The permanent magnet synchronous motors （PMSMs） may have chaotic behaviours for the uncertain values of parameters or under certain working conditions, which threatens the secure and stable operation of motor-driven...The permanent magnet synchronous motors （PMSMs） may have chaotic behaviours for the uncertain values of parameters or under certain working conditions, which threatens the secure and stable operation of motor-driven. It is important to study methods of controlling or suppressing chaos in PMSMs. In this paper, robust stabilities of PMSM with parameter uncertainties are investigated. After the uncertain matrices which represent the variable system parameters are formulated through matrix analysis, a novel asymptotical stability criterion is established. Some illustrated examples are also given to show the effectiveness of the obtained results.展开更多
Two model reference adaptive system （MRAS） estimators are developed for identifying the parameters of permanent magnet synchronous motors （PMSM） based on the Lyapunov stability theorem and the Popov stability crit...Two model reference adaptive system （MRAS） estimators are developed for identifying the parameters of permanent magnet synchronous motors （PMSM） based on the Lyapunov stability theorem and the Popov stability criterion, respectively. The proposed estimators only need online measurement of currents, voltages, and rotor speed to effectively estimate stator resistance, inductance, and rotor flux-linkage simultaneously. The performance of the estimators is compared and verified through simulations and experiments, which show that the two estimators are simple, have good robustness against parameter variation, and are accurate in parameter tracking. However, the estimator based on the Popov stability criterion, which can overcome parameter variation in a practical system, is superior in terms of response speed and convergence speed since there are both proportional and integral units in the estimator, in contrast to only one integral unit in the estimator based on the Lyapunov stability theorem. In addition, the estimator based on the Popov stability criterion does not need the expertise that is required in designing a Lyapunov function.展开更多
A permanent magnet synchronous motor （PMSM） may have chaotic behaviours under certain working conditions, especially for uncertain values of parameters, which threatens the security and stability of motor-driven ope...A permanent magnet synchronous motor （PMSM） may have chaotic behaviours under certain working conditions, especially for uncertain values of parameters, which threatens the security and stability of motor-driven operation. Hence, it is important to study methods of controlling or suppressing chaos in PMSMs. In this paper, the stability of a PMSM with parameter uncertainties is investigated. After uncertain matrices which represent the variable system parameters are formulated through matrix analysis, a novel asymptotical stability criterion is established by employing the method of Lyapunov functions and linear matrix inequality technology. An example is also given to illustrate the effectiveness of our results.展开更多
An adaptive PBC strategy for SM with a time-varying load torque to track fluxand speed trajectories was proposed.The key point of this method was the identificationof terms,known as workless forces,which appeared in t...An adaptive PBC strategy for SM with a time-varying load torque to track fluxand speed trajectories was proposed.The key point of this method was the identificationof terms,known as workless forces,which appeared in the dynamic equations of SM buthad no effect on the energy balance equation of the closed loop.PBC,combined withadaptive control schemes,not only preserved the advantages of PBC such as nonexistenceof singularity,but also rejected the flux and speed tracking error caused by statorand rotor resistance variation.The rotor currents of SM were estimated via a state observer.This algorithm simplified the control structure and enhanced the robustness of thecontrol system.The feasibility and effectiveness were confirmed by experimental resultsbased on dSPACE.展开更多
An adaptive synchronization control method is proposed for chaotic permanent magnet synchronous motors based on the property of a passive system. We prove that the controller makes the synchronization error system bet...An adaptive synchronization control method is proposed for chaotic permanent magnet synchronous motors based on the property of a passive system. We prove that the controller makes the synchronization error system between the driving and the response systems not only passive but also asymptotically stable. The simulation results show that the proposed method is effective and robust against uncertainties in the systemic parameters.展开更多
Due to high power density,high efficiency,and accurate control performance,permanent magnet synchronous motors(PMSMs)have been widely adopted in equipment manufacturing and energy transformation fields.To expand the s...Due to high power density,high efficiency,and accurate control performance,permanent magnet synchronous motors(PMSMs)have been widely adopted in equipment manufacturing and energy transformation fields.To expand the speed range under finite DC-bus voltage,extensive research on field weakening(FW)control strategies has been conducted.This paper summarizes the major FW control strategies of PMSMs,which are categorized into calculation-based methods,voltage closed-loop control methods,and model predictive control related methods.The existing strategies are analyzed and compared according to performance,robustness,and execution difficulty,which can facilitate the implementation of FW control.展开更多
