An Adaptive High Resolution Measuring System for Charcaterizing Transformers Subjected to Broadband Excitation
01 Nov 2005-pp 1-5
TL;DR: In this article, the authors proposed an adaptive architecture that characterizes all these events in a unified manner, based on the PXI hardware with necessary software developed under LABVIEW environment.
Abstract: Several phenomena in transformers are best analyzed in the frequency domain when energized by broadband excitation. These include dielectric behavior to lightning impulse, winding deformation during transport and structural failure during short circuit tests. We propose an adaptive architecture that characterizes all these events in an unifying manner. The developed instrument is based on the PXI hardware with necessary software developed under LABVIEW environment. Experimental results using the developed instrument are reported to demonstrate its versatility.
Citations
More filters
TL;DR: In this paper, an objective formulation of the impulse analysis problem from a signal analysis viewpoint is proposed, where the winding response is quintessentially that of a deterministic network to a finite energy signal, with breakdown and partial discharge being inherently nonlinear events.
Abstract: We propose an objective formulation of the impulse analysis problem from a signal analysis viewpoint. The winding response is quintessentially that of a deterministic network to a finite energy signal, with breakdown and partial discharge being inherently nonlinear events. A significant improvement to the acquisition of waveforms is demonstrated by a virtual instrument approach. It retains the advantages of the time- and frequency-domain methods. The drawbacks of the transfer function method are highlighted and a new piecewise linear approach is proposed for analysis. Experiments on a discrete lumped parameter model of the winding are used to validate the PXI based instrument.
30 citations
Additional excerpts
...deformations during short-circuit tests [25]....
[...]
References
More filters
Book•
01 Jan 1988TL;DR: In this article, the authors present a design-oriented course for operational amplifiers and analog ICs, which includes additional problems, more in-depth coverage of negative feedback, more effective layout, updated technology (current feedback and folded-cascode amplifiers, and low-voltage amplifiers), and increased topical coverage (current-feedback amplifier, switching regulators and phase-locked loops).
Abstract: Franco's "Design with Operational Amplifiers and Analog Integrated Circuits, 3e" is intended for a design-oriented course in applications with operational amplifiers and analog ICs. It also serves as a comprehensive reference for practicing engineers.
This new edition includes enhanced pedagogy (additional problems, more in-depth coverage of negative feedback, more effective layout), updated technology (current-feedback and folded-cascode amplifiers, and low-voltage amplifiers), and increased topical coverage (current-feedback amplifiers, switching regulators and phase-locked loops).
Table of contents
1 Operational Amplifier Fundamentals
2 Circuits with Resistive Feedback
3 Active Filters: Part I
4 Active Filters: Part II
5 Static Op Amp Limitations
6 Dynamic Op Amp Limitations
7 Noise
8 Stability
9 Nonlinear Circuits
10 Signal Generators
11 Voltage References and Regulators
12 D-A and A-D Converters
13 Nonlinear Amplifiers and Phase-Locked Loops
696 citations
TL;DR: In this article, a transfer function method is presented as a tool to detect axial displacement and radial deformation of transformer windings using two test transformers and detailed mathematical models were developed for the test objects and a comparison was carried out between measured and calculated results.
Abstract: Short circuit currents or forces during transport can cause mechanical displacements of transformer windings. The transfer function method is presented as a tool to detect these displacements. In order to be able to evaluate the measurements, the correlation between the characteristics of transfer functions and possible damages must be known. Axial displacement and radial deformation of transformer windings have been studied in this research work using two test transformers. The primary winding of the first transformer for axial displacement has 31 double disk coils (1.3 MVA, 10 kV) and the secondary winding is a four layer winding. The second transformer for the study of radial deformation has 30 double disk coils (1.2 MVA, 10 kV) as primary winding and a one layer winding as secondary winding. The detailed mathematical models were developed for the test objects and a comparison was carried out between measured and calculated results. It is shown that this model can present the behavior of the transformer windings in the frequency domain in the case of sound and displaced conditions.
348 citations
TL;DR: In this article, the authors present a method for calculating terminal and internal impedance versus frequency for a lumped parameter model of a transformer, where the transformer's total frequency response can be accurately determined from this impedance data directly, i.e., the terminal resonance and anti-resonance and internal amplification factor characteristic can be calculated for a single or three-phase transformer model.
Abstract: This paper presents a method for calculating terminal and internal impedance versus frequency for a lumped parameter model of a transformer The transformer's total frequency response can be accurately determined from this impedance data directly, ie, the terminal resonance and anti-resonance and internal amplification factor characteristic can be calculated for a single or three-phase transformer model Since most equipment associated with power system operation can be accurately modeled with lumped parameter networks, this method also provides an accurate, straightforward method for determining the resonance characteristic of those systems An additional significance of this method is that the accuracy of the calculation is limited only by the user's ability to represent the equipment or system Heretofore, the accuracy of this calculation was limited by the simplifying assumptions required of the network model by each solution method This paper presents the definitions and mathematical theory underlying the method Two examples are presented in which comparisons are made between measured and calculated values for a helical air core coil and a 200 MVA single-phase autotransformer The agreement is excellent
149 citations
Book•
01 Jan 1999
TL;DR: This book discusses signals and Signal Processing, including AC/DC Signal Conversion, Analog Signal Switching, Multiplexing and Sampling, and more.
Abstract: Signals and Signal Processing. Voltage Amplification. Current-to-Voltage and Voltage-to-Current Conversion. Linear Analog Functions. AC/DC Signal Conversion. Other Nonlinear Analog Functions. Analog Signal Filtering. Analog Signal Switching, Multiplexing and Sampling. Error Analysis and Reduction. Interference and Its Reduction. Noise, Drift and Their Reduction. Appendices. Index.
145 citations
16 May 2005
TL;DR: In this article, a new method of testing and analyzing winding deformation online without untanking is presented, and a comparison of Fourier transform and Wigner-Ville distribution methods of analysis is carried out.
Abstract: Transformers are required to demonstrate the ability to withstand short circuit currents. Over currents due to short circuit can cause winding deformation. A new method of testing and analyzing winding deformation online without untanking is presented in this paper. A study of alternate excitations to detect winding deformation is made. A comparison of Fourier transform and Wigner-Ville distribution methods of analysis is carried out
9 citations