Partial discharge diagnostic system for smart distribution networks using directionally calibrated induction sensors (original) (raw)
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Improved algorithm for online partial discharge location in cables
2011
Partial discharge diagnostics is the most widely used tool to assess the insulation condition of medium voltage cables which allows informed maintenance planning so that such ageing assets can be in service even after the designed life span. Basically PD diagnostics may be divided into three phases namely Detection, Location and Decision making. Pulses generated due to PD activity are fast varying pulses having pulse widths of the order of a few hundreds of nano seconds. High frequency current probes calibrated in apparent charge are used to detect these fast varying pulses. The discharge site needs to be located after detection to enable cable repair. Accuracy of the discharge site location reduces the cost and repair time. Conventional single ended PD location method is well suited for off-line PD location. Global positioning system (GPS) and pulse injection techniques have been used by other researchers to synchronize double sided PD detection systems. In the long term these meth...
Intelligent fault diagnosis for on-line condition monitoring in smart distribution networks
2012 IEEE International Conference on Condition Monitoring and Diagnosis, 2012
Partial discharge (PD) measurements can be regarded as an effective and reliable tool for on-line condition monitoring and asset management of high voltage (HV) apparatus. Recently, a novel application is observed in the monitoring of falling trees on covered-conductor (CC) overhead distribution lines. In this paper, Rogowski and Pearson coils are used as sensors to detect PDs for this specific application. These sensors are non-intrusive and superior to the conventional PD detecting methods. In the next stage of future developments, the wired sensor will be converted into a wireless one. The challenges faced while implementing future wireless technology are also described here. In future, the wireless sensors will be integrated into distribution management system (DMS) to detect and localize the falling trees. The proposed intelligent fault diagnosis system will improve the safety of CC lines and make them more attractive to utilities due to reduced maintenance costs and visual inspection work. In addition, the reliability of the distribution system will improve which is one of the significant characteristics of the future smart distribution networks.
A simple approach of partial discharge source location in high voltage cables
Transactions of the Institute of Measurement and Control, 2017
This article presents a new approach of partial discharges (PD) source location in power cables. The main advantage of this approach is the detection of the propagation direction of the PD. The method provides a pattern named by the authors PD+D, which, in contrast to the well–known phase-resolved partial discharge (PRPD) pattern, graphically shows the direction of PD propagation and uses the polarity of a sensor array on top of the magnitudes of the positive and negative parts of each PD pulse to detect the direction of propagation, is described in detail. The proposed technique is useful for the evaluation and diagnosis of power cables, since it can identify incipient faults. The attained results that demonstrate the value of this methodology and their scope and limitations are discussed.
Development of smart online partial discharge monitoring system for medium voltage power cable
International Journal of Power Electronics and Drive System (IJPEDS), 2019
This paper presents, the development of smart online partial discharge (PD) monitoring system for medium voltage (MV) underground power cable. PD monitoring is the highly efficient tool to monitor insulation degradation for high voltage (HV) equipment in order to avoid failures or breakdown. Selection of improved technology and performance of PD detection sensor, effective measurement technique and smart user friendly of graphical user interface (GUI) system are contributed towards the development of efficient monitoring system. This paper addresses three main aspects which are needed in completing the monitoring system. They are, the use of Rogowski coil (RC) as detection sensor, processing unit using Alterra board and integrated with GUI PD monitoring system for underground cable using LabVIEW. The monitoring system is compared to the conventional method with the PD signal used is measured from the real on-site measurement in order to analyse its performance. The analysis is performed in MATLAB and LabVIEW software's environment and the maximum peak of PD signal is enabled to view using GUI which complete with the location information of PD source. Furthermore, this paper has contributed to solve the problem in selection the simplified and practical approach for PD sensor and monitoring system. In the perspective of automated condition monitoring, this smart online PD monitoring system provides a complete solution towards latest industrial revolutions
ADVANCED SOLUTION FOR ON-SITE DIAGNOSIS OF MEDIUM VOLTAGE POWER CABLES NETWORK
The Medium Voltage (MV) cable network forms a large part of the distribution company's physical capital. The MV network has a huge influence on interruption which customers suffer, due to the defects in MV network. Defects are not only harm to customers, but also to the distribution network company workers. In the last four years in South Cairo Electricity Distribution Company (SCEDC) increasing in the rate of the failures in MV power cables numbers is observed. It is noticed that 47 % to 49 % of the recorded faults are caused by breakdown of joints and terminations of medium voltage cables. This paper describes the latest developments and the off-line PD measurements by using Very Low Frequency (VLF) as an energizing method according to IEEE. It is interesting in this paper to investigate the conventional method by 50 Hz AC voltages, VLF 0.1 Hz (Sinusoidal), VLF 0.1 Hz (rectangular) and DC waveform and compare the PD magnitudes of each source to others. Addition to use VLF-PD as diagnostic technique with the two previous detection methods simultaneously for MV XLPE single core cables and compare the measurement results of each other on-site.
