Partial discharge detection by using combined VHF and AE sensors in XLPE power cables (original) (raw)
Related papers
Development process and testing of partial discharge detection device on medium voltage XLPE cable
Indonesian Journal of Electrical Engineering and Computer Science
High voltage assets play a vital role in providing uninterrupted power to the consumers and any slight problems experienced by the assets may cause losses in millions of dollars to businesses. Therefore it is of utmost importance to monitor the health of high voltage assets. This research presents the development process of a Partial Discharge (PD) device that is able to detect PD acoustic waves for monitoring high voltage assets purposes. Medium voltage Cross-Linked Polyethylene (XLPE) cable was used which was introduced with spherical void defects at the joints of the cable that functioned to produce PD acoustic waves. Outcome of the development processes provides the finished design of the PD sensing device, known as Partial Discharge Detection (PDD) device. The functionality of the PDD device was also assessed through controlled experimentations, and they proved to be successful. Pure PD waveform captured by the ultrasonic sensor was similar when compared to a HFCT sensor’s pure...
Partial Discharges Classification Methods in XLPE Cable: A Review
IEEE Access
Partial discharge (PD) signal classification analysis on cross-linked polyethylene (XLPE) cables is complex, requiring a comprehensive understanding of the characteristics of PD patterns. In the realm of high-voltage electrical insulation, PD pattern characteristics, such as PD charge and inception voltage, are essential as assessment criteria in diagnostics systems using PD classifiers. This paper provides a review of various PD patterns and classifiers used by previous researchers, specifically for XLPE cables. In addition, the differences of the research on various sensor development based on PD detection in the past 27 years are also discussed. The repeatability, recognition accuracy, recognition speed, and effect of feature sizes on each PD classification method are reviewed and explained. The review indicates that the pattern recognition for PD signal using artificial neural network (ANN) exhibits better performance in terms of accuracy and repeatability than the other methods, and the reduction of feature size does not affect the accuracy of ANN. INDEX TERMS Partial discharge (PD), cross-linked polyethylene (XLPE) cable, solid insulator, pattern recognition, feature extraction, artificial neural network (ANN)
European Transactions on Electrical Power, 2007
Based on experimental investigations a theoretical model of a sensor f o r partial discharge (P D) detection on high-voltage cross-linked polyethylene (XLPE)-insulated cables respectively joints has been developed. The model handles radial symmetric sensors and is based on the Finite-Difference Time-Domain (FDTD) method in which a cylindrical coordinate system is exploited. The calculation providesfield values at each node of the FDTD grid. The field pattern in the cable and sensor at different time steps is used to investigate the coupling mechanism of the sensor. It is also used f o r parametric studies of the sensoc e. g. the dependence of the sensitivity on geometrical characteristics of the senso< which is investigated theoretically as well as experimentally. Results of computer simulation are in a good agreement with experimental data derived f o r such sensors.
On-line Partial Discharge Detection in Cables - 1997
This paper describes a11 on-line partial discharge (PD) detection technique in power cables. The technique uses a digital spectrum anal?/zer with a high-frequency preampl(fier and several types of highfrequency inductive sensors. In extruded and inipregnated power cables, the PD detection IS nrade in the VHF range. The suitability and the sensitivity of the VfIF technique were checked agoinst two other conventionnl PD detecting methods (Pulse Phase Annlyzer and Fast Digital Scope) by performing PD n~ea.surenrents i n EPR-insulated cable under laboratory-coiitrollerl concli tioiis. The sui to b i li ty an cl semci tivi ty of the VHkmethod were as good CIS the two conventionnl PD de te cti 011 171 e th o CIS. The VHF method then wns u.secl to conduct on-.cite PD nrea.surenrent.s in se\)eral power cables. These nreasurements were conclucted while the cables were in .service. Special care wns given to distinguish between external electroningnetic noise and electronragnetic signals produced by the PD activities inside the cnhle insulation.
