Current optimization-based control of dual three-phase PMSM for low-frequency temperature swing reduction

In this paper,a control scheme based on current optimization is proposed for dual three-phase permanent-magnet synchronous motor(DTP-PMSM)drive to reduce the low-frequency temperature swing.The reduction of temperature swing can be equivalent to reducing maximum instantaneous phase copper loss in this paper.First,a two-level optimization aiming at minimizing maximum instantaneous phase copper loss at each electrical angle is proposed.Then,the optimization is transformed to a singlelevel optimization by introducing the auxiliary variable for easy solving.Considering that singleobjective optimization trades a great total copper loss for a small reduction of maximum phase copper loss,the optimization considering both instantaneous total copper loss and maximum phase copper loss is proposed,which has the same performance of temperature swing reduction but with lower total loss.In this way,the proposed control scheme can reduce maximum junction temperature by 11%.Both simulation and experimental results are presented to prove the effectiveness and superiority of the proposed control scheme for low-frequency temperature swing reduction.

Speed Regulation Method Using Genetic Algorithm for Dual Three-phase Permanent Magnet Synchronous Motors

Dual three-phase Permanent Magnet Synchronous Motor(DTP-PMSM)is a nonlinear,strongly coupled,high-order multivariable system.In today’s application scenarios,it is difficult for traditional PI controllers to meet the requirements of fast response,high accuracy and good robustness.In order to improve the performance of DTP-PMSM speed regulation system,a control strategy of PI controller based on genetic algorithm is proposed.Firstly,the basic mathematical model of DTP-PMSM is established,and the PI parameters of DTP-PMSM speed regulation system are optimized by genetic algorithm,and the modeling and simulation experiments of DTP-PMSM control system are carried out by MATLAB/SIMULINK.The simulation results show that,compared with the traditional PI control,the proposed algorithm significantly improves the performance of the control system,and the speed output overshoot of the GA-PI speed control system is smaller.The anti-interference ability is stronger,and the torque and double three-phase current output fluctuations are smaller.

Electromagnetic Performance Prediction for the Symmetrical Dual Three-phase Surface-mounted PMSM under Open-phase Faults Based on Accurate Subdomain Model

The paper presents an accurate analytical subdomain model for predicting the electromagnetic performance in the symmetrical dual three-phase surface-mounted permanent magnet synchronous machine(PMSM)under open-phase faulty conditions.The model derivations are extended from previous accurate subdomain models accounting for slotting effects.Compared with most conventional subdomain models for traditional three-phase machines with nonoverlapping winding arrangement,the subdomain model proposed in this paper applied for the 24-slot/4-pole dual three-phase machine with symmetrical overlapping winding arrangement.In order to investigate the postfault electromagnetic performance,the reconfigured phase currents and then current density distribution in stator slots under different open-circuit conditions are discussed.According to the developed model and postfault current density distribution,the steady-state electromagnetic performance,such as the electromagnetic torque and unbalanced magnetic force,under open-circuit faulty conditions are obtained.For validation purposes,finite element analysis(FEA)is employed to validate the analytical results.The result indicate that the postfault electromagnet performance can be accurately predicted by the proposed subdomain model,which is in good agreement with FEA results.

Model Predictive Torque Control for a Dual Three-phase PMSM Using Modified Dual Virtual Vector Modulation Method

Single voltage vectors applied in the conventional model predictive torque control(MPTC)for multiphase motors do not only suffer from serious torque and stator flux ripples but also cause the large harmonic current.To address the aforementioned challenges,an MPTC using a modified dual virtual vector modulation method is proposed to improve the operational performance of a dual three-phase permanent magnet synchronous motor.Virtual voltage vectors are synthesized as the candidate control set to restrain the harmonic current.A transformation method is introduced to consider both the stator flux and torque in the duty cycle modulation.The torque and stator flux ripples are simultaneously reduced by addressing the limitations of nonuniform units.Furthermore,the null voltage vector is then inserted to expand the modulation range and improve the steady-state performance.Moreover,the sawtooth carrier is adopted to address the challenge of the asymmetric switch sequence caused by the modified modulation.Finally,the experimental results are presented to verify the effectiveness and superiority of the proposed MPTC method.

