scholarly journals STUDY AND SIMULATION OF PARTIAL DISCHARGE OF DIFFERENT INSULATORS

2018 ◽  
Vol 6 (12) ◽  
pp. 135-139
Author(s):  
Khushboo Patareya ◽  
Arun Pachori
Keyword(s):  
High Voltage ◽  
Partial Discharge ◽  
Partial Discharges ◽  
Insulating Material ◽  
Insulation Failure

In this paper, we are studying about partial discharge of insulator with various parameters simulated in MATLAB. There are many types of insulator available in markets which have some impurities. The partial discharges are occurred due to presence of air impurity or void in the insulating material. The insulation failure occurs in high voltage power equipment’s due to Partial discharges, which readily generates at void or rough conductor profiles of equipment’s.

scholarly journals STUDY AND PERFORMANCE OF PARTIAL DISCHARGE OF MODEL FOR DIFFERENT TYPE INSULATION MATERIALS WITH CAPACITANCE VALUE

2021 ◽  
Vol 8 (12) ◽  
pp. 323-327
Author(s):  
Neetu Baghelkar ◽  
Abhishek Dubey
Keyword(s):  
High Voltage ◽  
Transmission Lines ◽  
Partial Discharge ◽  
Electrical Equipment ◽  
Partial Discharges ◽  
Electrical System ◽  
Insulating Material ◽  
Different Types ◽  
And Performance ◽  
Short Time

The properties of the insulating material must be the best to avoid failure of electrical equipment. Partial discharges act as electrical sparks that occur within insulation and the high-voltage electrical system. The different types of voltage and current pulses are produced, which last for a very short time. Partial discharge is taking place in high voltage power equipment such as cables, transmission lines and transformers, etc.

scholarly journals Device for online monitoring of insulation faults in high-voltage switchgears

2021 ◽  
Vol 17 (2) ◽  
pp. 155014772199928
Author(s):  
Jiajia Song ◽  
Jinbo Zhang ◽  
Xinnan Fan
Keyword(s):  
Fourier Transform ◽  
High Voltage ◽  
Online Monitoring ◽  
Pulse Current ◽  
Partial Discharge ◽  
Current Method ◽  
Capacitive Sensor ◽  
Accurate Diagnosis ◽  
Partial Discharges ◽  
Urgent Problem

Partial discharges are the major cause of deterioration in the insulation characteristics of switchgears. Therefore, timely detection of partial discharge in switchgear and potential insulation faults is an urgent problem that needs to be addressed in the power supervision industry. In this study, a device was proposed for online monitoring of high-voltage switchgears based on pulse current method and ozone (O3) detection. The pulse current method obtains the PD signal by monitoring the phase holes on the switch indicator. Occurrence of a partial discharge in a certain phase leads to the production of a discharge pulse, which can be coupled out by a capacitive sensor. The current spectrum and the O3 produced by partial discharge were processed via fast Fourier transform for accurate diagnosis of the occurrence of partial discharge and its severity in switchgears. The proposed method allows for convenient acquisition of the partial discharge signal, simple installation of the device, and realization with inexpensive sensors.

scholarly journals Influence of Insulating Material Properties on Partial Discharges at DC Voltage

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4305
Author(s):  
Marek Florkowski
Keyword(s):  
Material Properties ◽  
Dielectric Material ◽  
Partial Discharge ◽  
Partial Discharges ◽  
Time Interval ◽  
Post Discharge ◽  
Insulating Material ◽  
Dc Voltage ◽  
The Impact

Understanding a partial discharge mechanism at direct current (DC) is an actual research topic that requires both modeling, simulations and measurements. This paper describes an influence of insulating material properties on partial discharges at DC voltage. Modifications of the traditional model reflecting the conditions of partial discharges (PD) inception and post discharge processes at DC voltage have been proposed. The aim was to show the partial discharge mechanisms and draw attention to the role of parameters of insulation materials adjacent to the cavity at DC voltage. The investigations were performed on two kinds of dielectric material used in power cables. Various combinations of specimens were designed to reveal the effect of the material resistivity on the PD activity. Key observations referred to the impact of the void adjacent material resistance on the partial discharge inception voltage threshold at DC voltage. The modified PD model was applied to analyze both inception and post discharge recovery stage. The role of dielectric properties of material adjacent to the void was investigated, highlighting its impact during static inception stage and in charging stage. Despite many simplifications introduced in the model, measurement results have confirmed the role of the dielectric material surrounding the void on partial discharge dynamics. The average time interval between PD pulses revealed a systematic relationship with respect to the applied voltage and specimen resistivity. This value can be considered in the future research for diagnostic indicator at DC voltage.

