Study of Capacitance and Dissipation Factor Tip-Up to Evaluate the Condition of Insulating Systems for High Voltage Rotating Machines

In order to investigate the significance of the capacitance and dissipation factor measurements as a function of test voltage for insulating systems of high-voltage rotating machines a series of measurements have been done on simple epoxy resin specimens and actual stator bars which have been manufactured based on the epoxy VPI technology. The possibilities of proposition of a relation between the maximum variation of the dissipation factor and capacitance with applied test voltage and the relative volume of the air-filled voids were investigated. Also the stator bars have been aged by different accelerated aging procedures and the changes of the capacitance and dissipation factor as a function of voltage were studied during the aging procedures.

[1]  G.C. Stone,et al.  Electrical insulation for rotating machines-design, evaluation, aging, testing, and repair - Book Review , 2004, IEEE Electrical Insulation Magazine.

[2]  M. Beyer,et al.  Hochspannungstechnik : theoretische und praktische Grundlagen , 1986 .

[3]  M. Kaufhold,et al.  Interface phenomena in stator winding insulation - challenges in design, diagnosis, and service experience , 2002 .

[4]  I. J. Kemp,et al.  Degradation of epoxy resin by partial discharges , 2000 .

[5]  Thomas W. Dakin,et al.  The Relation of Capacitance Increase with High Voltages to Internal Electric Discharges and Discharging Void Volume , 1958, Transactions of the American Institute of Electrical Engineers Part III Power Apparatus and Systems.

[6]  Greg C. Stone,et al.  A thermal cycling type test for generator stator winding insulation , 1991 .

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

[8]  K. Kimura.  Progress of insulation ageing and diagnostics of high voltage rotating machine windings in Japan , 1993, IEEE Electrical Insulation Magazine.

[9]  Ian Culbert,et al.  Electrical insulation for rotating machines : design, evaluation, aging, testing, and repair , 2003 .

[10]  H. Borsi,et al.  Partial discharge and dielectric response behaviour of insulation systems for high voltage rotating machines under electrical stress , 2004, The 17th Annual Meeting of the IEEE Lasers and Electro-Optics Society, 2004. LEOS 2004..