The document provides an overview of partial discharge (PD) measurement procedures using an online wave tracking system (OWTS). It discusses several key steps:
1. Ensuring a good measurement connection is critical to avoid noise and detect PDs. Proper earthing and shielding of cables is important.
2. Calibration determines the cable's propagation velocity for PD localization and can identify joints. It is important for accurate results.
3. Measurement involves systematically increasing voltage from 0kV to 1.3U0 while recording PD inception (PDIV) and extinction (PDEV) voltages. Multiple readings are averaged.
4. The quick overview automatically maps PDs but manual evaluation is still needed to analyze concentrations and
The document discusses improving productivity through self-management. It introduces a time management matrix that categorizes tasks as important/not important and urgent/not urgent. Using this matrix, people can identify how they spend their time and prioritize important long-term goals over urgent but unimportant tasks. Becoming a self-manager involves identifying one's roles and goals, scheduling daily tasks, and adapting to focus on important priorities and maintain balance.
This document discusses time management techniques and principles. It defines time management and identifies key concepts like planning, prioritization and goal setting. It emphasizes the importance of having an effective time management process to improve productivity and lower stress. Some tips discussed include using time logs to analyze time usage, scheduling quality time without interruptions, and controlling documents, workspace and phone to minimize distractions.
The document discusses strategies for managing time effectively to reduce stress. It identifies common "time bandits" like social media and breaks that waste time. Effective time management techniques are presented, including prioritizing tasks, saying no to nonessential work, focusing on quality over quantity, using a 10-minute rule, and monitoring time usage. The importance of a healthy lifestyle to improve efficiency is also emphasized.
Ledyard High School Class of 1990 slideshow 2Chris Davis
This document summarizes a class reunion for the Ledyard High School Class of 1990. It includes photos from classmates' early years, high school years, and current lives. It also notes important events from 1990 and photos from graduation. The reunion photos capture classmates reconnecting and catching up on the lives and families they have built in the years since high school.
Explore:
The difference between “important” and “urgent”, and how to deal with each
The “time stealers” – what they are and how to avoid them
What is “quality time” and how you can create it
Dealing with the e-mail mountain – the 4 Ds
1) The document contains 4 engineering problems involving the calculation of stresses, forces, and deformations in mechanical structures under applied loads.
2) In problem 1, the normal stresses in the aluminum and brass layers of a composite bar are calculated.
3) Problem 2 determines the stresses in the steel core and aluminum shell of an assembly under compression, as well as the total deformation.
4) Problem 3 finds the change in length, stress, and distributed forces in three supporting rods with different cross-sectional areas.
5) The final problem calculates the reactions, stresses, and deflection at point C in a structure composed of steel and brass rods.
1. The document describes an Ethernet Cable Discharge Event (CDE) test and measurement system.
2. The system aims to simulate and analyze ESD events from charged Ethernet cables. It includes modules to charge different cable types and arrangements and control the discharge sequence.
3. Key features allow testing of various cable setups, controlling the status of each wire, monitoring discharge waveforms, and remote control integration. Calibration components and procedures are also described.
The document discusses improving productivity through self-management. It introduces a time management matrix that categorizes tasks as important/not important and urgent/not urgent. Using this matrix, people can identify how they spend their time and prioritize important long-term goals over urgent but unimportant tasks. Becoming a self-manager involves identifying one's roles and goals, scheduling daily tasks, and adapting to focus on important priorities and maintain balance.
This document discusses time management techniques and principles. It defines time management and identifies key concepts like planning, prioritization and goal setting. It emphasizes the importance of having an effective time management process to improve productivity and lower stress. Some tips discussed include using time logs to analyze time usage, scheduling quality time without interruptions, and controlling documents, workspace and phone to minimize distractions.
The document discusses strategies for managing time effectively to reduce stress. It identifies common "time bandits" like social media and breaks that waste time. Effective time management techniques are presented, including prioritizing tasks, saying no to nonessential work, focusing on quality over quantity, using a 10-minute rule, and monitoring time usage. The importance of a healthy lifestyle to improve efficiency is also emphasized.
Ledyard High School Class of 1990 slideshow 2Chris Davis
This document summarizes a class reunion for the Ledyard High School Class of 1990. It includes photos from classmates' early years, high school years, and current lives. It also notes important events from 1990 and photos from graduation. The reunion photos capture classmates reconnecting and catching up on the lives and families they have built in the years since high school.
Explore:
The difference between “important” and “urgent”, and how to deal with each
The “time stealers” – what they are and how to avoid them
What is “quality time” and how you can create it
Dealing with the e-mail mountain – the 4 Ds
1) The document contains 4 engineering problems involving the calculation of stresses, forces, and deformations in mechanical structures under applied loads.
