Location of Repository

The effect of high voltage fields on epoxy laminates

By Mohammed Nasser Ajour

Abstract

This thesis describes the characterisation of epoxy/glass fibre composite material\ud before and progressively through electrical and thermal ageing. Glass fibre reinforced\ud epoxy (GFRE) material is used in pressboard transformers for optical telecommunication systems, typically at voltages between 1 and 2kV. The material was characterised by means of space charge measurements using the Pulsed Electroacoustic (PEA) technique, Dielectric response, Dynamic Mechanical Analysis (DMA), Differential Scanning Calorimetry (DSC), and Scanning Electronic\ud Microscopy (SEM). An ageing programme was set up to follow the thermal and electrical ageing (at DC fields) of the GFRE by the same means. \ud \ud The results show a q-dc transport process with an activation energy of 1.1eV. The qdc\ud process is associated with a charge transport process on the surface of the fibres. The results for the aged samples show delamination and debonding between the\ud epoxy and the glass fibre at the glass epoxy interface. The delamination creates free\ud volumes and voids which lead to partial discharge and hence failure. Electrical ageing can be characterised in term of dielectric, PEA, and DSC responses. Thermal ageing does not produce the same effect as electrical ageing. The samples that were only\ud thermally aged behave in the same way as un-aged samples

Publisher: University of Leicester
Year: 2003
OAI identifier: oai:lra.le.ac.uk:2381/858

