Abstract: Transmission-line transformers are circuits useful for microwave impedance matching applications due to their broad operating bandwidth. Multimode feed network is composed of two substructures, which are constituted by the transmission-line transformer. Beginning with the broadband transmission-line transformer with 4:1 impedance transformation, supposing the currents on the two lines...

Power transformers are among the most important and expensive equipments in the electric power systems. Consequently the transformer protection is an essential part of the system protection. This paper presents a new method for locating transformer winding faults such as turn-to-turn, turn-to-core, turn-totransformer body, turn-to-earth, and high voltage winding to low voltage winding. In this ...

This paper provides a new approach for power flow and modeling analysis of three phase unbalanced radial distribution systems (URDS) using the simple forward/backward sweep-based algorithm. A three phase load flow solution is proposed considering voltage regulator and transformer with detailed load modeling, for the transformer modeling symmetrical components theory is used and zero sequence-vo...

The use of buck-derived topologies for unity power factor ac-to-dc applications is limited by their inherent inability to draw current from the line in those intervals, during the line half period, in which the input voltage is lower than the output one. This drawback is overcome in the proposed high-quality rectifier based on the forward topology with secondary-side resonant reset. The employe...

A pair of ion cyclotron range of frequencies (ICRF) antennas in the large helical device (LHD), HAS antennas showed high efficiency in minority ion heating. However the low loading resistance must be increased to prevent breakdown in transmission line. Moreover, the voltage and the current around the feed-through must be reduced to protect it. For these purpose, we developed a design procedure ...

Single phase voltage converter structure with isolation transformer for applications in traction vehicles is presented. This paper shows simulation model of this type of converter and transformer model with modern magnetic material in OrCAD-PSpice simulation program. Two PWM control techniques are compared in order to eliminate voltage and current oscillations in primary winding of the transfor...

This paper presents an artificial neural network (ANN) based scheme for fault identification in power transformer protection. The proposed scheme is featured by the application of ANN to identifying system patterns, the unique choice of harmonics of positive sequence differential currents as ANN inputs, the effective handling of current transformer (CT) saturation with an ANN based approach, an...

This paper presents an artificial neural network (ANN) approach to predicting and classifying distribution transformer specific iron losses, i.e., losses per weight unit. The ANN is trained to learn the relationship of several parameters affecting iron losses. For this reason, the ANN learning and testing sets are formed using actual industrial measurements, obtained from previous completed tra...

Two stochastic methods for locating global minimum and optimal design parameters of a rectifier power transformer, by Genetic Algorithm (GA) and Simulated Annealing (SA) are presented. A closed form expression for actual phase current waveform of the rectifier transformer is derived and a comparison is made with the approximate waveform normally considered for fixing the transformer rating. The...