The Hybrid Power Electronic Transformer (HPET) has been proposed as an efficient and economical solution to some of the problems caused by Distributed Energy Resources new types loads in existing AC distribution systems. Despite this, HPET limitations on control it can exert due its fractionally-rated Converter. Various topologies with different capabilities have proposed, being necessary inves...

Power transformers are protected by different relays that operate independently. Malfunction of each relay has a major role in reducing the reliability of the protection system. In order to mitigate the main drawbacks of the power transformer relays, an overall protection scheme is presented in this paper. This scheme proposes a novel multi criterion algorithm using decision-making based on fuz...

Frequency response analysis (FRA) is a sensitive ‎method established for testing the mechanical integrity of ‎transformers. However, interpretation of FRA signature still ‎needs expert opinions and there is no FRA interpretation code ‎generally accepted. Various mechanical faults with different ‎extents on power transformers are required to aid FRA ‎interpretation. To address this challenge, in...

In this paper, the properties of the physical and chemical materials, such as low loss amorphous HB1 core, high temperature resistance winding and insulation vegetable oil have been developed for use in liquid-immersed power transformer. The measured results of magnetic properties with different ferromagnetic materials core were obtained. Considering winding property for operation above 95°C co...

| This paper deals with design improvements on graded insulation of power transformers using transient electric eld analysis and a visualization technique. The calculation method for transient electric eld analysis inside a power transformer impressed with impulse voltage is presented: Initially, the concentrated electric network for the power transformer is constructed by dividing transformer ...

This research work is an initiative to characterize the thermal behavior of power transformers in presence of winding short circuit faults as one of the most important causes of failures in power transformers. The paper contributes for this matter by accurately estimating the excessive power losses and temperature rise due to winding short circuit faults, through a circuit-magnetic-thermal FEM ...

A shipboard power system is a stiff, isolated power system. Power is generated locally, and distributed over short distances making the system vulnerable to transients. Power quality problems such as voltage sags, which arise due to a fault or a pulsed load, can cause interruptions of critical loads. This can be of a serious concern for the survivability of a combat ship. A series voltage injec...

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

An audio transformer is used in a guitar amplifier to match the impedances of the power amplifier and a loudspeaker. It is important to understand the influence of the audio transformer on the overall sound quality for realistic tube amplifier emulation. This paper proposes to simulate the audio transformer using a wave digital filter model, which is based on the gyrator-capacitor analogy. The ...