Permanent magnet linear synchronous motor(PMLSM)has the advantages of high thrust density and good control accuracy,which can be applied in high-power and high-speed occasions.In this paper,the analytical models are e...Permanent magnet linear synchronous motor(PMLSM)has the advantages of high thrust density and good control accuracy,which can be applied in high-power and high-speed occasions.In this paper,the analytical models are established to obtain the electromagnetic performance for the PMLSMs with dual secondaries and dual primaries.The air-gap flux density and the electromagnetic thrust are also obtained by the finite element model to verify theoretical analysis.Besides,an improved structure is also put forward in order to suppress the thrust fluctuation of the PMLSM.Finally,the advantages and disadvantages of two PMLSMs topologies are listed.These analyses would provide a guide for the design of PMLSMs applied in high-power and high-speed occasions.展开更多
This paper presents a method for compensating the force ripple in permanent magnet linear synchronous motors(PMLSMs)by adopting a composite feedforward compensation scheme.Firstly,the vector control system of PMLSMs i...This paper presents a method for compensating the force ripple in permanent magnet linear synchronous motors(PMLSMs)by adopting a composite feedforward compensation scheme.Firstly,the vector control system of PMLSMs is described,and various force disturbances influencing the electromagnetic thrust are analyzed.As a result,the mathematical model of the whole system considering the force ripple is established.Then,a novel composite feedforward compensation scheme is proposed,which consists of a recursive least squares(RLS)parameter identification component and two feedforward compensation loops corresponding to the reference position trajectory and the force ripple,respectively.Finally,the effectiveness and advantages of the proposed composite feedforward compensation are demonstrated by simulation.The main incentive of this paper is the combination with the composite feedforward compensation loop corresponding to the reference position trajectory to improve the compensation effect of force ripple in PMLSMs.展开更多
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...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.展开更多
Permanent magnet synchronous motors(PMSMs)are typical electromechanical energy-conversion systems,in which the electrical and mechanical subsystems interact and impact each other.However,existing studies have investig...Permanent magnet synchronous motors(PMSMs)are typical electromechanical energy-conversion systems,in which the electrical and mechanical subsystems interact and impact each other.However,existing studies have investigated these two subsystems independently and failed to determine the coupling effect between electrical signals and mechanical vibrations.To address these gaps,a comprehensive electromechanical coupled model is proposed herein.This model integrates the PMSM model based on the winding function and the rotor-bearing dynamics model.The developed model can take into account the variations in inductance and current caused by non-uniform air-gap distribution.The electromechanical dynamic responses of the PMSM under rotor-bearing vibration and rotor eccentricity conditions are systematically analysed using this model.Results demonstrate that the proposed model improved the accuracy of both internal and external excitation representation in PMSMs compared with the conventional models.The dynamic behaviour of the rotor-bearing system is distinctly reflected in the electrical signals,and the variation laws of rotor eccentric distance and eccentric angle on the dynamic characteristics of the PMSM are revealed.The proposed model provides theoretical support for investigating the electromechanical coupled effect in PMSMs and offers an effective approach for state detection and fault diagnosis of motor-driven systems.展开更多
Sine-wave drive and square-wave drive are two common motor control strategies.This study constructs a mathematical model capable of predicting the distribution of electromagnetic force waves in synchronous reluctance ...Sine-wave drive and square-wave drive are two common motor control strategies.This study constructs a mathematical model capable of predicting the distribution of electromagnetic force waves in synchronous reluctance motors(SynRMs)under these two drive methods,and comparatively analyzes the vibration phenomena induced by electromagnetic forces under different drive methods.It aims to provide an effective tool for predicting the distribution of electromagnetic force waves in SynRMs,while exploring the influence of drive modes on their vibration characteristics.The study focuses on a 4-pole,36-slot 5.5 kW SynRM.Based on the magnetomotive force(MMF)-permeance method,incorporating the special rotor structure and the characteristics of current harmonics under square-wave drive,an air-gap flux distribution function is established.Meanwhile,Maxwell’s stress tensor method is adopted to analyze how the air-gap flux density relates to electromagnetic excitation force waves.Subsequently,this analysis is applied to forecast the spatiotemporal distribution features of radial electromagnetic force waves.Finite element simulations are conducted to compute the modal and vibration responses of the SynRM,followed by a comparative analysis of the vibration characteristics under the two drive methods.Additionally,a 6-pole,36-slot SynRM is used for additional comparative verification.Ultimately,the effectiveness of the simulation results is verified through experiments.展开更多
