# Selection Method Called

Selection Method Called M.N. Dubyago, N.K. Poluyanovich

CR SIGNAL SELECTION METHOD BY WAVELET TRANSFORM

The work is devoted to forecasting the residual life of insulation of power cable lines, based on the electric method of measuring partial discharges of the PD. The task is to distinguish useful signals (PD) from interference of various origins. To solve the problem, it is proposed to use the wavelet transform method. Mathematical models of pulses of the Czech Republic are presented. A mathematical model of filtering the original signal is given. The paper puts forward some requirements for the implementation of wavelet transform. It has been established that the requirements put forward are most fully satisfied by Daubechies wavelets, which is confirmed by calculations.

Partial discharges – diagnostics – power cable lines – discrete wavelet transform.

M.N. Dubyago, N.K. Poluyanovich

SIGNAL FREQUENCY DISCHARGES SELECTION METHOD USING WAVELET TRANSFORM

The paper is devoted to forecasting of a residual resource of isolation of the power cable lines, based on an electrical method of measurement of partial discharge PD. The posed problem is to pick out useful signals (PD) among different types of noises. To solve the problem wavelet transform method is introduced. Mathematical models of PD impulses are given. Mathematical model of original signal filtering is given. The paper advances some requirements for the wavelet transform implementation. There was determined that Daubechies wavelet fully meets those requirements. This is proved by computing results.

Partial discharge- diagnostics- power cable lines- discrete wavelet transform.

The lack of an algorithm for measuring the actual PD signals against the background of industrial interference still does not allow creating effective automatic PD measurement systems in the monitoring mode under operating voltage and thereby ensuring proper control of the technical condition of the equipment. A special role is given to the PD registration method, as the most effective in detecting local defects. The complexity of the PD measurement technique lies in the difficulty in distinguishing useful signals (in this case, PD signals) from various types of interference.   