Dielectric frequency response of oil-paper composite insulation modified by nanoparticles

The research on dielectric frequency response of oil-paper composite insulation modified by nanoparticles has been carried out in order to seek possible way to improve insulation properties thereof. Before and after nanoparticles being added, the dielectric frequency responses of oil-paper composite insulation with different moisture contents at different temperatures have been measured within the frequency from 0.1 mHz to 1 MHz. The Cole-Cole relaxation model has been used to analyzing the measured data. The results show that the variation rules of insulation condition can be indicated by the parameters of relaxation model. By adding nanoparticles, a new low frequency relaxation appeared.

[1]  G. Montanari,et al.  Polymer nanocomposites as dielectrics and electrical insulation-perspectives for processing technologies, material characterization and future applications , 2004, IEEE Transactions on Dielectrics and Electrical Insulation.

[2]  K. Raj,et al.  AC (60 Hz) and impulse breakdown strength of a colloidal fluid based on transformer oil and magnetite nanoparticles , 1998, Conference Record of the 1998 IEEE International Symposium on Electrical Insulation (Cat. No.98CH36239).

[3]  L. Schadler,et al.  Polymer nanocomposite dielectrics-the role of the interface , 2005, IEEE Transactions on Dielectrics and Electrical Insulation.

[4]  W.S. Zaengl,et al.  Applications of dielectric spectroscopy in time and frequency domain for HV power equipment , 2003, IEEE Electrical Insulation Magazine.

[5]  K. Younsi,et al.  The future of nanodielectrics in the electrical power industry , 2004, IEEE Transactions on Dielectrics and Electrical Insulation.

[6]  W. S. Zaengl,et al.  Dielectric spectroscopy in time and frequency domain for HV power equipment. I. Theoretical considerations , 2003 .

[7]  A. Jonscher.  Dielectric relaxation in solids , 1983 .

[8]  C. Ekanayake,et al.  Field experiences with measurements of dielectric response in frequency domain for power transformer diagnostics , 2006, IEEE Transactions on Power Delivery.

[9]  T. Lewis.  Interfaces are the dominant feature of dielectrics at the nanometric level , 2004, IEEE Transactions on Dielectrics and Electrical Insulation.

[10]  B. M. Berkovskiĭ,et al.  Magnetic Fluids and Applications Handbook , 1996 .

[11]  W. S. Zaengl,et al.  Dielectric Response Methods for Diagnostics of Power Transformers , 2003 .

[12]  D. Linhjell,et al.  Aging of oil-impregnated paper in power transformers , 2004, IEEE Transactions on Power Delivery.

[13]  G.N. Wu,et al.  Modeling of transient moisture equilibrium in oil-paper insulation , 2008, IEEE Transactions on Dielectrics and Electrical Insulation.

[14]  A. Graczkowski,et al.  Frequency response of oil impregnated pressboard and paper samples for estimating moisture in transformer insulation , 2006, IEEE Transactions on Power Delivery.

[15]  S. K. Saha.  Observation of giant dielectric constant in an assembly of ultrafine Ag particles , 2004 .

[16]  P. Purkait,et al.  Understanding the impacts of moisture and thermal ageing on transformer's insulation by dielectric response and molecular weight measurements , 2008, IEEE Transactions on Dielectrics and Electrical Insulation.

[17]  P. Purkait,et al.  Investigation of polarization and depolarization current measurements for the assessment of oil-paper insulation of aged transformers , 2004, IEEE Transactions on Dielectrics and Electrical Insulation.

[18]  Chandima Ekanayake,et al.  Diagnosis of Moisture in Transformer Insulation - Application of frequency domain spectroscopy , 2006 .

[19]  T. K. Saha,et al.  Experience with Return Voltage Measurements for Assessing Insulation Conditions in Service Aged Transformers , 2002, IEEE Power Engineering Review.

[20]  D. Linhjell,et al.  Dielectric response of mineral oil impregnated cellulose and the impact of aging , 2007, IEEE Transactions on Dielectrics and Electrical Insulation.