Two-level voltage source inverters with pulse width modulation(PWM)generate multiple carrier harmonics,thereby exciting high-frequency noise from the motor.Based on a special dual-branch three-phase permanent magnet s...Two-level voltage source inverters with pulse width modulation(PWM)generate multiple carrier harmonics,thereby exciting high-frequency noise from the motor.Based on a special dual-branch three-phase permanent magnet synchronous motor(PMSM),a method that utilizes a known modified space vector PWM technique is proposed.This method is able to suppress unpleasant high-frequency vibration noise as well as acoustic noise more effectively than other methods.Vibration noise near the twice carrier frequency is eliminated,and PWM vibration noise around the carrier frequency is also reduced.In particular,vibration and acoustic noise at the twice carrier frequency are eliminated using a carrier phase-shift of 0.5πand the special winding structure of the dual-branch PMSM.The effectiveness of the proposed method is confirmed using detailed experimental results.展开更多
Permanent magnet synchronous motors(PMSMs)are widely used because of their high power/torque density and high efficiency,particularly in applications with strict requirements for arrangement space or weight,such as in...Permanent magnet synchronous motors(PMSMs)are widely used because of their high power/torque density and high efficiency,particularly in applications with strict requirements for arrangement space or weight,such as in the electric vehicle(EV)and aerospace fields.Recently,the PMSM torque ripple problem has received increasing interest because PMSM drive requirements continuously improve.For applications with complex transmission and a wide speed range,torque ripple can easily cause system resonance,which deteriorates the driving performance.The research status and latest progress in the minimization of PMSM torque ripple based on harmonic injection are discussed.First,the causes of PMSM torque ripple are analyzed.Subsequently,the research status of the PMSM analytical model is introduced,and multiple current harmonic control and optimization methods are described in detail.Finally,future development trends in this field are analyzed.展开更多
Small signal stability analysis is conducted for an asymmetrical six-phase synchronous motor in comparison with its equivalent three-phase counterpart.For this purpose,a linearized model of the six-phase synchronous m...Small signal stability analysis is conducted for an asymmetrical six-phase synchronous motor in comparison with its equivalent three-phase counterpart.For this purpose,a linearized model of the six-phase synchronous motor is developed using the dq0 approach,which is used in eigenvalue criteria to determine absolute stability in comparison with its equivalent three-phase counterpart.The analysis includes a comparison of the variation in evaluated eigenvalues associated with the stator and rotor sides according to changes in both the three and six-phase machine parameters and working conditions.Key analytical results are experimentally investigated and validated on a test rig.展开更多
To solve the problem of temperature rise caused by the high power density of high-speed permanent magnet synchronous traction motors,the temperature rise of various components in the motor is analyzed by coupling the ...To solve the problem of temperature rise caused by the high power density of high-speed permanent magnet synchronous traction motors,the temperature rise of various components in the motor is analyzed by coupling the equivalent thermal circuit method and computational fluid dynamics.Also,a cooling strategy is proposed to solve the problem of temperature rise,which is expected to prolong the service life of these devices.First,the theoretical bases of the approaches used to study heat transfer and fluid mechanics are discussed,then the fluid flow for the considered motor is analyzed,and the equivalent thermal circuit method is introduced for the calculation of the temperature rise.Finally,the stator,rotor loss,motor temperature rise,and the proposed cooling method are also explored through experiments.According to the results,the stator temperature at 50,000 r/min and 60,000 r/min at no-load operation is 68℃ and 76℃,respectively.By monitoring the temperature of the air outlets inside and outside the motor at different speeds,it is also found that the motor reaches a stable temperature rise after 65 min of operation.Coupling of the thermal circuit method and computational fluid dynamics is a strategy that can provide the average temperature rise of each component and can also comprehensively calculate the temperature of each local point.We conclude that a hybrid cooling strategy based on axial air cooling of the inner air duct of the motor and water cooling of the stator can meet the design requirements for the ventilation and cooling of this type of motors.展开更多
