永磁同步电机最大转矩电流比控制的FPGA设计与实现

本文提出了一种永磁同步电机最大转矩电流比控制FPGA的设计,以提高电磁转矩的响应速度、稳态特性以及减小磁链脉动,具有良好的动态特性。在数据的处理方面采用自定义的方式对小数运算进行处理,极大的提高系统的精度,同时也兼顾了系统性能的优化和资源的分配。验证了控制策略具有良好的动态响应、稳态特性、转矩脉动小,在全速范围内对永磁同步电机参数的变化具有较强的鲁棒性,是一种高性能的交流调速方式。     

永磁同步电机直接转矩控制技术研究

与异步电机相比,永磁同步电机具有结构简单、功率因数高、转矩惯量比大等优点。但是它也存在定子和转矩脉动大,开关频率不恒定等诸多问题。该文针对永磁同步电机直接转矩控制中出现的转矩脉动较大的问题,提出了一种永磁同步电机无磁链闭环直接转矩模糊控制的方法。该方法采用模糊控制器作为转速环的控制器,并去除磁链闭环,加入磁链限幅环节,将转矩作为控制目标,通过模糊控制器的优化,得出系统具有良好动态性能和自适应性。     

永磁无刷直流电动机位置传感器精度对脉动转矩抑制效果的影响研究

采用峰谷互补方法对永磁无刷直流电动机的脉动转矩进行抑制时,2台电机脉动转矩波形的对称性和正弦性与抑制效果密切相关,而位置传感器的精度直接影响电机脉动转矩的波形特性.基于此,首先通过实验测定了2种位置传感器在电机运行时其输出信号的相位差、占空比和响应速度,并进行了分析.然后搭建实验平台测定了电机在2种位置传感器工况下脉动...     

开关磁阻电机转矩脉动优化研究

转矩脉动是造成电机振动和噪声的主要原因。为降低开关磁阻电机转矩脉动,研究了一种新型转子齿形,即在传统平行转子齿形的两侧添加半椭圆形辅助铁芯。利用有限元法,对一台12/8极开关磁阻电机建模,通过参数化仿真,得到最优改进模型。同时,为了进一步降低转矩脉动,优化功率变换器开关角,缓解换相时引起的转矩跃变。通过仿真计算得到最佳开通角和关断角组合方案,不仅可以显著降低开关磁阻电机的转矩脉动,而且还缓解了双凸极造成的局部饱和。该方法从根源上减小双凸极结构造成的局部饱和和换相时引起的转矩较大跃变,对于其它的双凸极电机都有借鉴意义。     

电动汽车用开关磁阻电机瞬时转矩控制系统研究

介绍开关磁阻电机(SRM)作为电动汽车驱动电机的优势和潜力;根据电动汽车的行驶工况要求和电机自身的转矩特性,设计基于转矩分配策略的车用开关磁阻电机直接瞬时转矩控制(DITC)系统;并基于所设计的控制策略,在matlab/simulink软件中搭建控制系统仿真模型。仿真结果表明,所制定的控制策略改善开关磁阻电机的转矩脉动,使SRM能够满足电动汽车对动力性、系统响应以及乘坐舒适性的要求。     

基于谐波注入的永磁电机转矩脉动抑制策略研究

为解决多相永磁电机的转矩脉动问题,该文基于解析法、仿真以及实验的方法,提出一种抑制该类电机转矩脉动的方法。该文首先推导适用于任意相电机反电动势谐波和齿槽转矩引起的脉动转矩的通用解析表达式。然后,基于此模型,从控制的角度出发,提出通过采用电流谐波注入以补偿齿槽转矩和反电动势谐波的控制策略,分析所需注入的电流谐波特性的一般表达式。为验证所提出方法的有效性,以一台三相12槽10极表贴式永磁同步电机为例,通过Matlab/Simulink设计同时考虑反电动势谐波和齿槽转矩的电机仿真模型,搭建基于谐波注入的电机控制系统。此外,为进一步验证所提出的方法正确性,文章也进行相应的实验验证。研究结果表明：补偿前后电机的转矩脉动峰峰值从1.5 N·m降低到0.5 N·m,转速波动从±2.5 r/min降低到±0.7 r/min。     

