Ensuring a stable and efficient transformer operation is very crucial task nowadays, especially with the integration of modern sensitive electrical equipment appliances down line. However, maloperation still cannot be completely avoided, particularly existence inrush current that possess similar characteristics as fault currents when occurred. Thus, this paper proposes an enhanced method for id...

In this paper we present a combinatorial scheme based on hidden Markov models (HMM) and wavelet transform (WT) to discriminate between magnetizing inrush currents and internal faults in power transformers. HMMs are powerful tools for transient classification which compute the maximum likelihood probability between training and testing data signals for identification. The WT is employed to extra...

Continuous monitoring of Power transformer is very much essential during its operation. Incipient faults inside the tank and winding insulation needs careful attention. Traditional ratio methods and Duval triangle can be employed to diagnose the incipient faults. Many times correct diagnosis due to the borderline problems and the existence of multiple faults may not be possible. Artificial inte...

Transformers are normally designed and built for use at rated frequency and sinusoidal load current. A non-linear load on a transformer leads to harmonic power losses which cause increased operational costs and additional heating in transformer parts. It leads to higher losses, early fatigue of insulation, premature failure and reduction of the useful life of the transformer. To prevent these p...

VAR support should be supplied as close to the load as possible to minimize transmission losses. For voltage control and for improvement of total power factor in a distribution system the circuit- breaker switched capacitor banks can be used. The problems with this solution are the voltage steps caused by the large sizes of the capacitor banks as well as the transients caused on insertion. Thyr...

Recently, there has been an increased interest in the use of artificial neural networks various branches electric power industry including relay protection. Аrtificial are one fastest growing areas intelligence technology. аrtificial engineering, Existing microprocessor-based protection devices a traditional digital signal processing monitored signals which is reduced to multiplying values succ...

We present the conditions in which a toroidal type, line frequency, power transformer can yield reduced stray magnetic field, reduced weight and size, and improved efficiency over an E-I laminate transformer in single phase linear power supplies. These benefits must be considered in relation to the disadvantages of slightly higher cost and greater inrush current. WHY CHOOSE A LINEAR POWER SUPPL...

This article presents a nonlinear equivalent circuit model of an isolated dc-dc converter with 3-phase medium frequency transformer. The takes into account the magnetic cross saturation core-type circuit. is suitable in detailed electromagnetic transient simulations power systems involving converters. developed using Lagrange energy method. It involves matrix dynamic inductances containing term...