2) In problem 1, the normal stresses in the aluminum and brass layers of a composite bar are calculated.
3) Problem 2 determines the stresses in the steel core and aluminum shell of an assembly under compression, as well as the total deformation.
4) Problem 3 finds the change in length, stress, and distributed forces in three supporting rods with different cross-sectional areas.
5) The final problem calculates the reactions, stresses, and deflection at point C in a structure composed of steel and brass rods.
1. The document describes an Ethernet Cable Discharge Event (CDE) test and measurement system.
2. The system aims to simulate and analyze ESD events from charged Ethernet cables. It includes modules to charge different cable types and arrangements and control the discharge sequence.
3. Key features allow testing of various cable setups, controlling the status of each wire, monitoring discharge waveforms, and remote control integration. Calibration components and procedures are also described.
A tester simulatively generates "High energy induced lightning noise" which induced to distribution lines or communication lines by ground potential fluctuation caused by lightning strikes.
Conforming to IEC 61000-4-5 Ed.3, IEC61000-4-12 Ed.3(RINGWAVE 100kHz)and ANSI IEEE62-45(2002) *
1. Electrical installation testing should only be done by qualified electricians using the proper equipment. Testing includes both dead testing of de-energized circuits and live testing of energized circuits.
2. Dead testing checks the insulation resistance and continuity of ring circuits and other circuits. Live testing checks polarity, earth loop impedance, prospective short circuit current, and RCD operation.
3. Specific tests include ring circuit loop tests, circuit loop tests, insulation resistance tests, polarity tests, earth loop impedance tests, and RCD tests. Proper procedures and acceptable readings are defined for each test.
Thorne & Derrick UK are official distributors of the SebaKMT range of LV-HV Cable Fault Location instruments including cable sheath testers and cable sheath fault prelocation and pinpointing units. SebaKMT are the leading manufacturer of measurement equipment for the diagnosis of cable networks and for cable fault location. Cable faults are the ''natural enemy'' of reliability. The innovative SebaKMT products make it possible to quickly localise low and high voltage cable faults without causing damage to fault-free parts of the cable.
1. The document discusses electrical safety topics such as protection devices, residual current devices (RCDs), maximum demand calculations, cable selection, voltage drop, fault loop impedance, and mains earthing neutral (MEN) connections.
2. It provides information on circuit breaker operation, RCD functioning, methods for calculating maximum demand and cable sizing, and guidelines for determining allowable fault loop impedance.
3. The document also outlines procedures for safely isolating circuits, and explains the purpose of MEN connections at the main switchboard to complete an electrical earthing system.
This document describes experiments conducted to measure high voltage alternating current (HVAC) and high voltage direct current (HVDC) using standard spheres. The experiments were conducted in the Department of Electrical Engineering at Dr. Subhash University. The document provides the circuit diagrams, equipment used, theory behind the measurements, procedures followed and tabular columns to record results for HVAC and HVDC measurements using standard sphere gaps.
The Fluke 1621 is a basic earth ground tester that features 3-pole Fall-of-Potential and 2-pole ground resistance testing methods. It has a convenient size, rugged holster, and large LCD display that make it suitable for use in various work environments. The tester offers simple operation and intuitive functionality for electrical contractors, utility engineers, and ground specialists to efficiently measure and record ground values.
This document provides an executive summary of a 400kV switchyard project in Mundra, India. It includes lists of typical switchyard drawings, quality work being done on the switchyard including earthing and bolting, testing equipment being used, applications of equipment like CTs and isolators, the SCADA system, transformer oil standards, inspection procedures, stringing of transmission lines, project issues, documentation, and project management and quality management functions. Quality control tools mentioned include control charts.
Pemesanan produk, hubungi PT Siwali Swantika melalui WhatsApp, Jakarta : 0811-1519-949 (chat only) | Surabaya : 0811-1519-948 (chat only). Kunjungi website kami di www.siwali.com, untuk detail informasi spesifikasi dan model alat.
The Easytest 20 kV is a compact and lightweight AC cable tester that provides reliable testing of cables after installation or repair. It can test cables up to 2 km in length at voltages up to 20 kV AC, avoiding the issues with polarisation that occur with DC testing. The Easytest has configurable test sequences and can store test results, making it useful for quality assurance after cable work.
Surge wave generators (SWG) are used with reflectometers for cable fault location. They generate surges that create arcs at faults, allowing transient waves to be recorded and fault distances to be determined. SWGs are available for voltages up to 3500kV and energies up to 3500J. They use switchable capacitors and surge stages to optimize energy for prelocation and pinpointing faults. A Digiphone receiver uses the difference in arrival time between electromagnetic and acoustic signals to precisely locate faults.