scholarly journals Experimental determination of partial discharges in a model of a digital instrument transformer by differential method

Vestnik IGEU ◽  
2019 ◽  
pp. 32-42
Author(s):  
A.V. Gusenkov ◽  
V.D. Lebedev ◽  
S.N. Litvinov ◽  
S.A. Slovesny ◽  
A.A. Yablokov
Keyword(s):  
Condition Monitoring ◽  
High Voltage ◽  
Partial Discharge ◽  
Essential Elements ◽  
Differential Method ◽  
Partial Discharges ◽  
Discharge Characteristics ◽  
Reliability Indicators ◽  
Instrument Transformer ◽  
Inductive Sensors

Power facilities are now implementing the concept of smart grid and its essential elements – high-voltage digital current and voltage transformers. However, the implementation of digital technologies is slowed down by the lack of operation experience and reliability indicators. One of the main causes of high-voltage equipment failures is insulation damage. The most informative parameters determined by insulation evaluation are partial discharge characteristics. There are rated values of these characteristics for rotating electrical machines and power transformers measured by external equipment. But the existing method of partial discharge analysis cannot be applied to digital current and voltage transformers as there are no criteria for tripping of the innovative equipment with comprehensive insulation. All this urges us to study the possibility to determine experimentally the characteristics of partial discharges in the insulation of digital current and voltage transformers by using embedded inductive sensors in order to develop a method for condition monitoring of digital current and voltage transformers and improving of their reliability. In this work, we have used a model of digital current and voltage transformers, a high-voltage test unit, a digital multi-input oscciloscope and inductive sensors. The experiment includes: detecting partial discharges in the model of digital current and voltage transformers by the external bridge connection, recording the voltage at which partial discharges occur in the simulated fault area, measuring the corresponding value of the apparent charge of the partial discharge, detecting partial discharges in the model of digital current and voltage transformers by a differential method with the help of embedded inductive sensors. The characteristics of partial discharges in the simulated fault area have been experimentally determined on a model of digital current and voltage transformers. The pulse voltage on the embedded inductive sensor corresponding to the apparent charge of 80 pC was equal to 600 mV at the test voltage of 2,7 kV. Embedded inductive sensors allow implementing the method of insulation condition monitoring for digital current and voltage transformers in accordance with the partial discharge characteristics both at the stages of production and operation extending the potential of the electronic (microprocessor) module and increasing the reliability of digital current and voltage transformers.

scholarly journals Measuring Setup for Investigation and Visualization of the Percolation Phenomenon in Non-Оrdered Models of Metal-Dielectric Nanocomposites

2020 ◽  
Vol 11 (3) ◽  
pp. 171-178 ◽  
Author(s):  
P. Okal
Keyword(s):  
High Voltage ◽  
Partial Discharge ◽  
Metallic Phase ◽  
Partial Discharges ◽  
Measuring System ◽  
Voltage Transformer ◽  
Initial Voltage ◽  
Measuring Probe ◽  
Test Models ◽  
In Series

The study uses the phenomenon of high voltage partial discharge to investigate the phenomenon of percolation and visualisation of the percolation channel. The phenomenon of partial discharges is very similar to the quantum tunneling phenomenon observed in metal-dielectric nanocomposites. In both cases the flow of alternating current occurs in the absence of direct contact between the metallic phase particles.A measuring stand was developed and constructed to test models of metal dielectric nanocomposites using high voltage partial discharge. The stand consists of a 110 kV high voltage transformer, a voltage regulator protecting the constant rate of high voltage rise, a measuring system consisting of a measuring probe, voltmeters and a computer. The communication between the measuring probe and the voltmeter was made in digital technology with the use of fiber optic technology, which allowed the meter to communicate with the computer without any errors and eliminated the interference caused by a strong electromagnetic field resulting from the use of high voltage.Systems modelling metal-dielectric composites were built, consisting of metallic elements in the form of disks, randomly distributed on the surface of the dielectric matrix. The number of disks was increased in series of 40 in each. The maximum number of disks was 1520. The dependence was determined of one of the important parameters characterising an partial discharge, i. e. the initial voltage, at which an electric current starts to flow between electrodes, on the concentration of the metallic phase. On the basis of these results, a percolation threshold was established for a matrix with a random distribution of metallic phase elements, the value of which is about 50 %. Films and pictures of partial discharges with visible percolation channels were taken with the camera with which the stand was equipped.

