Fault-Tolerant Operation of Five-Phase Permanent Magnet Synchronous Motor with Independent Phase Driving Control

The multi-phase motor drive system with multiple H-bridge power supply has high fault tolerance,which is widely used in aerospace,electric vehicle,ship integrated power system and other fields.In this paper,a fault-tolerant control strategy based on decoupling control and stator current compensation is proposed for the propulsion system of five-phase PMSM with independent neutrals.Firstly,the mathematical model of PMSM is established by using vector space decoupling method;Secondly,a stator current compensation method is adopted to carry out fault-tolerant control after the motor has single-phase and two-phase open-circuit faults and the fault-tolerant control system based on decoupling control is established;Finally,the decoupling control model and the fault-tolerant control of stator current compensation are verified by the simulation and experiment.The simulation and experiment results show that the method can reduce the torque ripple caused by the stator winding open-circuit fault,and the operation performance of the motor under fault condition is significantly improved.

Driving Range Parametric Analysis of Electric Vehicles Driven by Interior Permanent Magnet Motors Considering Driving Cycles

This paper presents parametric analysis of driving range of electric vehicles driven by V-type interior permanent magnet motors aiming at maximum driving range,i.e.,minimal total energy consumption of the motors over a driving cycle.Influence of design parameters including tooth width,slot depth,split ratio(the ratio of inner diameter to outer diameter of the stator),and V-type magnet angle on the energy consumption of the motors and driving range of electric vehicles over a driving cycle is investigated in detail.The investigation is carried out for two typical driving cycles with different characteristics to represent different conditions:One is high-speed,low-torque cycle-Highway Fuel Economy Test and the other is low-speed,high-torque cycle-Artemis Urban Driving Cycle.It shows that for both driving cycles,the same parameters may have different influence on the energy consumption of the motors,as well as driving range of electric vehicles.

Optimization Design of High-speed Interior Permanent Magnet Motor with High Torque Performance Based on Multiple Surrogate Models

In order to obtain better torque performance of high-speed interior permanent magnet motor(HSIPMM) and solve the problem that electromagnetic optimization design is seriously limited by its mechanical strength, a complete optimization design method is proposed in this paper. The object of optimization design is a 15 kW、20000 r/min HSIPMM whose permanent magnets in rotor is segmented. Eight structural dimensions are selected as its optimization variables. After design of experiment(DOE), multiple surrogate models are fitted, a set of surrogate models with minimum error is selected by using error evaluation indexes to optimize, the NSGA-II algorithm is used to get the optimal solution. The optimal solution is verified by load test on a 15 kW, 20000 r/min HSIPMM prototype. This paper can be used as a reference for the optimization design of HSIPMM.

Analysis of temperature field for a surface-mounted and interior permanent magnet synchronous motor adopting magnetic-thermal coupling method

Aiming at obtaining high power density of surface-mounted and interior permanent magnet synchronous motor(SIPMSM),it is important to accurately calculate the temperature field distribution of SIPMSM,and a magnetic-thermal coupling method is proposed.The magnetic-thermal coupling mechanism is analyzed.The thermal network model and finite element model are built by this method,respectively.The effects of power frequency on iron losses and temperature fields are analyzed by the magnetic-thermal coupling finite element model under the condition of rated load,and the relationship between the load and temperature field is researched under the condition of the synchronous speed.In addition,the equivalent thermal network model is used to verify the magnetic-thermal coupling method.Then the temperatures of various nodes are obtained.The results show that there are advantages in both computational efficiency and accuracy for the proposed coupling method,which can be applied to other permanent magnet motors with complex structures.

Application of neural networks for permanent magnet synchronous motor direct torque control

Neural networks require a lot of training to understand the model of a plant or a process. Issues such as learning speed, stability, and weight convergence remain as areas of research and comparison of many training algorithms. The application of neural networks to control interior permanent magnet synchronous motor using direct torque control （DTC） is discussed. A neural network is used to emulate the state selector of the DTC. The neural networks used are the back-propagation and radial basis function. To reduce the training patterns and increase the execution speed of the training process, the inputs of switching table are converted to digital signals, i.e., one bit represent the flux error, one bit the torque error, and three bits the region of stator flux. Computer simulations of the motor and neural-network system using the two approaches are presented and compared. Discussions about the back-propagation and radial basis function as the most promising training techniques are presented, giving its advantages and disadvantages. The system using back-propagation and radial basis function networks controller has quick parallel speed and high torque response.