This document summarizes techniques for locating faults in underground power cables. It discusses using a microcontroller to determine the distance of a fault from the base station in kilometers by applying a low DC voltage through resistors representing the cable and detecting voltage drops. Tracer and terminal methods for fault location are described. Using fiber optic distributed temperature sensors and neural networks for fault identification are also summarized. The document provides block diagrams of the proposed underground cable fault distance system conveyed over GSM and its components including the power supply, microcontroller, rectifier, voltage regulator, and relay.
This document is an owner's manual for the DT830 Series 3 1/2 Digital Multimeter. It provides specifications for the multimeter's functions including DC voltage, AC voltage, DC current, resistance, temperature, transistor testing, diode testing, continuity testing, and battery testing. It also describes the multimeter's controls and display, safety information, and instructions for taking measurements and replacing batteries.
This document discusses voltage testing and partial discharge measurement techniques for power cable accessories. It provides:
1) An overview of the objective to compare cable testing best practices and determine cable defects using partial discharge methods.
2) A description of an ACRF test system used, including its components like an HV reactor, control unit, and voltage divider.
3) Details on partial discharge measurement methods like using high frequency current transformers and coupling capacitors to detect discharges in cables.
4) The conclusion that resonant testing between 20-300Hz along with partial discharge detection reduces risks from cable systems after installation by locating faults.
How to Use the DTX-MFM2 Fiber Modules to Test Installed Corning Multimode Pre...Fluke Networks
The Corning Pretium EDGE® Tap Module allows passive tapping into optical networks for monitoring purposes. The modules contain splitters that divide each optical signal into two
outputs, one for network link traffic and one for monitoring.
This document provides instructions for operating a digital clamp meter. It includes specifications for the meter such as its display, accuracy, measurement functions, and safety information. The key functions of the meter are described, including how to make current, voltage, resistance, diode, continuity, and non-contact voltage measurements. Battery replacement instructions and safety warnings are also provided.
Brugg Kabel AG uses silicone insulation for high voltage cable accessories up to 400kV. Routine partial discharge (PD) testing is done on prefabricated joints to ensure quality and detect defects. On-site PD measurements after installation can accurately detect PD above 5pC and localize faults. Directional coupler sensors allow sensitive PD detection and localization in unscreened environments. PD testing is important for ensuring reliability of joints and avoiding premature failures during operation.
This document provides steps for properly preparing coaxial cable and terminating connectors for use in CCTV systems. It discusses that transmission media such as cable, connectors and installation methods account for over 65% of failures in CCTV systems. The document then provides 10 detailed steps for stripping cable, attaching connectors, testing connections, and labeling cables to help ensure optimal video quality and troubleshooting. Key steps include properly stripping cable, flaring the braid, crimping the connector, checking resistance values during testing, and labeling both ends of cables.
This document provides specifications for an EPS2U 650W power supply model EP2A5651A-B. It includes details on the power supply's input/output electrical specifications, environmental requirements, safety certifications, and labeling. The power supply has an input voltage range of 90-264VAC and can provide up to 650W of continuous power on its regulated outputs of +3.3V, +5V, +12V, -12V and +5VSB. It meets various EMI and safety standards and is rated to operate from 0-50°C with 5-95% humidity.
Discover the latest insights on Data Driven Maintenance with our comprehensive webinar presentation. Learn about traditional maintenance challenges, the right approach to utilizing data, and the benefits of adopting a Data Driven Maintenance strategy. Explore real-world examples, industry best practices, and innovative solutions like FMECA and the D3M model. This presentation, led by expert Jules Oudmans, is essential for asset owners looking to optimize their maintenance processes and leverage digital technologies for improved efficiency and performance. Download now to stay ahead in the evolving maintenance landscape.
A tester simulatively generates "High energy induced lightning noise" which induced to distribution lines or communication lines by ground potential fluctuation caused by lightning strikes.
Conforming to IEC 61000-4-5 Ed.3, IEC61000-4-12 Ed.3(RINGWAVE 100kHz)and ANSI IEEE62-45(2002) *
1. Electrical installation testing should only be done by qualified electricians using the proper equipment. Testing includes both dead testing of de-energized circuits and live testing of energized circuits.
2. Dead testing checks the insulation resistance and continuity of ring circuits and other circuits. Live testing checks polarity, earth loop impedance, prospective short circuit current, and RCD operation.
