Selected Papers from 2020 IEEE International Conference on High Voltage Engineering (ICHVE 2020)

The 2020 IEEE International Conference on High Voltage Engineering (ICHVE 2020) was held on 6–10 September 2020 in Beijing, China. The conference was organized by the Tsinghua University, China, and endorsed by the IEEE Dielectrics and Electrical Insulation Society. This conference has attracted a great deal of attention from researchers around the world in the field of high voltage engineering. The forum offered the opportunity to present the latest developments and different emerging challenges in high voltage engineering, including the topics of ultra-high voltage, smart grids, and insulating materials

Effect of water on electrical properties of Refined, Bleached, and Deodorized Palm Oil (RBDPO) as electrical insulating material

This paper describes the properties of refined, bleached, deodorized palm oil (RBDPO) as having the potential to be used as insulating liquid. There are several important properties such as electrical breakdown, dielectric dissipation factor, specific gravity, flash point, viscosity and pour point of RBDPO that was measured and compared to commercial mineral oil which is largely in current use as insulating liquid in power transformers. Experimental results of the electrical properties revealed that the average breakdown voltage of the RBDPO sample, without the addition of water at room temperature, is 13.368 kV. The result also revealed that due to effect of water, the breakdown voltage is lower than that of commercial mineral oil (Hyrax). However, the flash point and the pour point of RBDPO is very high compared to mineral oil thus giving it advantageous possibility to be used safely as insulating liquid. The results showed that RBDPO is greatly influenced by water, causing the breakdown voltage to decrease and the dissipation factor to increase; this is attributable to the high amounts of dissolved water

Outdoor Insulation and Gas Insulated Switchgears

This book focuses on theoretical and practical developments in the performance of high-voltage transmission line against atmospheric pollution and icing. Modifications using suitable fillers are also pinpointed to improve silicone rubber insulation materials. Very fast transient overvoltage (VFTO) mitigation techniques, along with some suggestions for reliable partial discharge measurements under DC voltage stresses inside gas-insulated switchgears, are addressed. The application of an inductor-based filter for the protective performance of surge arresters against indirect lightning strikes is also discussed

Noise reduction and source recognition of partial discharge signals in gas-insulated substation

Ph.DDOCTOR OF PHILOSOPH

Life assessment and life extension of high voltage equipment in transmission substations.

Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2004.In order to sustain transmission grid availability and reliability it is imperative that the condition of vital and costly high voltage equipment is ascertained on a continuous or regular basis. It is necessary to establish the effective diagnostic tools or surveillance devices that can be used to assess equipment condition. Emphasis has been placed on refining well-established and more novel but developing condition assessment techniques. It is important to note that condition assessment of equipment also allows the opportunity to predict failure. Based on a complete and systematic assessment, the failure of defective equipment may be evident or predicted in time, thus preventing a forced outage and loss of valuable 'system minutes'. It has also become necessary to extend the life of existing equipment since most of them are reaching the end of their useful life. Replacement strategies have proven to be ineffective due to financial and resource constraints experienced by utilities. Life extension is the work required to keep equipment operating economically beyond its anticipated life, with optimum availability, efficiency and safety. One of its principal components is condition assessment, with the possibility of predicting remnant life. As a result, refurbishment projects are then raised. Refurbishment by replacement, uprating, modifications or change of design of certain key components to extend the life usually requires a substantial amount of capital to be invested. These projects must be economically justified. This thesis focuses on establishing condition assessment techniques for major power equipment such as power transformers. Assessment techniques for instrument transformers and circuit breakers are included, since these are commonly replaced or modified under refurbishment projects. An experimental investigation was carried out to determine the effectiveness of integrating data of two diagnostic techniques i.e. dissolved gas analysis (on-line) and acoustic detection of partial discharges. It was found that there is a correlation between data obtained from an acoustic detection system and an on-line single gas (Hydrogen) analyser. By integrating the data of both on-line monitoring systems, the diagnostic process is further enhanced. In addition, the location of a fixed discharge source was verified by using an acoustic detection system. Further, the sensitivity of the acoustic technique to partial discharge inception voltage, relative to the established electrical detection technique was determined for the experimental arrangement used. The results obtained indicated that this is an effective technique for the evaluation of activity within a transformer structure

Partial Discharge Location Technique for Covered-Conductor Overhead Distribution Lines

In Finland, covered-conductor (CC) overhead lines are commonly used in medium voltage (MV) networks because the loads are widely distributed in the forested terrain. Such parts of the network are exposed to leaning trees which produce partial discharges (PDs) in CC lines. This thesis presents a technique to locate the PD source on CC overhead distribution line networks. The algorithm is developed and tested using a simulated study and experimental measurements. The Electromagnetic Transient Program-Alternative Transient Program (EMTP-ATP) is used to simulate and analyze a three-phase PD monitoring system, while MATLAB is used for post-processing of the high frequency signals which were measured. A Rogowski coil is used as the measuring sensor. A multi-end correlation-based technique for PD location is implemented using the theory of maximum correlation factor in order to find the time difference of arrival (TDOA) between signal arrivals at three synchronized measuring points. The three stages of signal analysis used are: 1) denoising  by applying discrete wavelet transform (DWT); 2) extracting the PD features using the absolute or windowed standard deviation (STD) and; 3) locating the PD point. The advantage of this technique is the ability to locate the PD source without the need to know the first arrival time and the propagation velocity of the signals. In addition, the faulty section of the CC line between three measuring points can also be identified based on the degrees of correlation. An experimental analysis is performed to evaluate the PD measurement system performance for PD location on CC overhead lines. The measuring set-up is arranged in a high voltage (HV) laboratory. A multi-end measuring method is chosen as a technique to locate the PD source point on the line. A power transformer 110/20 kV was used to energize the AC voltage up to 11.5 kV/phase (20 kV system). The tests were designed to cover different conditions such as offline and online measurements. The thesis evaluates the possibility of using a Rogowski coil for locating faults in MV distribution lines and a test bench of a 20 kV distribution network is developed. Different fault scenarios are simulated including earth and phase faults, arcing faults and faults caused by leaning trees. Results favourably show the possibility of using a Rogowski coil for locating faults in distribution networks.  

Aspects and directions of internal arc protectio

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