This presentation represents Power system Protection & Transient Stability introduction.
Protection systems must be designed with both primary protection and backup protection in case primary protection devices fail
There are several common protection schemes; multiple overlapping schemes are usually used
To avoid inadvertent tripping for faults on other transmission lines, impedance relays usually have several zones of protectionIn order to study the transient response of a power system we need to develop models for the generator valid during the transient time frame of several seconds following a system disturbance
This document summarizes a lecture on power system protection and transient stability. It discusses radial and networked power system protection schemes, including inverse-time overcurrent relays, directional relays, impedance relays, and differential relays. It also covers sequence of events recording, fault location using GPS, and an overview of power system transient stability.
This lecture discusses power system protection and transient stability. It provides examples of how different types of relays like directional, impedance, and differential relays are used to protect transmission lines and other equipment. Sequence of events recording with GPS time synchronization is discussed for fault location. Models for generator electrical dynamics, mechanical dynamics, and the swing equation are presented. Transient stability analysis considers the pre-fault, faulted, and post-fault system states. Numerical integration and direct methods like the equal area criteria are presented for solving transient stability problems. An example of a single machine infinite bus system is analyzed.
(1) Five classical types of busbar protection systems are discussed: system protection, frame-earth protection, differential protection, phase comparison protection, and directional blocking protection. System protection and phase comparison protection are only suitable for small substations, while frame-earth and differential protection are discussed in more detail.
(2) Frame-earth protection measures fault current flowing from the switchgear frame to earth. Differential protection compares currents flowing into and out of the busbar and trips if they are not equal.
(3) Modern digital differential algorithms aim to improve filtering, response time, restraint techniques, and transient blocking compared to classical schemes.
DigSILENT PF - 06 (es) short circuit theoryHimmelstern
This document provides an overview of short-circuit calculations, including the basic principles, models used, and time dependence of short-circuit currents. It discusses the symmetrical components method for analyzing faults and different types of short circuits based on involved phases. Models for common electrical components like transformers, lines, and generators are also presented. The document is intended as training material for performing short-circuit analyses.
This document provides an overview of short-circuit calculations, including the following key points:
- Short-circuit calculations are used for system planning and operations to ensure equipment ratings are not exceeded and protective devices are properly coordinated.
- The time dependence of short-circuit current is important, as it affects equipment loading. Key current parameters analyzed at different time domains are defined.
- The symmetrical components method is used to split three-phase systems into positive, negative, and zero sequence networks to simplify analysis.
- Short-circuits are classified based on the phases involved: three-phase, phase-to-phase, phase-to-phase-ground, or single-phase ground.
- Common system elements
The document discusses various types of equipment used in electrical distribution systems including transformers, circuit breakers, load break switches, and capacitor banks. It then describes methods of neutral grounding for distribution systems and the advantages of grounding such as improved safety and fault protection. Five methods of neutral earthing are outlined: unearthed neutral system, solidly earthed system, resistance earthed system, resonant earthed system, and earthing transformer system. Fault locators installed at substations are also summarized, which identify fault events, types, and calculate the distance to the fault location.
The document discusses voltage sags and interruptions. It covers sources of sags and interruptions such as faults in the distribution system. Methods to estimate voltage sag performance and mitigate sags are described, including reducing faults, improving fault clearing time, modifying the supply system, and using voltage stabilizers. Active series compensators and static transfer switches are discussed as technologies to improve power quality during sags. Ferroresonant transformers can handle most sag conditions by maintaining nearly constant output voltage.
The switchyard functions to transmit power from generating stations to the electrical grid at incoming voltages and allow for switching via switchgears. It interfaces between the power plant and grid. There are two main types of switchyards: air insulated and gas insulated. The switchyard contains various equipment like busbars to distribute power, insulators to support conductors, surge arresters to protect from overvoltage, isolators to isolate lines, wave traps to prevent communication interference, and circuit breakers and relays to isolate faulty lines. Differential protection relays compare currents at the boundaries of protected equipment like power lines or transformers to accurately and quickly detect internal faults.
This document summarizes a lecture on power system protection and transient stability. It discusses radial and networked power system protection schemes, including inverse-time overcurrent relays, directional relays, impedance relays, and differential relays. It also covers sequence of events recording, fault location using GPS, and an overview of power system transient stability.
This lecture discusses power system protection and transient stability. It provides examples of how different types of relays like directional, impedance, and differential relays are used to protect transmission lines and other equipment. Sequence of events recording with GPS time synchronization is discussed for fault location. Models for generator electrical dynamics, mechanical dynamics, and the swing equation are presented. Transient stability analysis considers the pre-fault, faulted, and post-fault system states. Numerical integration and direct methods like the equal area criteria are presented for solving transient stability problems. An example of a single machine infinite bus system is analyzed.
