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
To achieve the manufacturing of Thin-Wall and High-Rib Components(TWHRC)with high precision,a novel heavy load Multi-DOF Envelope Forming Press(MEFP)with Parallel Kinematic Mechanism(PKM),driven by six Permanent Magne...To achieve the manufacturing of Thin-Wall and High-Rib Components(TWHRC)with high precision,a novel heavy load Multi-DOF Envelope Forming Press(MEFP)with Parallel Kinematic Mechanism(PKM),driven by six Permanent Magnet Synchronous Motors(PMSMs),is developed.However,on account of the heavy forming load,the PMSM parameters are in great variation.Meanwhile,the PMSM is always in a transient state caused by fast time-varying forming load,resulting in low identification precision of varied PMSM parameters and control precision of PMSM under traditional parameter identification methods.To solve this problem,a novel Sliding Mode Control Method with Enhanced PMSM Parameter Identification(SMCMEPPI)for heavy load MEFP is proposed.Firstly,the kinematic model of MEFP is established.Secondly,the variation law of PMSM parameters under heavy load is revealed.Thirdly,an enhanced PMSM parameter identification method is proposed,in which the q axis current of PMSM is used to represent the changing rate of forming load and the adjustment factor is first proposed to remove improper input of PMSM parameter identification online.Fourthly,the Electromechanical Coupling Dynamic Model(ECDM)of MEFP,which includes identified PMSM parameters,is developed.Finally,based on the developed ECDM,a novel SMCMEPPI is proposed to realize the high-precision control of heavy load MEFP.The experimental results indicate that the proposed SMCMEPPI can significantly improve the control precision of heavy load MEFP.展开更多
A narrow resonance bandwidth of an energy harvesters limits its response to the wide frequency spectrum in ambient environ-ments.This work proposes an addition of a nonlinear restoring force applied to a triboelectric...A narrow resonance bandwidth of an energy harvesters limits its response to the wide frequency spectrum in ambient environ-ments.This work proposes an addition of a nonlinear restoring force applied to a triboelectric nanogenerator(TENG)to tune and broaden the resonance bandwidth.This restoring force is applied by permanent magnets at both sides of the slider and two external magnets.The noncontact strategy is adopted between the slider and the grating electrodes to avoid the wear of electrodes and energy loss caused by friction.The results show that compared with the linear system,the nonlinear noncontact TENG(NN-TENG)can increase the peak current from 6.3μA to 7.89μA,with an increment of about 25%,increase the peak power from 650μW to 977μW,increasing by about 50%,and increase the bandwidth from 0.5 Hz to 7.75 Hz,increasing by about1400%.This work may enable a new strategy to boost the bandwidth and output power of TENG through nonlinear oscillators.展开更多
Implementing resonators with geometrical nonlinearities in vibrational energy harvesting systems leads to considerable enhancement of their operational bandwidths. This advantage of nonlinear devices in comparison to ...Implementing resonators with geometrical nonlinearities in vibrational energy harvesting systems leads to considerable enhancement of their operational bandwidths. This advantage of nonlinear devices in comparison to their linear counterparts is much more obvious especially at small-scale where transition to nonlinear regime of vibration occurs at moderately small amplitudes of the base excitation. In this paper the nonlinear behavior of a disc-shaped piezoelectric laminated harvester considering midplane-stretching effect is investigated. Extended Hamilton’s principle is exploited to extract electromechanically coupled governing partial differential equations of the system. The equations are firstly order-reduced and then analytically solved implementing perturbation method of multiple scales. A nonlinear finite element method(FEM) simulation of the system is performed additionally for the purpose of verification which shows agreement with the analytical solution to a large extent. The frequency response of the output power at primary resonance of the harvester is calculated to investigate the effect of nonlinearity on the system performance. Effect of various parameters including mechanical quality factor, external load impedance and base excitation amplitude on the behavior of the system are studied. Findings indicate that in the nonlinear regime both output power and operational bandwidth of the harvester will be enhanced by increasing the mechanical quality factor which can be considered as a significant advantage in comparison to linear harvesters in which these two factors vary in opposite ways as quality factor is changed.展开更多
Triboelectric nanogenerators(TENGs)represent a promising next‐generation renewable energy technology.TENGs have become increasingly popular for harvesting vibration energy in the environment due to their advantages o...Triboelectric nanogenerators(TENGs)represent a promising next‐generation renewable energy technology.TENGs have become increasingly popular for harvesting vibration energy in the environment due to their advantages of lightweight,broad range of material choices,low cost,and no pollution.However,issues such as input force irregularity,working bandwidth,efficiency calculation,and dynamic modeling hinder the use of TENGs in industrial or practical applications.In this paper,the modeling process of the dynamical system of a TENG is reviewed from the perspective of energy flow.In addition,this paper reviews the main contributions made in recent years to achieve optimized output based on springs,magnetic forces,and pendulums,and introduces different ways to increase the bandwidth of TENGs.Finally,the main problems of TENGs in the process of harvesting vibration energy are discussed.This review may serve as a practical reference for methods to convert irregular mechanical input sources into optimized output performance toward the commercialization of TENGs.展开更多
