scholarly journals Impact of Power Transformer Oil-Temperature on the Measurement Uncertainty of All-Acoustic Non-Iterative Partial Discharge Location

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1385
Author(s):  
Vladimir Polužanski ◽  
Nenad Kartalović ◽  
Boško Nikolić
Keyword(s):  
Measurement Uncertainty ◽  
Power Transformer ◽  
Partial Discharge ◽  
Transformer Oil ◽  
Power Transformers ◽  
Acoustic Sensors ◽  
Temperature Variations ◽  
Discharge Location ◽  
The Mean ◽  
And Control

In this paper, the influence of the variation in transformer oil temperature on the accuracy of the all-acoustic non-iterative method for partial discharge location in a power transformer is researched. The research can improve power transformers’ testing and monitoring, particularly given the large transformer oil temperature variations during real-time monitoring. The research is based on quantifying the contribution of oil temperature to the standard combined measurement uncertainty of the non-iterative algorithm by using analytical, statistical, and Monte Carlo methods. The contribution can be quantified and controlled. The contribution varied significantly with different mutual placements of partial discharge and acoustic sensors. The correlation between the contribution and the mean distance between partial discharge and acoustic sensors was observed. Based on these findings, the procedure to quantify and control the contribution in practice was proposed. The procedure considers the specificity of the method’s mathematical model (the assumption that the oil temperature is constant), the non-iterative algorithm’s nonlinearity, and the large variations in transformer oil temperature. Existing studies did not consider the significant effect of the oil temperature on the combined measurement uncertainty of partial discharge location influenced by those phenomena. The research is limited to partial discharge located in the transformer oil.

scholarly journals UHF Partial Discharge Location in Power Transformers via Solution of the Maxwell Equations in a Computational Environment

Sensors ◽  
2019 ◽  
Vol 19 (15) ◽  
pp. 3435 ◽  
Author(s):  
Luiz Nobrega ◽  
Edson Costa ◽  
Alexandre Serres ◽  
George Xavier ◽  
Marcus Aquino
Keyword(s):  
Electromagnetic Waves ◽  
Partial Discharge ◽  
Propagation Delay ◽  
Power Transformers ◽  
Computational Simulations ◽  
3D Space ◽  
Computational Environment ◽  
Three Phase ◽  
Discharge Location ◽  
Particle Swarm Optimisation Algorithm

This paper presents an algorithm for the localisation of partial discharge (PD) sources in power transformers based on the electromagnetic waves radiated by a PD pulse. The proposed algorithm is more accurate than existing methods, since it considers the effects of the reflection, refractions and diffractions undergone by the ultra-high frequency (UHF) signal within the equipment tank. The proposed method uses computational simulations of the electromagnetic waves generated by PD, and obtains the time delay of the signal between each point in the 3D space and the UHF sensors. The calculated signals can be compared with the signals measured in the field, so that the position of the PD source can be located based on the best correlation between the simulated propagation delay and the measured data. The equations used in the proposed method are defined as a 3D optimisation problem, so that the binary particle swarm optimisation algorithm can be used. To test and demonstrate the proposed algorithm, computational simulations were performed. The solutions were sufficient to identify not only the occurrence of defects, but also the winding and the region (top, centre or base) in which the defect occurred. In all cases, an accuracy of greater than 15 cm was obtained for the location, in a 180 MVA three-phase transformer.

FEM Simulation of PD Acoustic Signal Propagation in Transformers

2013 ◽  
Vol 448-453 ◽  
pp. 2278-2285
Author(s):  
Yue Dong ◽  
Yong Qian ◽  
Hai Feng Ye ◽  
Xiu Chen Jiang
Keyword(s):  
Power Transformer ◽  
Ultrasonic Method ◽  
Partial Discharge ◽  
Fem Simulation ◽  
Signal Amplitude ◽  
Signal Propagation ◽  
Ultrasonic Waves ◽  
Diagnostic Methods ◽  
Power Transformers ◽  
The Finite Element Method

In order to study propagation process of partial discharge ultrasonic signal in power transformer, the finite element method is used for simulation modeling and calculation. Ultrasonic waves can be activated by partial discharges (PD) in power transformers. The ultrasonic method is used for evaluating the insulation condition of power transformers by analyzing the partial discharge signals information which is detected by AE sensors. Compared with other diagnostic methods the AE method causes relatively low disturbance, and measuring apparatus is simple and easy to use. This technique is noninvasive and immune to electromagnetic noise. Simulate partial discharge sources of different positions respectively. Achieved results indicate that the space and time distributions of the acoustic pressure depend on the induction position. Furthermore, a greater pressure gradient is observed in domains with higher speed of sound while the signal amplitude decays when it moves away from the PD source.

