Research On The Numerical Inversion Calculation Methods Of Over-voltage Based On The Wide Band Transfer Characteristics Of Apparatus

This paper mainly developed one numerical inversion calculation method of overvoltage based on the project"one new overvoltage on-line monitoring method based on the transfer characteristic of PT". The research includes as follows:1. The scattering parameters of potential transformer, secondary cable and voltage divider was measured by Agilent4395A Network/Spectrum/Impedance Analyzer. The voltage transfer function of 2-port could be calculated by scattering parameter, and it was approximated by the vector fitting method.2. The saturation characteristic of oil immersed JDJ-10 PT was measured by power frequency test transformer,and it was verified that the saturation characteristic is linear in the range of 0～4.5 times rated voltage.3. Made secondary cable equivalent to the 1+1 transmission line and bulit the 2-port network model,and calculated the per unit length distribution parameter by finite element method ,and derived its 2-port transfer function .We verified the correctness by the measured transfer function.4. Developed two numerical inversion calculation methods of primary system of PT based on Fourier transform and recursive convolution seperately and verified the correctness by the measured data.