(1) Five classical types of busbar protection systems are discussed: system protection, frame-earth protection, differential protection, phase comparison protection, and directional blocking protection. System protection and phase comparison protection are only suitable for small substations, while frame-earth and differential protection are discussed in more detail.
(2) Frame-earth protection measures fault current flowing from the switchgear frame to earth. Differential protection compares currents flowing into and out of the busbar and trips if they are not equal.
(3) Modern digital differential algorithms aim to improve filtering, response time, restraint techniques, and transient blocking compared to classical schemes.
DigSILENT PF - 06 (es) short circuit theoryHimmelstern
This document provides an overview of short-circuit calculations, including the basic principles, models used, and time dependence of short-circuit currents. It discusses the symmetrical components method for analyzing faults and different types of short circuits based on involved phases. Models for common electrical components like transformers, lines, and generators are also presented. The document is intended as training material for performing short-circuit analyses.
This document provides an overview of short-circuit calculations, including the following key points:
- Short-circuit calculations are used for system planning and operations to ensure equipment ratings are not exceeded and protective devices are properly coordinated.
- The time dependence of short-circuit current is important, as it affects equipment loading. Key current parameters analyzed at different time domains are defined.
- The symmetrical components method is used to split three-phase systems into positive, negative, and zero sequence networks to simplify analysis.
- Short-circuits are classified based on the phases involved: three-phase, phase-to-phase, phase-to-phase-ground, or single-phase ground.
- Common system elements
The document discusses various types of equipment used in electrical distribution systems including transformers, circuit breakers, load break switches, and capacitor banks. It then describes methods of neutral grounding for distribution systems and the advantages of grounding such as improved safety and fault protection. Five methods of neutral earthing are outlined: unearthed neutral system, solidly earthed system, resistance earthed system, resonant earthed system, and earthing transformer system. Fault locators installed at substations are also summarized, which identify fault events, types, and calculate the distance to the fault location.
The document discusses voltage sags and interruptions. It covers sources of sags and interruptions such as faults in the distribution system. Methods to estimate voltage sag performance and mitigate sags are described, including reducing faults, improving fault clearing time, modifying the supply system, and using voltage stabilizers. Active series compensators and static transfer switches are discussed as technologies to improve power quality during sags. Ferroresonant transformers can handle most sag conditions by maintaining nearly constant output voltage.
The switchyard functions to transmit power from generating stations to the electrical grid at incoming voltages and allow for switching via switchgears. It interfaces between the power plant and grid. There are two main types of switchyards: air insulated and gas insulated. The switchyard contains various equipment like busbars to distribute power, insulators to support conductors, surge arresters to protect from overvoltage, isolators to isolate lines, wave traps to prevent communication interference, and circuit breakers and relays to isolate faulty lines. Differential protection relays compare currents at the boundaries of protected equipment like power lines or transformers to accurately and quickly detect internal faults.
This document describes various principles of relay operation used in power systems. It discusses several categories of relays including level detection relays, magnitude comparison relays, differential relays, phase angle comparison relays, distance relays, pilot relays, harmonic content relays, and frequency sensing relays. It also describes some common relay designs such as plunger-type electromechanical relays and their operating characteristics. Relay principles can be based on detecting changes in current, voltage, phase angles, harmonic components, or frequency during fault conditions.
1) The document describes the performance of a quadrilateral relay for protection of extra high voltage transmission lines during faults with high resistance.
2) A PSCAD/EMTDC model of a 300km transmission line is developed and a quadrilateral relay scheme with two zones is designed and tested under different fault conditions.
3) Simulation results show that the quadrilateral relay can accurately detect faults located in zones 1 and 2 and is well-suited for providing flexible protection during high resistance faults on EHV transmission lines.
System protection detects problems on the power system like short circuits, abnormal conditions, and equipment failures. It protects components like generators, transformers, transmission lines, buses, and capacitors. Protective relays monitor current and voltage to detect issues. Current and potential transformers scale currents and voltages for relay inputs. Generator protection methods include differential, impedance, and voltage relays. Transformer protection uses fuses, overcurrent, and differential schemes. Transmission line protection employs overcurrent, directional, distance, and pilot schemes like blocking and permissive transfer trip to isolate faults.
This presentation described in a National Level Conference in CITM College Jaipur named as POWER SYSTEM PROTECTION TECHNIQUE: A REVIEW. This was presented by Sahid Raja Khan B.Tech. (Electrical Engineering) Hons.
