This paper presents analysis, modeling, and design of a low-harmonic, isolated, active-clamped SEPIC rectifier for future avionics applications. Simpler converter dynamics, high switching frequency, zerovoltage-switching, and a single-layer transformer construction result in an efficiency of 90% and a very low total harmonic distortion over 400 -800 Hz line frequency variation.

The two-inductor boost converter with an auxiliary transformer has been previously proposed for the applications where a large difference between the input and the output voltages is required. In the isolated version of the converter implementation, however, the leakage inductance of the high frequency isolation transformer presents an adverse effect and will cause significant voltage ringing o...

The advancement in semiconductor technology has provided a new alternative to the hundred year old conventional transformer technology by providing an elegant solution using Solid State Transformer (SST). The SST is applied semiconductor technology for changing the voltage ratio. The SST can achieve high power density as well as operation at high frequency, thus reducing the size and the cost. ...

This paper presents a new approach for classifying transient phenomena in power transformers, which may be implemented in digital relaying for transformer differential protection. Discrimination of various operating conditions of the power transformer is achieved by combining wavelet transform with Adaptive Neuro Fuzzy Inference system (ANFIS). The wavelet transform is applied for the analysis ...

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...

SoFT is a new method and tool which measures and models linear electrical network components in a wide frequency band with unprecedented accuracy. This is achieved by a special modal based measurement technique in combination with suitable rational fitting and passivity enforcement methods. The models are easily imported into most commonly used simulation software. This paper demonstrates the S...

Three-phase synchronous motors are widely used in the industrial motor driven systems. Variable frequency drives (VFDs) which allow soft-start of motors produce PWM voltage. Numerical relays are used in the protection schemes of these high voltage motors. The location of current transformer (CT) is an important criterion in the protection circuit. Impact of harmonics and the location of current...

In this paper we propose transformer-based solutions to several power quality problems. Elsewhere we have shown how to solve the acoustical noise emission problems. In this paper we introduce toroidal transformers with reduced inrush currents, transformers with reduced electromagnetic emissions, and other transformers useful to reduce the transfer of harmonics. With the low-inrush transformers ...

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...