Zero-sequence Current Suppressing Strategy for Dual Three-phase Permanent Magnet Synchronous Machines Connected with Single Neutral Point

Dual three-phase permanent-magnet synchronous machines(DTP-PMSM)connected with a single neutral point provide a loop for zero-sequence current(ZSC).This paper proposes a novel space vector pulse width modulation(SVPWM)strategy to suppress the ZSC.Five vectors are selected as basic voltage vectors in one switching period.The fundamental and harmonic planes and the zero-sequence plane are taken into consideration to synthesis the reference voltage vector.To suppress the ZSC,a non-zero zero-sequence voltage(ZSV)is generated to compensate the third harmonic back-EMF.Rather than triangular carrier modulation,the sawtooth carrier modulation strategy is used to generate asymmetric PWM signals.The modulation range is investigated to explore the variation of modulation range caused by considering the zero-sequence plane.With the proposed method,the ZSC can be considerably reduced.The simulated and experimental results are presented to validate the effectiveness of the proposed modulation strategy.

双PMSM统一模型预测系统的转速同步控制

双电机控制系统中,负载扰动、参数变化以及加减速运行等因素都会导致系统不稳定,同步误差增大。针对以上问题,设计了一种基于双电机统一预测模型的转速同步控制系统。首先,在传统的双电机交叉耦合控制结构的基础上,建立双电机统一模型,并构造分段价值函数以更精确地调节跟踪误差和同步误差。其次,为提高系统的动态性能和鲁棒性,设计了比例积分和分数阶滑模复合同步控制器(Proportional integral+fractional order sliding mode control,PI+FOSMC)。最后,在两台永磁同步电机(Permanent magnet synchronous motor,PMSM)上进行了仿真。结果表明,双电机统一模型预测系统具有较强的动态性能和鲁棒性,可提高系统同步精度。

基于谐波电流抑制的双三相PMSM容错型直接转矩控制

针对六相PMSM电机直接转矩控制系统在缺相运行时存在的转矩脉动大和电流谐波大等问题,提出了改进方法。根据矢量空间解耦的思想,推导出电机缺相后的数学模型和电压矢量方程,通过方程画出缺相后的电压矢量在基波平面和谐波平面的分布,分析了电压利用率的问题,在利用原始矢量制作出电机故障前后共用一个开关表的基础上,加入虚拟矢量合成后减少电流谐波的想法,以减小电机在直接转矩控制系统中缺相运行时的转矩脉动和电流谐波。利用虚拟合成矢量制作出电机在故障前后共用的一个开关表。仿真建模并验证了该方法的正确性。

九开关逆变器供电的双Y移30°PMSM开路故障诊断

本文在双Y移30°PMSM逻辑动态模型基础上,提出一种九开关变换器开关管开路故障诊断方法。建立九开关变换器开关管通断信号与电机相电压之间的逻辑关系,推导出电机驱动系统逻辑动态模型,通过逻辑动态模型提供的电压先验信息与含有故障信息的电压实际输出值比较,提取故障信息,可对任一开关管开路故障进行准确定位。

不同相移角度绕组对双三相永磁同步电机电磁性能的影响分析

由于双三相永磁同步电机两套三相绕组之间可采用不同相移角度,以一台24槽22极双三相永磁同步电机为例,分析了相移角度对电机性能的影响规律.首先,基于各槽绕组磁动势间的相位关系,推导了在采用单层绕组和双层绕组时,两套三相绕组之间可行的空间相移角度,即0°、15°和30°,并对比分析了不同空间相移角度绕组产生的电枢磁动势频谱;然后,结合电枢磁动势谐波和电机电磁性能之间的关系,通过有限元仿真,验证了0°、15°和30°相移角度的绕组拓扑对不平衡磁拉力、反电势、平均转矩和转矩脉动等电磁性能的影响规律;最后,制作了2台单层和双层空间相移30°绕组的样机,并通过实验验证了理论和有限元仿真分析的正确性.结果表明:空间相移0°存在明显的不平衡磁拉力;空间相移30°电机平均转矩最大,转矩脉动最小.