Chapter 3 electrical-protection_system (hat, trafo, generatör, bara koruma)Oktay Yaman
This document discusses electrical protection systems. It covers key considerations in designing protection systems such as reliability, selectivity, speed, sensitivity, and fault data. Protection zones, primary and backup protection, instrument transformers, and required system studies are also described. The goal of protection systems is to quickly detect and isolate faulty components while minimizing disruption to the rest of the electric system. Factors like component quality, maintenance, and protection schemes/relays influence reliability. Selectivity and speed requirements vary based on economic and system stability factors. Protection must operate reliably under minimum fault conditions and remain stable under loads.
An adaptive protection scheme to prevent recloser-fuse miscoordination in dis...iosrjce
IOSR Journal of Electrical and Electronics Engineering(IOSR-JEEE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of electrical and electronics engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electrical and electronics engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
This document discusses an adaptive protection scheme to prevent recloser-fuse miscoordination in distribution feeders with distributed generation. The presence of distributed generation can interfere with the coordination between reclosers and fuses by changing fault current levels. The proposed method adaptively modifies recloser time dial settings to address this issue. The method is tested on a simulation of an actual distribution feeder assuming different distributed generation capacities and locations. Optimization is also performed to determine the optimal location and capacity of two distributed generation units while maintaining recloser-fuse coordination and minimizing losses.
1) The document introduces an electrical power system lab that uses an Analog Model Power System (AMPS) to simulate various power system configurations and behaviors.
2) The objectives are to familiarize students with power system structure, transmission lines, power flow, and the supervisory control and data acquisition (SCADA) system. Tests will be conducted by varying transmission line impedances and load types and comparing results to theoretical calculations.
3) Detailed procedures are provided for setting up resistive and inductive loads on the AMPS and conducting tests while varying transmission line impedances from 100% to 70% to 30% and recording voltage, current, and power flow measurements.
1) The document describes the simulation of a differential relay for transformer protection using MATLAB/Simulink. A differential relay operates by comparing the current flowing into and out of a transformer and tripping the circuit breaker if there is a difference, indicating an internal fault.
2) The simulation models a power system including a transformer protected by a differential relay. Current transformers measure the primary and secondary currents which are compared in the relay.
3) Under normal operation the currents match and the relay does not trip, but internal faults create a difference that causes the relay to send a trip signal to the circuit breakers to isolate the fault. The simulation tests the relay under different fault conditions.
Need for protection
Nature and causes of faults
Types of faults
Fault current calculation using symmetrical components
Zones of protection
Primary and back up protection
Essential qualities of protection
Typical protection schemes.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
This document discusses various methods of neutral grounding systems for electrical power systems, including their advantages and disadvantages. It describes ungrounded systems, solidly grounded systems, and various resistance grounded systems such as low resistance, high resistance, and resonant grounding. Resistance grounding limits fault currents to reduce equipment damage while still allowing faults to be detected. High resistance grounding further limits currents to below 10 amps, requiring a detection system since faults will not trip breakers. Resonant grounding uses inductive reactance to cancel out the capacitive fault current. Earthing transformers provide an alternative return path for faults on delta windings.
Double Circuit Transmission Line Protection using Line Trap & Artificial Neur...IRJET Journal
This document presents a technique for protecting double circuit transmission lines using line traps and artificial neural networks. Line traps are placed at the terminals of the protected line to detect faults based on high frequency transients. An artificial neural network is trained using the RMS voltage and current signals to classify fault types. MATLAB simulation studies were conducted to model a 300km, 25kV, 50Hz transmission system with three zones. RMS measurements from one end were used to train the neural network to classify faults. The neural network approach provides fast, secure and reliable protection for double circuit transmission lines.
This document contains an outline for a project on building a black box system for a car. It includes chapters on embedded systems, transformers, microcontrollers, software used, and conclusions. The chapters cover topics like embedded system design cycles, ideal transformer equations, voltage regulators, rectifiers, filters, and the AT89S52 microcontroller's memory and UART. The document provides details on the various components and concepts involved in the project.
A Load Shedding Scheme Based On Frequency Response Model With Fast Voltage St...IRJET Journal
This document presents a load shedding technique that considers both frequency response and voltage stability to stabilize power systems during disturbances. The technique uses a frequency response model to determine the amount of load shedding needed based on the rate of change of frequency. It also uses the Fast Voltage Stability Index and Line Stability Index to monitor voltage stability and determine necessary undervoltage load shedding. The method is tested on an IEEE 6 bus system model developed in PowerWorld Simulator. It classifies loads as vital and non-vital and aims to shed non-vital loads first to minimize impacts while maintaining system stability.