Fault localization on power cables using time delay estimation of partial discharge signals
International Journal of Electrical and Computer Engineering (IJECE), 2023
Precise localization of partial discharge (PD) sources on power cables is vital to prevent power line failures that can lead to significant economic losses for electrical suppliers. This study proposes four methods to estimate the time delay of PD signals under electromagnetic interference, including white Gaussian noise (WGN) and discrete sinusoidal interference (DSI), using denoised PD signals with signal-to-noise ratios ranging from 10.6 to-7.02 dB. The maximum peak detection (MPD) and cross-correlation (CC) approaches, as well as two new techniques, interpolation cross-correlation (ICC) and envelope cross-correlation (ECC), are evaluated for their effectiveness in PD source localization. The researchers employ the time difference of arrival (TDoA) algorithm to compute PD location using the double-end PD location algorithm, where the PD location precision serves as an indicator of the accuracy of the time delay estimation methods. The study concludes that CC and ICC are the most suitable methods for estimating the time delay of PD signals in the PD location algorithm, as they exhibit the lowest error rates. These results suggest that CC and ICC can be used effectively for precise PD source localization under electromagnetic interference on power cables.
Energies, 2019
High impedance faults (HIFs) have been a major concern for protecting distribution systems and public safety hazards when involving downed conductors. The deployment of smarter grids brings new technologies for smart monitoring, automation, and protection of distribution networks. This paper presents a new method for a series of HIF detection and location in primary distribution feeders, using voltage unbalance measurements collected from smart meters (SMs) installed at low-voltage end-users. The methodology was tested in MATLAB and Simulink through steady-state simulations of a typical 13.8 kV distribution system, under load unbalance and different fault scenarios. Results show that the proposed method is robust and accurate for the detection of blown fuses and broken conductors, with or without ground faults, located either at the source or the load-side. The ease of implementation in SM design, formulation of parameters, and reliable simulation results show potential real-life applications.
Electric Power Systems Research, 2010
Service continuity is one of the major aspects in the definition of the quality of the electrical energy, for this reason the research in the field of faults diagnostic for distribution systems is spreading ever more. Moreover the increasing interest around modern distribution systems automation for management purposes gives faults diagnostics more tools to detect outages precisely and in short times. In this paper, the applicability of an efficient fault location and characterization methodology within a centralized monitoring system is discussed. The methodology, appropriate for any kind of fault, is based on the use of the analytical model of the network lines and uses the fundamental components rms values taken from the transient measures of line currents and voltages at the MV/LV substations. The fault location and identification algorithm, proposed by the authors and suitably restated, has been implemented on a microprocessor-based device that can be installed at each MV/LV substation. The speed and precision of the algorithm have been tested against the errors deriving from the fundamental extraction within the prescribed fault clearing times and against the inherent precision of the electronic device used for computation. The tests have been carried out using Matlab Simulink for simulating the faulted system.
A Comparison of Double-End Partial Discharge Localization Algorithms in Power Cables
Energies
The double-end partial discharge (PD) measurement method is the most common method for measuring and localizing PD sources in power cables. The sensitivity of the PD sensor, the processing speed of the data acquisition unit, and the method of the PD localization algorithm are the three main keys to ensuring the accuracy of the PD source localization on power cables. A new multi-end PD localization algorithm known as segmented correlation trimmed mean (SCTM) has recently demonstrated excellent accuracy in the localization of PD sources on power cables. The algorithm, however, is only applicable to multi-end PD measurement methods. In this paper, the mathematical equation of the SCTM algorithm is customized to match the double-end PD measurement method. A MATLAB simulation was conducted to assess the performance of the SCTM algorithm in the double-end PD measurement method. The maximum peak detection (MPD) algorithm, segmented correlation (SC), and SCTM algorithm were compared as PD l...