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The objective of this two-part paper is to provide clarity to physical concepts used in the field of transformer modeling, to dispel common misconceptions regarding numerical instabilities, and to present unified modeling techniques for low-frequency transients. This paper focuses on proper modeling of nonlinearities (magnetizing branches) since these components are critical to determine the low-frequency...
The inrush currents related to the connection of generator devices is a typical matter of concern in situation with long distribution lines or/and under low short circuit power values at the PCC. This situation is usual for offshore devices. In this case, it is analyzed the magnetization current of the hydro generator developed by Magallanes Renewables supposed to be installed at the EMEC tidal test...
Recently, an increasing concern has been raised about turn-to-turn faults (TTFs) in power transformers, because these faults can lead to severe transformer insulation failure and consequently, its outage. Generally, it is impossible to experimentally analyze the transformer behavior under such faults, since the implementation of those experiments may be substantially destructive. Therefore, computer-aided...
This paper describes a method to establish turn-to-turn fault model of transformer based on fault analysis expert system. This method can be an advanced application function to be merged into protective relay management system. This paper also establishes differential equations of multi-winding transformer. The turn-to-turn fault winding can be divided to two parts: normal winding and fault winding...
This paper deals with the diagnostics system of power transformers created as parametrical model by means of 3D Finite Element Analysis (FEA). This parametrical model and diagnostics system is used for power transformer 25 MVA and it can be used for all kind of transformers. The following important parameters are investigated from diagnostic point of view: equivalent circuit parameters and capacity...
Internal fault detection in transformers provides early warning of electrical failure and could prevent forced outages with the consequential costs. To detect and diagnose transformer internal faults it is required a model. This paper presents a methodology to model internal transformer faults. The short circuit model was developed on base of the behavior of the windings when this fault occurs. The...
Heat dissipation is always a problem in large power transformers. Increased market competency demands for accurate determination of the thermal profile across the transformer. This paper presents a thermal model to simulate the thermal behavior of the electrical utility transformers. The thermal model is arrived at using the principle of thermal electrical analogy and the fact that the losses in the...
This paper, which is an extended version of Referenced paper, presents a new transformer model displaying hysteresis using MATLABtrade Simulink environment. The proposed model displays a complete scheme for the simulation of three phase transformers. The new model is mainly based on transmission line model (TLM) of power system using lumped parameters. The developed model is particularly suitable...
A free SPICE version allowing general circuit simulation is used teaching power electronics. There is no lock on the circuit size, stabile and user friendly operation is experienced. A collection of transformer, converter and drive system models are implemented to investigate the usability of the programme in high power electronics.
This paper presents a novel method of modeling internal faults in a power transformer. The method leads to a model which is compatible with commercial phasor-based software packages. Consequently; it enables calculation of fault currents in any branch of the network due to a winding fault of a power transformer. These currents can be used for evaluation of protective relayspsila performance and can...
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