The multifrequency voltage(MFV)stress,including switching impulses and harmonics,commonly appearing in the modern power system will stimulate the multifrequency impedance dynamics behaviours of electrical insulation.T...The multifrequency voltage(MFV)stress,including switching impulses and harmonics,commonly appearing in the modern power system will stimulate the multifrequency impedance dynamics behaviours of electrical insulation.Therefore,this article presents a novel concept of insulation resilience response(IRR)by employing polymer insulation materials,which may be extended to electrical insulation resilience(EIR).The focus is on understanding reversible recovery performance and supporting physics-informed condition assessment for electrical insulation exposed to MFV.The underlying physical mechanisms and modelling methodologies are integrated to characterise the IRR behaviours of polymer insulation systems.The multifrequency dielectric/impedance properties of different resin dielectrics under diverse temperatures are comparatively investigated as proofofconcept cases.Furthermore,multidimensional sensitivity indicators are developed to quantify the electrical insulation resilience behaviour.A radar plot representation integrating resilience sensitivity indicators qualitatively assesses the IRR behaviours of polymer insulation systems.Additionally,a quantification methodology,including the resilience index(RI)and time-varied RI(TVRI),is proposed for the reversible recovery performance analysis for electrical insulation,respectively.Ultimately,an application-oriented framework derived from TVRI is provided to analyse the recovery performance evolution behaviours of electrical insulation under complex operating conditions.This offers a key theoretical foundation for insulation performance characterisation and condition analysis for high-voltage power equipment.展开更多
Diagnosing insulation intrinsic ageing is essential for preventing insulation failure of submarine cables,and in case of failure,helping in any decision about maintenance actions.In this study,a novel aged cable diagn...Diagnosing insulation intrinsic ageing is essential for preventing insulation failure of submarine cables,and in case of failure,helping in any decision about maintenance actions.In this study,a novel aged cable diagnosis approach based on high-voltage frequency domain spectroscopy(HV-FDS)with broader frequency width is proposed to analyse the high-field polarisation characteristics and conductivity behaviour of 500 kV submarine polymeric cables insulation,aiming to support the evaluation of overall insulation ageing.The measurement principle of HV-FDS and relaxation mechanism are stated,and then focus is on studying the extent of change of polarisation and conduction properties of submarine cables insulation as a function of ageing stress and time.Moreover,the high-field polarisation characteristics and conductivity behaviour are discussed in-depth based on the carrier transport and trap properties.Finally,the novel diagnostic indicator based on the high-field characteristics is extracted to quantify the thermal ageing state of submarine cables insulation.Results show that the high-field polarisation characteristics and conductivity behaviour seem to become sensitive diagnostic quantities if measured at reasonably high voltage,which are able to reveal mechanisms associated with thermo-oxidative ageing as that generated in the testing procedure considered in this paper.Sensitivity is considerably higher than that experienced in typical dielectric spectroscopy approaches.展开更多
In order to ensure the safe operation of submarine cables,it is of great significance to analyse the insulation state of submarine cables from the perspectives of microstructure,carrier transport characteristics and m...In order to ensure the safe operation of submarine cables,it is of great significance to analyse the insulation state of submarine cables from the perspectives of microstructure,carrier transport characteristics and macroscopic dielectric properties.In this study,based on the high-voltage frequency domain spectroscopy(HV-FDS)measurement system,HV-FDS experiments of fresh and thermally aged submarine cables were carried out under continuous(0.5,2,4 and 10 kV)and cyclic(2-10-2 kV)applied alternating voltages.Then,combining the changes of the microstructure structure of cross-linked poly-ethylene(XLPE)insulation,the aggregate structure deterioration model of XLPE was proposed to discuss the physical mechanism of HV-FDS characteristics of submarine cables under different voltages and insulation states.Results show that the HV-FDS characteristics of submarine cables have significant voltage dependence under contin-uous voltage excitation.The HV-FDS of submarine cables show memory characteristics under cyclic voltage excitation.Compared with the fresh submarine cable,the thermally aged submarine cable shows more significant voltage dependence and memory charac-teristics of HV-FDS.The memory characteristics of HV-FDS are mainly determined by the carriers transport and the interfacial polarisation caused by the accumulation of polar particles at the electrode/dielectric interface.This study covers the correlation mecha-nism among the microstructure,carrier transport and macroscopic HV-FDS properties of submarine cable insulation,which lays a foundation for further research and condition evaluation of submarine cables.展开更多
基金supported by the Science and Technology Project of State Grid Corporation of China(Grant 5500-202455120A-1-1-ZN).