基于有限集模型预测控制BPMSMS输出性能研究

针对无轴承电机支撑的永磁同步电主轴运行时的电流响应不灵敏、转矩脉动和转子振动等问题,提出基于有限集模型预测控制算法的BPMSMS控制策略。在完整的BPMSMS电压模型基础上,考虑转矩电流和转子位移的影响,进一步推导悬浮绕组模型预测电流方程,建立完整的无轴承永磁同步电主轴模型预测控制下的电流数学模型。根据使用的代价函数分别求出转矩控制和悬浮力控制的最优开关状态量,使得实际电流与参考电流误差更小,以此获得更好的转矩控制效果和转子振动抑制效果。仿真实验结果表明：在有限集模型预测控制下,BPMSMS具有更好的电流跟踪效果,转矩脉动小;在外加负载和干扰力时也能实现转子的稳定悬浮,系统鲁棒性较好。     

基于改进樽海鞘群算法的PMSM变论域模糊控制

目的 为提高自动化包装流水线的生产效率,针对永磁同步电机PI控制器参数无法适时调整而引起的稳态误差较大、抗干扰性差等问题,提出一种基于改进樽海鞘群算法的新型变论域模糊控制器。方法 通过游走策略和变异分布策略对樽海鞘群智能算法的位置更新进行改进,同时加入过界个体的加权位置修正与劣势个体二次迁移,并将优化后的算法与变论域模糊PI控制器相结合,用于调节伸缩因子,以获得对永磁同步电机更好的控制效果。结果 仿真表明,文中改进后的控制器较传统PI控制器有效减小了静态误差;同时优化后的控制器令PMSM在变速和变载工况下响应更快,较改进前的樽海鞘群算法作用下PI控制器在变速和变载工况下的超调量分别降低约21.35%和62.85%。结论 算法优化伸缩因子后得到的变论域模糊控制与其他控制相比,更有效地提高了系统的鲁棒性,改善了系统的控制性能,减小了损耗。     

基于新型趋近律的永磁同步电机动态性能优化

目的 提高永磁同步电机作业时的响应精度和速度,优化其动态反馈性能,解决传统滑模控制中趋近时间与系统抖振相矛盾的问题。方法 采用三闭环控制结构,位置环与电流环采用模糊PID控制方法,速度环采用基于新型趋近律的改进滑模控制方法,添加扰动观测器并给予系统扰动补偿。结果 仿真与在环硬件测试结果表明,文中提出的控制方法与传统三闭环滑模控制相比,相同时间内电机转子位置响应速度提前了0.123 s且无超调,同时明显降低了电磁转矩波动幅度。结论 文中设计的新型趋近律有效改善了传统滑模控制存在的问题,建立的控制系统有效提高了永磁同步电机的响应精度和速度,削弱了永磁同步电机作业时的抖振程度,具有良好的鲁棒性。     

永磁无刷直流电动机低脉动转矩研究

针对永磁无刷直流电动机在运行过程中存在明显脉动转矩的问题,研究了一种新结构低脉动转矩永磁无刷直流电动机。首先对普通永磁无刷直流电动机在电流换相、极弧系数小于1和电枢反应等3种因素下的脉动转矩进行了物理解析;然后以脉动转矩的变化规律为切入点,提出一种通过电机本体产生2个幅值相同、频率相同、相位互差180°电角度的脉动转矩,实现脉动转矩峰谷互补的抑制策略,并通过理论分析找到了脉动转矩峰谷互补的实现方法;最后研制了低脉动永磁无刷直流电动机及控制器,通过实验验证了脉动转矩抑制的有效性,与普通永磁无刷直流电动机相比,实验结果表明可以减少约70%的脉动转矩。     

A current ripple reduction of a high-speed miniature brushless direct current motor using instantaneous voltage control

High-speed miniature brushless direct current motor (BLDCM) is used in robots and medical applications because of its high-torque and high-speed characteristics. When compared with the general BLDCM, a high-speed miniature BLDCM has a low electrical time-constant. The current and torque ripple are very high when compared with the conventional pulse-width modulation (PWM) control scheme in the conduction period because of the inherent electrical characteristics. The authors propose a simple instantaneous source voltage and phase current control for torque ripple reduction of a high-speed miniature BLDCM. To reduce the switching current ripple, instantaneously controlled source voltage is supplied to the inverter system according to the motor speed and the load torque. In addition, a fast hysteresis current controller can keep the phase current within a limited band. Computer simulations and experimental results up to 40 000 rpm show the effectiveness and verification of the proposed control scheme.     