Concept and Viability of High Temperature Superconductor Fault Current Limite...IOSR Journals
This document discusses the concept and viability of using a high temperature superconductor fault current limiter (HTSFCL) for power system protection. It begins with an introduction to the increasing fault current levels in power systems due to rising loads. It then reviews previous fault current limiting methods and outlines the ideal characteristics of a fault current limiter. The document focuses on modeling and simulating an HTSFCL using MATLAB. The HTSFCL design incorporates superconducting and stainless steel layers. Simulation results show the HTSFCL's ability to limit fault currents within a cycle by transitioning from a superconducting to resistive state as temperature rises during a fault.
Substation design involves considering many factors to ensure safety, reliability, maintainability and the ability to expand the system over time. Key components in a substation include circuit breakers, transformers, busbars, isolators, current and potential transformers, surge arrestors, shunt reactors, and capacitors. The functions of this equipment include switching, voltage transformation, power transfer, protection, insulation and surge protection. Associated systems that support substation function include earthing systems, lighting, protection relays, control cables, and fire suppression systems.
This document summarizes key concepts from a lecture on transformers, generators, loads, and power flow analysis in power systems:
1) It discusses load tap changing (LTC) transformers, which have tap ratios that can be varied to regulate voltages, phase shifting transformers which control phase angle to regulate power flow, and autotransformers which are more compact but lack electrical isolation.
2) It introduces models for loads as constant power or constant impedance and generators as constant voltage or constant power sources.
3) It explains that power flow analysis is used to determine how power flows through a network and to calculate voltages and currents, using iterative techniques due to the nonlinear nature of constant power loads.
This document describes various principles of relay operation used in power systems. It discusses several categories of relays including level detection relays, magnitude comparison relays, differential relays, phase angle comparison relays, distance relays, pilot relays, harmonic content relays, and frequency sensing relays. It also describes some common relay designs such as plunger-type electromechanical relays and their operating characteristics. Relay principles can be based on detecting changes in current, voltage, phase angles, harmonic components, or frequency during fault conditions.
1) The document describes the performance of a quadrilateral relay for protection of extra high voltage transmission lines during faults with high resistance.
2) A PSCAD/EMTDC model of a 300km transmission line is developed and a quadrilateral relay scheme with two zones is designed and tested under different fault conditions.
3) Simulation results show that the quadrilateral relay can accurately detect faults located in zones 1 and 2 and is well-suited for providing flexible protection during high resistance faults on EHV transmission lines.
System protection detects problems on the power system like short circuits, abnormal conditions, and equipment failures. It protects components like generators, transformers, transmission lines, buses, and capacitors. Protective relays monitor current and voltage to detect issues. Current and potential transformers scale currents and voltages for relay inputs. Generator protection methods include differential, impedance, and voltage relays. Transformer protection uses fuses, overcurrent, and differential schemes. Transmission line protection employs overcurrent, directional, distance, and pilot schemes like blocking and permissive transfer trip to isolate faults.
This presentation described in a National Level Conference in CITM College Jaipur named as POWER SYSTEM PROTECTION TECHNIQUE: A REVIEW. This was presented by Sahid Raja Khan B.Tech. (Electrical Engineering) Hons.
Chapter 3 electrical-protection_system (hat, trafo, generatör, bara koruma)Oktay Yaman
This document discusses electrical protection systems. It covers key considerations in designing protection systems such as reliability, selectivity, speed, sensitivity, and fault data. Protection zones, primary and backup protection, instrument transformers, and required system studies are also described. The goal of protection systems is to quickly detect and isolate faulty components while minimizing disruption to the rest of the electric system. Factors like component quality, maintenance, and protection schemes/relays influence reliability. Selectivity and speed requirements vary based on economic and system stability factors. Protection must operate reliably under minimum fault conditions and remain stable under loads.
An adaptive protection scheme to prevent recloser-fuse miscoordination in dis...iosrjce
IOSR Journal of Electrical and Electronics Engineering(IOSR-JEEE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of electrical and electronics engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electrical and electronics engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
This document discusses an adaptive protection scheme to prevent recloser-fuse miscoordination in distribution feeders with distributed generation. The presence of distributed generation can interfere with the coordination between reclosers and fuses by changing fault current levels. The proposed method adaptively modifies recloser time dial settings to address this issue. The method is tested on a simulation of an actual distribution feeder assuming different distributed generation capacities and locations. Optimization is also performed to determine the optimal location and capacity of two distributed generation units while maintaining recloser-fuse coordination and minimizing losses.
1) The document introduces an electrical power system lab that uses an Analog Model Power System (AMPS) to simulate various power system configurations and behaviors.
2) The objectives are to familiarize students with power system structure, transmission lines, power flow, and the supervisory control and data acquisition (SCADA) system. Tests will be conducted by varying transmission line impedances and load types and comparing results to theoretical calculations.