3. Specific tests include ring circuit loop tests, circuit loop tests, insulation resistance tests, polarity tests, earth loop impedance tests, and RCD tests. Proper procedures and acceptable readings are defined for each test.
Thorne & Derrick UK are official distributors of the SebaKMT range of LV-HV Cable Fault Location instruments including cable sheath testers and cable sheath fault prelocation and pinpointing units. SebaKMT are the leading manufacturer of measurement equipment for the diagnosis of cable networks and for cable fault location. Cable faults are the ''natural enemy'' of reliability. The innovative SebaKMT products make it possible to quickly localise low and high voltage cable faults without causing damage to fault-free parts of the cable.
1. The document discusses electrical safety topics such as protection devices, residual current devices (RCDs), maximum demand calculations, cable selection, voltage drop, fault loop impedance, and mains earthing neutral (MEN) connections.
2. It provides information on circuit breaker operation, RCD functioning, methods for calculating maximum demand and cable sizing, and guidelines for determining allowable fault loop impedance.
3. The document also outlines procedures for safely isolating circuits, and explains the purpose of MEN connections at the main switchboard to complete an electrical earthing system.
This document describes experiments conducted to measure high voltage alternating current (HVAC) and high voltage direct current (HVDC) using standard spheres. The experiments were conducted in the Department of Electrical Engineering at Dr. Subhash University. The document provides the circuit diagrams, equipment used, theory behind the measurements, procedures followed and tabular columns to record results for HVAC and HVDC measurements using standard sphere gaps.
The Fluke 1621 is a basic earth ground tester that features 3-pole Fall-of-Potential and 2-pole ground resistance testing methods. It has a convenient size, rugged holster, and large LCD display that make it suitable for use in various work environments. The tester offers simple operation and intuitive functionality for electrical contractors, utility engineers, and ground specialists to efficiently measure and record ground values.
This document provides an executive summary of a 400kV switchyard project in Mundra, India. It includes lists of typical switchyard drawings, quality work being done on the switchyard including earthing and bolting, testing equipment being used, applications of equipment like CTs and isolators, the SCADA system, transformer oil standards, inspection procedures, stringing of transmission lines, project issues, documentation, and project management and quality management functions. Quality control tools mentioned include control charts.
Pemesanan produk, hubungi PT Siwali Swantika melalui WhatsApp, Jakarta : 0811-1519-949 (chat only) | Surabaya : 0811-1519-948 (chat only). Kunjungi website kami di www.siwali.com, untuk detail informasi spesifikasi dan model alat.
The Easytest 20 kV is a compact and lightweight AC cable tester that provides reliable testing of cables after installation or repair. It can test cables up to 2 km in length at voltages up to 20 kV AC, avoiding the issues with polarisation that occur with DC testing. The Easytest has configurable test sequences and can store test results, making it useful for quality assurance after cable work.
Surge wave generators (SWG) are used with reflectometers for cable fault location. They generate surges that create arcs at faults, allowing transient waves to be recorded and fault distances to be determined. SWGs are available for voltages up to 3500kV and energies up to 3500J. They use switchable capacitors and surge stages to optimize energy for prelocation and pinpointing faults. A Digiphone receiver uses the difference in arrival time between electromagnetic and acoustic signals to precisely locate faults.
This document summarizes techniques for locating faults in underground power cables. It discusses using a microcontroller to determine the distance of a fault from the base station in kilometers by applying a low DC voltage through resistors representing the cable and detecting voltage drops. Tracer and terminal methods for fault location are described. Using fiber optic distributed temperature sensors and neural networks for fault identification are also summarized. The document provides block diagrams of the proposed underground cable fault distance system conveyed over GSM and its components including the power supply, microcontroller, rectifier, voltage regulator, and relay.
This document is an owner's manual for the DT830 Series 3 1/2 Digital Multimeter. It provides specifications for the multimeter's functions including DC voltage, AC voltage, DC current, resistance, temperature, transistor testing, diode testing, continuity testing, and battery testing. It also describes the multimeter's controls and display, safety information, and instructions for taking measurements and replacing batteries.
This document discusses voltage testing and partial discharge measurement techniques for power cable accessories. It provides:
1) An overview of the objective to compare cable testing best practices and determine cable defects using partial discharge methods.
2) A description of an ACRF test system used, including its components like an HV reactor, control unit, and voltage divider.
3) Details on partial discharge measurement methods like using high frequency current transformers and coupling capacitors to detect discharges in cables.
4) The conclusion that resonant testing between 20-300Hz along with partial discharge detection reduces risks from cable systems after installation by locating faults.