In traditional analytical method(AM),the magnetic saturation is always ignored to simplify the calculation process.However,synchronous reluctance motors(SynRMs)often operate around saturation point to achieve higher t...In traditional analytical method(AM),the magnetic saturation is always ignored to simplify the calculation process.However,synchronous reluctance motors(SynRMs)often operate around saturation point to achieve higher torque density.Therefore,a new AM is proposed,in which the saturation of stator iron has been considered.The key of the proposed method includes a saturation factor,and an iterative method is adopted to compute the saturation factor in the SynRM by increasing the air-gap length.Especially,the proposed AM can be applied to a SynRM even with shifted-asymmetrical-salient-poles.In the process of AM,the expression of stator magnetomotive force(MMF)is built firstly.Additionally,the air-gap density including slotting effect and salient-poles is calculated.Then,the rotor MMF under saturation of the stator iron is obtained.Therefore,the precision of the instantaneous torque can be improved significantly.Eventually,by the verification of finite elements method(FEM)and experiments,the torque performance of SynRMs with shifted asymmetrical rotor can be predicted accurately by the proposed AM.展开更多
This paper proposes an artificial neural network for monitoring and detecting the eccentric error of synchronous reluctance motors.Firstly,a 15 kWsynchronous reluctance motor is introduced and took as a case study to ...This paper proposes an artificial neural network for monitoring and detecting the eccentric error of synchronous reluctance motors.Firstly,a 15 kWsynchronous reluctance motor is introduced and took as a case study to investigate the effects of eccentric rotor.Then,the equivalent magnetic circuits of the studied motor are analyzed and developed,in cases of dynamic eccentric rotor and static eccentric rotor condition,respectively.After that,the analytical equations of the studied motor are derived,in terms of its air-gap flux density,electromagnetic torque,and electromagnetic force,followed by the electromagnetic finite element analyses.Then,the modal analyses of the stator and the whole motor are performed,respectively,to explore the natural frequency and the modal shape of the motor,by which the further vibrational analysis is possible to be conducted.The vibration level of the housing is furtherly studied to investigate its relationship with the rotor eccentricity,which is validated by the prototype test.Furthermore,an artificial neural network,which has 3 layers,is proposed.By taking the air-gap flux density,the electromagnetic force,and the vibrational level as inputs,and taking the eccentric distance as output,the proposed neural network is trained till the error smaller than 5%.Therefore,this neural network is obtaining the input parameters of the tested motor,based on which it is automatically monitoring and reporting the eccentric error to the upper-level control center.展开更多
Rotor of Synchronous reluctance motor(SynRM)usually has multiple flux barrier structure for the purpose of higher electromagnetic torque and lower torque ripple.Two different strategies are used in this paper for roto...Rotor of Synchronous reluctance motor(SynRM)usually has multiple flux barrier structure for the purpose of higher electromagnetic torque and lower torque ripple.Two different strategies are used in this paper for rotor structure optimization and a compromised strategy for fully squeeze the potential of each related parameters is developed.Performance of resulted rotor structure is evaluated to verify the optimization procedure.展开更多
This paper proposes an extended-flux model with core-loss resistance of SynRMs （synchronous reluctance motors） and precise torque estimation without core-loss measurement and position encoder. The proposed torque es...This paper proposes an extended-flux model with core-loss resistance of SynRMs （synchronous reluctance motors） and precise torque estimation without core-loss measurement and position encoder. The proposed torque estimation is useful for precise MTPA （maximum torque per ampere） control of position sensorless controlled SynRMs, which is achieved with the assistance of active and reactive powers.展开更多
基金supported by the National Natural Science Foundation of China (Grant No 60604007)
文摘The permanent magnet synchronous motors （PMSMs） may have chaotic behaviours for the uncertain values of parameters or under certain working conditions, which threatens the secure and stable operation of motor-driven. It is important to study methods of controlling or suppressing chaos in PMSMs. In this paper, robust stabilities of PMSM with parameter uncertainties are investigated. After the uncertain matrices which represent the variable system parameters are formulated through matrix analysis, a novel asymptotical stability criterion is established. Some illustrated examples are also given to show the effectiveness of the obtained results.
