The document describes a new HVDC field probe developed by ABB to measure electric fields around HVDC equipment. It discusses the probe's design, which uses optical fibers and is less than 20mm in diameter to measure close to surfaces. The document also details calibration of the probe in a plane gap, measurements of fields around a HVDC bushing and cable termination, and findings that an RC model agrees with measurements at short times but deviations occur over longer times likely due to nonlinear conductivity effects. In conclusion, the probe provides robust field measurement data that helps design HVDC equipment and develop more accurate simulation models.
High voltage technology & insulation testingZeeshan Akhtar
About HV Transmission, distribution, Voltage level classification, Insulation testing.
Part 1
What is High Voltage?
Why Needed
Levels of Voltages
Application of High Voltage
Electrical Insulation and Dielectrics
Part 2
Design & Test Issues for High Voltage
Aircraft Electric Power System
Introduction to the importance of HV in electric actuator systems
Basic review of HV design
Discussion of test methods
Summary
Part 3
Voltage Testing & Partial Discharge Measurement For Power Cable Accessories
Introduction
Ac Test After Installation
Acrf Test System
Schematic Diagram Of Test System
Arallel Operation Mode Of Test System
Artial Discharge Methods & Principle.
Iscussion & Conclusion.
High voltage technology & insulation testingZeeshan Akhtar
About HV Transmission, distribution, Voltage level classification, Insulation testing.
Part 1
What is High Voltage?
Why Needed
Levels of Voltages
Application of High Voltage
Electrical Insulation and Dielectrics
Part 2
Design & Test Issues for High Voltage
Aircraft Electric Power System
Introduction to the importance of HV in electric actuator systems
Basic review of HV design
Discussion of test methods
Summary
Part 3
Voltage Testing & Partial Discharge Measurement For Power Cable Accessories
Introduction
Ac Test After Installation
Acrf Test System
Schematic Diagram Of Test System
Arallel Operation Mode Of Test System
Artial Discharge Methods & Principle.
Iscussion & Conclusion.
A transducer is a device which transforms a non-electricalphysical quantity (i.e. temperature, sound or light) into anelectrical signal (i.e. voltage, current, capacity…)
Generation of High D.C. Voltage (HVDC generation)RP6997
Generation of high dc voltage using different methods like half wave and full wave rectifier, voltage doubler circuits, voltage multiplier circuits, cockcroft-walton circuits and van de graaff generators.
Design, Planning and Layout of high voltage laboratory vishalgohel12195
Design, Planning and Layout of high voltage laboratory
Test equipment provided in high voltage lab
Activity and study in high voltage lab
Classification of high voltage lab
Clearance of high voltage Lab
Layout of high voltage lab
Safety
Shielding of the high voltage lab
NGS for Infectious Disease Diagnostics: An Opportunity for Growth Alira Health
Infectious diseases are a major public health concern causing over 3.5 million deaths worldwide. Diagnosing patients as quickly and effectively as possible is crucial for managing disease outbreaks. Next-generation sequencing (NGS) provides unique capabilities to understand the genetic profile of infectious disease patients that no other technology can match.
Whole-genome metagenomics allows clinicians to take a deeper dive into pathogens by generating big-data about their characteristics. This data can be rapidly analyzed using complex bioinformatics software algorithms to achieve clinical-grade diagnostic accuracy. In a healthcare system shifting towards personalized medicine, NGS can provide clinicians the tools that they need to prescribe individualized treatments to save patients who were previously untreatable. The result is improved quality of care, better treatment regimes, and cost-saving healthcare.
Step by Step, from Liquid Biopsy to a Genomic Biomarker: Liquid Biopsy Series...QIAGEN
Liquid biopsies enable us to monitor the evolution of genetic aberrations in primary tumors as they shed the tumor cells into the circulation. The limitation is the ability to detect these low frequency genetic aberrations in a consistent manner to understand short- and long-term implications and how this information will be used in the clinic. This slidedeck will cover the challenges and solutions associated with multiple steps as one starts with liquid biopsy and move towards finding a new biomarker.