How to Use the DTX-MFM2 Fiber Modules to Test Installed Corning Multimode Pre...Fluke Networks
The Corning Pretium EDGE® Tap Module allows passive tapping into optical networks for monitoring purposes. The modules contain splitters that divide each optical signal into two
outputs, one for network link traffic and one for monitoring.
This document provides instructions for operating a digital clamp meter. It includes specifications for the meter such as its display, accuracy, measurement functions, and safety information. The key functions of the meter are described, including how to make current, voltage, resistance, diode, continuity, and non-contact voltage measurements. Battery replacement instructions and safety warnings are also provided.
Brugg Kabel AG uses silicone insulation for high voltage cable accessories up to 400kV. Routine partial discharge (PD) testing is done on prefabricated joints to ensure quality and detect defects. On-site PD measurements after installation can accurately detect PD above 5pC and localize faults. Directional coupler sensors allow sensitive PD detection and localization in unscreened environments. PD testing is important for ensuring reliability of joints and avoiding premature failures during operation.
This document provides steps for properly preparing coaxial cable and terminating connectors for use in CCTV systems. It discusses that transmission media such as cable, connectors and installation methods account for over 65% of failures in CCTV systems. The document then provides 10 detailed steps for stripping cable, attaching connectors, testing connections, and labeling cables to help ensure optimal video quality and troubleshooting. Key steps include properly stripping cable, flaring the braid, crimping the connector, checking resistance values during testing, and labeling both ends of cables.
This document provides specifications for an EPS2U 650W power supply model EP2A5651A-B. It includes details on the power supply's input/output electrical specifications, environmental requirements, safety certifications, and labeling. The power supply has an input voltage range of 90-264VAC and can provide up to 650W of continuous power on its regulated outputs of +3.3V, +5V, +12V, -12V and +5VSB. It meets various EMI and safety standards and is rated to operate from 0-50°C with 5-95% humidity.
Discover the latest insights on Data Driven Maintenance with our comprehensive webinar presentation. Learn about traditional maintenance challenges, the right approach to utilizing data, and the benefits of adopting a Data Driven Maintenance strategy. Explore real-world examples, industry best practices, and innovative solutions like FMECA and the D3M model. This presentation, led by expert Jules Oudmans, is essential for asset owners looking to optimize their maintenance processes and leverage digital technologies for improved efficiency and performance. Download now to stay ahead in the evolving maintenance landscape.
Software Engineering and Project Management - Introduction, Modeling Concepts...Prakhyath Rai
Introduction, Modeling Concepts and Class Modeling: What is Object orientation? What is OO development? OO Themes; Evidence for usefulness of OO development; OO modeling history. Modeling
as Design technique: Modeling, abstraction, The Three models. Class Modeling: Object and Class Concept, Link and associations concepts, Generalization and Inheritance, A sample class model, Navigation of class models, and UML diagrams
Building the Analysis Models: Requirement Analysis, Analysis Model Approaches, Data modeling Concepts, Object Oriented Analysis, Scenario-Based Modeling, Flow-Oriented Modeling, class Based Modeling, Creating a Behavioral Model.
artificial intelligence and data science contents.pptxGauravCar
What is artificial intelligence? Artificial intelligence is the ability of a computer or computer-controlled robot to perform tasks that are commonly associated with the intellectual processes characteristic of humans, such as the ability to reason.
› ...
Artificial intelligence (AI) | Definitio
Redefining brain tumor segmentation: a cutting-edge convolutional neural netw...IJECEIAES
Medical image analysis has witnessed significant advancements with deep learning techniques. In the domain of brain tumor segmentation, the ability to
precisely delineate tumor boundaries from magnetic resonance imaging (MRI)
scans holds profound implications for diagnosis. This study presents an ensemble convolutional neural network (CNN) with transfer learning, integrating
the state-of-the-art Deeplabv3+ architecture with the ResNet18 backbone. The
model is rigorously trained and evaluated, exhibiting remarkable performance
metrics, including an impressive global accuracy of 99.286%, a high-class accuracy of 82.191%, a mean intersection over union (IoU) of 79.900%, a weighted
IoU of 98.620%, and a Boundary F1 (BF) score of 83.303%. Notably, a detailed comparative analysis with existing methods showcases the superiority of
our proposed model. These findings underscore the model’s competence in precise brain tumor localization, underscoring its potential to revolutionize medical
image analysis and enhance healthcare outcomes. This research paves the way
for future exploration and optimization of advanced CNN models in medical
imaging, emphasizing addressing false positives and resource efficiency.