T型三电平逆变器馈电双三相PMSM直接转矩控制

提出了一种T型三电平逆变器馈电双三相PMSM驱动系统直接转矩控制(DTC)策略。该系统既具有多相电机转矩脉动小、电流应力小和故障容错能力强的优点,也继承了T型三电平电机驱动谐波性能好、可靠性高的特点。该文所提出的基于双空间矢量调制(SVM)技术的直接转矩控制策略保留了DTC快速动态响应特性。与基于空间矢量解耦(VSD)的SVM技术相比,双SVM技术避免了复杂的矢量合成过程,并具有良好的谐波控制效果。所提出的控制策略还设计了谐波电流闭环控制器,能够有效抑制由绕组不对称、反电动势谐波、死区等非线性因素引起的低次谐波电流。通过实验验证了所提出的T型三电平逆变器馈电双三相PMSM驱动系统DTC策略的有效性。

非串级结构下的双三相永磁同步电机调速控制和电流谐波抑制研究

该文针对多源时变干扰影响的双三相永磁同步电机系统,研究其基波平面内的调速控制问题和谐波平面内的谐波电流抑制问题。首先,在基波平面采用非串级控制结构,通过构造广义比例积分观测器(generalized proportional integral observer,GPIO)估计转速环的多源快变干扰;然后,针对q轴电流的过流保护问题,在传统比例微分反馈控制器的基础上利用障碍函数设计思想,结合干扰估计信息,得到基于GPIO的电流约束复合控制器;其次,在谐波平面,通过设计2个GPIO精准估计电流环的多源快变干扰,并与比例反馈控制器结合形成复合控制器来抑制2个电流环中的谐波电流。最后,给出严谨的稳定性分析,并通过对比实验验证所提方法的有效性。

基于SVPWM的六相PMSM串联系统运行性能研究

研究双Y移30°六相PMSM双电机串联系统的SVPWM技术,分析该双电机串联系统的工作原理和六相逆变器的空间电压矢量分布情况,结合基于id=0的矢量控制策略,提出传统SVPWM和多维多相SVPWM技术,推导电压矢量作用时间的计算公式,讨论空间矢量工作平面的几种选择方法,并对比例法和比较法的工作平面选择方法进行仿真比较,并在比例法下对两种SVPWM对该系统在不同转速下的运行性能进行比较研究,得出多维多相SVP-WM是该串联系统更为有效的控制方法。

基于强化学习的刚性联接双电机系统无模型最优协调控制

双永磁同步电机系统具有模型参数不确定,外部负载变化以及快慢动态共存的特性,这为其最优协调控制带来挑战。该文提出一种基于强化学习的无模型最优协调控制方法。首先,采用传统的主从控制结构和PI控制器构建双永磁同步电机系统数学模型;其次,利用输出调节理论和最优控制理论,设计最优协调控制器,解决系统外部负载变化问题;然后,针对系统的模型参数不确定以及快慢动态共存特性,提出一种独立于模型参数的强化学习算法,学习控制器增益;最后,仿真和实验结果验证所提出的控制策略可以有效改善双电机系统速度跟踪性能和转矩同步性能。该文所提控制方法能够提高双电机系统的跟踪性能和同步性能,抑制未知时变负载的干扰,并避免参数不确定所带来的影响。

基于两台双三相PMSM串联系统的张力线速度控制

以两台双三相PMSM串联系统为基础搭建了张力与线速度控制的模型。详细分析了控制系统的基本原理,建立了张力观测器以及线速度观测器的模型。在Matlab/Simulink环境下通过仿真分析得出该模型可以实现对材料收放卷过程中的张力与线速度的控制,验证了所建模型的正确性。

Fault-tolerant stator flux oriented decoupling control for dual three-phase permanent magnet motor without diagnosis and reconfiguration

In this paper,the fault-tolerant capability of the existing stator-flux-oriented decoupling control(SFOC)for the DTP-PM motor is investigated,and a simple fault-tolerant SFOC is further designed to enhance fault tolerance.Firstly,the mathematical model of the DTP-PM motor in the stator-flux-oriented rotating coordinate system is analyzed.An SFOC is proposed to guarantee healthy operation performance,considering torque,flux linkage,and harmonic currents.Secondly,the coupling relationship under open-phase conditions is assessed.The assessed result shows that the coupling relationship between the harmonic and fundamental components results in conflicts and poor post-fault operation.Thirdly,the proposed SFOC includes an automatic deactivation module to detect conflicts with a variable threshold.The conflicted harmonic current controllers can be excluded automatically.Hence,fault-tolerant control can be remedied without diagnosing the specific fault scenario,and excellent faulttolerant capability can be achieved.Finally,experiments on a DTP-PM motor are carried out to verify the feasibility and effectiveness of the proposed strategy.