Partial discharge location in power transformers using wideband RF detection

2006 ◽  
Vol 13 (6) ◽  
pp. 1193-1199 ◽  
Author(s):  
Zhiguo Tang ◽  
Chengrong Li ◽  
Xu Cheng ◽  
Wei Wang ◽  
Jinzhong Li ◽  
...  
Keyword(s):  
Partial Discharge ◽  
Power Transformers ◽  
Discharge Location

Otkrivanje i analiza signala parcijalnih pražnjenja u energetskom transformatoru UHF metodom

2020 ◽  
Vol 22 (1-2) ◽  
pp. 96-101
Author(s):  
Đorđe Dukanac ◽  
Keyword(s):  
Detailed Analysis ◽  
Background Noise ◽  
Power Transformer ◽  
Partial Discharge ◽  
Spectral Composition ◽  
Partial Discharges ◽  
Power Transformers ◽  
Discharge Source ◽  
Useful Components

This paper presents the practical detection of partial discharge signals using a UHF sensor mounted on a power transformer and then the detailed analysis of a signal is done. The first part of the paper describes possible partial discharge sources in power transformers, UHF method and UHF sensor. In the second part of the paper, received signal at UHF sensor is considered. In order to accurately determine the magnitude of the partial discharge signal, especially if the location of the partial discharge source is far from the location of the UHF sensor, it is necessary to separate the signal from the background noise. This is only possible at intervals between individual bursts of the observed partial discharges. The spectral composition of the received signal is considered and a method for separating the present noise from the useful components of the partial discharge signal is established. The presumable main cause of partial discharges is evaluated.

Influence of electrical and thermal ageing on the mineral insulating oil performance for power transformer applications

2020 ◽  
Vol 62 (4) ◽  
pp. 222-231
Author(s):  
C Ranga ◽  
A Kumar ◽  
R Chandel
Keyword(s):  
Power Transformer ◽  
Stress Test ◽  
Oxidation Stability ◽  
Chemical Properties ◽  
Mineral Oil ◽  
Thermal Ageing ◽  
Test Cell ◽  
Transformer Oil ◽  
Power Transformers ◽  
Solid Dielectrics

In the present work, a new electrothermal combined stress test cell has been designed and fabricated to conduct accelerated electrothermal ageing. The fabricated test cell includes all possible real working conditions of the transformers. The effects of accelerated electrothermal ageing on the performance of power transformers with thermally upgraded Kraft (TUK), Nomex-910 and Nomex-410 solid dielectrics in conjunction with mineral oil have been investigated. The accelerated electrothermal ageing has been performed for a temperature range of 100°C to 220°C, along with 10 kV electrical stress. Subsequently, several electrical, thermal, mechanical and chemical properties of transformer oil and different paper dielectrics have been determined. It has been observed from the diagnostic test results that Nomex impregnated mineral oil samples have better electrothermal performance as well as oxidation stability when compared to the thermally upgraded Kraft oil samples. Therefore, Nomex insulating materials in conjunction with mineral oil are suggested as alternative solid dielectrics for power transformers in order to achieve better oxidation stability, improved thermal performance for long service runs and reduced operating and maintenance costs. It is envisioned that the present experimental study will be very beneficial to utility managers and end-users of power transformers.

Fiber Bragg Grating Hydrogen Sensor Applied for Partial Discharge Detection in Transformer Oil

2015 ◽  
Vol 738-739 ◽  
pp. 11-14 ◽  
Author(s):  
Ying Ting Luo ◽  
Hong Bin Wang ◽  
Wen Jun Zhu ◽  
Zhen Wu ◽  
Hong Tu Song ◽  
...  
Keyword(s):  
Light Intensity ◽  
Optical Fiber ◽  
Fiber Bragg Grating ◽  
Hydrogen Generation ◽  
Power Transformer ◽  
Partial Discharge ◽  
Hydrogen Sensor ◽  
Gas Analysis ◽  
Transformer Oil ◽  
Bragg Grating

Most optical hydrogen sensors are based on light intensity measurement and light intensity detection is vulnerable to the light source output and the optical fiber arrangement. To overcome the shortcomings, an optical fiber based sensor based on fiber Bragg grating (FBG) technique which is capable to measure the concentration of hydrogen dissolved is described in this paper. To examine the availability of monitoring initial hydrogen generation, a needle-to-plate partial discharge (PD) model was setup in the lab. The results between wavelength shifts of optical hydrogen sensor well agreed with conventional dissolved gas analysis (DGA), proving a potential utilization in the detection of dissolved hydrogen in power transformer.

Partial discharge location in power transformer windings using the wavelet Laplace function

2014 ◽  
Vol 111 ◽  
pp. 71-77 ◽  
Author(s):  
Daniel Guillen ◽  
Gina Idarraga-Ospina ◽  
Enrique Mombello
Keyword(s):  
Power Transformer ◽  
Partial Discharge ◽  
Discharge Location
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