交流永磁同步电机伺服系统模糊PID控制

分析了永磁同步电机(PMSM)在d-q轴的数学模型,结合传统PID控制和模糊PID控制的优点,根据永磁同步电机伺服控制系统随着负载变化或干扰因素影响,引起其对象特性参教或者结构发生改变,从而建立PID参数自调整的推理规则,设计了PMSM伺服控制系统的模糊PID参数自适应控制器.仿真结果表明,模糊PID控制器与传统PID控制器相比具有更好的动态稳定性,对外界干扰具有较强的鲁棒性.     

Simulation analysis of cogging torque of permanent magnet synchronous motor for electric vehicle

This paper proposes a new approach to study generation mechanism and influence factors of cogging torque of permanent magnet synchronous motors, in order to improve the operational performance and riding comfort of electric vehicle. Based on energy method and Fourier expansion, the method of predicting cogging torque is proposed. Two-dimensional finite element model of in-wheel motor is established by Maxwell software, and electromagnetic character of that is analyzed. Skew slot, pole arc coefficient and width of slot mouth are analyzed and studied by finite element method, in order to realize the change regularity of cogging torque. Cogging torque curves under the different skew slots, the different pole arc coefficients and the different widths of slot mouth are obtained, which can effectively reduce the cogging torque of in-wheel motor, but they still exists some limitations. The final simulation analysis results are in good agreement with the theoretical predicting results, which indicates that this method can be used to afford a theoretical basis to reduce the cogging torque and optimize the in-wheel motor of electric vehicle in the future.     

具有输入饱和的环形永磁力矩电动机自适应鲁棒控制

五轴联动数控机床中复合A/C轴直接驱动环形永磁力矩电动机伺服系统在输入饱和情况时易导致系统性能变差,甚至引起系统不稳定。针对系统中的输入饱和问题,基于反步法设计了饱和自适应鲁棒位置控制器,即设计一个虚拟控制律保证误差信号在每一步都收敛且有界。在控制器设计中构建非降函数处理执行器饱和,将控制输入限制在饱和范围内;对于参数不确定性,采用不连续投影算法进行在线参数估计。仿真结果表明该方法不仅使伺服系统在无输入饱和情况下具有较好的伺服性能,输入饱和情况下也能实现良好的跟踪性能。     

A Zeeman slower design with permanent magnets in a Halbach configuration

We describe a simple Zeeman slower design using permanent magnets. Contrary to common wire-wound setups, no electric power and water cooling are required. In addition, the whole system can be assembled and disassembled at will. The magnetic field is however transverse to the atomic motion and an extra repumper laser is necessary. A Halbach configuration of the magnets produces a high quality magnetic field and no further adjustment is needed. After optimization of the laser parameters, the apparatus produces an intense beam of slow and cold (87)Rb atoms. With typical fluxes of (1-5) × 10(10)?atoms/s at 30 m s(-1), our apparatus efficiently loads a large magneto-optical trap with more than 10(10) atoms in 1 s, which is an ideal starting point for degenerate quantum gas experiments.     

低速大力矩圆筒永磁直线电机齿槽力分析

为削弱圆筒永磁直线电机的齿槽力,采用了一种基于能量法和傅里叶分解的解析分析方法,推导出了圆筒直线电机与结构参数有关的齿槽力表达式。在此基础上,研究了定子极距所作的微小改变和极弧系数的优化选择对齿槽力的影响,提出了减少电机齿槽力的优化方案,并利用有限元法对其进行了验证。通过抽油机实际测试,其测试结果证明所提出的方法是正确有效的。     

电液伺服马达扭矩控制设计及优化

针对液压阀控马达扭矩伺服系统进行了研究。在对系统建模分析的基础上,采用PI控制策略对系统进行了控制优化,并用MATLAB对控制结果进行了时域仿真。结果表明控制取得了满意的效果。     

Novel sensor design for torque magnetometry

Torque magnetometry is a powerful method to determine a sample's magnetic properties. In a torque magnetometer, the sample under interest is mounted on a suitable sensor, the core part of the instrument. Piezoresistive atomic force microscope tips are proven to be very useful torque sensors and have already been optimized for the specific needs of torque magnetometry. However, this type of sensor did not offer the possibility of measuring torque along two perpendicular directions simultaneously without sacrificing sensitivity. In this article we demonstrate a fundamentally new sensor design based on the piezoresistive readout technique, which offers a large variability of measurement modes. With a symmetric arrangement of the sensor legs, concurrent two-axis measurements are easily possible with two separate readout circuits. Furthermore, the variability can be exploited by fabricating a thermometer on the sample platform to directly measure the sample temperature. Test measurements are in good agreement with elasticity calculations.     

