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 ...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.展开更多
This paper presents an improved finite control set model predictive current control(FCS-MPCC)of a five-phase permanent magnet synchronous motor(PMSM).First,to avoid including all the 32 voltage vectors provided by a t...This paper presents an improved finite control set model predictive current control(FCS-MPCC)of a five-phase permanent magnet synchronous motor(PMSM).First,to avoid including all the 32 voltage vectors provided by a two-level five-phase inverter into the control set,virtual voltage vectors are adopted.As the third current harmonics can be much reduced by virtual voltage vectors automatically,the harmonic items in the cost function of conventional FCS-MPCC are not considered.Furthermore,an adaptive control set is proposed based on voltage prediction.Best control set with proper voltage vector amplitude corresponding to different rotor speed can be achieved by this method.Consequently,current ripples can be largely reduced and the system performs much better.At last,simulations are established to verify the steady and transient performance of the proposed FCS-MPCC,and experiments based on a 2 kW five-phase motor are carried out.The results have validated the performance improvement of the proposed control strategy.展开更多
Five-phase permanent-magnet synchronous motors(PMSMs)offer high fault tolerance,low torque ripple,and high torque density.An open-circuit fault results in an asymmetric motor model,which causes direct current(DC)bias ...Five-phase permanent-magnet synchronous motors(PMSMs)offer high fault tolerance,low torque ripple,and high torque density.An open-circuit fault results in an asymmetric motor model,which causes direct current(DC)bias and harmonics,thus affecting operational performance with sensorless control under fault-tolerant conditions.To improve operational performance,this study proposes a novel sliding mode observer(SMO)based on an enhanced adaptive complex-coefficient filter(EACCF)for the sensorless vector-control strategy of a five-phase PMSM with an open-circuit fault.The novelty of the proposed strategy is the development of the EACCF,which is characterized by an effective DC bias and harmonic-attenuation capability.Additionally,the fundamental back electromotive force can be estimated without phase lag or amplitude attenuation using the SMO.By incorporating a phase-locked loop,the accuracy of position estimation can be improved under both healthy and open-circuit fault conditions.The sensorless control can not only restrain the fluctuating torque caused by open-circuit faults but also offers good steady-state and dynamic performances under healthy and open-circuit fault conditions.Experimental results are presented to demonstrate the feasibility of the proposed method.展开更多
The main drawbacks of traditional finite set model predictive control are high computational load,large torque ripple,and variable switching frequency.A less complex deadbeat(DB)model predictive current control(MPCC)w...The main drawbacks of traditional finite set model predictive control are high computational load,large torque ripple,and variable switching frequency.A less complex deadbeat(DB)model predictive current control(MPCC)with improved space vector pulse-width modulation(SVPWM)under a single-phase open-circuit fault is proposed.The proposed method predicts the reference voltage vector in the a-β subspace by employing the deadbeat control principle on the machine predictive model;thus,the exhaustive exploration procedure is avoided to relieve the computational load.To perform the constant switching frequency operation and achieve better steady-state performance,a modified SVPWM strategy is developed with the same conventional structure,which modulates the reference voltage vector.This new approach is based on a redesigned and adjusted post-fault virtual voltage vector space distribution that eliminates the y-axis harmonic components in the x-y subspace and ensures the generation of symmetrical PWM pulses.Meanwhile,the combined merits of the DB,MPCC,and SVPWM methods are realized.To verify the effectiveness of the proposed control scheme,comparative experiments are performed on a five-phase permanent magnet synchronous motor(PMSM)drive system.展开更多
单相开路故障的五相永磁同步电机(permanent-magnet synchronous motor,PMSM)采用有限集模型预测转矩和磁链控制(finite-control-set model predictive torque and flux control,FCS-MPTFC)策略,存在转矩脉动大、价值函数的权重系数整...单相开路故障的五相永磁同步电机(permanent-magnet synchronous motor,PMSM)采用有限集模型预测转矩和磁链控制(finite-control-set model predictive torque and flux control,FCS-MPTFC)策略,存在转矩脉动大、价值函数的权重系数整定困难、迭代计算量大以及共模电压(commonmode voltage,CMV)高等问题。为此,该文提出一种简化FCS-MPTFC策略。首先,建立五相PMSM在单相开路故障情况下的数学模型,并分析CMV产生的机理。其次,以抑制3次谐波电流的原则合成等幅值虚拟电压矢量(virtual voltage vector,V^(3)),并将转矩和磁链价值函数等效转化为电压价值函数,同时采用无差拍控制思想计算出参考电压矢量,进而通过合理划分扇区,直接获得最优V^(3)。最后,选择方向相反的两个基电压矢量代替零矢量,以减小开路故障下的CMV。仿真和实验结果表明:所提控制策略不仅能抑制单相开路故障导致的转矩脉动、降低计算负荷和CMV、抑制电流谐波,而且具有优良的稳态和动态性能。展开更多
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-to...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.展开更多
Multi-phase machines are so attractive for electrical machine designers because of their valuable advantages such as high reliability and fault tolerant ability.Meanwhile,fractional slot concentrated windings(FSCW)are...Multi-phase machines are so attractive for electrical machine designers because of their valuable advantages such as high reliability and fault tolerant ability.Meanwhile,fractional slot concentrated windings(FSCW)are well known because of short end winding length,simple structure,field weakening sufficiency,fault tolerant capability and higher slot fill factor.The five-phase machines equipped with FSCW,are very good candidates for the purpose of designing motors for high reliable applications,like electric cars,major transporting buses,high speed trains and massive trucks.But,in comparison to the general distributed windings,the FSCWs contain high magnetomotive force(MMF)space harmonic contents,which cause unwanted effects on the machine ability,such as localized iron saturation and core losses.This manuscript introduces several new five-phase fractional slot winding layouts,by the means of slot shifting concept in order to design the new types of synchronous reluctance motors(SynRels).In order to examine the proposed winding’s performances,three sample machines are designed as case studies,and analytical study and finite element analysis(FEA)is used for validation.展开更多
基金supported in part by the Fundamental Research Funds for Central Universities under Grant JUSRP121020the Natural Science Foundation of Jiangsu Province under Grant BK20210475。
文摘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.
