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
Leakage control in deep oil and gas wells is challenging,often leading to increased costs.In this study,a low-density,high-pressure resistant and thermally stable epoxy resin(BEPD)was synthesized by ring opening of 2,...Leakage control in deep oil and gas wells is challenging,often leading to increased costs.In this study,a low-density,high-pressure resistant and thermally stable epoxy resin(BEPD)was synthesized by ring opening of 2,2-bis(4-epoxypropoxyphenyl)propane cured with 1,8-diaminonaphthalene.The material was thoroughly characterized using fourier-transform infrared spectroscopy,a universal testing machine,thermogravimetric analysis,and density testing.Comprehensive experimental and simulation analyses were conducted to evaluate BEPD's dispersion stability,its impact on the rheological properties of drilling fluid,and its effectiveness as a leakage control agent.It exhibits a high compressive strength(250.12 MPa)and a thermal decomposition temperature of 337.75℃,making it suitable for high-temperature environments.Its irregular particle shape ensures a strong bond with surrounding strata,forming a stable plugging layer.With a density of 1.09 g/cm^(3),BEPD disperses well in plugging slurry,reducing sedimentation.At dosages between 1%and 4%,it doesn't significantly affect the rheology of the slurry and effectively prevents sedimentation.BEPD particles effectively plugged fractures ranging from 1 to 4 mm,withstanding pressures up to 11.5 MPa.This performance is due to its unique particle size distribution,where larger particles act as bridges and smaller particles fill gaps,forming a dense plugging layer.BEPD shows potential as a highly effective material for improving leakage control in deep well applications.展开更多
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 Open Fund of State Key Laboratory Oil and Gas Reservoir Geology and Exploitation(Southwest Petroleum University)(No.PLN2022-22,PLN2022-32)Science and Technology Cooperation Project of the CNPC-SWPU Innovation Alliance(No.2020CX040102,2020CX040201)+1 种基金Special Projects of Central Government Guiding Development of Local Science and Technology,China(No.2023ZYD0033)Natural Science Foundation of Sichuan Province(No.2025ZNSFSC0377).
文摘Leakage control in deep oil and gas wells is challenging,often leading to increased costs.In this study,a low-density,high-pressure resistant and thermally stable epoxy resin(BEPD)was synthesized by ring opening of 2,2-bis(4-epoxypropoxyphenyl)propane cured with 1,8-diaminonaphthalene.The material was thoroughly characterized using fourier-transform infrared spectroscopy,a universal testing machine,thermogravimetric analysis,and density testing.Comprehensive experimental and simulation analyses were conducted to evaluate BEPD's dispersion stability,its impact on the rheological properties of drilling fluid,and its effectiveness as a leakage control agent.It exhibits a high compressive strength(250.12 MPa)and a thermal decomposition temperature of 337.75℃,making it suitable for high-temperature environments.Its irregular particle shape ensures a strong bond with surrounding strata,forming a stable plugging layer.With a density of 1.09 g/cm^(3),BEPD disperses well in plugging slurry,reducing sedimentation.At dosages between 1%and 4%,it doesn't significantly affect the rheology of the slurry and effectively prevents sedimentation.BEPD particles effectively plugged fractures ranging from 1 to 4 mm,withstanding pressures up to 11.5 MPa.This performance is due to its unique particle size distribution,where larger particles act as bridges and smaller particles fill gaps,forming a dense plugging layer.BEPD shows potential as a highly effective material for improving leakage control in deep well applications.