基金supported by China Scholarship Council, National Natural Science Foundation of China (No. 60634020)Scientific Research Foundation of Education Ministry for the Doctors(No. 20060532026)
文摘Two model reference adaptive system （MRAS） estimators are developed for identifying the parameters of permanent magnet synchronous motors （PMSM） based on the Lyapunov stability theorem and the Popov stability criterion, respectively. The proposed estimators only need online measurement of currents, voltages, and rotor speed to effectively estimate stator resistance, inductance, and rotor flux-linkage simultaneously. The performance of the estimators is compared and verified through simulations and experiments, which show that the two estimators are simple, have good robustness against parameter variation, and are accurate in parameter tracking. However, the estimator based on the Popov stability criterion, which can overcome parameter variation in a practical system, is superior in terms of response speed and convergence speed since there are both proportional and integral units in the estimator, in contrast to only one integral unit in the estimator based on the Lyapunov stability theorem. In addition, the estimator based on the Popov stability criterion does not need the expertise that is required in designing a Lyapunov function.
基金supported by National Natural Science Foundation of China(61075065,60774045,61473314,U1134108)Ph.D.Programs Foundation of Ministry of Education of China(20110162110041)Science Foundation of Innovation Research Groups of National Natural Science Foundation of China(61321003)
基金Project supported by the National Natural Science Foundation of China (Grant No. 50775226)the Chongqing Natural Science Foundation (Grant No. CSTC, 2008BB3308)the Innovation Training Foundation of Chongqing University (Grant No. CDCX004)
文摘A permanent magnet synchronous motor （PMSM） may have chaotic behaviours under certain working conditions, especially for uncertain values of parameters, which threatens the security and stability of motor-driven operation. Hence, it is important to study methods of controlling or suppressing chaos in PMSMs. In this paper, the stability of a PMSM with parameter uncertainties is investigated. After uncertain matrices which represent the variable system parameters are formulated through matrix analysis, a novel asymptotical stability criterion is established by employing the method of Lyapunov functions and linear matrix inequality technology. An example is also given to illustrate the effectiveness of our results.
基金Supported by the National Basic Research Program of China(973 Program)(2005CB221505)the Special Scientific Research Foundation for Doctoral Subject of Colleges and Universities in China(20050248058)
文摘An adaptive PBC strategy for SM with a time-varying load torque to track fluxand speed trajectories was proposed.The key point of this method was the identificationof terms,known as workless forces,which appeared in the dynamic equations of SM buthad no effect on the energy balance equation of the closed loop.PBC,combined withadaptive control schemes,not only preserved the advantages of PBC such as nonexistenceof singularity,but also rejected the flux and speed tracking error caused by statorand rotor resistance variation.The rotor currents of SM were estimated via a state observer.This algorithm simplified the control structure and enhanced the robustness of thecontrol system.The feasibility and effectiveness were confirmed by experimental resultsbased on dSPACE.
基金Project supported by the Key Program of National Natural Science Foundation of China (Grant No. 50937001)the National Natural Science Foundation of China (Grant Nos. 10862001 and 10947011)the Construction of Key Laboratories in Universities of Guangxi,China (Grant No. 200912)
文摘An adaptive synchronization control method is proposed for chaotic permanent magnet synchronous motors based on the property of a passive system. We prove that the controller makes the synchronization error system between the driving and the response systems not only passive but also asymptotically stable. The simulation results show that the proposed method is effective and robust against uncertainties in the systemic parameters.