A transducer is a device which transforms a non-electricalphysical quantity (i.e. temperature, sound or light) into anelectrical signal (i.e. voltage, current, capacity…)
Generation of High D.C. Voltage (HVDC generation)RP6997
Generation of high dc voltage using different methods like half wave and full wave rectifier, voltage doubler circuits, voltage multiplier circuits, cockcroft-walton circuits and van de graaff generators.
Design, Planning and Layout of high voltage laboratory vishalgohel12195
Design, Planning and Layout of high voltage laboratory
Test equipment provided in high voltage lab
Activity and study in high voltage lab
Classification of high voltage lab
Clearance of high voltage Lab
Layout of high voltage lab
Safety
Shielding of the high voltage lab
NGS for Infectious Disease Diagnostics: An Opportunity for Growth Alira Health
Infectious diseases are a major public health concern causing over 3.5 million deaths worldwide. Diagnosing patients as quickly and effectively as possible is crucial for managing disease outbreaks. Next-generation sequencing (NGS) provides unique capabilities to understand the genetic profile of infectious disease patients that no other technology can match.
Whole-genome metagenomics allows clinicians to take a deeper dive into pathogens by generating big-data about their characteristics. This data can be rapidly analyzed using complex bioinformatics software algorithms to achieve clinical-grade diagnostic accuracy. In a healthcare system shifting towards personalized medicine, NGS can provide clinicians the tools that they need to prescribe individualized treatments to save patients who were previously untreatable. The result is improved quality of care, better treatment regimes, and cost-saving healthcare.
Step by Step, from Liquid Biopsy to a Genomic Biomarker: Liquid Biopsy Series...QIAGEN
Liquid biopsies enable us to monitor the evolution of genetic aberrations in primary tumors as they shed the tumor cells into the circulation. The limitation is the ability to detect these low frequency genetic aberrations in a consistent manner to understand short- and long-term implications and how this information will be used in the clinic. This slidedeck will cover the challenges and solutions associated with multiple steps as one starts with liquid biopsy and move towards finding a new biomarker.
Dr Scott Hollier and Associate Professor Denise Wood present at Web For All 2013 on the Professional Certificate in Web Accessibility and how the course is enabling the Australian Government to comply with WCAG 2.0.
Digital RNAseq Technology Introduction: Digital RNAseq Webinar Part 1QIAGEN
QIAseq RNA is a revolutionary turnkey solution for digital gene expression analysis by NGS. From 10 genes to 1000, from one sample to 100, QIAseq RNA delivers precise results on both ION and Illumina sequencing platforms. The data from QIAseq RNA is directly comparable to expression analysis derived from whole transcriptome sequencing or by qRTPCR, only better, cheaper, faster, and more flexible. This webinar will describe the principles of digital expression analysis by NGS, and review the features and benefits of the QIAseq system, options available, and the integrated data analysis package.
Avec Windows 7 et Windows Server 2008 R2 les Services de Bureau Distant (Remote Desktop Services) proposent une infrastructure de publication améliorée pour fournir des applications distantes directement dans le menu Démarrer ou le bureau de l'utilisateur, ou encore au travers d'un portail Web mais aussi, des postes de travail virtualisés (VDI). Cette session traitera en détail des aspects : scenarii d’usage, architecture, optimisation avec la virtualisation, nouveautés du SP1 et conception clés d'une telle infrastructure.
http://howpk.com/download-education-recruitment-application-form/
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The following slides are a very brief excerpt of a 60 minute keynote I’m giving at Eurosonic Noorderslag, Europe’s most important live music industry conference
The ppt is a short description about how to ascertain the validity, ie; sensitivity and specificity of a screening test as well as their predictive powers. you can also find the technique to ascertain the best possible screening test through the help of an ROC curve...
The presentation is intended for Clinical Trial programmers or statisticians who are working on the solid tumor studies in oncology. There are three types of studies in oncology: Solid Tumor, Lymphoma and Leukemia. The solid tumor study usually follow RECIST (Response Evaluation Criteria in Solid Tumor) while Lymphoma follows Cheson and Leukemia follows study-specific criteria. The presentation will provide the brief introduction of RECIST 1.1 such as lesions (target, non target and new) and their selection criteria (size, number and etc). It will also discuss how the changes in tumor measurements will lead to responses (Complete Response, Partial Response, Stable Disease, Progression Disease and Not Evaluable).