Encoderless Five-phase PMa-SynRM Drive System Based on Robust Torque-speed Estimator with Super-twisting Sliding Mode Control

In this paper,a robust torque speed estimator(RTSE)for linear parameter changing(LPC)system is proposed and designed for an encoderless five-phase permanent magnet assisted synchronous reluctance motor(5-phase PMa-SynRM).This estimator is utilized for estimating the rotor speed and the load torque as well as can solve the speed sensor fault problem,as the feedback speed information is obtained directly from the virtual sensor.In addition,this technique is able to enhance the 5-phase PMa-SynRM performance by estimating the load torque for the real time compensation.The stability analysis of the proposed estimator is performed via Schur complement along with Lyapunov analysis.Furthermore,for improving the 5-phase PMa-SynRM performance,five super-twisting sliding mode controllers(ST-SMCs)are employed with providing a robust response without the impacts of high chattering problem.A super-twisting sliding mode speed controller(ST-SMSC)is employed for controlling the PMa-SynRM rotor speed,and four super-twisting sliding mode current controllers(ST-SMCCs)are employed for controlling the 5-phase PMa-SynRM currents.The stability analysis and the experimental results indicate the effectiveness along with feasibility of the proposed RTSE and the ST-SMSC with ST-SMCCs approach for a 750-W 5-phase PMa-SynRM under load disturbance,parameters variations,single open-phase fault,and adjacent two-phase open circuit fault conditions.

Performance Analysis and Comparison of Two Fault-Tolerant Model Predictive Control Methods for Five-Phase PMSM Drives

Model predictive current control(MPCC)and model predictive torque control(MPTC)are two derivatives of model predictive control.These two control methods have demonstrated their strengths in the fault-tolerant control of multiphase motor drives.To explore the inherent link,the pros and cons of two strategies,the performance analysis and comparative investigation of MPCC and MPTC are conducted through a five-phase permanent magnet synchronous motor with open-phase fault.In MPCC,the currents of fundamental and harmonic subspaces are simultaneously employed and constrained for a combined regulation of the open-circuit fault drive.In MPTC,apart from the torque and the stator flux related to fundamental subspace,the x-y currents are also considered and predicted to achieve the control of harmonic subspace.The principles of two methods are demonstrated in detail and the link is explored in terms of the cost function.Besides,the performance by two methods is experimentally assessed in terms of steady-state,transition,and dynamic tests.Finally,the advantages and disadvantages of each method are concluded.

Improved Sensorless Operation of Interior PM BLAC Motor Drives with Reduced-Order EKF

It is a challenge to realise an EKF-based sensorless controller for an Interior Permanent Magnet （IPM） brushless ac motor drive due to the influence of nomlinearities and rotor saliency. An improved reduced-order EKF method is presented, reducing the rotor position estimation error of an IPM motor, as evident in [1] due to the neglect of saliency. The effectiveness of the proposed method is verified experimentally.

Short-circuit fault-tolerant control for five-phase fault-tolerant permanent magnet motors with trapezoidal back-EMF

When a short-circuit fault occurs in a phase,the faulty phase needs to be removed artificially from the system because of the loss of the capability to generate torque.In this case,both the short-circuit current and phase-loss fault would generate additional torque ripples.In this study,a novel fault-tolerant control strategy is introduced to achieve low torque ripple operation of five-phase fault-tolerant permanent magnet synchronous motors with trapezoidal back electromotive force(FTPMSM-TEMF)in the event of a short-circuit fault.The key concept of this method is to compensate for the torque ripples caused by the short-circuit current and the adverse effect of the phase-loss.Based on the torque expression under fault conditions,the torque ripple caused by the short-circuit current can be offset by injecting a certain pulsating component into the torque expression in the phase-loss condition.This would result in smooth operation under fault conditions.Moreover,to track the fault-tolerant alternating currents,the model of the deadbeat current predictive control is extended and restructured for the fault condition.The effectiveness and feasibility of the proposed fault-tolerant strategy are verified by experimental results.