基金This work was supported in part by the National Natural Science Foundation of China under 61374125。
文摘This paper presents an improved finite control set model predictive current control(FCS-MPCC)of a five-phase permanent magnet synchronous motor(PMSM).First,to avoid including all the 32 voltage vectors provided by a two-level five-phase inverter into the control set,virtual voltage vectors are adopted.As the third current harmonics can be much reduced by virtual voltage vectors automatically,the harmonic items in the cost function of conventional FCS-MPCC are not considered.Furthermore,an adaptive control set is proposed based on voltage prediction.Best control set with proper voltage vector amplitude corresponding to different rotor speed can be achieved by this method.Consequently,current ripples can be largely reduced and the system performs much better.At last,simulations are established to verify the steady and transient performance of the proposed FCS-MPCC,and experiments based on a 2 kW five-phase motor are carried out.The results have validated the performance improvement of the proposed control strategy.
基金Supported by the National Natural Science Foundation of China(52277052).
文摘Five-phase permanent-magnet synchronous motors(PMSMs)offer high fault tolerance,low torque ripple,and high torque density.An open-circuit fault results in an asymmetric motor model,which causes direct current(DC)bias and harmonics,thus affecting operational performance with sensorless control under fault-tolerant conditions.To improve operational performance,this study proposes a novel sliding mode observer(SMO)based on an enhanced adaptive complex-coefficient filter(EACCF)for the sensorless vector-control strategy of a five-phase PMSM with an open-circuit fault.The novelty of the proposed strategy is the development of the EACCF,which is characterized by an effective DC bias and harmonic-attenuation capability.Additionally,the fundamental back electromotive force can be estimated without phase lag or amplitude attenuation using the SMO.By incorporating a phase-locked loop,the accuracy of position estimation can be improved under both healthy and open-circuit fault conditions.The sensorless control can not only restrain the fluctuating torque caused by open-circuit faults but also offers good steady-state and dynamic performances under healthy and open-circuit fault conditions.Experimental results are presented to demonstrate the feasibility of the proposed method.
基金Supported in part by the National Natural Science Foundation of China under Grant 52025073in part by the Key Research and Development Program of Jiangsu Province under Grant BE2018107,and in part by the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘The main drawbacks of traditional finite set model predictive control are high computational load,large torque ripple,and variable switching frequency.A less complex deadbeat(DB)model predictive current control(MPCC)with improved space vector pulse-width modulation(SVPWM)under a single-phase open-circuit fault is proposed.The proposed method predicts the reference voltage vector in the a-β subspace by employing the deadbeat control principle on the machine predictive model;thus,the exhaustive exploration procedure is avoided to relieve the computational load.To perform the constant switching frequency operation and achieve better steady-state performance,a modified SVPWM strategy is developed with the same conventional structure,which modulates the reference voltage vector.This new approach is based on a redesigned and adjusted post-fault virtual voltage vector space distribution that eliminates the y-axis harmonic components in the x-y subspace and ensures the generation of symmetrical PWM pulses.Meanwhile,the combined merits of the DB,MPCC,and SVPWM methods are realized.To verify the effectiveness of the proposed control scheme,comparative experiments are performed on a five-phase permanent magnet synchronous motor(PMSM)drive system.
文摘单相开路故障的五相永磁同步电机(permanent-magnet synchronous motor,PMSM)采用有限集模型预测转矩和磁链控制(finite-control-set model predictive torque and flux control,FCS-MPTFC)策略,存在转矩脉动大、价值函数的权重系数整定困难、迭代计算量大以及共模电压(commonmode voltage,CMV)高等问题。为此,该文提出一种简化FCS-MPTFC策略。首先,建立五相PMSM在单相开路故障情况下的数学模型,并分析CMV产生的机理。其次,以抑制3次谐波电流的原则合成等幅值虚拟电压矢量(virtual voltage vector,V^(3)),并将转矩和磁链价值函数等效转化为电压价值函数,同时采用无差拍控制思想计算出参考电压矢量,进而通过合理划分扇区,直接获得最优V^(3)。最后,选择方向相反的两个基电压矢量代替零矢量,以减小开路故障下的CMV。仿真和实验结果表明:所提控制策略不仅能抑制单相开路故障导致的转矩脉动、降低计算负荷和CMV、抑制电流谐波,而且具有优良的稳态和动态性能。
文摘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.
文摘Multi-phase machines are so attractive for electrical machine designers because of their valuable advantages such as high reliability and fault tolerant ability.Meanwhile,fractional slot concentrated windings(FSCW)are well known because of short end winding length,simple structure,field weakening sufficiency,fault tolerant capability and higher slot fill factor.The five-phase machines equipped with FSCW,are very good candidates for the purpose of designing motors for high reliable applications,like electric cars,major transporting buses,high speed trains and massive trucks.But,in comparison to the general distributed windings,the FSCWs contain high magnetomotive force(MMF)space harmonic contents,which cause unwanted effects on the machine ability,such as localized iron saturation and core losses.This manuscript introduces several new five-phase fractional slot winding layouts,by the means of slot shifting concept in order to design the new types of synchronous reluctance motors(SynRels).In order to examine the proposed winding’s performances,three sample machines are designed as case studies,and analytical study and finite element analysis(FEA)is used for validation.
