Coupled Electromagnetic-Thermal-Fluidic Analysis of Permanent Magnet Synchronous Machines with a Modified Model

The researches on the heat generation and dissipa-tion of the permanent magnet synchronous machines(PMSMs)are integrated problems involving multidisciplinary studies of electromagnetism,thermomechanics,and computational fluid dynamics.The governing equations of the multi-physical prob-lems are coupled and hard to be solved and illustrated.The high accuracy mathematical model in the algebraically integral con-servative forms of the coupled fields is established and computed in this paper.And the equation coupling with the fluid flow and the temperature variation is modified to improve the positive definiteness and the symmetry of the global stiffness matrix.The computational burden is thus reduced by the model modification.A 20kW 4500rpm permanent magnet synchronous machine(PMSM)is taken as the prototype,and the calculation results are validated by experimental ones.

Modeling and Hardware-in-the-Loop System Realization of Electric Machine Drives-A Review

This paper presents a state-of-the-art review in modeling approach of hardware in the loop simulation(HILS)realization of electric machine drives using commercial real time machines.HILS implementation using digital signal processors(DSPs)and field programmable gate array(FPGA)for electric machine drives has been investigated but those methods have drawbacks such as complexity in development and verification.Among various HILS implementation approaches,more efficient development and verification for electric machine drives can be achieved through use of commercial real time machines.As well as implementation of the HILS,accurate modeling of a control target system plays an important role.Therefore,modeling trend in electric machine drives for HILS implementation is needed to be reviewed.This paper provides a background of HILS and commercially available real time machines and characteristics of each real time machine are introduced.Also,recent trends and progress of permanent magnet synchronous machines(PMSMs)modeling are presented for providing more accurate HILS implementation approaches in this paper.

基于MPCC的PMSM电流传感器故障诊断与容错控制

针对电流传感器在永磁同步电机系统运行时发生的故障,提出一种基于模型预测电流控制的电流传感器故障诊断与容错控制方案。控制器依次遍历8种电压矢量,得出下一周期最优预测电流,并与下一周期的实测电流比较,以实现快速诊断。利用预测相电流代替故障相电流实现故障后的容错控制。仿真验证了系统在电流传感器突发故障时诊断与容错方法的有效性与可行性。

基于模糊全阶滑模观测器的PMSM无传感器控制

为解决传统滑模观测器采用固定滑模增益在永磁同步电机转子位置检测低速抖振严重的问题,提出了旨在提高宽调速范围滑模抖振抑制性能的模糊自适应调节滑模增益的全阶滑模观测器。首先,以定子电流与扩展反电动势为观测对象构建全阶滑模观测器,采用定子电流实际值与观测值的误差和误差变化率为输入量构建模糊控制规则,并根据实时观测的电机转速,实现在不同转速时的滑模增益自适应调节。然后,采用双曲正切函数代替传统的符号开关函数实现软开关切换的连续滑模控制,并且为消除转速造成的影响,采用归一化正交锁相环获得扩展反电动势中准确的转子位置信息。最后,搭建了永磁同步电机驱动试验平台,在低速与中高速范围内分别进行实验验证。实验结果表明,相比于传统滑模观测器,所提算法在宽调速范围时控制性能更具有优势。

A Survey on Fault Diagnosis and Fault Tolerant Methodologies for Permanent Magnet Synchronous Machines

This paper presents a comprehensive survey of fault diagnosis and fault tolerant approaches for permanent magnet synchronous machines(PMSM).PMSMs are prominent in the pervading usage of electric motors,for their high efficiency,great robustness,reliability and low torque inertia.In spite of their extensive appliance,they can be quite non-resilient and inadequate in operation when faults appear in motor drive apparatus such as inverters,stator windings,sensors,etc.These may lead to insulation failure,torque fluctuations,overcurrent or even system collapse.On that account,fault diagnosis and fault tolerant methods are equipped to enhance the stability and robustness in PMSMs.Progressive methodologies of PMSM fault diagnosis and tolerance are classified,discussed,reviewed and compared in this paper,beginning with mat hematical modeling of PMSM and then scrutinizing various fault conditions in PMSMs.Finally,the scope of research on the topic is highlighted.The contribution of this review is to emphasize optimistic schemes and to assist researchers with the latest trends in this field for future directions.