3) Detailed procedures are provided for setting up resistive and inductive loads on the AMPS and conducting tests while varying transmission line impedances from 100% to 70% to 30% and recording voltage, current, and power flow measurements.
1) The document describes the simulation of a differential relay for transformer protection using MATLAB/Simulink. A differential relay operates by comparing the current flowing into and out of a transformer and tripping the circuit breaker if there is a difference, indicating an internal fault.
2) The simulation models a power system including a transformer protected by a differential relay. Current transformers measure the primary and secondary currents which are compared in the relay.
3) Under normal operation the currents match and the relay does not trip, but internal faults create a difference that causes the relay to send a trip signal to the circuit breakers to isolate the fault. The simulation tests the relay under different fault conditions.
Need for protection
Nature and causes of faults
Types of faults
Fault current calculation using symmetrical components
Zones of protection
Primary and back up protection
Essential qualities of protection
Typical protection schemes.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
This document discusses various methods of neutral grounding systems for electrical power systems, including their advantages and disadvantages. It describes ungrounded systems, solidly grounded systems, and various resistance grounded systems such as low resistance, high resistance, and resonant grounding. Resistance grounding limits fault currents to reduce equipment damage while still allowing faults to be detected. High resistance grounding further limits currents to below 10 amps, requiring a detection system since faults will not trip breakers. Resonant grounding uses inductive reactance to cancel out the capacitive fault current. Earthing transformers provide an alternative return path for faults on delta windings.
Double Circuit Transmission Line Protection using Line Trap & Artificial Neur...IRJET Journal
This document presents a technique for protecting double circuit transmission lines using line traps and artificial neural networks. Line traps are placed at the terminals of the protected line to detect faults based on high frequency transients. An artificial neural network is trained using the RMS voltage and current signals to classify fault types. MATLAB simulation studies were conducted to model a 300km, 25kV, 50Hz transmission system with three zones. RMS measurements from one end were used to train the neural network to classify faults. The neural network approach provides fast, secure and reliable protection for double circuit transmission lines.
This document contains an outline for a project on building a black box system for a car. It includes chapters on embedded systems, transformers, microcontrollers, software used, and conclusions. The chapters cover topics like embedded system design cycles, ideal transformer equations, voltage regulators, rectifiers, filters, and the AT89S52 microcontroller's memory and UART. The document provides details on the various components and concepts involved in the project.
A Load Shedding Scheme Based On Frequency Response Model With Fast Voltage St...IRJET Journal
This document presents a load shedding technique that considers both frequency response and voltage stability to stabilize power systems during disturbances. The technique uses a frequency response model to determine the amount of load shedding needed based on the rate of change of frequency. It also uses the Fast Voltage Stability Index and Line Stability Index to monitor voltage stability and determine necessary undervoltage load shedding. The method is tested on an IEEE 6 bus system model developed in PowerWorld Simulator. It classifies loads as vital and non-vital and aims to shed non-vital loads first to minimize impacts while maintaining system stability.
Concept and Viability of High Temperature Superconductor Fault Current Limite...IOSR Journals
This document discusses the concept and viability of using a high temperature superconductor fault current limiter (HTSFCL) for power system protection. It begins with an introduction to the increasing fault current levels in power systems due to rising loads. It then reviews previous fault current limiting methods and outlines the ideal characteristics of a fault current limiter. The document focuses on modeling and simulating an HTSFCL using MATLAB. The HTSFCL design incorporates superconducting and stainless steel layers. Simulation results show the HTSFCL's ability to limit fault currents within a cycle by transitioning from a superconducting to resistive state as temperature rises during a fault.
Substation design involves considering many factors to ensure safety, reliability, maintainability and the ability to expand the system over time. Key components in a substation include circuit breakers, transformers, busbars, isolators, current and potential transformers, surge arrestors, shunt reactors, and capacitors. The functions of this equipment include switching, voltage transformation, power transfer, protection, insulation and surge protection. Associated systems that support substation function include earthing systems, lighting, protection relays, control cables, and fire suppression systems.
This document summarizes key concepts from a lecture on transformers, generators, loads, and power flow analysis in power systems:
1) It discusses load tap changing (LTC) transformers, which have tap ratios that can be varied to regulate voltages, phase shifting transformers which control phase angle to regulate power flow, and autotransformers which are more compact but lack electrical isolation.
2) It introduces models for loads as constant power or constant impedance and generators as constant voltage or constant power sources.
3) It explains that power flow analysis is used to determine how power flows through a network and to calculate voltages and currents, using iterative techniques due to the nonlinear nature of constant power loads.
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.
Build the Next Generation of Apps with the Einstein 1 Platform.