Investigation of PD detection on XLPE cables
The insulation lifetime of XLPE power cables is determined by several factors. One of the most important of these is the occurrence of partial discharge (PD) in the dielectric. The ability to detect and locate the PD sources is limited by attenuation and distortion of the high frequency PD pulses as they propagate through the cable. This paper presents the results of measurements of PD pulses that are generated by an artificial PD defect with capacitance-coupled sensors used for the detection of PD, rather than a high frequency current transformer (HFCT). The results show that the external capacitance sensors have a number of advantages, such as better sensitivity, for the detection of PD pulses. PD pulse waveforms were evaluated by three different integral methods in order to estimate the best way to characterise the PD pulses. The PD pulse is severely attenuated and distorted with increasing length of the power cable and the frequency of the PD pulse and some means of characterising is necessary. Simulation results are compared with test measurement results and it has been found that the cable model developed and used was able to predict the measurement results accurately.
Partial Discharge Measurement and Monitoring on High Voltage XLPE Cables
To check production quality, partial discharge (PD) measurements are performed on underground cables or cable drums. PD impulses propagate through the cable and are reflected at the ends and on joints. By measuring the delay between the impulse which is directly coming into the PD instrument and the impulse which is reflected at the end, a location of the PD source can be done. Due to reflections, partial discharges generally occur as pulse groups, which can lead to superimposed oscillations of the PD filter which is required to determine the charge value as per IEC 60270. With a new approach of simultaneous measurement at different receiver frequencies the superposition effects can be eliminated. With PD monitoring the reliability and availability of the equipment will increase and the life time of the cable lines will be extended. Other important benefits of monitoring are higher safety for the personnel and reduced environmental risks. In the paper recommendations are given for t...
2013
The purpose of this paper is to investigate the effect of PD (partial discharge) activity within medium voltage XLPE (cross-linked polyethylene) cables. The effect of partial discharge was studied by means of a number of simulations. The simulations were based on the well-known three capacitor model for partial discharge. An equivalent circuit was derived for partial discharge due to a single void in the insulation material of a power cable. The results obtained from the simulations will form the basis of the design proses of a non-intrusive condition monitoring technique. The technique is based on the classification of discharge activity according to five levels of PD. Future work will include the improvement of the simulation model by investigating the high frequency model of a power cable as well as the statistical nature of PD activity. This will improve the accuracy of the simulation results when compared to actual measurements. The work discussed in this paper will be used to ...
Condition Monitoring of Medium Voltage Electrical Cables by Means of Partial Discharge Measurements
SAIEE Africa Research Journal, 2014
The purpose of this paper is to discuss condition monitoring (CM) of medium voltage electrical cables by means of partial discharge (PD) measurements. Electrical cables are exposed to a variety of operational and environmental stressors. The stressors will lead to the degradation of the cable's insulation material and ultimately to cable failure. The premature failure of cables can cause blackouts and will have a significant effect on the safety of such a network. It is therefore crucial to constantly monitor the condition of electrical cables. The first part of this paper is focussed on fundamental theory concepts regarding CM of electrical cables as well as PD. The derivation of mathematical models for the simulation of PD is also discussed. The simulation of discharge activity is due to a single void within the insulation material of medium voltage cross-linked polyethylene (XLPE) cables. The simulations were performed in the MATLAB ® Simulink ® environment, in order to investigate the effects of a variety of parameters on the characteristics of the PD signal. A nonintrusive CM technique was designed for the detection of PD activity within cables. The CM technique was used to measure and analyse practical PD data. Two MATLAB ® programs were designed to analyse the PD data in both the time-domain and frequency-domain.
Indonesian Journal of Electrical Engineering and Computer Science
A partial discharge described as anon-linear electrical break-down even that happened in a section of insulating area between two conduct which are at different potentials the damage of the insulating material, these conductors have a different insulating material potential of damage, under AC voltage discharge interval process. In this paper, we propose a Matlab /Simulation software. A detailed analysis of the partial discharge (PD) signal in the underground electric power conductor performed for monitoring, and investigation of numerous effects associated with the partial discharge event, such as heat ,phonic and electrical. Thus, to gain the important data of the insulating material status.
Challenges of partial discharge diagnostics of low-voltage cables
Journal of Electrostatics, 2013
Partial discharge measurement is one of the most important diagnostic methods to detect local faults in insulation systems. Detection of local faults in low-voltage cables would be attractive for condition assessment of power plant secondary cables. The construction of low-voltage cables is different from the medium and high voltage ones, preventing the direct application of the already developed models and methods. An analysis of partial discharge detection and evaluation methods for low-voltage cable diagnostics are given in this paper. Some laboratory measurement results are also presented and the identified issues are described in this paper.