scholarly journals Electrostatic field theoretic approach to analyze the partial discharge phenomenon pertaining to insulation degradation

2018 ◽  
Vol 7 (2) ◽  
pp. 842
Author(s):  
Shubhankan Mukherjee ◽  
Adhir Baran Chattopadhyay ◽  
Sunil Thomas
Keyword(s):  
High Voltage ◽  
Electrostatic Field ◽  
Single Photon ◽  
Partial Discharge ◽  
Void Formation ◽  
Semiconductor Layer ◽  
Surface Discharge ◽  
Avalanche Breakdown ◽  
Theoretic Approach ◽  
Insulation Failure

This paper elucidates the application of electrostatic field theory to analyze partial discharge due to the void formation inside the insulating material. Formation of voids leads to accumulation of static charges leading to capacitance build-up. The most probable cause of insulation failure is due to the subjection of high voltage. Prolonged high voltage poses a threat and leads to insulation failure. Failures occur in the tip gap between the conductor and insulating material’s inner periphery. Probable causes of such failures are corona discharge, surface discharge and treeing, leading to formation of Lichtenberger figures in the material and cavity discharge. This paper presents a way of fabricating the inner lining of the insulator with a semiconductor layer obeying avalanche breakdown at breakdown voltage or voltages at which partial discharge is likely to occur. With the onset of high voltage which can cause a discharge, the semiconductor experiences avalanche breakdown giving out a single photon ejection by Geiger mode (principle). A superior prevention method of using Teflon for insulation instead of XLPE/PILC has been suggested and simulated using COMSOL. Detection using Avalanche photo-detector(LiDAR) may enable us to track the probable location of the occurrence of partial discharge and isolate the system.

scholarly journals Using the Method of Harmonic Distortion Analysis in Partial Discharge Assessment in Mineral Oil in a Non-Uniform Electric Field

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4830
Author(s):  
Alper Aydogan ◽  
Fatih Atalar ◽  
Aysel Ersoy Yilmaz ◽  
Pawel Rozga
Keyword(s):  
Electric Field ◽  
Leakage Current ◽  
High Voltage ◽  
Partial Discharge ◽  
Harmonic Distortion ◽  
Mineral Oil ◽  
Significant Rise ◽  
Partial Discharges ◽  
Uniform Electric Field ◽  
Different Diameters

In high-voltage equipment, it is vital to detect any failure in advance. To do this, a determination of the partial discharges occurring at different voltage types as well as at different electrode configurations is essential for observing the oil condition. In this study, an experimental setup consisting of a needle–semi-sphere electrode configuration immersed in mineral oil is prepared for laboratory experiment. In such a way, a non-uniform electric field is created and the leakage currents are monitored from the grounded electrode. A total of six different electrode configurations are analyzed during the tests by the use of hemispheres of different diameters as grounded electrodes and copper and steel pointed (medical) needle high-voltage electrodes. In the experiments, the partial discharges occurring at four different voltage levels between 5.4 and 10.8 kV are measured and recorded. The effect of the different electrode configurations and voltage levels on the harmonic distortion are noted and discussed. It is experimentally confirmed that it is possible to measure the leakage current caused by the partial discharges of the corona type in oil at the different metal points, creating high-voltage electrodes and different electric field distributions based on the proposed non-invasive measurement technique. The studies showed that there is a significant rise of even harmonic components in the leakage current during the increase in the partial discharge intensity with the 5th harmonic as dominant.

scholarly journals Partial Discharge Measurements in HV Rotating Machines in Dependence on Pressure of Coolant

10.14311/298 ◽  
2002 ◽  
Vol 42 (1) ◽  
Author(s):  
I. Kršňák ◽  
I. Kolcunová
Keyword(s):  
Theoretical Analysis ◽  
High Voltage ◽  
Partial Discharge ◽  
Partial Discharges ◽  
Rotating Machines ◽  
Theoretical Assumptions ◽  
Discharge Measurements

The influence of the pressure of the coolant used in high voltage rotating machines on partial discharges occurring in stator insulation is discussed in this paper. The first part deals with a theoretical analysis of the topic. The second part deals with the results obtained on a real generator in industrial conditions. Finally, theoretical assumptions and obtained results are compared.

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