Rejoignez Philippe Ozil pour une session de workshops qui vous guidera à travers les détails de la plateforme Einstein 1, l'importance des données pour la création d'applications d'intelligence artificielle et les différents outils et technologies que Salesforce propose pour vous apporter tous les bénéfices de l'IA.
Height and depth gauge linear metrology.pdfq30122000
Height gauges may also be used to measure the height of an object by using the underside of the scriber as the datum. The datum may be permanently fixed or the height gauge may have provision to adjust the scale, this is done by sliding the scale vertically along the body of the height gauge by turning a fine feed screw at the top of the gauge; then with the scriber set to the same level as the base, the scale can be matched to it. This adjustment allows different scribers or probes to be used, as well as adjusting for any errors in a damaged or resharpened probe.
Digital Twins Computer Networking Paper Presentation.pptxaryanpankaj78
A Digital Twin in computer networking is a virtual representation of a physical network, used to simulate, analyze, and optimize network performance and reliability. It leverages real-time data to enhance network management, predict issues, and improve decision-making processes.
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/)
Generative AI Use cases applications solutions and implementation.pdfmahaffeycheryld
Generative AI solutions encompass a range of capabilities from content creation to complex problem-solving across industries. Implementing generative AI involves identifying specific business needs, developing tailored AI models using techniques like GANs and VAEs, and integrating these models into existing workflows. Data quality and continuous model refinement are crucial for effective implementation. Businesses must also consider ethical implications and ensure transparency in AI decision-making. Generative AI's implementation aims to enhance efficiency, creativity, and innovation by leveraging autonomous generation and sophisticated learning algorithms to meet diverse business challenges.
https://www.leewayhertz.com/generative-ai-use-cases-and-applications/
Prediction of Electrical Energy Efficiency Using Information on Consumer's Ac...PriyankaKilaniya
Energy efficiency has been important since the latter part of the last century. The main object of this survey is to determine the energy efficiency knowledge among consumers. Two separate districts in Bangladesh are selected to conduct the survey on households and showrooms about the energy and seller also. The survey uses the data to find some regression equations from which it is easy to predict energy efficiency knowledge. The data is analyzed and calculated based on five important criteria. The initial target was to find some factors that help predict a person's energy efficiency knowledge. From the survey, it is found that the energy efficiency awareness among the people of our country is very low. Relationships between household energy use behaviors are estimated using a unique dataset of about 40 households and 20 showrooms in Bangladesh's Chapainawabganj and Bagerhat districts. Knowledge of energy consumption and energy efficiency technology options is found to be associated with household use of energy conservation practices. Household characteristics also influence household energy use behavior. Younger household cohorts are more likely to adopt energy-efficient technologies and energy conservation practices and place primary importance on energy saving for environmental reasons. Education also influences attitudes toward energy conservation in Bangladesh. Low-education households indicate they primarily save electricity for the environment while high-education households indicate they are motivated by environmental concerns.
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.
1. Lecture 22
Power System Protection, Transient Stability
Professor Tom Overbye
Department of Electrical and
Computer Engineering
ECE 476
POWER SYSTEM ANALYSIS
2. 1
Announcements
Be reading Chapters 9 and 10
After exam read Chapter 11
HW 9 is 8.4, 8.12, 9.1,9.2 (bus 2), 9.14; do by Nov 10 but
does not need to be turned in.
Start working on Design Project. Firm due date has been
extended to Dec 1 in class
Second exam is on Nov 15 in class. Same format as first
exam, except you can bring two note sheets (e.g., the one
from the first exam and another)
Exam/solution from 2008 will be posted on website shortly
Exam covers through Chapter 10
3. 2
In the News: Boulder municipalization
• Last week Boulder, CO narrowly voted to move
forward with municipalization of their electric grid
• Currently Boulder is in the Xcel Energy electric service
territory (Xcel is a large Investor Owned Utility)
• Xcel has recently decided not to continue funding
the Boulder “SmartGridCity” initiative, which has
cost $45 million, triple its original cost.
• Xcel does not wish to sell its electric grid in
Boulder, saying it would be extremely expensive
for Boulder to go on their own.
Source: NY Times 11/3/11; Thanks to Margaret for pointing out this story
4. 3
Power System Protection
Main idea is to remove faults as quickly as possible
while leaving as much of the system intact as
possible
Fault sequence of events
1. Fault occurs somewhere on the system, changing the
system currents and voltages
2. Current transformers (CTs) and potential transformers
(PTs) sensors detect the change in currents/voltages
3. Relays use sensor input to determine whether a fault has
occurred
4. If fault occurs relays open circuit breakers to isolate fault
5. 4
Power System Protection
Protection systems must be designed with both
primary protection and backup protection in case
primary protection devices fail
In designing power system protection systems
there are two main types of systems that need to be
considered:
1. Radial: there is a single source of power, so power
always flows in a single direction; this is the
easiest from a protection point of view
2. Network: power can flow in either direction:
protection is much more involved
6. 5
Radial Power System Protection
Radial systems are primarily used in the lower
voltage distribution systems. Protection actions
usually result in loss of customer load, but the
outages are usually quite local.