Applications of artificial Intelligence in Mechanical Engineering.pdfAtif Razi
Historically, mechanical engineering has relied heavily on human expertise and empirical methods to solve complex problems. With the introduction of computer-aided design (CAD) and finite element analysis (FEA), the field took its first steps towards digitization. These tools allowed engineers to simulate and analyze mechanical systems with greater accuracy and efficiency. However, the sheer volume of data generated by modern engineering systems and the increasing complexity of these systems have necessitated more advanced analytical tools, paving the way for AI.
AI offers the capability to process vast amounts of data, identify patterns, and make predictions with a level of speed and accuracy unattainable by traditional methods. This has profound implications for mechanical engineering, enabling more efficient design processes, predictive maintenance strategies, and optimized manufacturing operations. AI-driven tools can learn from historical data, adapt to new information, and continuously improve their performance, making them invaluable in tackling the multifaceted challenges of modern mechanical engineering.
Null Bangalore | Pentesters Approach to AWS IAMDivyanshu
#Abstract:
- Learn more about the real-world methods for auditing AWS IAM (Identity and Access Management) as a pentester. So let us proceed with a brief discussion of IAM as well as some typical misconfigurations and their potential exploits in order to reinforce the understanding of IAM security best practices.
- Gain actionable insights into AWS IAM policies and roles, using hands on approach.
#Prerequisites:
- Basic understanding of AWS services and architecture
- Familiarity with cloud security concepts
- Experience using the AWS Management Console or AWS CLI.
- For hands on lab create account on [killercoda.com](https://killercoda.com/cloudsecurity-scenario/)
# Scenario Covered:
- Basics of IAM in AWS
- Implementing IAM Policies with Least Privilege to Manage S3 Bucket
- Objective: Create an S3 bucket with least privilege IAM policy and validate access.
- Steps:
- Create S3 bucket.
- Attach least privilege policy to IAM user.
- Validate access.
- Exploiting IAM PassRole Misconfiguration
-Allows a user to pass a specific IAM role to an AWS service (ec2), typically used for service access delegation. Then exploit PassRole Misconfiguration granting unauthorized access to sensitive resources.
- Objective: Demonstrate how a PassRole misconfiguration can grant unauthorized access.
- Steps:
- Allow user to pass IAM role to EC2.
- Exploit misconfiguration for unauthorized access.
- Access sensitive resources.
- Exploiting IAM AssumeRole Misconfiguration with Overly Permissive Role
- An overly permissive IAM role configuration can lead to privilege escalation by creating a role with administrative privileges and allow a user to assume this role.
- Objective: Show how overly permissive IAM roles can lead to privilege escalation.
- Steps:
- Create role with administrative privileges.
- Allow user to assume the role.
- Perform administrative actions.
- Differentiation between PassRole vs AssumeRole
Try at [killercoda.com](https://killercoda.com/cloudsecurity-scenario/)
Batteries -Introduction – Types of Batteries – discharging and charging of battery - characteristics of battery –battery rating- various tests on battery- – Primary battery: silver button cell- Secondary battery :Ni-Cd battery-modern battery: lithium ion battery-maintenance of batteries-choices of batteries for electric vehicle applications.
Fuel Cells: Introduction- importance and classification of fuel cells - description, principle, components, applications of fuel cells: H2-O2 fuel cell, alkaline fuel cell, molten carbonate fuel cell and direct methanol fuel cells.
3. One of the most important parts of the PD measurement is ensuring a
good connection to the test-object.
A faulty connection to the test-object could cause the following problems:
increased Background noise;
PD‘s at the near termination;
no PD‘s;
„not loading“ the test-object.
Measurement connection
4. Earthing requirements:
when having a corroded earthing or sheath, remove corrosion (on the place where
the connectors will be connected)
otherwise increased Background noise
when possible always connect the sheath of the extension-cable directly on the
sheath of the test object
Otherwise increased damping of the signals
always connect the earthing of the test-van itself on the same point as the sheath of
the extension cable
because of loop, increased Background noise
Measurement connection
Earthing
Copper corosion
5. With the connection of the extension cable it should be observed that the
unshielded part of the cable does not touch or is close to earthed
components.
Earthed components are:
- Floor
- Switchgear
- Cabledrum
- Sheath of the extension cable
A minimum clearance of 5 till 10cm is strictly
necessary.
(between unshielded part and earthed component)
Measurement connection
Connecting extension cable
7. During the measurement the following requirements apply.
Current-transformers (CT‘s) can be left connected;
Voltage-transformers (VT‘s) must be disconnected;
Surge-arresters ideally have to be disconnected. They can be left connected,
however the chance exists that the cable at voltages >= U0 cannot be loaded
anymore since the leakage current through the surge-arrester is to high;
Other two phases have to be earthed during the measurement.