Design and performance characteristic analysis of servo valve-type water hydraulic poppet valve

For water hydraulic system control, the flow or pressure control using high-speed solenoid valve controlled by PWM control method could be a good solution for prevention of internal leakage. However, since the PWM control of on-off valves cause extensive flow and pressure fluctuation, it is difficult to control the water hydraulic actuators precisely. In this study, the servo valve-type water hydraulic valve using proportional poppet as the main valve is designed and the performance characteristics of the servo valve-type water hydraulic valve are analyzed. Furthermore, it is demonstrated through experiments that a decline in control chamber pressure that follows the change of pilot flow is caused by the occurrence of cavitation around the proportional poppet, and that fundamental characteristics of the developed valve remain unaffected by the occurrence of cavitation.     

Reliability-based robust design optimization for torque ripple reduction considering manufacturing uncertainty of interior permanent magnet synchronous motor

Journal of Mechanical Science and Technology - This study performed reliability-based robust design optimization (RBRDO) of stator and rotor shape of the IPM type electric motor to reduce the...     

低速高转矩密度永磁同步电机的设计研究

针对目前桨翼飞行器用驱动电机转矩密度低的问题,从电磁、水冷、结构等多方面入手,设计了一款低速高转矩密度永磁同步电机(PMSM).首先,根据技术指标设计电磁方案,研究了永磁同步电机的转矩特性,提高额定工况下的转矩输出能力;其次,设计一种轴向外流道水冷系统,仿真结果表明散热效果明显;最后,对电机结构进行优化,实现电机轻量化...     

Influence of magnetic reluctances of magnetic elements on servo valve torque motors

The current research of electro-hydraulic servo valves mainly focuses on the vibration, pressure oscillating and source of noise. Unfortunately, literatures relating to the study of the influence of the magnetic reluctances of the magnetic elements are rarely available. This paper aims to analyze the influence of the magnetic reluctances of the magnetic elements on torque motor. Considering these magnetic reluctances ignored in previous literatures, a new mathematical model of servo valve torque motor is developed and proposed based on the fundamental laws of electromagnetism. By using this new mathematical model and the previous models, electromagnetic torque constant and magnetic spring stiffness are evaluated for a given set of torque motor parameters. A computer simulation by using AMESim software is also performed for the same set of torque motor parameters to verify the proposed model. The theoretical results of electromagnetic torque constant and magnetic spring stiffness evaluated by the proposed model render closer agreement with the simulation results than those evaluated by the previous models. In addition, an experimental measurement of the magnetic flux densities in the air-gaps is carried out by using SFL218 servo valve torque motor. Compared with the theoretical results of the magnetic flux densities in the air-gaps evaluated by the previous models, the theoretical results evaluated by the proposed model also show better agreement with the experimental data. The proposed model shows the influence of the magnetic reluctances of the magnetic elements on the servo valve torque motor, and offers modified and analytical expressions to electromagnetic torque constant and magnetic spring stiffness. These modified and analytical expressions could provide guidance more accurately for a linear control design approach and sensitivity analysis on electro-hydraulic servo valves than the previous expressions.     

Novel integrated position measurement unit for stepping motor servo control

Rotor position detection is important for motor servo system design. In general, there are two kinds of methods to obtain the position information in real time, sensor or sensorless methods. The sensor methods use position sensors such as optical encoder. This will greatly increase the cost of the system, and the sensor with high precision is difficult to be installed. On the other hand, the sensorless method can reduce the cost, but the reliability and complexity of the algorithm is still the problems. In this paper, a new low-cost integrated position feedback unit, which is composed of the integrated position sensor, signal processing hardware and software, is described. The sensor is easy to manufacture and has better precision with the help of signal processing circuit and software based on DSP. The sensor can obtain absolute rotating angle using inductance detection method, and it is originally designed and used for a 2-phase hybrid stepping motor position servo system. The integrated sensor and the proper control strategy make the system become a low-cost high-performance position servo system. Even though the feedback unit is originally designed for a 2-phase hybrid stepping motor, the same unit also can be used with other types of motors.     

磁流变伺服阀的设计与动态特性研究

利用磁流变液体可控的特性,设计了一新型伺服阀--磁流变伺服阀,介绍了该阀的结构特点及工作原理,建立了由该阀构成系统的数学模型并进行了理论分析.分析表明,与传统液压控制系统相比,由磁流变伺服阀控制的系统更易获得反应速度快、稳定性高、精度高等动态特性,能满足一般小功率、低压系统控制系统的要求.     

