The increasing utilization of piezoelectric transformers (PT) in power electronics requires fundamental analysis and design of PT power converters. In addition, the possibility of overcoming the essential limitations of PT power ability by a combined operation of PTs needs to be examined. These studies could provide wide opportunities for PT exploitation in power electronic circuits. The main o...

This paper presents an efficient wavelet and neural network (WNN) based approach for distinguishing magnetizing inrush currents from internal fault currents in three phase power transformers. The wavelet transform is applied first to decompose the current signals of the power transformer into a series of detailed wavelet components. The values of the detailed coefficients obtained can discrimin...

From a safety and security point of view, the electrical energy distribution infrastructure needs to be protected.. In this paper solutions to increase the safety aspects of substation components, power lines and power transformers are discussed. Also security solutions related to perimeter intrusion detection in substations and remote surveillance of power transformer installations are introdu...

the behaviour of power transformers is very like to ideal ones. their characteristic matrices can not be determined directly, because the elements of the characteristic matrices are either close to infinity or zero. on the other hand, strong coupling between two transformer windings causes the determinant of these matrices to become zero. therefore, conversion of these matrices to each other wi...

The estimation of harmonic components of power voltage signals is one of the measurements prescribed by the power quality (PQ) standards (IEC 61000-4-30, 2008). In general, the harmonic components originate from non-linear elements connected to the power system such as non-linear loads (e.g., switched-mode power supplies) or transformers. An example of a distorted voltage measured in an office ...