What kind of field-distribution we have got in joints???
Measurement connection
Connection during measurement
8. Needs to be applied for „short“ cables to decrease the frequency:
e.g. XLPE cables < 300m
at Error message: “Frequency too high, please use additional capacitor!”
Important, earth properly!!! -> otherwise PD can be created
Test
Object
Measurement connection
Additional capacitor
10. Important for the measurement!
Data entry of U0 (for 20kV cables enter 11.6kV as
U0)
Data entry of the cable-length
Joint-entry; acc. to position from near
termination.
Load loading an existing Startmask (e.g.
created by the Excel-Macro);
Clone (Copying) copying an existing
Startmask (creating new folder with
current date and time);
OK accepting the standard definition;
New creating a new Startmask;
Hint: With three one-phase cables first
enter the data as a single three-phase
cable afterwards change it to three one-
phase cables.
Generating Startmask
12. Goal of the calibration is to:
measure according to the international norm IEC 60270;
determine the propagation velocity v of the cable, which is required for the
localization.
Additionally joints can be recognized in this modus.
However attention has to be paid!!!!!
Faulty calibrations can lead to:
Extremely high background noise;
A scattered PD-Mapping (PD‘s not on straight line) because of difference in v ‘s.
Calibration
13. Connect between core and sheath;
Twist connection cables as far as possible;
Always keep the frequency on 100Hz.
SebaKMT recommends to calibrate the Calibrator every two years
and to replace the batteries every year (no matter what the battery
indication shows).
Calibration
Connection
100Hz
500pC
14. Always start calibration with the highest value (100nC).
Note: The only exception is cables shorter than 300m, then start with 500pC.
SebaKMT recommends to calibrate the entire range from 100nC to 200
(100)pC. This to avoid time-consuming re-calibration.
Especially 100 und 200pC can sometimes not be calibrated because of
high background noise activity. „What doesn‘t go, does not go…“
When the automatic calibration takes to long it is better to stop the
automatic calibration and continue manually. Best practice is to use the
PgUp and PgDn keys instead of the logarithmic slide-bar on the left hand
side!!!
Calibration
The calibration
15. One calibration for all
phases is sufficient.
At three singe-phase
cables change Phase
to „All“.
Calibration
The calibration
16. Press arrow in upper
right-hand corner.
move yellow marker
to the maximum of
the reflection of the
joint and the distance
of the joint can be
read.
Calibration
Joint recognition
17. Check VHF
For cables shorter
then 100m the
following settings
are required:
1)Press setup and
check if VHF is
turned on;
(is automatically
turned on for cables shorter
than 500m)
2)Adjust slide-bar to
short cable;
3)Then continue
with the calibration. 1
2
Calibration
Calibration of short cable lengths
18. For long cables or cables with a high attenuation it could happen that the
endreflection is not visible anymore. How to set the second marker then?
Approach in such cases:
a) Set 100nC, stop automatic calibration and
manually increase the amplification until an
end-reflection becomes visible.
b) Move second marker to the correct position
and adjust amplification level back to 80%
level.
c) Notice the v and position the marker for
further calibrations based on this v.
When at a) no end-reflection could have been
recognized, the second marker has to be set,
based on a v of 160m/µsec.
Of course always measure from both ends!!!
Calibration
Calibration of long cable lengths
19. Cable-data:
Voltage: 20kV
Type: NA2XS(f)2Y
Year: 2006
Length: 3500m
Joints: 6 pieces
All_1000.cal
N:...All_1000.cal Monday, May 26, 2008 8:16 PM
Time (us)
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
Range
[%]
100
90
80
70
60
50
40
30
20
10
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
One side will do.
Calibration
Example attenuation of the cable
20. Cable-data:
Voltage: 10kV
Type: NAKBA
Year: 1970
Length: 570m
Joints: 3 pieces
All_1000.cal
N:...All_1000.cal 09/04/2010 08:35
Time (us)
12
11
10
9
8
7
6
5
4
3
2
1
0
Range
[%]
100
90
80
70
60
50
40
30
20
10
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
Measurement from both sides
recommended!!
Calibration
Example attenuation of the cable
22. The calibration provides the user from valuable information. Based on the
calibration it e.g. becomes clear if a measurement has to be performed from
both sides yes or no.
This decision for measuring from both ends is depending on the attenuation
of the cable.
The attenuation is influenced by several factors:
Cable-type (Isolation)
Cable condition (new, aged)
Voltage class
Manufacturer
Number of joints
Generally we recommend to measure cables from both sides if they are
longer then 2km. However as the following examples will show that this will
not always be correct!!!! Better is to always make the decision based on the
calibration itself.
