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
In the field of high-power electric drives, multiphase motors have the advantages of high power-density, excellent fault tolerance and control flexibility. But their decoupling control and modulation process are much ...In the field of high-power electric drives, multiphase motors have the advantages of high power-density, excellent fault tolerance and control flexibility. But their decoupling control and modulation process are much more complicated compared with three-phase motors due to the increased degree of freedom. Finite control set model predictive control can reduce the difficulties of controlling six-phase motors because it does not require modulation process. In this paper, a cascaded model predictive control strategy is proposed for the optimal control of high-power six-phase permanent magnet synchronous motors. Firstly, the current prediction model of torque and harmonic subspaces are established by decoupling the six-phase spatial variables. Secondly, a cascaded cost function with fault-tolerant capability is proposed to eliminate the weighting factor in the cost function. And finally, the proposed strategy is demonstrated through theoretical analysis and experiments. It is validated that the proposed method is able to maintain excellent steady-state control accuracy and fast dynamic response while significantly reduce the control complexity of the system. Besides, it can easily achieve fault-tolerant operation under open-phase fault.展开更多
This paper proposes a novel control approach for fault-tolerant control of dual three-phase permanent magnet synchronous motor(PMSM) under one-phase open-circuit fault.A modified six-phase static coordinate transforma...This paper proposes a novel control approach for fault-tolerant control of dual three-phase permanent magnet synchronous motor(PMSM) under one-phase open-circuit fault.A modified six-phase static coordinate transformation matrix and an extended rotating coordinate transformation matrix are investigated considering the influence of the fifth harmonic space on fault-tolerant control. These mathematical models are further analyzed in the fundamental space and the fifth harmonic space after the fault and to eliminate the coupling between the d-q axis voltage equation in the fundamental wave space and the d-q axis voltage equation in the fifth harmonic space, a secondary rotation coordinate transformation matrix is proposed. To achieve the purpose of reducing torque ripple, the fault-tolerant control method proposed in this paper not only takes the minimum copper loss as the constraint condition, but also injects the fifth harmonic current. The experimental result of current and torque is used to verify the accuracy of fault-tolerant control.展开更多
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 investigation of inverter fault-tolerant operation for a permanent magnet synchronous motor （PMSM） direct torque control （DTC） system under various inverter faults. The performance of a faul...This paper presents an investigation of inverter fault-tolerant operation for a permanent magnet synchronous motor （PMSM） direct torque control （DTC） system under various inverter faults. The performance of a faulty standard 6-switch inverter driven PMSM DTC system is analyzed. To avoid the loss or even disaster caused by the inverter faults, a topology-modified inverter with fault-tolerant capability is introduced, which is reconfigured as a 3-phase 4-switch inverter. The modeling of the 4-switch inverter is then analyzed and a novel DTC strategy with a unique nonlinear perpendicular flux observer and feedback compensation scheme is proposed for obtaining a continuous, disturbance-flee drive system. The simulation and experimental results demonstrate that the proposed inverter fault-tolerant PMSM DTC system is able to operate stably and continuously with acceptable static and pretty good dynamic performance.展开更多
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 p...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.展开更多
To diagnose the Open-Circuit(OC)fault in the novel fault-tolerant electric drive system,based on d-q-axis current signal,a strong robustness diagnosis strategy is proposed and investigated.Fewer independent power supp...To diagnose the Open-Circuit(OC)fault in the novel fault-tolerant electric drive system,based on d-q-axis current signal,a strong robustness diagnosis strategy is proposed and investigated.Fewer independent power supplies and converters are required in the novel fault-tolerant electric drive system based on Dual-Winding Permanent Magnet Motor(DWPMM),and the system’s reliability,usage ratio and power density have been improved compared to the conventional fault-tolerant motor drive system.However,the novel fault-tolerant electric drive system has the OC fault diagnostic false alarms issue when load changes suddenly or under light-load condition.And it lacks the research on the diagnostic method when the system encounters intermittent OC fault in power switches.By theory derivation,simulation and experimental verification,it can be concluded that the proposed strong robustness OC fault diagnosis strategy based on d-q-axis current signal can overcome the OC fault diagnostic false alarms issue when load changes suddenly or under light-load condition.And it can detect and locate the OC fault of single-phase winding in real time,and diagnose the intermittent OC fault of power switches.展开更多
It is difficult for the traditional PI controller to meet high-performance control requirements under the demagnetization fault of a permanent magnet synchronous motor(PMSM).To address this problem,this study proposes...It is difficult for the traditional PI controller to meet high-performance control requirements under the demagnetization fault of a permanent magnet synchronous motor(PMSM).To address this problem,this study proposes a novel sliding mode fault-tolerant control method for PMSM demagnetization faults.First,the mathematical model of PMSM under demagnetization fault state is established,and the reasons for poor fault tolerance of the conventional PI controller are analyzed.A new convergence law is used to design the speed loop sliding mode feedback controller,and its stability is demonstrated.Meanwhile,an adaptive forgetting factor recursive least squares(AFRLS)flux linkage observer is designed to keep the controller parameter values in line with the actual motor parameter values,to reduce the impact of demagnetization faults on motor control performance and achieve fault-tolerant control of demagnetization faults.Finally,simulation and experimental comparison with conventional PI control demonstrate that the proposed method is more robust and resistant to interference.展开更多
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In the field of high-power electric drives, multiphase motors have the advantages of high power-density, excellent fault tolerance and control flexibility. But their decoupling control and modulation process are much more complicated compared with three-phase motors due to the increased degree of freedom. Finite control set model predictive control can reduce the difficulties of controlling six-phase motors because it does not require modulation process. In this paper, a cascaded model predictive control strategy is proposed for the optimal control of high-power six-phase permanent magnet synchronous motors. Firstly, the current prediction model of torque and harmonic subspaces are established by decoupling the six-phase spatial variables. Secondly, a cascaded cost function with fault-tolerant capability is proposed to eliminate the weighting factor in the cost function. And finally, the proposed strategy is demonstrated through theoretical analysis and experiments. It is validated that the proposed method is able to maintain excellent steady-state control accuracy and fast dynamic response while significantly reduce the control complexity of the system. Besides, it can easily achieve fault-tolerant operation under open-phase fault.