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the National Science and Technology Major Project of China(No.2019-Ⅶ-0017-0158)the National Natural Science Foundation of China(Nos.U2037204,U21A20131)the Innovative Research Team Development Program of Ministry of Education of China(No.IRT17R83)for the support given to this research。
文摘To achieve the manufacturing of Thin-Wall and High-Rib Components(TWHRC)with high precision,a novel heavy load Multi-DOF Envelope Forming Press(MEFP)with Parallel Kinematic Mechanism(PKM),driven by six Permanent Magnet Synchronous Motors(PMSMs),is developed.However,on account of the heavy forming load,the PMSM parameters are in great variation.Meanwhile,the PMSM is always in a transient state caused by fast time-varying forming load,resulting in low identification precision of varied PMSM parameters and control precision of PMSM under traditional parameter identification methods.To solve this problem,a novel Sliding Mode Control Method with Enhanced PMSM Parameter Identification(SMCMEPPI)for heavy load MEFP is proposed.Firstly,the kinematic model of MEFP is established.Secondly,the variation law of PMSM parameters under heavy load is revealed.Thirdly,an enhanced PMSM parameter identification method is proposed,in which the q axis current of PMSM is used to represent the changing rate of forming load and the adjustment factor is first proposed to remove improper input of PMSM parameter identification online.Fourthly,the Electromechanical Coupling Dynamic Model(ECDM)of MEFP,which includes identified PMSM parameters,is developed.Finally,based on the developed ECDM,a novel SMCMEPPI is proposed to realize the high-precision control of heavy load MEFP.The experimental results indicate that the proposed SMCMEPPI can significantly improve the control precision of heavy load MEFP.
基金supported by HKSAR the Research Grants Council Early Career Scheme(Grant No.24206919)Guangdong Basic and Applied Basic Research Foundation(Project No.2020A1515111161)This work was supported in part by the Project of Hetao Shenzhen-Hong Kong Science and Technology Innovation Cooperation Zone(HZQB-KCZYB-2020083).
文摘A narrow resonance bandwidth of an energy harvesters limits its response to the wide frequency spectrum in ambient environ-ments.This work proposes an addition of a nonlinear restoring force applied to a triboelectric nanogenerator(TENG)to tune and broaden the resonance bandwidth.This restoring force is applied by permanent magnets at both sides of the slider and two external magnets.The noncontact strategy is adopted between the slider and the grating electrodes to avoid the wear of electrodes and energy loss caused by friction.The results show that compared with the linear system,the nonlinear noncontact TENG(NN-TENG)can increase the peak current from 6.3μA to 7.89μA,with an increment of about 25%,increase the peak power from 650μW to 977μW,increasing by about 50%,and increase the bandwidth from 0.5 Hz to 7.75 Hz,increasing by about1400%.This work may enable a new strategy to boost the bandwidth and output power of TENG through nonlinear oscillators.
文摘Implementing resonators with geometrical nonlinearities in vibrational energy harvesting systems leads to considerable enhancement of their operational bandwidths. This advantage of nonlinear devices in comparison to their linear counterparts is much more obvious especially at small-scale where transition to nonlinear regime of vibration occurs at moderately small amplitudes of the base excitation. In this paper the nonlinear behavior of a disc-shaped piezoelectric laminated harvester considering midplane-stretching effect is investigated. Extended Hamilton’s principle is exploited to extract electromechanically coupled governing partial differential equations of the system. The equations are firstly order-reduced and then analytically solved implementing perturbation method of multiple scales. A nonlinear finite element method(FEM) simulation of the system is performed additionally for the purpose of verification which shows agreement with the analytical solution to a large extent. The frequency response of the output power at primary resonance of the harvester is calculated to investigate the effect of nonlinearity on the system performance. Effect of various parameters including mechanical quality factor, external load impedance and base excitation amplitude on the behavior of the system are studied. Findings indicate that in the nonlinear regime both output power and operational bandwidth of the harvester will be enhanced by increasing the mechanical quality factor which can be considered as a significant advantage in comparison to linear harvesters in which these two factors vary in opposite ways as quality factor is changed.
基金This work was supported by HKSAR,the Research Grants Council Early Career Scheme(Grant No.24206919)the Guangdong Basic and Applied Basic Research Foundation(Project No.2020A1515111161)This work was supported in part by the Project of Hetao Shenzhen-Hong Kong Science and Technology Innovation Cooperation Zone(HZQB-KCZYB-2020083).
文摘Triboelectric nanogenerators(TENGs)represent a promising next‐generation renewable energy technology.TENGs have become increasingly popular for harvesting vibration energy in the environment due to their advantages of lightweight,broad range of material choices,low cost,and no pollution.However,issues such as input force irregularity,working bandwidth,efficiency calculation,and dynamic modeling hinder the use of TENGs in industrial or practical applications.In this paper,the modeling process of the dynamical system of a TENG is reviewed from the perspective of energy flow.In addition,this paper reviews the main contributions made in recent years to achieve optimized output based on springs,magnetic forces,and pendulums,and introduces different ways to increase the bandwidth of TENGs.Finally,the main problems of TENGs in the process of harvesting vibration energy are discussed.This review may serve as a practical reference for methods to convert irregular mechanical input sources into optimized output performance toward the commercialization of TENGs.
