The dynamic soft sensor based on a single Gaussian process regression(GPR) model has been developed in fermentation processes.However,limitations of single regression models,for multiphase/multimode fermentation proce...The dynamic soft sensor based on a single Gaussian process regression(GPR) model has been developed in fermentation processes.However,limitations of single regression models,for multiphase/multimode fermentation processes,may result in large prediction errors and complexity of the soft sensor.Therefore,a dynamic soft sensor based on Gaussian mixture regression(GMR) was proposed to overcome the problems.Two structure parameters,the number of Gaussian components and the order of the model,are crucial to the soft sensor model.To achieve a simple and effective soft sensor,an iterative strategy was proposed to optimize the two structure parameters synchronously.For the aim of comparisons,the proposed dynamic GMR soft sensor and the existing dynamic GPR soft sensor were both investigated to estimate biomass concentration in a Penicillin simulation process and an industrial Erythromycin fermentation process.Results show that the proposed dynamic GMR soft sensor has higher prediction accuracy and is more suitable for dynamic multiphase/multimode fermentation processes.展开更多
This paper proposes a new consequent-pole permanent magnet vernier machine(CPMVM),which can be regarded as a combination of two conventional CPMVM with opposite polarities.Based on the simplified axial magnetic circui...This paper proposes a new consequent-pole permanent magnet vernier machine(CPMVM),which can be regarded as a combination of two conventional CPMVM with opposite polarities.Based on the simplified axial magnetic circuit model,it is verified that the proposed CPMVM can reduce the unipolar leakage flux.In order to reduce the torque ripple of machine and improve the output torque of machine,the flux barrier is placed on the rotor of the proposed machine.Then,the parameters of the proposed CPMVM are optimized and determined.Moreover,the electromagnetic performance,including no-load air-gap flux density,average torque and torque ripple,flux linkage,back-electromotive force,cogging torque,average torque,torque ripple,power factor and loss,is compared with conventional surface-mounted permanent magnet vernier machine(SPMVM)and CPMVM.Finally,it is demonstrated that proposed CPMVM with flux barrier can effectively reduce the unipolar leakage flux and greatly reduce the torque ripple of machine.Also,compared with the SPMVM,the proposed CPMVM with flux barrier saves more than 45%of the permanent magnet material without reducing output torque.展开更多
Permanent-magnet(PM)machines have attracted a lot of interest in various applications since they have the merits of high torque density,high power density and high efficiency.However,issue of poor fault tolerance of t...Permanent-magnet(PM)machines have attracted a lot of interest in various applications since they have the merits of high torque density,high power density and high efficiency.However,issue of poor fault tolerance of the conventional PM machines restricts their practical applications in the field of safety-critical applications,e.g.aerospace,electric vehicle,electrical propulsion and wind power generator applications.An enormous amount of work has been done to improve the fault-tolerant capability of PM machines.This paper will review research work on PM fault-tolerant machines up-to-date,including modular design,short-circuit current limitation design,redundant design,ease of thermal dissipation of PM design,and torque enhancement design techniques.The work of this paper can provide some references for future studies and engineering applications of PM fault-tolerant machines for safety-critical applications.展开更多
The inset-surface permanent magnet(ISPM)machine can achieve the desired electromagnetic performance according to the traditional deterministic design.However,the reliability and quality of the machine may be affected ...The inset-surface permanent magnet(ISPM)machine can achieve the desired electromagnetic performance according to the traditional deterministic design.However,the reliability and quality of the machine may be affected by the essential manufacturing tolerances and unavoidable noise factors in mass production.To address this weakness,a comprehensive multi-objective optimization design method is proposed,in which robust optimization is performed after the deterministic design.The response surface method is first adopted to establish the optimization objective equation.Afterward,the sample points are obtained via Monte Carlo simulation considering the design-variable uncertainty.The Design for Six Sigma approach is adopted to ensure the robustness of the design model.Furthermore,the barebones multi-objective particle swarm optimization algorithm is used to obtain a compromise solution.A prototype is manufactured to evaluate the effectiveness of the proposed method.According to the finite-element analysis and experimental tests,the electromagnetic performance and reliability of the machine are significantly enhanced with the proposed method.展开更多