基金supported by the Research Fund for the National Natural Science Foundation of China(52125701).
文摘Due to high power density,high efficiency,and accurate control performance,permanent magnet synchronous motors(PMSMs)have been widely adopted in equipment manufacturing and energy transformation fields.To expand the speed range under finite DC-bus voltage,extensive research on field weakening(FW)control strategies has been conducted.This paper summarizes the major FW control strategies of PMSMs,which are categorized into calculation-based methods,voltage closed-loop control methods,and model predictive control related methods.The existing strategies are analyzed and compared according to performance,robustness,and execution difficulty,which can facilitate the implementation of FW control.
基金This work has been partly supported in part by National Natural Science Foundation of China under Grants 51877093 and 51707079in part by the National Key Research and Development Program of China under Grant YS2018YFGH000200,in part by the Key Technical Innovation Program of Hubei Province under Grant 2019AAA026.
文摘Permanent magnet linear synchronous motor(PMLSM)has the advantages of high thrust density and good control accuracy,which can be applied in high-power and high-speed occasions.In this paper,the analytical models are established to obtain the electromagnetic performance for the PMLSMs with dual secondaries and dual primaries.The air-gap flux density and the electromagnetic thrust are also obtained by the finite element model to verify theoretical analysis.Besides,an improved structure is also put forward in order to suppress the thrust fluctuation of the PMLSM.Finally,the advantages and disadvantages of two PMLSMs topologies are listed.These analyses would provide a guide for the design of PMLSMs applied in high-power and high-speed occasions.
基金the National Natural Science Foundation of China(Nos.61374043 and 61603392)the China Postdoctoral Science Foundation Funded Project(Nos.2013M530278 and 2014T70558)
文摘This paper presents a method for compensating the force ripple in permanent magnet linear synchronous motors(PMLSMs)by adopting a composite feedforward compensation scheme.Firstly,the vector control system of PMLSMs is described,and various force disturbances influencing the electromagnetic thrust are analyzed.As a result,the mathematical model of the whole system considering the force ripple is established.Then,a novel composite feedforward compensation scheme is proposed,which consists of a recursive least squares(RLS)parameter identification component and two feedforward compensation loops corresponding to the reference position trajectory and the force ripple,respectively.Finally,the effectiveness and advantages of the proposed composite feedforward compensation are demonstrated by simulation.The main incentive of this paper is the combination with the composite feedforward compensation loop corresponding to the reference position trajectory to improve the compensation effect of force ripple in PMLSMs.
基金supported in part by the Liaoning Provincial Department of Education Key Research Project under JYT2020160by the Liaoning Provincial Department of Education General Project under LJKZ0224。
文摘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.
基金supported by the National Natural Science Foundation of China(Grant Nos.52275132,52388102)the National Key R&D Program of China(Grant No.2022YFB3402100)the Sichuan Science and Technology Program(Grant No.2024NSFTD0011)。
文摘Permanent magnet synchronous motors(PMSMs)are typical electromechanical energy-conversion systems,in which the electrical and mechanical subsystems interact and impact each other.However,existing studies have investigated these two subsystems independently and failed to determine the coupling effect between electrical signals and mechanical vibrations.To address these gaps,a comprehensive electromechanical coupled model is proposed herein.This model integrates the PMSM model based on the winding function and the rotor-bearing dynamics model.The developed model can take into account the variations in inductance and current caused by non-uniform air-gap distribution.The electromechanical dynamic responses of the PMSM under rotor-bearing vibration and rotor eccentricity conditions are systematically analysed using this model.Results demonstrate that the proposed model improved the accuracy of both internal and external excitation representation in PMSMs compared with the conventional models.The dynamic behaviour of the rotor-bearing system is distinctly reflected in the electrical signals,and the variation laws of rotor eccentric distance and eccentric angle on the dynamic characteristics of the PMSM are revealed.The proposed model provides theoretical support for investigating the electromechanical coupled effect in PMSMs and offers an effective approach for state detection and fault diagnosis of motor-driven systems.
