVA, 220 V, 60 Hz synchronous generator     

Principle of Operation and Feature Investigation of a New Topology of Hybrid Excitation Synchronous Machine

We present a new topology of hybrid excitation synchronous machine (HESM) and describe operational principles and features of the new configuration. Using the radial/axial distribution of the magnetic field, we develop an equivalent magnetic circuit model. We obtain magnetic flux, flux density, and induced voltage with various electrical magnetomotive forces by calculating the nonlinear magnetic circuit equation. We studied the Influence on the radial magnetic field of the axial magnetic field by 3-D finite-element method. The results are in good agreement with calculation by our magnetic circuit model. Our findings indicate that the air-gap flux density of a flux-concentrating HESM is high and the magnetic field in the air gap can be successfully regulated. Experimental results of 3 kVA prototype machine verify the feasibility of the structure and the correctness of our analysis.      

Voltage and frequency control of parallel operated synchronous generator and induction generator with STATCOM in micro hydro scheme

Parallel operation of synchronous and induction generators in micro hydro scheme is presented. The synchronous generator has an exciter, which provides a fixed excitation to produce normal rated terminal voltage at full resistive load. On the other hand, the induction generator has neither exciter nor speed controller. Static compensator (STATCOM) is connected to the common bus for terminal voltage and frequency control. A resistive dump load is connected across the DC link capacitor of STATCOM through a chopper to control active power. Simulink model is developed to perform transient analysis of the proposed scheme. Experimental results are presented to compare with the simulation results. It is found that connection of an induction generator in parallel with the synchronous is much simpler than connecting two synchronous generators in parallel.     

自同步振动及振动同步传动的机电耦合机理

自同步振动和振动同步传动在机械工程上已获得成功应用 ,但是振动机械实现自同步振动和振动同步传动的过渡过程长期以来却一直不明确 ,利用现有的振动机械模型还不能定量解释系统从不同步到同步、或是从一种同步状态过渡到另一种同步状态的物理过程。本文对此进行了专门的研究 ,在传统的振动机械模型基础上建立了电机 -振动机械系统的机电耦合模型 ,利用该模型进行数值模拟对过渡过程中的一系列实际现象做出了合理的定量解释 ,揭示了自同步振动和振动同步传动的机电耦合机理     

机组式凹印机可视化监控平台的研究与开发

目的 为解决凹版印刷生产过程中监控系统功能单一、可视化程度低、信息利用率低等问题，构建一种基于数字孪生的监控系统四层架构模型。方法 通过SolidWorks、3DS Max、Unity 3D三维建模软件搭建凹印机虚拟场景，基于Modbus TCP/IP协议采集设备的实时数据，使用SQL Server数据库对设备数据分类存储，并结合凹印机虚实映射逻辑结构，编写C#脚本实现物理实体与虚拟模型间的同步映射，完成监控系统的开发。结果 该监控平台实现了凹印机的虚实同步运行、状态监控、套准偏差监控和健康管理等功能，为印刷企业智能化运维提供了可行方案。结论 与传统印刷装备监控相比，基于数字孪生的监控系统突破了时间、空间、投入成本等条件的限制，操作者可实时掌握凹印机的生产信息、运行状态、历史信息等，极大地提高了设备稳定生产的效率，降低了企业的成本。     

一类电力系统的分岔和奇异性分析

研究了单机无穷大系统在外部周期性激励负荷扰动作用下的非线性动力学行为：运用多尺度法分析了单机无穷大系统主共振的解析解及其稳定性,根据系统的分岔方程,运用C-L方法分析了主共振响应在不同系统参数下的不同分岔模式,研究表明该系统的不同分岔模式与其运行参数和结构参数有密切联系;数值仿真表明随着激励幅值的变化,该系统具有由倍周期分岔通往混沌直至增幅振荡失步的丰富动力学行为,从而为电力系统中同步发电机的同步运行、振荡失步提供理论指导。     

基于神经网络 PID 的造纸机多电机同步控制研究

目的为提高生产的质量和降低纸的断头率,研究造纸机多电机同步控制的方法。方法应用Matlab/Simulink建立模型和仿真实验,分析主从同步控制结构和并行同步控制结构,在并行同步控制结构的基础上,引入基于神经网络PID算法的速度补偿器。结果仿真结果表明,引入速度补偿后,2台电机的转速逐渐上升至给定速度,且速比稳定保持在1.01。在t=2 s只有第2台电机的负载转矩发生变化时,2台电机的转速基本没有下降。结论该方法增强了造纸机多电机同步控制系统的同步跟随能力,提升了抗干扰性能,可以有效避免在造纸机运行过程中,电机负载转矩突变造成的纸张过紧断纸、过松褶皱,为造纸机多电机提供了一种新的同步控制的方法。     