The figure shows
potential protection
schemes for a
radial system. The
bottom scheme is
preferred since it
results in less lost load
7. 6
Radial Power System Protection
In radial power systems the amount of fault current is
limited by the fault distance from the power source:
faults further done the feeder have less fault current
since the current is limited by feeder impedance
Radial power system protection systems usually use
inverse-time overcurrent relays.
Coordination of relay current settings is needed to
open the correct breakers
8. 7
Inverse Time Overcurrent Relays
Inverse time overcurrent relays respond instan-
taneously to a current above their maximum setting
They respond slower to currents below this value
but above the pickup current value
9. 8
Inverse Time Relays, cont'd
The inverse time characteristic provides backup
protection since relays further upstream (closer to
power source) should eventually trip if relays closer
to the fault fail
Challenge is to make sure the minimum pickup
current is set low enough to pick up all likely faults,
but high enough not to trip on load current
When outaged feeders are returned to service there
can be a large in-rush current as all the motors try to
simultaneously start; this in-rush current may re-trip
the feeder
10. 9
Inverse Time Overcurrent Relays
Relays have
traditionally been
electromechanical
devices, but are
gradually being
replaced by
digital relays
Current and time
settings are ad-
justed using dials
on the relay
11. 10
Protection of Network Systems
In a networked system there are a number of
difference sources of power. Power flows are
bidirectional
Networked system offer greater reliability, since
the failure of a single device does not result in a
loss of load
Networked systems are usually used with the
transmission system, and are sometimes used with
the distribution systems, particularly in urban areas
12. 11
Network System Protection
Removing networked elements require the opening
of circuit breakers at both ends of the device
There are several common protection schemes;
multiple overlapping schemes are usually used
1. Directional relays with communication between
the device terminals
2. Impedance (distance) relays.
3. Differential protection
13. 12
Directional Relays
Directional relays are commonly used to protect
high voltage transmission lines
Voltage and current measurements are used to
determine direction of current flow (into or out of
line)
Relays on both ends of line communicate and will
only trip the line if excessive current is flowing into
the line from both ends
– line carrier communication is popular in which a high
frequency signal (30 kHz to 300 kHz) is used
– microwave communication is sometimes used
14. 13
Impedance Relays
Impedance (distance) relays measure ratio of
voltage to current to determine if a fault exists on a
particular line
1 1
12 12
Assume Z is the line impedance and x is the
normalized fault location (x 0 at bus 1, x 1 at bus 2)
V V
Normally is high; during fault
I I
xZ
15. 14
Impedance Relays Protection Zones
To avoid inadvertent tripping for faults on other
transmission lines, impedance relays usually have
several zones of protection:
– zone 1 may be 80% of line for a 3f fault; trip is
instantaneous
– zone 2 may cover 120% of line but with a delay to prevent
tripping for faults on adjacent lines
– zone 3 went further; most removed due to 8/14/03 events
The key problem is that different fault types will
present the relays with different apparent
impedances; adequate protection for a 3f fault gives
very limited protection for LL faults
16. 15
Impedance Relay Trip Characteristics
Source: August 14th 2003 Blackout Final Report, p. 78
17. 16
Differential Relays
Main idea behind differential protection is that
during normal operation the net current into a
device should sum to zero for each phase
– transformer turns ratios must, of course, be considered
Differential protection is used with geographically
local devices
– buses
– transformers
– generators
1 2 3 0 for each phase
except during a fault
I I I
18. 17
Other Types of Relays
In addition to providing fault protection, relays are
used to protect the system against operational
problems as well
Being automatic devices, relays can respond much
quicker than a human operator and therefore have
an advantage when time is of the essence
Other common types of relays include
– under-frequency for load: e.g., 10% of system load must
be shed if system frequency falls to 59.3 Hz
– over-frequency on generators
– under-voltage on loads (less common)
19. 18
Sequence of Events Recording
During major system disturbances numerous relays
at a number of substations may operate
Event reconstruction requires time synchronization
between substations to figure out the sequence of
events
Most utilities now have sequence of events
recording that provide time synchronization of at
least 1 microsecond
20. 19
Use of GPS for Fault Location
Since power system lines may span hundreds of
miles, a key difficulty in power system restoration is
determining the location of the fault
One newer technique is the use of the global
positioning system (GPS).