Improved direct torque control of induction motor with dither injection

In this paper, a three-level inverter-fed induction motor drive operating under Direct Torque Control (DTC) is presented. A triangular wave is used as dither signal of minute amplitude (for torque hysteresis band and flux hysteresis band respectively) in the error block. This method minimizes flux and torque ripple in a three-level inverter fed induction motor drive while the dynamic performance is not affected. The optimal value of dither frequency and magnitude is found out under free running condition. The proposed technique reduces torque ripple by 60% (peak to peak) compared to the case without dither injection, results in low acoustic noise and increases the switching frequency of the inverter. A laboratory prototype of the drive system has been developed and the simulation and experimental results are reported.     

Torque ripple reduction in direct torque controlled five-phase induction motor using modified five-level torque comparator

The five-phase induction motor inherently has the minimal torque ripple. However, when it is controlled by direct torque control (DTC) technique, the torque ripple increases due to the presence of a hysteresis torque comparator. The classical five-level torque comparator is presented in the previous literatures to control the torque ripple. However, this comparator has the drawback of wrong selection of zero voltage vectors inside the inner band on the positive side of the comparator, which enables the torque ripple to increase and dc-link utilization to decrease. In this paper, in order to reduce the torque ripple and to increase the dc-link utilization, a modified five-level torque comparator is proposed, which selects either medium or small voltage vectors instead of zero voltage vectors inside the inner band on the positive side of the comparator. In addition to torque ripple reduction and improvement in dc-link utilization, the proposed comparator significantly improves the quality of phase current. All the available 32 voltage vectors are selected through the proposed five-level torque comparator based on the location of x–y stator flux in order to eliminate the x–y stator flux so as to obtain reduced distortion in the phase current. By employing all the available voltage vectors, the freedom of utilization of all voltage vectors in the five-phase induction motor DTC drive is availed. The proposed five-level torque comparator is compared to its classical five-level counterpart through simulation and experimental results in order to validate the proposed DTC strategy.     

基于负载观测的PMSM滑模抗扰动自适应控制

实际转速值是转角微分得到的,基于转速的观测器设计会引入微分突变．本文在滑模变指数趋近率控制的基础上,针对实际应用的永磁同步电机（permanent magnet synchronous motor, PMSM）提出了一种新的负载转矩降阶观测器设计方法,以可直接测量的转角为已知观测对象,避免引入微分突变,将观测到的负载转矩成比例地前馈补偿,以削弱负载扰动对控制性能的影响,实现滑模抗扰动自适应控制．一方面,通过理论推导,得出所提出策略的理论计算方法;另一方面,以一应用案例,建立了与实际逼近的离散仿真系统．仿真验证了观测器的无超调和快速响应特性,并通过与普通滑模控制对比分析,验证了采用该方法设计的PMSM调速系统具有动态响应快和抗外界干扰能力强的高鲁棒特性．     

电动车用永磁同步电机的转矩阶次特征分析

针对电动汽车车身阶次振动和车内噪声的主要振源—永磁同步电机的转矩波动,首先通过转矩测量试验测得了电机24阶以内的动态、高阶转矩信号,分析与揭示了永磁同步电机转矩信号的阶次特性现象;为解释该试验现象,从理论上建立了一种考虑非正弦永磁磁场分布、开槽、时间谐波电流的永磁同步电机转矩波动数学模型,获得了谐波转矩的解析解,预测了转矩波动的阶次与频率,进而提出了试验测量动态、高阶转矩信号的转速判据。试验研究和理论研究表明：永磁同步电机的转矩具有明显的阶次波动特征,主要阶次有h-1、2（h-1）、6i+h-1、 6i-h+1阶（h∈N,且由变频器决定;i∈N）;h次时间谐波电流将单独引起h-1、2（h-1）阶的转矩波动,h次时间谐波电流、非正弦永磁磁场分布、开槽将共同引起6i+h-1、6i-h+1阶的转矩波动。     

一种新的包装机电机算法切换系统设计

目的 研究不同工况下包装机生产线中异步电机控制算法的在线灵活切换。方法 选用2种异步电机高性能控制策略FOC和DTC作为包装机电机算法的切换对象,研究2种算法的共同基础,得出新的FOC_DTC算法作为切换系统的过渡算法,有效解决2种控制策略在线相互切换带来的转矩、电流突变等问题,并且在硬件平台上与直接切换方案、重置PI切换方案进行对比。结果 在满足包装机各个工况要求的前提下,混合FOC_DTC切换系统在切换响应时间、切换平滑度和切换效率上比上述2种方案更优越,切换响应时间提高了2%,切换转矩尖峰降低了30%。结论 通过使用混合FOC_DTC切换系统,包装机在不同工况下可以在线实时切换动力系统电机的控制算法,在平滑度和响应时间上比其他方案有明显的优势。     