IPMSM全速域无位置传感器控制策略

为了实现内置式永磁同步电机(IPMSM)无位置传感器系统全速域运行,提出一种改进型IPMSM复合控制策略。首先,在零低速域选用高频旋转电压注入法实现对电机转速和转子位置的估计;其次,在中高速域,为了削弱传统滑模观测器中开关函数造成的系统抖振问题,构造新型超螺旋滑模观测器,提高系统的观测精度;最后,引入差分进化算法优化过渡速域权重系数,实现不同观测方法间的合理切换,完成全速域下转子位置和转速的高精度辨识。研究结果表明,所提算法能够实现电机全速域运行,且具有良好的动态性能。

基于ADE优化的IPMSM全速域无传感器控制

为了实现内置式永磁同步电机(IPMSM)全速域的无传感器控制和切换速域的平滑过渡,提出了一种基于自适应差分进化(ADE)算法优化的复合控制方法。分别在零低速域、中高速域采用旋转高频电压注入法和滑模观测器法来对电机转速和转子位置进行估算,并在切换速域采用基于ADE算法的权重系数优化法来实现上述两种控制方法的平滑切换,从而实现IPMSM全速域无传感器控制。仿真结果表明:提出的复合控制方法能够实现电机全速域的无感控制和切换速域的平滑过渡,且具有良好的稳定性。

齿调制作用下转子开槽对永磁电机电磁振动影响

为了研究齿调制作用下转子表面开槽对永磁同步电机电磁振动的影响,以小功率分数槽集中绕组(FSCW)内置永磁同步电机(IPMSM)为研究对象,通过麦克斯韦应力张量法推导径向电磁力波的频率及空间阶数特征。分析齿调制作用在FSCW-IPMSM中将空间高阶电磁力波调制为低阶电磁力波的过程,并给出转子表面开槽在齿调制作用影响下与电磁振动间的联系。研究表明,转子表面开槽结构的改变会使各次谐波磁场发生变化,进而改变以极数阶电磁力波为代表的高阶电磁力波的幅值。在齿调制作用下,这些高阶电磁力波会被调制为幅值较高的低阶电磁力波,并引起不同幅度的低阶振动。然后建立C型、V型两种不同转子表面开槽结构的10极12槽FSCW-IPMSM电磁及结构有限元分析模型并进行仿真分析。结果表明,极数阶即10阶电磁力波会被调制为2阶并引起2阶振动,且两种不同开槽结构间的电磁振动存在着高达22.1%的差异。最后,在一台10极12槽样机上进行振动实验,验证理论与仿真分析结果。

磁链分区的磁场增强型永磁电机全速域模型预测直接转矩控制

磁场增强型内置式永磁(flux intensifying interior permanent magnet,FI-IPM)电机的反凸极(L_(q)<L_(d))特性,使得正向d轴电流增强磁场,提高输出转矩的同时,也使得弱磁升速时d轴电流正负交替变化,电流角度变化大,磁链波动大,进而造成转矩脉动大、电流畸变振荡、响应速度慢等问题。针对这些问题,该文提出一种基于磁链分区的磁场增强型内置式永磁电机全速域模型预测直接转矩控制控制策略。根据FI-IPM电机速度运行区域与磁链状态映射关系,构建磁链和转矩预测模型。在此基础上,提出磁链分区控制,引入磁链差值判断增磁和弱磁运行区,并进行磁链补偿,解决不同速度运行域之间切换的震荡和不稳定问题。最后,通过实验验证所提出控制策略的有效性,为该类电机在电驱动系统中的应用提供技术方案。

基于参数辨识的低速永磁同步电机MTPA控制策略

在永磁同步电机运行过程中,由于铁芯材料磁导率呈非线性变化而导致电感变化,继而在最大转矩电流控制比(MTPA)控制下出现固有的计算参数与实际参数不匹配现象,严重影响了电机的动态性能和运行工况下的稳定性。针对这一现象,该文采用高频注入原理,通过对高频注入产生的响应信号解调辨识得到实时的电感参数,然后令辨识得到的电感参数参与到MTPA计算中,保证了参数辨识的准确性和电机运行的稳定性,避免了最大转矩电流控制参数与电机不匹配导致的失控问题。最后,采用DSP LAUNCHXL-F28379D为控制核心的实验平台对所提方法进行了验证,实验结果表明该方法能够有效辨识电感参数并实现最大转矩电流控制。

Multi-Objective Optimization of Surface-Mounted and Interior Permanent Magnet Synchronous Motor Based on Taguchi Method and Response Surface Method

The surface-mounted and interior permanent magnet synchronous motor(SIPMSM)has the characteristics of multiple variables,strong coupling and nonlinearity.In order to improve the performance of SIPMSM,this paper presents a multi-objective optimal design process using Taguchi and response surface methodology(RSM).The peak value of cogging torque(PVCT),ratio value of average torque and permanent magnet weight(RTW),torque ripple and back-EMF total harmonics distortion(ETHD)are selected as optimization goals.The experiment matrix is established by Taguchi method,and analyzed the tendency and proportion of the effect of the optimization parameters on SIPMSM performance.The rules of choosing multi-objective optimization parameters are obtained.The least-squares method is used to establish the optimal objective function,and RSM is used to obtain the resolutions of the optimization objective function.Comparing the initial performance with optimized performance verifies the effectiveness of the proposed method.