Improved Hybrid Method to Calculate Inductances of Permanent Magnet Synchronous Machines with Skewed Stators Based on Winding Function Theory

An improved hybrid method combining two dimensional(2D)finite element analysis(FEA)and the analytical method is put forward to calculate the stator winding inductance and synchronous inductance influenced by stator skewing technique.Based on winding function theory(WFT),the improved method proposes two factors to describe variable inductances along the stator skewing angles.Comprehensive simulations are then performed on three interior permanent magnet synchronous machines(IPMSMs),one normal and two skewed machines(half slot and one slot pitch skewing respectively).Extensive experiments are conducted on relevant prototypes with good correlation.Moreover,analysis and comparisons are made as to the influence of different skewing angles on the inductances and torque-speed curves.It is found that Ld increases and Lq decreases by skewing,leading to the reduction of the rotor saliency and maximal torque capability,but increase of the flux weakening capability.

PMSM滑模观测器无位置传感器控制研究

永磁同步电机(PMSM)以其高效、大转矩输出而得到了广泛应用。现有永磁同步电机驱动系统调速多采用位置传感器获取转子位置以及速度信号,使得驱动调速控制系统成本增加,同时系统的可靠性也有所降低。针对此不足,研究了永磁同步电机的无位置传感器控制,深入分析并设计了基于改进滑模观测器的永磁同步电机矢量控制系统,通过引入锁相环技术解决了系统抖动问题,基于MATLAB搭建了系统仿真模型。最后以TMS320F2812DSP控制芯片为核心,搭建了实验测试平台,通过控制一台1 k W表贴式永磁同步电机,实现了永磁同步电机的无位置传感器滑模观测器控制,验证了所提出方法的正确性。

一种基于无速度传感器的PMSM的转子角度、转速估计方法

针对基于无速度传感器的永磁同步电机,提出了一种新的转子角度、转速估计方法。该方法基于静止坐标系对永磁同步电机的转子进行角度、转速估计,可以在避免传统估计方案中基于锁相环的转子磁链定向过程的同时,消除可能引起系统不稳定的局部环,进而提高估计方法的动态性能。为获得转子角度估计值,该方法并不直接对快速变化的转子角度计算值进行滤波,而是首先对缓慢变化的转子角度初值进行滤波,然后再将其叠加到快速变化的有偏转子角度计算值上,从而获得转子角度的无偏估计。针对典型的1.5 MW直驱风力发电系统的仿真实验结果显示,该估计方法的稳态特性与传统反电势锁相环法类似,但动态特性得到了显著的提高。

基于模糊逻辑的PMSM转矩谐波反馈控制

为了应对永磁同步电机(PMSM)驱动系统的转矩脉动问题,设计了一种基于模糊逻辑和转速谐波反馈的PMSM转矩脉动优化控制策略。控制方案中使用转速谐波幅值和增量作为闭环模糊逻辑电流控制器的输入,以达到控制转矩脉动的目的,由于采用的是电机转速测量,故不依赖于电机参数,且避免了一些系统非线性因素影响,从而鲁棒性较好。分析了PMSM输出转矩谐波和转速谐波的相关性,并基于分析建立了转矩谐波数学模型,方便了控制器的设计。基于PMSM驱动系统实验室平台,进行了不同负载工况下的驱动试验,试验结果验证了该控制策略的有效性。

基于方波注入的无滤波器PMSM初始位置检测

针对内置式永磁同步电机矢量控制中,转子初始位置误差会对其启动和运行产生严重的不良影响的问题,提出了一种在无滤波器高频方波信号注入过程中插入一段等幅值正反脉冲,通过比较d轴响应电流并结合位置观测器的方法,获取转子初始位置,实现电机的无传感器任意位置低速带载启动。利用MATLAB/Simulink搭建电机及观测器模型,仿真结果表明该方法得到的初始位置十分准确,最大误差约为3.6°。最后,通过硬件实验实现了电机任意位置带载启动且位置误差均在3.6°之内。