Suggested articles

Preview

Citations

  1. (1992). A fractal pore model for Aschie’s law in doi
  2. (1998). A high field pulsed electro-acoustic apparatus for space charge and external circuit current measurements within solid insulators”, J.Meas.Sci and Technol. doi
  3. (1983). A New Approach to the Structure of Imperfect Materials and their Relaxation Spectroscopy”., doi
  4. (1996). A new model for electrical ageing and breakdown in dielectrics”, doi
  5. A text book of sound, doi
  6. (2001). A.see “High field space charge measurements in XLPE using a novel pulsed electro-acoustic system”
  7. Accelerated Ageing of High Voltage Encapsulated Transformer for Electronic Applications”, doi
  8. An approximate Method for Deducing Dielectric Loss Factor From Direct Current Measurement”, doi
  9. (1986). Analysis of Electric Stress Distribution in Cavities Embedded Within Dielectric Structures” doi
  10. and power-law regimes in the frequency response of general determinate fractal circuit”, Physical Review B. doi
  11. (1998). And T.J Lewis.” A Mechanical Origin For Electrical Ageing And Breakdown In doi
  12. (1998). and T.J.Lewis “ Electric Field induced Viscoelastic Changes doi
  13. (1984). Anomalous Low -frequency Dispersion”, doi
  14. (2002). Application of polymer ageing models to cable geometry and time-tofailure distributions”, PhD Thesis,
  15. (1996). Breakdown Strength of Various Epoxy Resins for Resin Molded Coils under High Temperatures”,
  16. (1988). Constant- Phase Angle and Power Law Regimes in the Frequency Response of A General Determinate Fractal Circuit”, The American Physical Society, Physical Review B, doi
  17. (1997). Crine, Chinh Dang,”Electrical Ageing of Extruded Dielectric Cables A Physical Model, doi
  18. (1997). Crine,” A Molecular Model to Evaluate the Impact of Ageing on Space Charge
  19. Designing and creating printed circuits”.
  20. (1987). Dielectric and Conduction processes doi
  21. Dielectric materials and applications”, doi
  22. (1995). Dielectric Measurements of Moisture Dynamics in Oil-impregnated Pressboard, doi
  23. (1983). Dielectric relaxation in solids”, doi
  24. Dielectric Response During Curing of ResinRich Insulation System for Rotating doi
  25. Dielectric Spectrometer- User Guide” Private issue provide with the system measurements.
  26. (1995). Dielectrometry Measurements of Moister Dynamic in Oil-impregnated Pressboard”, doi
  27. (1964). Electric Stress in Gaseous Cavities in Solid Dielectrics”PROC. doi
  28. Electrical degradation and breakdown in polymers”. doi
  29. (1992). Electrical degradation and breakdown in polymers”. Published by P.Peregrinus for IEE,London doi
  30. (1986). Electrical Effect at Interfaces and Surfaces”, doi
  31. Electronic Conduction in Polyethylene Naphthalate at High Electric Fields”, doi
  32. (1987). Frequency Response Analyser, Operating Manual, Solarton Instruments, Issue 2a, Part No 12550006,
  33. (1980). G.Sawa, M.Ieda,” Observation of Dielectric Breakdown Sites in Polyethylene thin film” doi
  34. (1995). Handbook of electrical and electronic insulating Materials”, second edition, doi
  35. (1998). high field pulsed electro-acoustic apparatus for space charge and external circuit current measurements within solid insulators”, J.Meas.Sci and Technol. doi
  36. (1994). High-field conduction and Breakdown in Insulating Polymers Present Situation and Future Prospects”, doi
  37. (1954). Hippel,.” Dielectrics and waves”, doi
  38. Ieda,”Electrical Conduction and Carrier Traps in Polymeric Materials”, doi
  39. Increase of Capacitance and tanδ Between Conductors on Printed Circuit Boards at Low Frequency Due to Ionic Migration”, doi
  40. (1999). Industrial application of space charge measurements in Japan”, doi
  41. (1991). Invariant behaviour classes for the response of simple fractal circuits”, doi
  42. (1991). Invariant behaviour for the response of simple fractal circuits. doi
  43. (2001). Investigation of the Structural Changes in LDPE and XLPE induced by High Electrical Stress”, PhD thesis, doi
  44. Maeno,Takashi; Tsukui,Tsutomu, “Observation of copper ionic migration in insulation layer by pulsed electroacoustic method”, doi
  45. Material Science, Third Edition, Chapman and Hall,
  46. (1970). Materials science for engineers”.,
  47. (2001). Measurements of space charge distribution in solid insulators under rapidly varying voltage using high voltage high speed pulsed electro-acoustic doi
  48. (1970). Mechanical properties of polymer and composite, doi
  49. (2003). Microstructural, Physical and Chemical Characterization of HV XLPE Cable III Peeling for an Electrical Aging Diagnostic Data doi
  50. (1999). Montanari,” A space charge Life Model for AC Electrical Ageing of Polymers doi
  51. (1997). Montanari,” Discussion of Space Charge Life Model featured in dc and ac Electrical Ageing of Polymeric Materials”. doi
  52. (0685). Mortimer.C “ Differential Scanning Calorimetry”. doi
  53. (1979). Non-Exponential decay in Dielectrics and doi
  54. Norma.P,” The use of Differential Scanning Calorimetry(DSC) in the prediction of metal composition and polymer characterisation,
  55. Parknelco product specifications, Electrochemical Corporation, 5 Dakota DriveLake Success, NY11042, see internet page www.parknelco.com
  56. (1977). Perkin-Elmer Corporation, Characterisation of thermosets,
  57. (1988). Phase Angle and Power Law Regimes in the Frequency Response of A General Determinate Fractal Circuit”, The American Physical Society, Physical Review B, Vol37, doi
  58. (1975). Polymer Chemistry an introduction, doi
  59. (1995). Polymer science and technology, London,
  60. (1995). Polymer science and technology”, London,
  61. (2001). Printed Circuits Handbook”, doi
  62. (1997). Review of Space Charge Measurements in Dielectrics”, doi
  63. Review: Ageing and related phenomena in Modern Electric Power Systems”,
  64. RFC 822. the contact at parknelco who supplied the information.
  65. (1964). Salvage.” Electric Stress in Gaseous Cavities doi
  66. (1981). Self-healing breakdown at Spherulite Boundaties of Polyethylene Thin doi
  67. (2001). T.J.Lewis “Ageing A Perspective”, doi
  68. (1971). T.J.Lewis, “Electrical conduction in polyethylene terephthalate and polyethylene films” J.Phys D: Appl.Phys, Vol.4, doi
  69. Takada “ Acoustic and Optical Methods for Measuring Electric Charge Distribution in Dielectrics”, doi
  70. The effect of Different Types of doi
  71. (1982). The Effect of Mechanical Stress
  72. (1982). The Effect of Temperature and doi
  73. The Effect of Temperature and Voltage on Dielectric Breakdown doi
  74. (1147). The Incorporation of Space Charge Degradation in the Life Model for Electrical Insulating Materials”, doi
  75. (1998). The micro-physics of charge in solid dielectrics “..
  76. (1978). The Morphology of Cross-Linked PE”, doi
  77. (1996). The use of Differential Scanning Calorimetry(DSC) in the prediction of metal composition and polymer characterisation, Ref.
  78. (1986). Theory of dielectrics: dielectrics constant and dielectric loss”, doi
  79. V Griseri.” Space charge and external current measurements of filler-free epoxy resin”, doi
  80. (1984). Water Treeing in Solid Dielectrics”, doi
  81. Williams.G,” Anelastic and Dielectric Effects in polymeric Solids”, doi

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.