Design of a fast computer-based partial discharge diagnostic system

Partial discharges cause progressive deterioration of insulating materials working in high voltage conditions and may lead ultimately to insulator failure. Experimental findings indicate that deterioration increases with the number of discharges and is consequently proportional to the magnitude and frequency of the applied voltage. In order to obtain a better understanding of the mechanisms of deterioration produced by partial discharges, instrumentation capable of individual pulse resolution is required. A new computer-based partial discharge detection system was designed and constructed to conduct long duration tests on sample capacitors. This system is capable of recording large number of pulses without dead time and producing valuable information related to amplitude, polarity, and charge content of the discharges. The operation of the system is automatic and no human supervision is required during the testing stage. Ceramic capacitors were tested at high voltage in long duration tests. The obtained results indicated that the charge content of partial discharges shift towards high levels of charge as the level of deterioration in the capacitor increases

Advanced high frequency partial discharge measuring system

This report explains the Advanced Partial Discharge Measuring System in ASU's High Voltage Laboratory and presents some of the results obtained using the setup. While in operation an insulation is subjected to wide ranging temperature and voltage stresses. Hence, it is necessary to study the effect of temperature on the behavior of partial discharges in an insulation. The setup described in this report can be used to test samples at temperatures ranging from -50 C to 200 C. The aim of conducting the tests described herein is to be able to predict the behavior of an insulation under different operating conditions in addition to being able to predict the possibility of failure

Role of Laboratory Education in Power Engineering: Is the Virtual Laboratory Feasible? Part I

IEEE PES sponsors a panel session in the summer power meeting in Seattle on laboratory education in power engineering. Six short papers and one full paper summarize the opinions of the panelist. This paper contains the summary of four of the presentations. The objective of the panel is to discuss the role of laboratory education in power engineering at both the graduate and undergraduate level. The question is what type of laboratory course is needed? Power electronics, electric machines, system simulation, etc? the second objective is to assess the status and value of computer based virtual laboratories. This includes the presentation of experience with virtual laboratories and a list of available tools. The teaching of power system operation can be improved using a simulation laboratory. The available simulation tools and the assessment of their values will be an important topic of the panel. The last presentation gives opposing views, arguing for the traditional laboratory us

Pilot study of the multicentre DISCHARGE trial: image quality and protocol adherence results of computed tomography and invasive coronary angiography (vol 30, pg 1997, 2020)

The original version of this article, published on 16 December 2019, unfortunately contained two mistakes.Cardiovascular Aspects of Radiolog

Investigation of Fuel Cell System Performance and Operation: A Fuel Cell as a Practical Distributed Generator

Information about this Project For information about this project contact

Breakdown Voltage of Compressed Sulfur Hexafluoride (SF 6 ) at Very Low Frequency / Low Frequency (30 kHz)

ABSTRACT The U.S. Navy is interested in evaluating the dielectric performance of SF 6 at 30 kHz in order to develop optimal bushing designs and to ensure reliable operation for the Very Low Frequency/ Low Frequency (VLF/LF) transmitting stations. The breakdown experiments of compressed SF 6 at 30 kHz in the pressure range of 1-5 atm were conducted in both the uniform field (plane-plane gap) and the non-uniform field (rod-plane gap). To understand the impact of pressure on the breakdown voltage of SF 6 at VLF/LF, empirical models of the dielectric strength of SF 6 were derived based on the experimental data and regression analysis. The pressure correction factors that present the correlation between the breakdown voltage of SF 6 at VLF/LF and that of air at 50/60 Hz were calculated. These empirical models provide an effective way to use the extensively documented breakdown voltage data of air at 60 Hz to evaluate the dielectric performance of SF 6 for the design of VLF/LF high voltage equipment. In addition, several breakdown experiments and similar regression analysis of air at 30 kHz were conducted as well. A ratio of the breakdown voltage of SF 6 to that of air at VLF/LF was calculated, from which a significant difference between the uniform gap and the non-uniform gap was observed. All the models and values provide useful information to evaluate and predict the performance of the bushings in practice