基于改进型滑模观测器的变频洗衣机用PMSM无位置传感器控制

针对永磁同步电机(PMSM)位置传感器成本高、维护难等问题,设计了一套用于变频洗衣机的PMSM无位置传感器控制方案。采用改进型滑模观测器(SMO)实现电机转子位置与转速的估算,通过三电阻采样方式来检测三相电流,有效地降低了系统成本。系统采用矢量控制模式,针对洗衣机负载波动大、运行速度高的特点,在电流内环设计中增加了电压前馈补偿解耦控制环节,与传统PI调节器相比,该方案能够改善电流跟踪效果,提高控制性能。最后,在洗衣机样机平台上进行了实验验证,实验结果证明该控制方案运行可靠,控制效果良好,能够满足洗衣机的工作要求。

SVPWM逆变器供电时FSCW-PMSM损耗特性研究

为探究空间矢量脉宽调制(space vector pulse width modulation,SVPWM)逆变器引入的时间谐波电流对分数槽集中绕组永磁同步电机(fractional-slot concentrated-winding permanent magnet synchronous machine,FSCW-PMSM)损耗特性的影响,文中提出一种SVPWM逆变器与FSCW-PMSM联合系统中电机损耗谐波特性分析方法。首先,理论分析了考虑时间谐波电流时电机损耗的时空谐波特性。其次,以一台三相双层绕组10极12槽PMSM为例,搭建电机与SVPWM逆变器的场路联合仿真模型,求解样机在恒转矩和恒功率调速时损耗的谐波特性,揭示各谐波损耗的产生机理。结果表明:转子谐波损耗由基波电流与次谐波、iZ±p次齿谐波和(f_(c)±4 f)/f、(f_(c)±2 f)/f次时间谐波电流与p、Z±p次空间谐波引起;定子铁芯谐波损耗由基波磁场、谐波励磁磁场及(f_(c)±4 f)/f、(f_(c)±2 f)/f次时间谐波电流引起。该结论适用于其他极槽组合的FSCW-PMSM。最后,通过实验验证了该分析方法的有效性。

基于ESO及NTD的PMSM无机械传感器位置控制

在分析永磁同步电机(PMSM)系统模型的基础上,提出了一种基于扩张状态观测器(ESO)及非线性跟踪微分器(NTD)的PMSM无机械传感器位置控制系统。控制系统通过基于ESO及NTD的观测器实时观测出电机转子位置及转速,在此基础上实现PMSM无机械传感器位置控制。仿真和实验结果表明该系统结构简单,控制快速、准确、无超调,对于外界干扰具有较强的鲁棒性。

计及开关频率分区优化的PMSM三电平模型预测控制

为降低传统三电平供电的永磁同步电机模型预测控制系统的开关频率,提出一种计及开关频率分区优化的PMSM三电平模型预测控制方法。首先,将空间电压矢量平面划分为12个扇区,并且根据上一时刻电压矢量所在位置,选择相邻扇区的电压矢量作为备选矢量。其次,加入对开关状态切换的限制,每个开关周期仅允许一相开关状态发生连续性跳变,减少备选矢量数量的同时能够有效降低开关频率。进一步,利用具有相同空间位置但对中点电位影响相反的正负冗余小矢量来平衡中点电位。最后,通过仿真和实验,验证该控制策略的有效性。

基于PR控制器的航空PMSM发电弱磁稳压方法

为了保证航空永磁同步电机发电系统在整个转速范围内能保持直流母线电压270 V恒定,而且谐波含量符合国军标要求,将基于电压反馈弱磁的PWM整流和比例谐振(PR)调节器相结合,利用增加负向去磁电流id减小电机反电动势,PR控制器可以对输入的交流信号在静止坐标系下进行无差调节,省去d轴和q轴电流的解耦项,易于实现谐波补偿,提高航空起动/发电系统的鲁棒性和航空电源质量。仿真和实验结果表明,该控制系统有效实现了宽转速范围的稳压及突加、突卸负载的高动态响应能力,输出电源具有高品质,满足航空电源国军标要求。