An optimized structure to weaken the vibration and noise of a new asymmetric permanent magnet-assisted synchronous reluctance motor(PMaSynRM)is proposed.The new asymmetric PMaSynRM has the advantages of a low torque r...An optimized structure to weaken the vibration and noise of a new asymmetric permanent magnet-assisted synchronous reluctance motor(PMaSynRM)is proposed.The new asymmetric PMaSynRM has the advantages of a low torque ripple and high fault tolerance.However,the asymmetric structure generates an unbalanced magnetic force(UMF),which results in vibration and noise problems.In this study,the vibration and noise of the motor are analyzed and optimized.First,the radial pressure is analyzed,and an optimized structure is proposed.The electromagnetic performance of the motor before and after optimization is analyzed using the finite element method.Second,a three-dimensional model is established,and modal analysis is conducted considering the orthotropy of the stator and effective windings.Finally,the vibration and noise are simulated and analyzed,and the validity of the analysis results is verified experimentally.The analysis results indicate that the optimized motor realizes a reduction in the motor vibration and noise.展开更多
In this paper,a new equivalent magnetic network(EMN)model is established for a spoke-type permanent magnet(PM)vernier(PMV)machine.Two different modeling methods are proposed for different parts of the PMV machine,cons...In this paper,a new equivalent magnetic network(EMN)model is established for a spoke-type permanent magnet(PM)vernier(PMV)machine.Two different modeling methods are proposed for different parts of the PMV machine,considering that their magnetic field distributions are quite different.Hierarchical modeling method is proposed for the modeling of the rotor as the magnetic intensity of the rotor iron core presents gradient distribution along the radial direction.Mesh based reluctance network method is used for the modeling of flux modulation poles with irregular and unstable magnetic field distributions.Moreover,accurate PM leakage permeance calculation formulae are deduced to improve the simulation precision.The electromagnetic parameters,such as flux linkage,back electromagnetic force,electromagnetic torque and iron loss are predicted by the proposed EMN model.Finally,finite element analysis(FEA)and experimental results are given to verify the effectiveness of the proposed methods.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
基金Supported by the Natural Science Foundation of Jiangsu Province of China(BK20130531)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD[2011]6)Jiangsu Government Scholarship
文摘The dynamic soft sensor based on a single Gaussian process regression(GPR) model has been developed in fermentation processes.However,limitations of single regression models,for multiphase/multimode fermentation processes,may result in large prediction errors and complexity of the soft sensor.Therefore,a dynamic soft sensor based on Gaussian mixture regression(GMR) was proposed to overcome the problems.Two structure parameters,the number of Gaussian components and the order of the model,are crucial to the soft sensor model.To achieve a simple and effective soft sensor,an iterative strategy was proposed to optimize the two structure parameters synchronously.For the aim of comparisons,the proposed dynamic GMR soft sensor and the existing dynamic GPR soft sensor were both investigated to estimate biomass concentration in a Penicillin simulation process and an industrial Erythromycin fermentation process.Results show that the proposed dynamic GMR soft sensor has higher prediction accuracy and is more suitable for dynamic multiphase/multimode fermentation processes.
基金supported in part by the National Natural Science Foundation of China under Projects 52177044 and 52025073in part by the China Postdoctoral Science Foundation under Project 2019T120395+3 种基金in part by Hong Kong Scholars Program under Project XJ2019031in part by the Natural Science Foundation of Jiangsu Higher Education Institutions under Project 21KJA470004in part by Qing Lan Project of Jiangsu Provincein part by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘This paper proposes a new consequent-pole permanent magnet vernier machine(CPMVM),which can be regarded as a combination of two conventional CPMVM with opposite polarities.Based on the simplified axial magnetic circuit model,it is verified that the proposed CPMVM can reduce the unipolar leakage flux.In order to reduce the torque ripple of machine and improve the output torque of machine,the flux barrier is placed on the rotor of the proposed machine.Then,the parameters of the proposed CPMVM are optimized and determined.Moreover,the electromagnetic performance,including no-load air-gap flux density,average torque and torque ripple,flux linkage,back-electromotive force,cogging torque,average torque,torque ripple,power factor and loss,is compared with conventional surface-mounted permanent magnet vernier machine(SPMVM)and CPMVM.Finally,it is demonstrated that proposed CPMVM with flux barrier can effectively reduce the unipolar leakage flux and greatly reduce the torque ripple of machine.Also,compared with the SPMVM,the proposed CPMVM with flux barrier saves more than 45%of the permanent magnet material without reducing output torque.