Initial rotor position estimation and sensorless direct torque control of surface-mounted permanent magnet synchronous motors considering saturation saliency

For a practical direct torque-controlled (DTC) permanent magnet synchronous motor (PMSM) drive system, the information of the initial rotor position, which is usually obtained by a mechanical position sensor, is essential for starting under the full load. To avoid the disadvantages of using mechanical position sensors, great efforts have been made on the development of sensorless control schemes. An initial rotor position estimation strategy is presented for a DTC PMSM drive based on a nonlinear model of PMSM incorporating both structural and saturation saliencies. In the new scheme, specially designed high-voltage pulses are applied to amplify the saturation saliencies. The peak currents corresponding to the voltage pulses are used, in combination with the inductance patterns, to determine the d-axis position and the polarity of the rotor. The presented initial rotor position identification strategy has been implemented in a sensorless DTC drive for a surface-mounted PMSM. Experiments are conducted to confirm the effectiveness of the method and the performance of the drive system.     

Optimisation techniques for a hysteresis current controller to minimise torque ripple in switched reluctance motors

The switched reluctance (SR) motor has many benefits owing to its low cost, simple design, rugged construction and comparatively high torque-to-mass ratio. Unlike DC and induction motors, the SR motor is intended to operate in deep magnetic saturation to increase the output power density. Because of the saturation effect and the variation of magnetic reluctance with respect to rotor position, all the relevant characteristics of the machine are highly non-linear functions of both rotor position and phase current. The ultimate outcome of all these non-linearities is that the generated torque contains significant ripples. The non-linearities in the SR motor have been extensively studied and many control strategies to reduce the generated torque ripples have been proposed in the literature. Modulation of phase current profile for generating torque in the SR motor with minimum ripples was the focus of most of the research. However, the main challenge to minimise the torque ripple is to design a current controller that is able to track the modulated phase current. In this work, new techniques to optimise the widely used hysteresis current controller are studied, and experimental verifications under closed-loop speed control with the modulated reference current data are presented. The experimental results indicate that the torque ripple is reduced to lie within 5% of the desired steady torque using the proposed optimisation techniques.     

光电跟踪系统力矩波动的自抗扰控制

为解决光电跟踪伺服系统受电机力矩波动影响产生的速度波动问题,提出了一种改进的自抗扰控制策略进行力矩波动补偿。该算法主要由两部分组成:通过扩张状态观测器辨识出系统扰动,然后将该扰动前馈到系统控制量中去,构成复合校正系统;反馈通道中采用两参数的比例微分控制器,可以保证系统的稳定性和良好的动态特性。仿真分析和实验结果表明:与同等闭环控制带宽的PI控制器相比,自抗扰控制器可以提高系统对扰动力矩的抑制能力,采用自抗扰补偿时,速度误差的峰值由1.88%降低到0.65%,速度误差的均方根值由0.8%降低到0.2%。实验结果证明提出的方法能够有效降低电机力矩波动的影响,提高速度平稳性。     

转速受限条件下TBM刀盘混合驱动系统控制器设计

传统全断面硬岩隧道掘进机（tunnel boring machine, TBM）刀盘转速同步控制方法是针对变频电机单一驱动源进行设计的,直接应用于混合驱动型TBM刀盘驱动系统易导致齿轮齿圈发生严重的偏载,显著降低TBM刀盘传动系统的使用寿命和TBM设备完好率。考虑到实际掘进过程中对刀盘转速的限制和系统参数漂移,采用自适应控制策略,针对电液混合驱动型TBM刀盘驱动系统设计基于驱动源力矩控制的转速控制方法。建立了齿轮齿圈传动系统模型,系统的参数不确定性得到充分考虑。通过MATLAB/AMESim联合仿真表明,该自适应控制系统对参数漂移具有补偿作用,在精确控制刀盘转速的同时,实现了不同类型驱动源间的负载力矩分配,原系统中的偏载问题得到了解决。电液混合驱动型TBM刀盘驱动系统通过液压马达和变频电机两种驱动源驱动特性的互补,有效提高了其地质适应性,并对提高掘进速度有着重要的作用。