Robust Position Anti-Interference Control for PMSM Servo System With Uncertain Disturbance

Aiming to suppress the influence of uncertain disturbances in the drive control of permanent magnet synchronous machines(PMSM),such as the parameter uncertainties and load disturbance,a robust anti-interference control for the angular position tracking control of a PMSM servo system has been proposed in this paper.During the position tracking,uncertain system disturbances being regarded as a lumped unknown term will be online observed by a nonlinear disturbance observer(NDOB),of which the influence will consequently be counteracted by a robust backstepping compensator(RBC).The asymptotical stability of proposed control scheme is analyzed and designed according to the Lyapunov stability criterion,and its convergence against the system uncertain disturbance is verified on a prototype PMSM servo platform and shows good performance in rotor angular position tracking and anti-interference.

基于带宽的PMSM飞轮储能系统PI控制器参数设计方法

相较于传统的电机控制系统,飞轮储能系统中电机的额定频率较高。PWM调制和采样部分的延时环节在控制系统中的影响不可忽视,已有的基于带宽的PI参数设计方法会使控制系统在频率较高时存在很大的相位滞后。在考虑延时环节的情况下推导了电流环的闭环传递函数、分析了其进行降阶处理的条件,并提出了一种新的基于带宽的电流环PI参数设计方法。同时将该方法应用于转速环和电压环的设计,实验结果证明了所提出方法的正确性和可行性。

An Enhanced Sensorless Control Scheme for PMSM Drives Considering Self-inductance Asymmetry

Inductance asymmetry,which is brought by inherent asymmetric parameters,manufacture tolerance,winding fault,cables with unequal lengths,etc.,of permanent-magnet synchronous machines(PMSMs)can cause current harmonics and inaccurate position estimation.This paper proposes an enhanced fundamental model based sensorless control strategy for PMSMs with asymmetric inductances.The proportional-integral-resonant current regulator is introduced to reduce the second-order harmonics of currents,but there are still negative sequence components in the estimated back-electromotive forces(EMFs),which can cause the position estimated error.Differing from conventional methods in which negative sequences are filtered out before the phase-locked loop(PLL)module,the proposed method directly applies the estimated back-EMF with negative sequences as the reference input of PLL.An improved PLL with a bi-quad filter is proposed to attenuate the arising second harmonic position error and heighten the steady-state accuracy.Then,this position error is used for asymmetric inductance identification and its result is utilized to update the observer model.Furthermore,the dynamic performance is improved by the output limitation on the bi-quad filter as well as the implementation of a fast-locking technique in the PLL.The effectiveness of the proposed scheme is verified by experimental results.

一种无位置传感器PMSM快速平滑起动方法

研究一种适用于利用反电动势估计转子位置的无位置传感器矢量控制起动策略。起动阶段使用转速开环、电流闭环控制方式,正常运行阶段为速度-电流全闭环控制。在两种控制方法切换过程中,使用2个过渡状态,以追求快速平滑切换。第一过渡状态使q轴电流平滑减小,以减小给定转速坐标系和估计转子坐标系的误差角;第二过渡状态使矢量控制使用的转子位置信息从给定转速积分得到的转子位置平滑过渡到估计转子位置,完成平滑起动过程。实验结果表明该方法是正确且可行的。

改进的滑模观测器实现PMSM无传感器控制

无传感器控制技术能提高永磁同步电机驱动系统可靠性、环境适应性,且降低系统成本。基于一阶滑模观测器的无位置控制系统中,低通滤波器提取反电动势时,将产生相位延迟和幅值衰减,常需相位补偿环节。随着转速降低,补偿环节的补偿作用变差,位置估计误差增大,带载能力大大下降;且现场应用中,理想的补偿系数不易得到,系统调试难度较大。针对该问题,提出用自适应复数滤波器替代低通滤波器的无位置控制实现方法。自适应复数滤波器具有零相移、无衰减的优良特性,能在较宽速域内实现反电动势的精确提取,故无需相位补偿环节。仿真和实验结果表明,所提策略简化了系统结构、大大提升了带载能力,且系统颤振不再随转速降低而增大,而呈现等颤振水平。