基金supported by the Science and Technology Project of State Grid Corporation of China Headquarters under Grant 5500-202416156A-1-1-ZN.
文摘Sine-wave drive and square-wave drive are two common motor control strategies.This study constructs a mathematical model capable of predicting the distribution of electromagnetic force waves in synchronous reluctance motors(SynRMs)under these two drive methods,and comparatively analyzes the vibration phenomena induced by electromagnetic forces under different drive methods.It aims to provide an effective tool for predicting the distribution of electromagnetic force waves in SynRMs,while exploring the influence of drive modes on their vibration characteristics.The study focuses on a 4-pole,36-slot 5.5 kW SynRM.Based on the magnetomotive force(MMF)-permeance method,incorporating the special rotor structure and the characteristics of current harmonics under square-wave drive,an air-gap flux distribution function is established.Meanwhile,Maxwell’s stress tensor method is adopted to analyze how the air-gap flux density relates to electromagnetic excitation force waves.Subsequently,this analysis is applied to forecast the spatiotemporal distribution features of radial electromagnetic force waves.Finite element simulations are conducted to compute the modal and vibration responses of the SynRM,followed by a comparative analysis of the vibration characteristics under the two drive methods.Additionally,a 6-pole,36-slot SynRM is used for additional comparative verification.Ultimately,the effectiveness of the simulation results is verified through experiments.
基金Supported by the National Natural Science Foundation of China(51577036,51437004).
文摘Two-level voltage source inverters with pulse width modulation(PWM)generate multiple carrier harmonics,thereby exciting high-frequency noise from the motor.Based on a special dual-branch three-phase permanent magnet synchronous motor(PMSM),a method that utilizes a known modified space vector PWM technique is proposed.This method is able to suppress unpleasant high-frequency vibration noise as well as acoustic noise more effectively than other methods.Vibration noise near the twice carrier frequency is eliminated,and PWM vibration noise around the carrier frequency is also reduced.In particular,vibration and acoustic noise at the twice carrier frequency are eliminated using a carrier phase-shift of 0.5πand the special winding structure of the dual-branch PMSM.The effectiveness of the proposed method is confirmed using detailed experimental results.
基金National Natural Science Foundation of China(52107052)in part by the Natural Science Foundation of Shandong Province(ZR2021QE222 and ZR2021YQ33).
文摘Permanent magnet synchronous motors(PMSMs)are widely used because of their high power/torque density and high efficiency,particularly in applications with strict requirements for arrangement space or weight,such as in the electric vehicle(EV)and aerospace fields.Recently,the PMSM torque ripple problem has received increasing interest because PMSM drive requirements continuously improve.For applications with complex transmission and a wide speed range,torque ripple can easily cause system resonance,which deteriorates the driving performance.The research status and latest progress in the minimization of PMSM torque ripple based on harmonic injection are discussed.First,the causes of PMSM torque ripple are analyzed.Subsequently,the research status of the PMSM analytical model is introduced,and multiple current harmonic control and optimization methods are described in detail.Finally,future development trends in this field are analyzed.
文摘Small signal stability analysis is conducted for an asymmetrical six-phase synchronous motor in comparison with its equivalent three-phase counterpart.For this purpose,a linearized model of the six-phase synchronous motor is developed using the dq0 approach,which is used in eigenvalue criteria to determine absolute stability in comparison with its equivalent three-phase counterpart.The analysis includes a comparison of the variation in evaluated eigenvalues associated with the stator and rotor sides according to changes in both the three and six-phase machine parameters and working conditions.Key analytical results are experimentally investigated and validated on a test rig.
