The paper presents the results of vibroacoustic investigations and the measurements of the acoustic pressure level (noise) of a transformer model. The measurements were taken at a full transformer load in two operation conditions: at a producer packeted core and at unpacketed core. Unpacketing consisted in loosing the screws pressing the particular core plates. Mechanical vibrations were regist...

In this paper, a compact tri-band impedance transformer by utilizing stubbed coupling line for matching a load at three arbitrary frequencies is proposed. The transformer is composed of two parts, and each part is constructed from parallel-coupled transmission lines. Two structures with different configurations of the proposed transformer have been given and analyzed. Then, the close-form equat...

An ultra-wide locking range transformer-based injection-locked frequency divider (ILFD) is presented. By making use of a 4-order transformer-based resonator and an inductive gain peaking technique, the proposed ILFD can achieve high performance in terms of wide locking range and low power consumption. Fabricated in a standard 65nm CMOS process with a core area of 0.18mm, the ILFD measures a loc...

in this paper are present the results of measurements of magnetic induction at some locationsin city bor (the east serbia) dating from the household electric devices and transformer stations suited near the residental areas. stress is on the extremely low frequent electromagnetic radiation from transformer stations and other high voltage instalations in urban areas. risk of the extremely low fr...

Certain level of mechanical deformations in winding does not hamper the normal performance of power transformer. However, such incipient deformations if unattended could result in permanent failure of transformer. To this end, an approach is proposed to assess the severity of mechanical deformations in transformer winding. These deformations get reflected as changes in its high frequency behavi...

The present paper deals with the analysis and development of noise-reduction transformer that has a filter function for conductive noise transmission. Two types of prototype noise-reduction transformers with two different output voltages are proposed. To determine an optimum design for the noise-reduction transformer, noise attenuation characteristics are discussed based on the experiments and ...

Solid-state transformer (SST); Medium frequency transformer; AC/AC converter; Matrix converter Abstract This paper presents a novel topology of solid-state transformer (SST). In the design process, the AC/DC, DC/AC and AC/AC converters have been integrated to achieve higher efficiency. To obtain higher efficiency from other SST with DC-link topologies, the AC/DC and DC/AC converters have been i...

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...

The power converter that feeds high-frequency, highvoltage transformers must be carefully designed due to parasitic components, mainly the secondary winding capacitance and the leakage inductance, that introduces resonances in relatively lowfrequency range, next to the switching frequency. This paper considers applications in which the load (resistive) has an unpredictable behavior, changing fr...

Low-power dichroic halogen lamps, usually used for display lighting, have low-voltage filament. The lightweight electronic transformer (ET), based on self-oscillating half-bridge high frequency inverter, are used to replace bulky and heavy conventional 50160 Hz step-down transformer. But their lamp current are rectangular like shape, leading to generate high electromagnetic noise and increase t...