Then, the presentation will introduce how RECIST 1.1 data are streamlined in CDISC – mainly in SDTM and ADaM. The presentation will introduce the new oncology SDTM domains - TU (Tumor Identification), TR (Tumor Results) and RS (Response) according to RECIST 1.1. The presentation will also show how ADaM datasets can be created for the tumor response evaluation and analysis in ORR (Objective Response Rate), PFS (Progression Free Survival) and TTP (Time to Progression).
This Lecture includes the Resistivity survey, field procedure, application advantage, limitaion, Apparant resistivity, VES (Vertical Electrical Sounding), Resistivity Profiling and IP Survey in brief.
Microelectronic technology
This report briefly discusses the need for Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs), their structure and principle of operation. Then it details the fabrication and characterization of the MOSFETs fabricated at the microelectronic lab at University of Malaya
shows the simulation and analysis of a MOSFET device using the MOSFet tool. Several powerful analytic features of this tool are demonstrated, including the following:
calculation of Id-Vg curves
potential contour plots along the device at equilibrium and at the final applied bias
electron density contour plots along the device at equilibrium and at the final applied bias
spatial doping profile along the device
1D spatial potential profile along the device
Assessment of Electric Field Distribution Inside 500/220 kV Open Distribution...IJAPEJOURNAL
The high level electric field intensity produced by high voltage (HV) equipments inside 500/220 kV substations is harmful for the human (staff) health. Therefore the minimum health and safety requirements regarding the exposure of workers to the risk arising from electric fields produced inside these substations is still considered as a competitive topic for utility designers, world health organization (WHO) and biomedical field researchers. It is very important to have knowledge about levels distribution of electric field intensity within these high voltage substations as early stage in the process of substation design. This paper presents results of investigation 50Hz electric field intensity distribution inside 500/220 kV power transmission substations in Cairo, Egypt. This paper presents a method for assessment the distribution of 50HZ electric field intensity distribution inside this substation, this method of analysis is based on the charge simulation technique (CSM). This study will serve for planning service works or for inspection of equipment on HV power transmission substations.
DISTRIBUTION OF ELECTRIC FIELD ANALYSIS IN 36 KV ROOF TOP BUSHING BY USING FE...Journal For Research
The electric field distribution in medium voltage roof top bushing is principally dependent on the geometry dimension and types of the materials used. The main target is to achieve a bushing design which has a good field stress control. Various combinations of conductive, insulated and earthed parts, connected with the bushing have been treated in the development phase. In this paper, two-dimensional (2D) axial-symmetrical model geometries of roof top bushing have been developed using finite element analysis (FEA) method, which is ANSYS MAXWELL software. These models have been used to obtain the electric filed distribution in roof top bushing model. The effect of the bushing permittivity, electrical conductivity, the width, length and the metallic interface on the electric field distribution in roof bushing structure were analysed. From this study, an understanding of electric field distribution in roof top bushing geometry may be attained, which may help in designing of medium voltage roof top bushing stress control. With the help of simulation result proposed the new design of roof top bushing and it is verified by different test.
Analysis Of 3C-Sic Double Implanted MOSFET With Gaussian Profile Doping In Th...IJRES Journal
The present work aims at the design of 3C-SiC Double Implanted Metal Oxide Semiconductor Field Effect Transistor (DIMOSFET) with Gaussian doping profile in drift region for high breakdown voltages. By varying the device height ‘h’, function constant m and peak concentration 𝑁0, analysis has been done for an optimum profile for high breakdown voltage. With Gaussian profile peak concentration 𝑁0 = 1016 𝑐𝑚−3 at drain end and m as 1.496 ×10−2cm, highest breakdown voltage of 6.84kV has been estimated with device height of 200μm.
Pandey S, White M. "Detection of dielectrophoretic driven passage of single cells through micro-apertures in a silicon nitride membrane".
Conf Proc IEEE Eng Med Biol Soc. 2004;2004:1956-9.
doi: 10.1109/IEMBS.2004.1403578. PMID: 17272098.
https://ieeexplore.ieee.org/document/1403578
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
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CW RADAR, FMCW RADAR, FMCW ALTIMETER, AND THEIR PARAMETERSveerababupersonal22
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Data file handling has been effectively used in the program.