永磁同步电动机直接转矩控制在Simulink下的建模仿真

根据永磁同步电动机的数学模型,结合直接转矩控制理论,利用Simulink软件,对永磁同步电动机的直接转矩控制进行建模并仿真.控制系统加入比例、积分(PI)调节器,研究表明,合理设置PI调节器的比例系数和积分系数,能提高转速响应的速度,动态响应加快;同时稳态误差,即超调量也能限制在较小的范围.     

摆头力矩电动机夹紧机构设计及优化分析

为了降低精密五轴铣床摆头中夹紧套的结构应力集中程度,采用Solidworks和ANSYS软件对其进行了结构优化设计.首先在Solidworks中创建未进行优化的建议模型,然后针对实际工况和使用条件对其进行分析优化,从而显著改善夹紧套的应力集中程度.     

永磁同步电机直接转矩控制的改进与仿真

永磁同步电机（PMSM）以其高效率、高功率因数等优点,在工业领域得到了广泛的应用。主要分析了永磁同步电机的直接转矩控制（DTC）系统,分析了零电压矢量对永磁同步电机的作用,构造了一种新型的含零电压矢量控制开关表,改进了传统的控制系统。仿真结果表明,正确地使用零电压矢量能够有效减少转矩脉动,改善系统性能。     

永磁同步电机无差拍直接转矩控制系统研究

针对传统永磁同步电机(PMSM)直接转矩控制(DTC)中存在的磁链、转矩脉动大、开关频率不固定等问题,提出了一种永磁同步电机的无差拍直接转矩控制(DB-DTC)方法,在离散化电机方程基础上利用无差拍控制原理计算出电压矢量,并结合了空间矢量调制技术(SVM)产生开关信号控制电机运行。同时针对离散系统运算耗时所带来的控制周期的误差,进一步基于永磁体同步电机数学模型,提出了一种电流观测器以预测下一控制周期的电流值,目的是准确估计定子磁链和转矩。研究结果表明,所提出的PMSM DB-DTC不仅继承了传统DTC动态响应快的优点,而且能极大程度地削弱定子磁链和转矩的脉动,该系统具有良好的动静态性能,电流观测器能预测定子电流,确保了PMSM DB-DTC系统的控制精度。     

Optimal design to reduce torque ripple of IPM motor with radial based function meta-model considering design sensitivity analysis

In this study, optimum design process to reduce a torque ripple was presented for an interior permanent magnet (IPM) type electric traction motor. Firstly, 2-D electromagnetic finite element analysis was conducted to analyze the characteristics of the torque ripple in a view of magnetic saturation as well as cogging torque. Then, design factors of stator shape and rotor shape affecting to the torque ripple was selected as design variables. Secondly, using selected design variables, sensitivity analysis was performed to select design variable more affecting to the torque ripple and output torque by using design of experiments method. Thirdly, radial based function meta-model was constructed based on the results of the design of experiments (DOE). Finally, the optimum design was performed by using the constructed meta-model and method of feasible direction. By using the presented optimum design process, it is confirmed that the torque ripple of the optimum design was reduced to compare with the initial design and that output torque performance of the optimum design was maintained.

     

U型无铁芯永磁直线电机样机设计与有限元分析

针对传统设计方法的盲目性、高成本、周期长的问题.通过设计一种应用于大行程精密定位台中的U型无铁芯永磁直线电机(PMLM),探讨了一种新的设计方法.在分析其定子磁路和动子绕组结构特点的基础上,初步设计了电机参数.采用Maxwell 2DTransient求解器模块对电机特性进行分析,得到了电机空载反电动势、电机磁链、定位力特性和电磁推力.通过理论设计和有限元分析相结合的方法,设计制造了一台实验样机,并进行了相关实验.实验结果表明,电机的重复定位精度达2 μm;加速度能在0.08x内达到14 m/s2,在不同速度下的反向电动势成线性关系且与理论分析的吻合.研究结果表明,样机达到了设计要求,验证了设计方法的可行性.     

直流电机位置伺服系统设计

以机械臂的驱动电机为研究对象,采用廉价的旋转电位器作为位置传感器,设计了基于单片机的直流电机位置闭环控制系统。首先,研究了直流电机的位置控制原理和实现方法,并提出了适用于该系统的力矩控制方式。然后,从设计指标出发,计算了电机的负载,选择了执行电机,并设计了系统的硬件电路和相应的控制程序。最后,重点对系统调试过程中出现的非线性问题进行了研究,针对机械产生的非线性问题提出了改进方案和补偿的方法,并应用到了系统实际设计中。成功实现了直流电动机在空载、负载这两种不同状态下的位置控制。