Diagnosis of the dielectric ageing of more of the substance by means of dielectric loss factor measurements on site with frequencies smaller than the frequencies of the public, electric supply networks

摘要

A method for the diagnosis of the dielectric ageing of more of the substance dielectrics consisting of oil / paper / particle board, oil / paper or mass / paper, in which in a first method step, a loss factor tan δ of the more of the substance dielectric in the case of a sequence of sinusoidal voltages with frequencies smaller than the frequencies of the public supply networks and rms values u₁, .., U_n, the magnitude of which may be mentioned are arranged so as to rise which is measured, characterized by the,in that, in a second process step the parameters a and b in a equation f (u) = ae^{–U / τ} + B, be so determined, that the as a function of the effective value u of the sinusoidal test voltage applied curve f (u) in the first process step with the measured values determined for the loss factor tan δ, plotted over the effective value u of the sinusoidal test voltage, wherein τ is defined as the difference u_n – U₁,in a further method step in the equation f (u) = ae^{–U / τ} + B is a naturally oscillated loss factor tan δ₀ = B is read off, which is a measure for the aging of the..