Analysis Of Ultra-wideband Signals Research Articles

Determination of transformer HV winding axial displacement occurrence, direction, and extent using time‐domain analysis of UWB signals

In this study, a new method is proposed to monitor axial displacement (AD) of transformer high-voltage (HV) winding using electromagnetic waves. The proposed method employed two receiving antennas and one transmitting antenna to exchange ultra-wideband (UWB) signals with the winding. The magnitude Euclidean distance (MED) index is used to compare the received signals when winding is sound or defective. Two receiving antennas receive signals at two different positions upon ADs in winding which causes different values in the amplitude of the received signals as well as the MED index of two receiving antennas. Hence, taking advantage of this feature, the occurrence, direction, and extent of AD can be identified. The proposed method is assessed using a simulation model. Then, experiments are conducted on an actual transformer winding using an experimental setup.

WA systems of Kravchenko-Rvachev functions and their modifications in analysis of ultra-wideband signals

WA systems of Kravchenko-Rvachev functions and their modifications in analysis of ultra-wideband signals

The use of atomic functions in the Choi-Williams analysis of ultrawideband signals

The atomic functions and the Kravchenko-Rvachev windows based on these functions are proposed as a tool in performing the Choi-Williams analysis of signals. A new class of nonlinear transforms (Choi-Williams-Rvachev transforms) has been considered. Advantages and disadvantages of such transforms are discussed. Possibilities of the Choi-Williams-Rvachev transforms are demonstrated using as an example the analysis of model ultrawideband signals.