基金supported by the National Natural Science Foundation of China under Grant 61603263。
文摘This paper proposes a novel control approach for fault-tolerant control of dual three-phase permanent magnet synchronous motor(PMSM) under one-phase open-circuit fault.A modified six-phase static coordinate transformation matrix and an extended rotating coordinate transformation matrix are investigated considering the influence of the fifth harmonic space on fault-tolerant control. These mathematical models are further analyzed in the fundamental space and the fifth harmonic space after the fault and to eliminate the coupling between the d-q axis voltage equation in the fundamental wave space and the d-q axis voltage equation in the fifth harmonic space, a secondary rotation coordinate transformation matrix is proposed. To achieve the purpose of reducing torque ripple, the fault-tolerant control method proposed in this paper not only takes the minimum copper loss as the constraint condition, but also injects the fifth harmonic current. The experimental result of current and torque is used to verify the accuracy of fault-tolerant control.
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Project supported by the National Natural Science Foundation of China (No. 50507017)the SRF for ROCS,SEM
文摘This paper presents an investigation of inverter fault-tolerant operation for a permanent magnet synchronous motor （PMSM） direct torque control （DTC） system under various inverter faults. The performance of a faulty standard 6-switch inverter driven PMSM DTC system is analyzed. To avoid the loss or even disaster caused by the inverter faults, a topology-modified inverter with fault-tolerant capability is introduced, which is reconfigured as a 3-phase 4-switch inverter. The modeling of the 4-switch inverter is then analyzed and a novel DTC strategy with a unique nonlinear perpendicular flux observer and feedback compensation scheme is proposed for obtaining a continuous, disturbance-flee drive system. The simulation and experimental results demonstrate that the proposed inverter fault-tolerant PMSM DTC system is able to operate stably and continuously with acceptable static and pretty good dynamic performance.
基金the National Natural Science Foundation of China(52077097,52025073,and 51991383)in part by the Natural Science Research Project of Higher Education Institutions of Jiangsu Province(20KJA470003)in part by the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘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.
基金supported by the National Natural Science Foundation of China(No.51807094)China Postdoctoral Science Foundation(No.2020M671499)+2 种基金Program for HighLevel Entrepreneurial and Innovative Talents Introduction of Jiangsu Province,China(No.[2019]20)Aeronautical Science Foundation of China(No.20200028059001)Jiangsu Planned Projects for Postdoctoral Research Funds,China(No.2020Z145)。
文摘To diagnose the Open-Circuit(OC)fault in the novel fault-tolerant electric drive system,based on d-q-axis current signal,a strong robustness diagnosis strategy is proposed and investigated.Fewer independent power supplies and converters are required in the novel fault-tolerant electric drive system based on Dual-Winding Permanent Magnet Motor(DWPMM),and the system’s reliability,usage ratio and power density have been improved compared to the conventional fault-tolerant motor drive system.However,the novel fault-tolerant electric drive system has the OC fault diagnostic false alarms issue when load changes suddenly or under light-load condition.And it lacks the research on the diagnostic method when the system encounters intermittent OC fault in power switches.By theory derivation,simulation and experimental verification,it can be concluded that the proposed strong robustness OC fault diagnosis strategy based on d-q-axis current signal can overcome the OC fault diagnostic false alarms issue when load changes suddenly or under light-load condition.And it can detect and locate the OC fault of single-phase winding in real time,and diagnose the intermittent OC fault of power switches.
基金Supported by the National Natural Science Foundation of China under Grant 52077011Hunan Provincial Natural Science Foundation 2024JJ7614,2024JJ7615 and 2024JJ6089+1 种基金Hunan Education Department Science Research Project under Grant 23B0785 and 23B0793Major Special Projects of Changsha under Grant kq2105001.
文摘It is difficult for the traditional PI controller to meet high-performance control requirements under the demagnetization fault of a permanent magnet synchronous motor(PMSM).To address this problem,this study proposes a novel sliding mode fault-tolerant control method for PMSM demagnetization faults.First,the mathematical model of PMSM under demagnetization fault state is established,and the reasons for poor fault tolerance of the conventional PI controller are analyzed.A new convergence law is used to design the speed loop sliding mode feedback controller,and its stability is demonstrated.Meanwhile,an adaptive forgetting factor recursive least squares(AFRLS)flux linkage observer is designed to keep the controller parameter values in line with the actual motor parameter values,to reduce the impact of demagnetization faults on motor control performance and achieve fault-tolerant control of demagnetization faults.Finally,simulation and experimental comparison with conventional PI control demonstrate that the proposed method is more robust and resistant to interference.