基于延迟校正扩张状态观测器的内置式永磁同步电机电流控制策略

高速电驱动场合会受到开关频率的限制,低载波比特性凸显,由此引起的控制延迟问题影响了内置式永磁同步电机(IPMSM)矢量控制系统性能。基于扩展电动势的建模方案能够获得IPMSM的对称化模型,有利于离散化分析和设计,以提升低载波比运行性能。扩张状态观测器(ESO)能够实现扩展电动势和扰动的集总观测,然而低载波比延迟问题影响了估算性能。该文在离散域中分析延迟影响,设计和对比研究了几种延迟影响抑制方案,即延迟校正扩张状态观测器,提升了估计精度。基于此,设计了IPMSM离散域电流控制方案,显著提升了电流响应特性。通过电动汽车驱动实验平台验证了该文的分析和设计。

转子温度空间分布差异诱发永磁电机局部失磁特性研究

永磁材料磁特性受工作温度影响较大,高工作温度下存在的不可逆失磁现象是永磁电机高可靠性设计的主要瓶颈。针对内置式磁路结构的高功率密度永磁电机用钕铁硼永磁材料的不可逆失磁问题,基于电机全域空间损耗、温度分布的差异,该文提出一种永磁体局部失磁分析模型与特性计算方法。通过磁体虚拟分块法建立基于温度、退磁率等变量的永磁材料磁特性分析模型,利用电磁场和温度场双向耦合的三维多物理场计算方法,得到电机转子永磁体损耗、温度和局部失磁的空间分布特性。最后,通过对一台115 kW、8极永磁电机样机转子永磁体温度和转子表面磁场的实验测试,验证了分析模型与计算方法的准确性,为永磁电机局部失磁问题研究及精细化防失磁设计提供依据。

基于敏感度分层优化的Halbach永磁电机电磁振动分析

为解决内置式永磁同步电机径向电磁力引起的电磁振动问题,提出一种分段永磁体采用Halbach充磁方式同时转子开设辅助槽的电机拓扑结构。首先,对电机气隙磁密、径向电磁力、电磁振动原理进行推导与分析,并建立有限元模型。其次,提出基于电磁场和机械场耦合的电磁振动分析方案,对电机径向电磁力进行时间空间阶次傅里叶分解,在机械场中,分析电机定子在不同频率下的振动加速度幅值大小,并计算出定子各阶模态。在此基础上,基于响应面法和多目标遗传算法构建电机参数敏感度分层优化方案,并求得样本点帕累托前沿从而确定电机最优参数,将优化后的电机与普通V型内置式电机进行比较。最后,在机械场中仿真得到转子所受等效应力和总变形,验证得所提电机结构符合机械设计要求。分析结果表明:所提出结构电机在不损失电磁转矩的基础上,径向电磁力幅值大幅度降低,抑制了齿槽转矩,改善了气隙磁密和反电势的正弦度,在提高电机电磁性能的同时抑制了电磁振动的发生。

基于电流检测误差补偿的嵌入式永磁同步电动机无位置传感器控制实验平台设计

对基于高频脉振电压注入法的无位置传感器控制策略而言,转速和转子位置的准确估计十分重要。在传统高频脉振电压注入法的基础上,针对电流检测误差问题,提出一种电流检测误差补偿方法。该方法在传统位置观测器的基础上,增加了参数自适应陷波器环节,通过实时参数修订,消除位置观测器中由电流检测误差引起的二次谐波,提高转速和转子位置估计的准确性。采用品质因数更高的二阶广义积分器提取高频电流,改善控制系统的动态性能。通过搭建实验平台验证了所提补偿方法的可行性。

基于参数辨识的IPMSM电流谐波自适应抑制方法研究

为了减小电机参数变化对电流谐波抑制效果的影响,提高谐波补偿电压的精度,提出了一种考虑参数变化的电流谐波抑制方法来抑制内置式永磁同步电机(IPMSM)控制系统中的电流谐波.在电流谐波抑制方法的基础上,引入遗忘因子递推最小二乘法(FFRLS)构建自适应电流谐波抑制环,通过FFRLS在线辨识IPMSM运行过程中的电机参数,并将参数变化的辨识结果引入到稳态谐波电压方程中,动态更新谐波补偿电压,从而减小了电机参数变化对谐波补偿电压产生的影响,提高了电流谐波抑制的效果.最后,仿真和实验结果验证了提出方法的正确性和有效性.