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6th International Conference on Machine Learning & Applications (CMLA 2024)ClaraZara1
6th International Conference on Machine Learning & Applications (CMLA 2024) will provide an excellent international forum for sharing knowledge and results in theory, methodology and applications of on Machine Learning & Applications.
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Using recycled concrete aggregates (RCA) for pavements is crucial to achieving sustainability. Implementing RCA for new pavement can minimize carbon footprint, conserve natural resources, reduce harmful emissions, and lower life cycle costs. Compared to natural aggregate (NA), RCA pavement has fewer comprehensive studies and sustainability assessments.
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Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)
Measurements of high voltage dc
1. Measurements of High Voltage DC
Fields inAir
PRESENTED BY
ASWANTH M RAJEEV
ANANDAVISHNU S
2. CONTENT
INTRODUCTION
DC FIELD MEASUREMENT PROBES
NEW ABB PROBES
VERIFICATION OF PROBE IN A PLANE
CONCLUSION
3. INTRODUCTION
The global demand for electric power continues to increase in most
countries but in particular in non-OECD (Organization for Economic
Cooperation and Development) countries.
For various reasons, high voltage direct current (HVDC) is often the
preferred technology for transmission of electric power over long
distances.
One of many challenges in the development of equipment for 800-kV DC
is the proper design of the insulation on the air side.
The electric field distribution in the air surrounding the equipment is one
of the key questions for designers. For traditional AC designs, the electric
field distribution can be numerically computed from the geometry and
dielectric permittivity of the materials involved.
A HVDC field probe measurement system recently developed by ABB is
presented, with a description of its basic design and properties.
The main reason for ABB to develop a HVDC field probe is to be able to
measure the DC field around full-scale HVDC insulators.
4. Conduction inAir
Air is widely used as the natural insulation medium in the electrical
industry. Overhead lines, converter stations, live tank breakers, etc., all
rely on the insulating properties of air.
In air, electrical conduction happens mainly due to the drift of singly
charged ions in the electric field. Such ions are produced naturally in air
due to cosmic radiation and the radioactive decay of the gaseous elements
of the decay chain of long lived radioactive elements.
As shown in Figure 1, there is a critical value of the electric field above
which small increases in the field lead to a rapid increase in current.
For air at atmospheric pressure, the transition to the so-called corona
regime occurs for fields around 2.5 to 3 kV/mm. While coronas are known
to occur in the vicinity of high voltage equipment, especially overhead
lines, typical HVDC equipment is designed to operate below the corona
inception level.
5. Voltage-current characteristics in air
Current density j of an air gap as a function of the applied
DC field E.
In the Ohmic region, at low fields, the current density
increases linearly with the applied field, until a saturation
field Es is reached.
For fields between Es and the corona inception field Ec ,
the current density carried by the air remains constant.
Above the corona inception field, electron-impact
ionization of neutral air molecule becomes possible,
leading to a rapid increase in the current density when
increasing the field
6. Many approaches can be used to calculate the electric field
distribution around air-insulated HVDC apparatus. The
simplest one uses a so-called “RC model,” where air is
modeled simply using an ohmic conductivity and an electric
permittivity.
For a more accurate description of the field distribution, a full
simulation of the drift of ions in air is required.
7. DC Field Measurement Probe System
Basically two types of devices are described in the literature:
probes based on electro-optic sensors and probes with self-
contained electronics .
Probes of the electro-optical type use the linear electro-optic
Pockels effect. The main components are an optically active
crystal, for example lithium niobate (LiNbO3), together with a
polarizer and quarter-wave plate.
The second type of probe described in the literature is the
optically insulated cylindrical field mill . This type of probe is
generally smaller than the ones of the electro-optical types.
This has the advantage of being able to measure very close to
an object without disturbing the field.
8. The NewABB Probe
To be able to measure DC electric fields around HVDC insulators , ABB decided
to develop in house a new DC field probe.
A specification was established and different measurement principles evaluated. To
be able to measure close to the surface of an object under potential, the diameter of
the probe should be less than 20 mm and it should be corona free over the relevant
field range.
