Assessment of transformer winding mechanical condition by low-voltage impulse method

2004 ◽  
Author(s):  
A.A. Drohyshevski
Keyword(s):  
Low Voltage ◽  
Mechanical Condition ◽  
Impulse Method ◽  
Transformer Winding

scholarly journals Thermal optimization research of oil-immersed transformer winding based on the support machine response surface

2021 ◽  
pp. 264-264
Author(s):  
Fating Yuan ◽  
Wentao Yang ◽  
Bo Tang ◽  
Yue Wang ◽  
Fa Jiang ◽  
...  
Keyword(s):  
Response Surface ◽  
Low Voltage ◽  
Hot Spot ◽  
Optimization Method ◽  
Design Parameters ◽  
Support Vector ◽  
Structure Parameters ◽  
Transformer Winding ◽  
Polynomial Response Surface ◽  
Spot Temperature

In this paper, the CFD (computational fluid dynamics) model is established for the low voltage winding region of an oil-immersed transformer according to the design parameters, and the detailed temperature distribution within the region is obtained by numerical simulation. On this basis, the RSM (response surface methodology) is adopted to optimize the structure parameters with the purpose of minimizing the hot spot temperature. After a sequence of designed experiments, the second-order polynomial response surface and the SVM (support vector machine) response surface are established respectively. The analysis of their errors shows that the SVM response surface can be better used to fit the approximation. Finally, the PSO (particle swarm optimization) algorithm is employed to get the optimal structure parameters of the winding based on the SVM response surface. The results show that the optimization method can significantly reduce the hot spot temperature of the winding, which provides a guiding direction for the optimal design of the winding structure of transformers.

A Mathematical Model for Studying the Pulse Flaw Detection of High-Voltage Transformer Windings

2021 ◽  
pp. 50-57
Author(s):  
Alexey V. LAVRINOVICH ◽  
◽  
Alexey V. MYTNIKOV ◽  
Keyword(s):  
Mathematical Model ◽  
Frequency Spectrum ◽  
Low Voltage ◽  
Power Transformer ◽  
Flaw Detection ◽  
Pulse Frequency ◽  
Voltage Transformer ◽  
Nanosecond Pulses ◽  
Transformer Winding ◽  
A Chain

The article presents the results from elaborating a power transformer mathematical model for modeling the processes of diagnosing the mechanical state of windings using the method of low-voltage nanosecond pulses. The model includes a chain representation of the transformer windings taking into account the dependence of the resistance and reactance of the turns on the frequency spectrum of the pulse supplied from the probing generator. The study of the pulse flaw detection processes carried out on the developed mathematical model has shown that the probing pulse frequency spectrum plays an essential role in locating the transformer winding flaw, in determining the flaw type (displacement of turns, inward radial displacement, buckling). The response signals obtained from application of the simulated probing pulse coincide satisfactorily with the response signals obtained during experiments on the transformer physical model. The developed model opens the possibility of determining, by calculation, transformer winding flaw location and type based on comparing the results of experimental responses during examinations of transformers using the method of low-voltage nanosecond pulses with the simulation results.

scholarly journals Investigation on the Resonant Oscillations in an 11 kV Distribution Transformer under Standard and Chopped Lightning Impulse Overvoltages with Different Shield Placement Configurations

Energies ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1466 ◽  
Author(s):  
Murthy ◽  
Azis ◽  
Yousof ◽  
Jasni ◽  
Othman ◽  
...  
Keyword(s):  
Equivalent Circuit ◽  
High Voltage ◽  
Low Voltage ◽  
Stress Distributions ◽  
Voltage Distribution ◽  
Distribution Transformer ◽  
Resonant Oscillation ◽  
Initial Voltage ◽  
Transformer Winding ◽  
Lightning Impulse

This paper presents an investigation on the resonant oscillations of an 11 kV layer-type winding transformer under standard and chopped lightning impulse overvoltage conditions based on calculated parameters. The resistances, inductances and capacitances were calculated in order to develop the transformer winding equivalent circuit. The impulse overvoltages were applied to the high voltage (HV) winding and the resonant oscillations were simulated for each of the layers based on different electrostatic shield placement configurations. It is found that the placement of grounded shields between layer 13 and layer 14 results in the highest resonant oscillation and non-linear initial voltage distribution. The oscillation and linear stress distributions are at the lowest for shield placement between the HV and low voltage (LV) windings.

Modeling of frequency response of transformer winding with axial deformations

2014 ◽  
Vol 63 (1) ◽  
pp. 5-17 ◽  
Author(s):  
K.M. Gawrylczyk ◽  
S. Banaszak
Keyword(s):  
Frequency Response ◽  
Computer Modeling ◽  
Failure Modes ◽  
Response Analysis ◽  
Frequency Response Analysis ◽  
Mechanical Condition ◽  
Distributed Parameters ◽  
Transformer Winding ◽  
Tlm Method ◽  
Lumped Parameters

Abstract One of important methods used for diagnostics of a transformer’s active part is Frequency Response Analysis (FRA). It allows to determine the mechanical condition of windings, their displacements, deformations and electric faults, as well as some problems with internal leads and connections, core and bushings. Still pending problem is interpretation of measurements results. One of approaches is application of computer modeling to simulate various failure modes and connected with them changes in FRA response. The paper presents two types of models, one based on lumped parameters with RLC elements, and one based on distributed parameters with TLM method. Both methods give similar results, comparable to real measurements of simulated coil

scholarly journals Analysis of winding temperature field under dynamic variable load of oil-immersed transformer

2021 ◽  
Vol 25 (4 Part B) ◽  
pp. 3009-3019
Author(s):  
Dapeng Xu ◽  
Yu Mao ◽  
Xiaohui Yang ◽  
Chunxu Qin ◽  
Haikun Shang ◽  
...  
Keyword(s):  
Temperature Field ◽  
Power Systems ◽  
High Voltage ◽  
Low Voltage ◽  
Hot Spot ◽  
Variable Load ◽  
Insulation Material ◽  
Dynamic Variable ◽  
Calculation Results ◽  
Transformer Winding

The research on the temperature field of the transformer winding under dynamic variable load is of great significance for ensuring the safe operation of power systems. This paper takes an SSP-360000/500 transformer as the research object, establishes a 2-D simulation model, and uses the finite volume method to analyze the high voltage winding and low voltage winding temperature distribution of the transformer under dynamic variable load. The simulation calculation results have been fully verified by the experimental data to make the successful prediction of the overall temperature and hot spot temperature position of forced oil circulation transformers with a guided structure. The results show that the most significant temperature raise occurs at the secondary end of the winding. In the case of dynamic variable load. The temperature raise of the winding becomes larger as the load increases, but before the rated load is in the stable temperature rise range, it can run safely for a long time. However, during overload operation, the average temperature raise of the high voltage winding may exceed its limit, the insulation material is damaged.

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