Calibration
What can we learn from the calibration?
26. 0kV
0,5U0
- Determine PDIV
- Save PDIV
- Increase voltage with 0,1U0
and every time save data
1U0
1,3U0
1,5U0
Save
PD existing No PD
- Determine PDIV
- Save PDIV
- Increase voltage with 0,1U0
and every time save data
- Determine and save PDIV
- Increase voltage with 0,1U0
and every time save data
- Determine and save PDEV
PD existing No PD
Save
PD existing No PD
Measurement
Measurment approach
27. Summary Data Collection Procedure
PDIV Less Than Uo Condition
Test Voltage Function Key Freq
0Uo F7 1
↑Uo →PDIV F8 1
1.0Uo F7 5
1.3Uo
F7 5
F9 1
PDIV More Than Uo Condition
Test Voltage Function Key Freq
0Uo F7 1
↑Uo →PDIV
F8 1
F7 5
1.3Uo
F7 5
F9 1
28. Practical tips:
Always select the proper PD-range, e.g. do not save PD‘s of 200pC
height with a PD-range of 5nC.
Or the other way around save PD‘s which are higher then the selected
PD-range!!!
Save as PDIV if from 2 of the 3 measurements PD is present;
Only save PDEV when PDIV ≥ U0;
Also for the PDEV perform 3 measurements and take the average value;
In total three data-sets have to be saved if the cable is PD-free (0kV, U0
and1.3U0).
Measurement
Practical tips
29. Determining the extinction voltage is then possible if PD‘s occur over
more then two AC cycles.
PDEV must not necessarily be saved at 1.3U0, if PD‘s occur over more
then two AC cycles directly determine the PDEV and save it.
Of major importance is to select the correct PD-range (500pC). Only in
this case PD‘s may clip. Goal is to determine the PDEV, not to save data
for the TDR analysis!!!
Selecting faulty PD-range will in most cases result in a PDEV higher then the PDIV, which is not possible!!!
Measurement
Determination of PDEV
30. 0
0
V0
t → s
t → s
kV
↑
V
i↑
PDIV
PDEV
0
0
V0
t → s
t → s
kV
↑
V
i↑
PDEV
PDIV
PDIV – Partial Discharge Inception Voltage; the voltage where the first discharges
appear (incept).
PDEV – Partial Discharge Extinction Voltage; the voltage where the discharges
disappear (extinct). In practice 10 to 35% below inception voltage.
PDEV below U0.
Dangerous
situation!! PD
remains after
overvoltage.
PDEV above U0.
PD only occurs
during
overvoltage
Measurement
Importance of PDEV
31. Dielectric losses are the losses that occur in the insulation material.
An increase in tanδ as function of the operating voltage like in the picture
below, means aged insulation or local weak-spots.
Values measured with the OWTS are given in percentages, according to the
value of the dielectric losses the following distinctions can be made:
Tan delta Condition of the cable
0.1 < tan δ < 0.9% dry
0.9% < tan δ < 2% moisture
tan δ > 2% wet
Measurement
Dielectric loss summary
33. The purpose of the Quick overview is to give a first estimation of the
condition of the cable.
Based on this overview direct measures can be scheduled e.g. replacement
of PD-affected joints.
However because it is an automatically compiled PD-mapping, a manual
evaluation is still required/ advised!!!
Evaluation „Quick Overview“
36. Check PD-concentrations
by right-clicking on PD spot
with the Mouse and select
„View PD-Pulse“
With help from the
„Threshold“ function PD-
concentrations can be
displayed more clearly
Based on these results
direct measures can be
scheduled e.g. replacement
of PD affected joints
However a manual
evaluation is always
required.
Evaluation „Quick Overview“
Step 3: Check quick overview result
39. The Cluster Strength is a new feature (only available as a Beta Version
and only functions when having OWTS Explorer V4.0) which looks to PD
concentrations.
If there is a weak spot, there will always be several PD pulses.
The software skips the cable parts where the PD concentration looking to
the cable length is 2 or less.
If two or less the PD will not be shown in the PD Mapping.
This new feature significantly increases the usability of the quick
overview function.
Note: scattered PD in paper-mass will also not be shown in a PD
mapping
Evaluation „Quick Overview“
New: Cluster strength (Beta Version only)
40. “Threshold” 0 pC and “Cluster strength” 0
Evaluation „Quick Overview“
New: Cluster strength (Beta Version only)
41. “Threshold” 0 pC and “Cluster strength” 40 (default)
Evaluation „Quick Overview“
New: Cluster strength (Beta Version only)