Numerical impulse response test to identify parametric models for closed-slot deep-bar induction motors

An impulse response test for estimating the electrical parameters of a deep-bar induction motor is studied. The impulse response test is performed within the two-dimensional finite-element analysis (FEA). The impulse excitation is applied to the stator voltage. Since the test is suitable for modelling the perturbations about a certain operation point, a small-signal model for the double-cage induction machine is derived. The skin effect is taken into account by using two parallel rotor branches. In addition to the small-signal parameters, the steady-state parameters are also estimated using the time-harmonic FEA. The impulse response test is based on the assumption of linear behaviour about an operation point. Thus, the effects of nonlinearity are studied by several methods     

高速同步带间歇传送装置的动态性能研究

目的为了解决间歇运动引起的振动和噪音问题,提高同步带传送的精度和可靠性,研究间歇运动对高速同步带传动装置的影响。方法通过研究一对带齿与轮齿的啮合接触问题,建立周期性载荷激励下带上相邻夹具间的振动平衡方程,在理论模型的指导下,利用Recurdyn软件建立高速同步带间歇传送系统动态仿真模型,分析系统位置精度和动态性能的影响因素。结果得到的数据表明,带元的粘弹性会造成同步带的横向及纵向振动,且带中段的定位精度较低。结论根据得到的间歇运动对高速同步带间歇传送装置动态性能的影响可以得出,采用带中段增设涨紧轮或者采用中间加钢丝的无拼接同步可提高同步带传送的可靠性。     

径向环形编织机机电一体化系统建模及控制策略研究

针对径向环形编织机电气特性与机械特性的差异导致的编织机电机易超载甚至被烧毁的问题,建立了编织机机电一体化系统模型。该模型包括编织环模型和牵引滑台模型,其中编织环模型由88个齿轮的闭合传动与4个永磁同步电机的同步驱动耦合而成,牵引滑台模型由永磁同步电机的驱动与滚珠丝杠的运动耦合而成。为了解决编织环上4个电机因齿侧间隙等的存在造成的负载不均,提出了转矩均衡控制方法,即：主电机受速度环和电流环双环闭合控制,从电机只受电流环控制;主电机速度环的输出量作为从电机电流环的给定量。为了较快地使编织环电机组的转速与滑台电机的转速满足协同关系,提出了跟踪性能与同步性能解耦控制方法即交叉耦合解耦控制方法,将跟踪误差补偿量按一定比例关系缩小至幅值以下,以凸显协调误差补偿的效果。进行了现场实验,结果表明,采取所提出的控制策略能够使编织环4个电机的输出转矩相差较小,而且在电机启动与加减速阶段可以使编织环主电机与滑台电机的转速达到协同要求的时间大幅缩短。根据控制策略设计了编织机伺服控制系统。研究结果对织物编织质量的提高起到了重要的指导作用。     

Dynamic control of the permanent magnet-assisted reluctance synchronous machine

A digital signal processor-based control system for the permanent magnet-assisted reluctance synchronous machine, with the emphasis on dynamic performance, is proposed. A classical design approach is used to design the current and speed controllers for the machine. The stator current of the machine is controlled in such a way that the current angle in the dq synchronous reference frame is constant. The load-torque is estimated using a state space observer and compensation current based on the estimated load is used to improve the dynamic performance of the drive. The control system design is machine specific as it relies on data from finite-element analysis. Simulated and measured results on a 110-kW power level show that the resulting control system is stable and robust with good dynamic performance     

同步发电机无传感器转速测量方法及应用

介绍了一种无需转速传感器的单片机检测同步发电机转速的方法.利用PIC16C57单片机的I/O端口直接从发电机输出的相电压取样,测定正半波的时间宽度作为测量动力机转速的依据,从而省去了转速传感器,简化了安装和调试,降低了系统成本,也简化了PIC16C57外围电路的设计.同时给出了晶闸管自励恒压交流同步发电机在防止低速励磁发生中的应用方法.     

造纸机速度链控制系统设计

目的为改善造纸机多电机同步控制效果,降低纸张生产过程断裂率,基于神经网络PID算法设计一种造纸机速度链控制系统。方法阐述造纸机的工艺流程,在此基础上建立造纸机速度同步控制数学模型。设计一个神经网络PID控制器,包括控制器结构和学习算法,可用于解决相关非线性问题,并进行仿真和试验研究。结果该控制系统具有较好的稳定性、适应性,响应速度较快,同步精度高。结论该方法增强了造纸机的同步跟随能力和抗干扰性能,可以有效避免断纸、褶皱等现象的发生,为造纸机多电机同步控制提供了一种有效的方法。