文摘The multifrequency voltage(MFV)stress,including switching impulses and harmonics,commonly appearing in the modern power system will stimulate the multifrequency impedance dynamics behaviours of electrical insulation.Therefore,this article presents a novel concept of insulation resilience response(IRR)by employing polymer insulation materials,which may be extended to electrical insulation resilience(EIR).The focus is on understanding reversible recovery performance and supporting physics-informed condition assessment for electrical insulation exposed to MFV.The underlying physical mechanisms and modelling methodologies are integrated to characterise the IRR behaviours of polymer insulation systems.The multifrequency dielectric/impedance properties of different resin dielectrics under diverse temperatures are comparatively investigated as proofofconcept cases.Furthermore,multidimensional sensitivity indicators are developed to quantify the electrical insulation resilience behaviour.A radar plot representation integrating resilience sensitivity indicators qualitatively assesses the IRR behaviours of polymer insulation systems.Additionally,a quantification methodology,including the resilience index(RI)and time-varied RI(TVRI),is proposed for the reversible recovery performance analysis for electrical insulation,respectively.Ultimately,an application-oriented framework derived from TVRI is provided to analyse the recovery performance evolution behaviours of electrical insulation under complex operating conditions.This offers a key theoretical foundation for insulation performance characterisation and condition analysis for high-voltage power equipment.
基金Project of Chongqing Human Resources and Social Security Bureau,Grant/Award Number:2020LY19Innovative Research Groups of the National Natural Science Foundation of China,Grant/Award Number:51321063111 Project,Grant/Award Number:BP0020005。
文摘Diagnosing insulation intrinsic ageing is essential for preventing insulation failure of submarine cables,and in case of failure,helping in any decision about maintenance actions.In this study,a novel aged cable diagnosis approach based on high-voltage frequency domain spectroscopy(HV-FDS)with broader frequency width is proposed to analyse the high-field polarisation characteristics and conductivity behaviour of 500 kV submarine polymeric cables insulation,aiming to support the evaluation of overall insulation ageing.The measurement principle of HV-FDS and relaxation mechanism are stated,and then focus is on studying the extent of change of polarisation and conduction properties of submarine cables insulation as a function of ageing stress and time.Moreover,the high-field polarisation characteristics and conductivity behaviour are discussed in-depth based on the carrier transport and trap properties.Finally,the novel diagnostic indicator based on the high-field characteristics is extracted to quantify the thermal ageing state of submarine cables insulation.Results show that the high-field polarisation characteristics and conductivity behaviour seem to become sensitive diagnostic quantities if measured at reasonably high voltage,which are able to reveal mechanisms associated with thermo-oxidative ageing as that generated in the testing procedure considered in this paper.Sensitivity is considerably higher than that experienced in typical dielectric spectroscopy approaches.
基金Innovative Research Groups of the National Natural Science Foundation of China,Grant/Award Number:51321063111 Project,Grant/Award Number:BP0820005。
文摘In order to ensure the safe operation of submarine cables,it is of great significance to analyse the insulation state of submarine cables from the perspectives of microstructure,carrier transport characteristics and macroscopic dielectric properties.In this study,based on the high-voltage frequency domain spectroscopy(HV-FDS)measurement system,HV-FDS experiments of fresh and thermally aged submarine cables were carried out under continuous(0.5,2,4 and 10 kV)and cyclic(2-10-2 kV)applied alternating voltages.Then,combining the changes of the microstructure structure of cross-linked poly-ethylene(XLPE)insulation,the aggregate structure deterioration model of XLPE was proposed to discuss the physical mechanism of HV-FDS characteristics of submarine cables under different voltages and insulation states.Results show that the HV-FDS characteristics of submarine cables have significant voltage dependence under contin-uous voltage excitation.The HV-FDS of submarine cables show memory characteristics under cyclic voltage excitation.Compared with the fresh submarine cable,the thermally aged submarine cable shows more significant voltage dependence and memory charac-teristics of HV-FDS.The memory characteristics of HV-FDS are mainly determined by the carriers transport and the interfacial polarisation caused by the accumulation of polar particles at the electrode/dielectric interface.This study covers the correlation mecha-nism among the microstructure,carrier transport and macroscopic HV-FDS properties of submarine cable insulation,which lays a foundation for further research and condition evaluation of submarine cables.
