Numerical model of the 10 kVA transformer with copper windings (original) (raw)

Experimental-simulation analysis for transformer single phase in resistive load condition

2009

Transformer is one of main components in electrical power system which role to increase or reduce voltage. Characteristics of transformer would be vital to ensure the voltage is fully transferred. This paper is presenting the study of transformer characteristics by using different approaches in experimental and simulation. This study focus on the output voltage, output current, the real power, the reactive power, the voltage regulations and efficiency resulting form different type of transformer in single phase system. Type of transformer been using in this experiment are the shell type, the toroidal type and the cut core type transformer in the resistive load condition. The analysed data are obtained from experiments as well as simulated model based on PSPICE Software. The result found that the shell type, the toroidal type and the cut-core transformer have produced 92%, 93% and 97% efficiency respectively in the resistive load condition.

Modeling and Analysis of Transformer

The transformers are an integral part of the power system. In transformers, the main consequence of harmonic currents is an increase in losses, mainly in windings, because of the deformation of the leakage fields. Higher losses mean that more heat is generated in the transformer so that the operating temperature increases, leading to deterioration of the insulation and a potential reduction in lifetime. Due to the non-linear loads, the transformers are much affected by the distorted currents and supply voltages which largely reduce its efficiency due to overheating. Nonlinear loads cause harmonics to flow in the power lines which can overload wiring and many desktops, personal computers present nonlinear loads to the AC supply because of their power supplies design (capacitor input power supply). In power transformers, the main consequence of harmonic currents is an increase in losses, mainly in windings, because of the deformation of the leakage fields. Higher losses mean that more heat is generated in the transformer so that the operating temperature increases, leading to deterioration of the insulation and a potential reduction in lifetime. As a result, it is necessary to reduce the maximum power load on the transformer, a practice referred to as de-rating, or to take extra care in the design of the transformer to reduce these losses. To estimate the de-rating of the transformer, the load's K Factor may be used. Thus analysing this problem and reducing the losses of the transformer has become a major area of research in today's scenario. This report includes the effects of non-sinusoidal supply voltage on the transformer excitation current and the core losses which includes eddy current and hysteresis losses. INTRODUCTION Events over the last several years have focused attention on certain types of loads on the electrical system that results in power quality problems for the user and utility alike. Equipment which has become common place in most facilities including computer power supplies, solid state lighting ballasts, adjustable speed drives (ASDs), and uninterruptible power supplies (UPSs) are examples of non-linear loads. It is forecast that before the end of the century, half of all electrical devices will operate with a nonlinear current draw. These nonlinear loads are the cause of current harmonics. Non-linear loads are loads in which the current waveform does not have a linear relationship with the voltage waveform. Non-linear loads generate voltage and current harmonics which can have adverse effects on equipment that are used to deliver electrical energy such as transformers, feeders, circuit breakers, which are subjected to higher heating losses due to harmonic currents consumed by non-linear loads. The discontinuous, Harmonic currents cause overheating of electrical distribution system wiring, transformer overheating and shortened transformer service life. Electrical fires resulting from distribution system wiring and transformer overheating were rare occurrences until harmonic currents became a problem. Transformers which provide power into an industrial environment are subject to higher heating losses due to harmonic generating sources (non-linear loads) to which they are connected. The major source of harmonic currents is the switch mode power supply found in most desktop computers, terminals, data processors and other office equipment is a good example of a non-linear load. The switching action of the computer power supply results in distortion of the current waveform [2]. Harmonics are produced by the diode-capacitor input section of power supplies. The diode-capacitor section rectifies the AC input power into the DC voltage used by the internal circuits. The personal computer uses DC voltage internally to power the various circuits and boards that make up the computer. The circuit of the power supply only draws current from the AC line during the peaks of the voltage waveform, thereby charging a capacitor to the Peak of the line voltage. The DC equipment requirements are fed from this capacitor and, as a result, the current waveform becomes distorted. The increasing usage of non-linear loads on electrical power systems is causing greater concern for the possible loss of transformer life. So, Manufacturers of distribution transformers have developed a rating system called K Factor, a design which is capable of withstanding the effects of harmonic load currents. The amount of harmonics produced by a given load is represented by the term "K" factor. The larger the "K" factor, the more harmonics are present [3].

Simulation And Analytical Investigation Of Different Combination Of Single Phase Power Transformers

2017

In this paper, the equivalent circuit of the ideal single-phase power transformer with its appropriate voltage current measurement was presented. The calculated values of the voltages and currents of the different connections single phase normal transformer and the results of the simulation process are compared. As it can be seen, the calculated results are the same as the simulated results. This paper includes eight possible different transformer connections. Depending on the desired voltage level, step-down and step-up application transformer is considered. Modelling and analysis of a system consisting of an equivalent source, transformer (primary and secondary), and loads are performed to investigate the combinations. The obtained values are simulated in PSpice environment and then how the currents, voltages and phase angle are distributed between them is explained based on calculation.