基金This work was supported in part by the National Natural Science Foundation of China(51422702)by the Six Talent Peaks Project of Jiangsu Province(2017-KTHY-011)。
文摘Permanent-magnet(PM)machines have attracted a lot of interest in various applications since they have the merits of high torque density,high power density and high efficiency.However,issue of poor fault tolerance of the conventional PM machines restricts their practical applications in the field of safety-critical applications,e.g.aerospace,electric vehicle,electrical propulsion and wind power generator applications.An enormous amount of work has been done to improve the fault-tolerant capability of PM machines.This paper will review research work on PM fault-tolerant machines up-to-date,including modular design,short-circuit current limitation design,redundant design,ease of thermal dissipation of PM design,and torque enhancement design techniques.The work of this paper can provide some references for future studies and engineering applications of PM fault-tolerant machines for safety-critical applications.
基金Supported by the National Natural Science Foundation of China(51907080)by the Natural Science Foundation of Jiangsu Province(BK20190848)by the China Postdoctoral Science Foundation(2019M661746).
文摘The inset-surface permanent magnet(ISPM)machine can achieve the desired electromagnetic performance according to the traditional deterministic design.However,the reliability and quality of the machine may be affected by the essential manufacturing tolerances and unavoidable noise factors in mass production.To address this weakness,a comprehensive multi-objective optimization design method is proposed,in which robust optimization is performed after the deterministic design.The response surface method is first adopted to establish the optimization objective equation.Afterward,the sample points are obtained via Monte Carlo simulation considering the design-variable uncertainty.The Design for Six Sigma approach is adopted to ensure the robustness of the design model.Furthermore,the barebones multi-objective particle swarm optimization algorithm is used to obtain a compromise solution.A prototype is manufactured to evaluate the effectiveness of the proposed method.According to the finite-element analysis and experimental tests,the electromagnetic performance and reliability of the machine are significantly enhanced with the proposed method.
文摘An optimized structure to weaken the vibration and noise of a new asymmetric permanent magnet-assisted synchronous reluctance motor(PMaSynRM)is proposed.The new asymmetric PMaSynRM has the advantages of a low torque ripple and high fault tolerance.However,the asymmetric structure generates an unbalanced magnetic force(UMF),which results in vibration and noise problems.In this study,the vibration and noise of the motor are analyzed and optimized.First,the radial pressure is analyzed,and an optimized structure is proposed.The electromagnetic performance of the motor before and after optimization is analyzed using the finite element method.Second,a three-dimensional model is established,and modal analysis is conducted considering the orthotropy of the stator and effective windings.Finally,the vibration and noise are simulated and analyzed,and the validity of the analysis results is verified experimentally.The analysis results indicate that the optimized motor realizes a reduction in the motor vibration and noise.
基金Supported by National Natural Science Foundation of China under Grant 51577084Key Project of Natural Science Foundation of Jiangsu Higher Education Institutions under Grant 15KJA470002the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘In this paper,a new equivalent magnetic network(EMN)model is established for a spoke-type permanent magnet(PM)vernier(PMV)machine.Two different modeling methods are proposed for different parts of the PMV machine,considering that their magnetic field distributions are quite different.Hierarchical modeling method is proposed for the modeling of the rotor as the magnetic intensity of the rotor iron core presents gradient distribution along the radial direction.Mesh based reluctance network method is used for the modeling of flux modulation poles with irregular and unstable magnetic field distributions.Moreover,accurate PM leakage permeance calculation formulae are deduced to improve the simulation precision.The electromagnetic parameters,such as flux linkage,back electromagnetic force,electromagnetic torque and iron loss are predicted by the proposed EMN model.Finally,finite element analysis(FEA)and experimental results are given to verify the effectiveness of the proposed methods.
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.