基于Simulink的双三相永磁同步电机外部短路影响研究

双三相永磁同步电机内有两套绕组,形成两个余度,在单余度故障时,另一余度可继续工作,保持一定性能。短路故障是电机系统中较为严酷的一种故障形式,本文使用电路仿真的方法基于Simulink搭建双三相永磁同步电机的模型并进行几种外部短路情况的分析,避免了传统分析方法在直观性、便捷性方面的不足,得到双三相永磁同步电机在单余度引出线短路与开关管短路的故障下运行的状态。并分析了故障余度的控制系统,切断控制系统可减小输出性能下降,而主动构造三相完全短路可减小输出波动。最后总结双三相永磁同步电机外部短路对电机运行状态的影响。

一种双模糊PI控制器在PMSM控制系统的研究

针对模糊自整定PI控制器的不足以及永磁同步电机(PMSM)矢量控制系统的非线性、参数时变等特点,为进一步改善永磁同步电机控制系统性能,在基本二维模糊PI控制器的基础上引入了一维模糊控制器,构成了一种双模糊PI控制器。对所提出的双模糊PI控制器的输入输出关系进行理论推导并进行结构解析,得出该控制器是一种非线性的变参数PID控制器。在SIMULINK中构建系统仿真结构框图,进行仿真分析。仿真结果表明所提出的双模糊PI控制器使得PMSM具有更好的稳态性能和抗干扰性能。

双Y移30°六相PMSM的滑模变结构控制技术

针对双Y移30°PMSM的基于空间矢量控制的直接转矩控制(SVM-DTC)技术中PI调节器拖慢系统响应速度的问题,提出一种旨在提高系统响应速度的自适应滑模变结构控制技术。根据系统动态变化参数,研究其状态运动轨迹,通过控制量的切换使系统状态沿着其状态运动轨迹运动,系统的状态在参数发生变化或出现外界干扰时有不变性,达到了提高动态响应的目的。最后,在仿真工具中搭建双Y移30°六相PMSM调速系统的仿真模型,仿真结果明该控制方法解决了PI调节器积分环节响应速度慢的问题,电机转速和转矩的超调量较小、鲁棒性好、可靠性高、具有较强的抗扰动性能。验证了所提方法的正确性和有效性。

双三相PMSM全速范围内无位置传感器控制研究

为满足电机系统高功率/转矩密度要求,同时避免极端工况下因传统传感器引起的可靠性降低问题,针对双三相永磁同步电机提出了适用于全速度范围内的无位置传感器控制策略。在零速起动阶段,采用高频信号注入法向定子侧叠加小幅高频电压信号,通过检测定子的高频电流负序分量,结合外差法,得到转子位置角的估计值;在电机完成启动之后,采用改进型滑模观测器法,根据滑模观测器数学表达式计算转子位置角,得到位置信号。通过在滑模观测器中,利用连续饱和函数代替传统开关函数,能有效的抑制高频抖振。在Matlab/Simulink环境下搭建了双三相永磁同步电机系统模型,通过仿真验证了系统性能。仿真结果表明所提出的方法具有较好的控制性能。

基于双模过调制的PMSM控制系统研究与实现

研究了一种基于双模过调制的PMSM控制方案。以PMSM为控制对象,设计了以STM32为主控芯片和DRV8301为驱动芯片的电机控制器;采用定子电流注入法,实现了对转子的有效定位;设计了SVPWM的双模过调制算法,进一步提高直流母线电压利用率。通过对控制器和控制算法进行验证,实验表明,采用过调制算法可在一定程度上提高电压利用率。