The detection level and resolution should be 0.01 kV/mm or better. To obtain high
quality results, the aim was to achieve a minimum accuracy of 5% at a field of 0.5
kV/mm.
Probe (26 mm long and 12 mm diameter) held in place by optical fiber to the left
and fiber loop and Kevlar thread to the right.
9. Large-Scale Probe Positioning System
To use the DC field probe for measurements around full-scale
HVDC insulators, a positioning system was developed. The
system consists of two 10-m-long glass-fiber-reinforced
epoxy masts fastened to supporting concrete foundations .
The positioning of the two carriages and tilting of the masts
are controlled by a motion controller located in a control
cubicle at the bottom of the masts.
Each carriage carries a dielectric box, containing a camera
and servo for rotation of the probe.The probe is connected
between the two dielectric boxes by a Kevlar line and an
optical fiber, the latter transmitting the signal from the
probe.
10. Schematic showing the large-scale probe positioning
system consisting of 10-m-long glass-fiber-reinforcedepoxy
masts (1 and 2), opticalfiber and Kevlar thread with attached
measurement probe in the center (3), and test object (4).
11. Verification of the Probe in a Plane Gap
1. Finite Element Model of the Probe
Two objectives must be met in a useful simulation of the probe.
First, the model should permit the evaluation of how the presence of
the probe affects the electric field around the probe, and second, it
should be possible to simulate the response of the probe for a given
electric field.
2. Proximity Effect
The FEM model of the probe can quantitatively explain this
observation. The analysis of the simulation shows that the
discrepancy is due to the distortion of the field created by the probe,
which acquires a position dependence when the probe is in the
vicinity of the plates.
13. Field MeasurementsAround a HVDC Wall
Bushing
The test setup comprised a HVDC wall bushing and a ground plane. The
ground plane was a vertical metallic disc at the end of the bushing to
simulate a wall.
The field distribution along different paths perpendicular to the bushing
surface were measured as well as the time for development from voltage
application. The measurements were performed at three different voltage
levels; 0.5U0, U0, and 1.5U0, where U0 represents the rated voltage for
the bushing.
The nonlinear effect has a significant influence on the field but only
locally around the bushing. At a distance of 1 m or more from the surface,
the increase in the field caused by the charging of the bushing is no longer
detectable.
14. Simulationresults indicate fieldstresses around the shed tips in the range
of 2 kV/mm, which couldbe enough to explainionizationof the air.
Another possibleexplanation of the observed nonlinearityis corona
from the ground potentialof the bushing, test setup, or at other points in
the test room.
15. Field MeasurementsAround a DC
Cable Termination
•Cross section of development downscaled prototype 525-kV DC cable
termination for field measurements and simulation studies.
• Green indicates the cable.
•The red arrow indicates where the semicon of the cable connects to the field
grading layer.
16. The termination basically consists of an outer hollow core composite tube
with silicone rubber sheds that is filled with SF6.
The cable semicon connects to the nonlinear field grading layer at 1,500
mm, and it extends all the way to the top of the termination, where it is in
electrical contact with the applied voltage. The top of the termination is
graded with a toroid.
Comparing the measurements with those simulated from an RC model,
good agreement is found for short times after voltage application, but
significant deviations are noted for longer times.
The field increases along the termination from the bottom to about 2,000
mm and then decreases slightly to 3,700 mm. Above 3,700 mm, the field
increases along the termination to the top.
At 1,500 mm, the cable semicon connects to the field grading layer that is
applied to the inside of the termination.
The nonlinear conductivity of the field grading layer likely contributes to a
more complex field distribution than may be explained by the RC model,
although a varying conductivity is applied in the model.
17. Conclusion
The DC field probe system described in this article
allows the measurement of the field surrounding full-
scale HVDC apparatus and has proven to give robust
and credible results.
The measurements have shown that the RC model
used in designing equipment gives reasonable results
as well as how large the discrepancies can be during
certain conditions.
In addition, this work has given valuable input to the
ongoing development of more advanced simulation
models for HVDC apparatus and provides the ability
to describe the nonlinear effects seen in the
measurements.