文摘To solve the problem of temperature rise caused by the high power density of high-speed permanent magnet synchronous traction motors,the temperature rise of various components in the motor is analyzed by coupling the equivalent thermal circuit method and computational fluid dynamics.Also,a cooling strategy is proposed to solve the problem of temperature rise,which is expected to prolong the service life of these devices.First,the theoretical bases of the approaches used to study heat transfer and fluid mechanics are discussed,then the fluid flow for the considered motor is analyzed,and the equivalent thermal circuit method is introduced for the calculation of the temperature rise.Finally,the stator,rotor loss,motor temperature rise,and the proposed cooling method are also explored through experiments.According to the results,the stator temperature at 50,000 r/min and 60,000 r/min at no-load operation is 68℃ and 76℃,respectively.By monitoring the temperature of the air outlets inside and outside the motor at different speeds,it is also found that the motor reaches a stable temperature rise after 65 min of operation.Coupling of the thermal circuit method and computational fluid dynamics is a strategy that can provide the average temperature rise of each component and can also comprehensively calculate the temperature of each local point.We conclude that a hybrid cooling strategy based on axial air cooling of the inner air duct of the motor and water cooling of the stator can meet the design requirements for the ventilation and cooling of this type of motors.
基金This work was supported in part by the National Natural Science Foundation of China(51707083)in part by the Natural Science Foundation of Jiangsu Province(BK20190848)+1 种基金in part by the China Postdoctoral Science Foundation(2019M661746)by the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘In traditional analytical method(AM),the magnetic saturation is always ignored to simplify the calculation process.However,synchronous reluctance motors(SynRMs)often operate around saturation point to achieve higher torque density.Therefore,a new AM is proposed,in which the saturation of stator iron has been considered.The key of the proposed method includes a saturation factor,and an iterative method is adopted to compute the saturation factor in the SynRM by increasing the air-gap length.Especially,the proposed AM can be applied to a SynRM even with shifted-asymmetrical-salient-poles.In the process of AM,the expression of stator magnetomotive force(MMF)is built firstly.Additionally,the air-gap density including slotting effect and salient-poles is calculated.Then,the rotor MMF under saturation of the stator iron is obtained.Therefore,the precision of the instantaneous torque can be improved significantly.Eventually,by the verification of finite elements method(FEM)and experiments,the torque performance of SynRMs with shifted asymmetrical rotor can be predicted accurately by the proposed AM.
文摘This paper proposes an artificial neural network for monitoring and detecting the eccentric error of synchronous reluctance motors.Firstly,a 15 kWsynchronous reluctance motor is introduced and took as a case study to investigate the effects of eccentric rotor.Then,the equivalent magnetic circuits of the studied motor are analyzed and developed,in cases of dynamic eccentric rotor and static eccentric rotor condition,respectively.After that,the analytical equations of the studied motor are derived,in terms of its air-gap flux density,electromagnetic torque,and electromagnetic force,followed by the electromagnetic finite element analyses.Then,the modal analyses of the stator and the whole motor are performed,respectively,to explore the natural frequency and the modal shape of the motor,by which the further vibrational analysis is possible to be conducted.The vibration level of the housing is furtherly studied to investigate its relationship with the rotor eccentricity,which is validated by the prototype test.Furthermore,an artificial neural network,which has 3 layers,is proposed.By taking the air-gap flux density,the electromagnetic force,and the vibrational level as inputs,and taking the eccentric distance as output,the proposed neural network is trained till the error smaller than 5%.Therefore,this neural network is obtaining the input parameters of the tested motor,based on which it is automatically monitoring and reporting the eccentric error to the upper-level control center.
文摘Rotor of Synchronous reluctance motor(SynRM)usually has multiple flux barrier structure for the purpose of higher electromagnetic torque and lower torque ripple.Two different strategies are used in this paper for rotor structure optimization and a compromised strategy for fully squeeze the potential of each related parameters is developed.Performance of resulted rotor structure is evaluated to verify the optimization procedure.
文摘This paper proposes an extended-flux model with core-loss resistance of SynRMs （synchronous reluctance motors） and precise torque estimation without core-loss measurement and position encoder. The proposed torque estimation is useful for precise MTPA （maximum torque per ampere） control of position sensorless controlled SynRMs, which is achieved with the assistance of active and reactive powers.
