For higher concentration of inclusions, an effective medium approximation (EMA) method is used to investigate the bulk effective response of weakly nonlinear composites, which are subject to the constitutive relatio...For higher concentration of inclusions, an effective medium approximation (EMA) method is used to investigate the bulk effective response of weakly nonlinear composites, which are subject to the constitutive relation of electric displacement and electric field, Dα = εαE +Xα|E|^2 E. As an example of three dimensions, under the external AC and DC electric fields Eapp = Eα(1 + sinωt), we have derived the general effective nonh'near response of composites by the EMA method for higher concentration of spherical inclusions. Furthermore, the effective nonlinear responses at harmonics are predicted.展开更多
This paper uses the perturbation method to study effective response of nonlinear cylindrical coated composites. Under the external AC and DC electric field Ea (1 +sin ωt), the local potentials of composites at all...This paper uses the perturbation method to study effective response of nonlinear cylindrical coated composites. Under the external AC and DC electric field Ea (1 +sin ωt), the local potentials of composites at all harmonic frequencies are induced. An effective nonlinear response to composite is given for the cylindrical coated inclusions in the dilute limit.展开更多
As the effect of climate plays a significant role in corona discharge under combined voltages,the variation of corona inception voltage with different air pressure and humidities is studied.An experimental platform,ba...As the effect of climate plays a significant role in corona discharge under combined voltages,the variation of corona inception voltage with different air pressure and humidities is studied.An experimental platform,based on a rod-to-plane electrode,is constructed with adjustable air pressure from 0.06 MPa to 0.10 MPa and with a relative humidity(RH)from 20%to 90%.The variation of ultraviolet(UV)photon count and corona inception voltage is obtained at various climate conditions under different applied voltages:the single AC,single DC,and combined AC-DC.It turns out that all the corona inception voltages decline with the drop of air pressure and the rise of humidity under different applied voltages.The influence between different voltages primarily relies on space charge,as more AC components make it easier to accumulate positive ions.The existence of AC makes ions move forward and backward while the existence of DC dominates the polarity of corona and general drift directions.At last the fitting formula of hybrid corona inception voltage combining air pressure and relative humidity is given.展开更多
基金The project supported by National Natural Science Foundation of China under Grant Nos.40476026 and 10374026
文摘For higher concentration of inclusions, an effective medium approximation (EMA) method is used to investigate the bulk effective response of weakly nonlinear composites, which are subject to the constitutive relation of electric displacement and electric field, Dα = εαE +Xα|E|^2 E. As an example of three dimensions, under the external AC and DC electric fields Eapp = Eα(1 + sinωt), we have derived the general effective nonh'near response of composites by the EMA method for higher concentration of spherical inclusions. Furthermore, the effective nonlinear responses at harmonics are predicted.
文摘This paper uses the perturbation method to study effective response of nonlinear cylindrical coated composites. Under the external AC and DC electric field Ea (1 +sin ωt), the local potentials of composites at all harmonic frequencies are induced. An effective nonlinear response to composite is given for the cylindrical coated inclusions in the dilute limit.
基金supported by the National Natural Science Foundation of China(51877082)Fok Ying-Tong Education Foundation(151058)the Fundamental Research Funds for the Central Universities(2019MS011).
文摘As the effect of climate plays a significant role in corona discharge under combined voltages,the variation of corona inception voltage with different air pressure and humidities is studied.An experimental platform,based on a rod-to-plane electrode,is constructed with adjustable air pressure from 0.06 MPa to 0.10 MPa and with a relative humidity(RH)from 20%to 90%.The variation of ultraviolet(UV)photon count and corona inception voltage is obtained at various climate conditions under different applied voltages:the single AC,single DC,and combined AC-DC.It turns out that all the corona inception voltages decline with the drop of air pressure and the rise of humidity under different applied voltages.The influence between different voltages primarily relies on space charge,as more AC components make it easier to accumulate positive ions.The existence of AC makes ions move forward and backward while the existence of DC dominates the polarity of corona and general drift directions.At last the fitting formula of hybrid corona inception voltage combining air pressure and relative humidity is given.