The purpose of this study is to generate a highly stable DC current by using a superconducting transformer. For the first trial stage, a 100 A class superconducting transformer was designed and fabricated for operation at the temperature of liquid nitrogen. The secondary coil of the transformer was wound with a superconducting Bi-2223 tape, and the turn ratio of the primary and secondary windin...

Photovoltaic(PV) systems are expected to play an important role in future energy production. An asymmetrical interleaved high step-up converter is used to get high step up gain to step up the input energy which is obtained from PV panel without operating at an extreme duty ratio. The traditional inverter which is used to convert the converter output energy from DC to AC, contains a line frequen...

A high efficiency and operating life of grid feeding solar photovoltaic (PV) inverters are demanded. Because of reduced dclink capacitor requirement, current source inverter (CSI) offers higher reliability than the voltage source based solar inverter. Nonetheless, conventional three-phase pulse width modulated (PWM) current source based solar inverter injects high earth leakage current into the...

this paper presents the application of the fuzzy-neuro method toinvestigate transformer inrush current. recently, the frequency environment ofpower systems has been made more complicated and the magnitude of the secondharmonic in inrush current has been decreased because of the improvement of caststeel. therefore, traditional approaches will likely mal-operate in the case ofmagnetizing inrush w...

High-frequency loss in transformer windings using stranded wire is analyzed. A complete loss prediction method is presented. The interstrand resistivity, which is an important parameter to determine the power loss, is measured experimentally. The analytical model is solved to get an optimal pitch, which specifies the degree of twisting that results in minimum loss. A transformer using a strande...

A platform implemented with Digital Signal Controllers (DSCs) developed for real time studies of the dynamic behavior of the air-gapped current transformers (CTs) used in power grid protection and measurement systems is presented. The implemented algorithms simulate the fault current in an electric power system as well as the transient response of the current transformer. It is also presented a...

The key idea of current deep learning methods for dense prediction is to apply a model on a regular patch centered on each pixel to make pixel-wise predictions. These methods are limited in the sense that the patches are determined by network architecture instead of learned from data. In this work, we propose the dense transformer networks, which can learn the shapes and sizes of patches from d...

The squared-field-derivative method for calculating eddy-current (proximity-effect) losses in round-wire or litz-wire transformer and inductor windings is derived. The method is capable of analyzing losses due to two-dimensional and three-dimensional field effects in multiple windings with arbitrary waveforms in each winding. It uses a simple set of numerical magnetostatic field calculations, w...

A new passive 28-step current shaper for three-phase rectification is proposed in this paper. With a phase-shifting transformer on the ac side and six interphase transformers on the dc side, per-phase input current can be shaped into a 28-step sinusoidal waveform. The total harmonic distortion of ac input currents obtained is 6.54%, lower than one-half of that in a conventional 12-pulse convert...