A methodology for obtaining by measurements the transformer physical-circuital model parameters

Modeling a transformer usually requires all its construction data, which is very difficult to obtain for the units in operation; for new transformers manufacturers are not usually willing to provide this information. This paper presents a procedure to obtain the parameters of the transformer physical-circuital model based on data obtained from external measurements, without need for design data. This was done by using different tests, some routine tests like losses and other special tests such as frequency response or FRA. It is also presented the application of the procedure to obtain the model of a 15-KVA 13200 / 244 V single-phase transformer, and its use to simulate the frequency response.

Nonlinear Transformer Model for Circuit Simulation

A transformer model which consists of a nonlinear core with hysteresis and multiple windings is described as implemented in DSPICE, Daisy's proprietary version of the popular circuit simulator SPICE. The analytical formulation of the major and minor loops, and, the transition algorithm between hysteresis loops is described. The modeling of losses, and frequency and temperature dependence is also presented. and wire losses are modeled. Additional effects such as wire &in effect and temperature dependence are also included. ln the signal ac analysis the transformer is modeled as frequency dependent lossy mutual inductors. For both analyses, air gap and the related fringe field effect are modeled by extending the magnetic path length of the core appropriately. In the transformer model library [8] parasitic capacitances and leakage in-ductances are added to the core and windings of the trans

A Single-Phase Two-Winding Transformer Dynamic Model for Circuit Simulators

2015

Transformers are magnetic components widely used in switched-mode power electronics systems. The non-linear hysteresis behavior of the magnetic material and the high frequency effects in both core and windings have significant effects on system's efficiency, reliability and power losses. This behavior can be modeled using simple fast models or complex accurate models in order to predict and improve the transformer behavior before realization. This paper is summarized by proposing a non-linear dynamic model of transformers for use in circuit simulators. This model allows winding and core modeling including the material's accurate nonlinear dynamic hysteresis behavior. The magnetic component model is implemented in the circuit simulation software " Simplorer " using VHDL-AMS modeling language. It is validated for a medium-frequency nanocrystalline core transformer. Effects of frequency and waveform on computed efficiencies are discussed and validated thanks to experi...

Detailed modelling and simulation of single-phase transformers for research and educational purposes

Indonesian Journal of Electrical Engineering and Computer Science, 2021

COVID-19 pandemic, despite its devastating impact, accelerated the shift to e-learning in higher education. Particularly in the electrical machines courses, that often include laboratory experiments. However, no detailed models of transformers, developed in Simulink/MATLAB®, were reported in the literature. Hence, in this paper, a virtual laboratory consists of models of single-phase transformers was built for the first time. The proposed models are easy to use and modify, and allow all machines’ parameters to be altered for students to replicate easily to support and enhance the learning process of electrical machines courses. Consequently, the developed models are effective tools for educational and research purposes. Dynamic models of single-phase, two-winding, transformers and step-up and step-down auto-transformers were developed using Simulink/MATLAB®. Two different approaches for modelling were proposed, the block diagram representation and Simscape based models. The two mode...

Designing and Manufacturing a Single-Phase Transformer and Analyzing Its Performance

Journal of Energy Research and Reviews

Aims: This work aims to design a single-phase transformer for analyzing its performance based on some requirements. Study Design: At first, requirements are set, then the design was completed using AutoCAD, after that the designed machine was simulated in MATLAB Simulink, manufactured in real-time in the laboratory, tested experimentally, and then the equivalent circuit parameters were computed from the experimental data. Place and Duration of Study: The design, manufacturing, simulation, and performance testing were conducted in the electrical machine 1 laboratory of American International University-Bangladesh (AIUB). It took around four months to complete the whole task. Methodology: This work is a bit expensive and complicated process for students without any funds. So, a group was formed with eight students. The tasks were to design, simulate, implement, and test a single-phase transformer that would step down 220 V (ac) to 110 V (ac) having a 440 VA capacity, and core loss sh...

Simulation, design and fabrication of an efficient single phase transformer

2015 Power Generation System and Renewable Energy Technologies (PGSRET), 2015

Transformer is a vital component of electric power systems for transmission and distribution. Robust design for the efficiency enhancement is the main stress in the fabrication of a transformer. Efficiency of a practical transformer is limited by the losses which are accounted for the design and manufacturing imperfections. This paper deals with the simulation, design and fabrication of a 0.30 KVA, Single phase, Shell type, tapped transformer. Design and fabrication of this transformer has been made possible by the special calculations and design procedure. Simulation has been performed in MATLAB. Open circuit test and short-circuit tests have been performed to investigate the losses and efficiency of the designed transformer. Simulation results and experimental results have been compared which are closely matching.

Advanced modeling of solid state transformer

2018

The solid state transformer (SST) is seen as a proper replacement of the conventional iron-and-copper transformer in the future smart grid . The SST offers several benefits (e.g. enhanced power quality performance or reactive power control at both primary and secondary sides) that can be of paramount importance for the development of the smart grid . This research focuses on the development and implementation of an advanced model of a three stage bidirectional SST in Matlab/Simulink. The goal is to obtain an realistic SST model (i.e. as close to the real SST as possible) that could duplicate the performance of a real MV/LV SST. This considered design consists of three main stages: medium voltage (MV) stage, isolation stage, and low voltage (LV) stage. When the power flows from the MV side to the LV side, the input power-frequency ac voltage is converted into a MV dc voltage by the three-phase ac/dc converter, which in such case works as rectifier. The isolation stage, which includes...