GPS can provide time synchronization of about 1
microsecond
Since the traveling electromagnetic waves propagate
at about the speed of light (300m per microsecond),
the fault location can be found by comparing arrival
times of the waves at each substation
21. 20
Power System Transient Stability
In order to operate as an interconnected system all of
the generators (and other synchronous machines)
must remain in synchronism with one another
– synchronism requires that (for two pole machines) the
rotors turn at exactly the same speed
Loss of synchronism results in a condition in which
no net power can be transferred between the
machines
A system is said to be transiently unstable if
following a disturbance one or more of the
generators lose synchronism
22. 21
Generator Transient Stability Models
In order to study the transient response of a power
system we need to develop models for the generator
valid during the transient time frame of several
seconds following a system disturbance
We need to develop both electrical and mechanical
models for the generators
24. 23
Generator Electrical Model
The simplest generator model, known as the
classical model, treats the generator as a voltage
source behind the direct-axis transient reactance;
the voltage magnitude is fixed, but its angle
changes according to the mechanical dynamics
'
( ) sin
T a
e
d
V E
P
X
25. 24
Generator Mechanical Model
Generator Mechanical Block Diagram
m
D
e
( )
mechanical input torque (N-m)
J moment of inertia of turbine & rotor
angular acceleration of turbine & rotor
T damping torque
T ( ) equivalent electrical torque
m m D e
m
T J T T
T
26. 25
Generator Mechanical Model, cont’d
s
s s
s s
In general power = torque angular speed
Hence when a generator is spinning at speed
( )
( ( ))
( )
Initially we'll assume no damping (i.e., 0)
Then
m m D e
m m D e m
m m D e
D
m e
T J T T
T J T T P
P J T P
T
P P
s
( )
is the mechanical power input, which is assumed
to be constant throughout the study time period
m
m
J
P
27. 26
Generator Mechanical Model, cont’d
s
s s
s
s
( )
rotor angle
( )
inertia of machine at synchronous speed
Convert to per unit by dividing by MVA rating, ,
( ) 2
m e m
m s
m
m m s
m m
m e m
B
m e s
B B B
P P J
t
d
dt
P P J J
J
S
P P J
S S S
2 s
28. 27
Generator Mechanical Model, cont’d
s
2
2
( ) 2
2
( ) 1
(since 2 )
2
Define H per unit inertia constant (sec)
2
All values are now converted to per unit
( ) Define
Then ( )
m e s
B B B s
m e s
s s
B B s
s
B
m e
s s
m e
P P J
S S S
P P J
f
S S f
J
S
H H
P P M
f f
P P
M
29. 28
Generator Swing Equation
This equation is known as the generator swing equation
( )
Adding damping we get
( )
This equation is analogous to a mass suspended by
a spring
m e
m e
P P M
P P M D
kx gM Mx Dx
30. 29
Single Machine Infinite Bus (SMIB)
To understand the transient stability problem we’ll
first consider the case of a single machine
(generator) connected to a power system bus with a
fixed voltage magnitude and angle (known as an
infinite bus) through a transmission line with
impedance jXL
32. 31
SMIB Equilibrium Points
'
Equilibrium points are determined by setting the
right-hand side to zero
sin
a
M
d L
E
M D P
X X
'
'
th
1
sin 0
Define X
sin
a
M
d L
d L
M th
a
E
P
X X
X X
P X
E
33. 32
Transient Stability Analysis
For transient stability analysis we need to consider
three systems
1. Prefault - before the fault occurs the system is
assumed to be at an equilibrium point
2. Faulted - the fault changes the system equations,
moving the system away from its equilibrium
point
3. Postfault - after fault is cleared the system
hopefully returns to a new operating point
34. 33
Transient Stability Solution Methods
There are two methods for solving the transient
stability problem
1. Numerical integration
this is by far the most common technique, particularly
for large systems; during the fault and after the fault the
power system differential equations are solved using
numerical methods
2. Direct or energy methods; for a two bus system
this method is known as the equal area criteria
mostly used to provide an intuitive insight into the
transient stability problem
35. 34
SMIB Example
Assume a generator is supplying power to an
infinite bus through two parallel transmission lines.
Then a balanced three phase fault occurs at the
terminal of one of the lines. The fault is cleared by
the opening of this line’s circuit breakers.
36. 35
SMIB Example, cont’d
Simplified prefault system
1
The prefault system has two
equilibrium points; the left one
is stable, the right one unstable
sin M th
a
P X
E
37. 36
SMIB Example, Faulted System
During the fault the system changes
The equivalent system during the fault is then
During this fault no
power can be transferred
from the generator to
the system
38. 37
SMIB Example, Post Fault System
After the fault the system again changes
The equivalent system after the fault is then
39. 38
SMIB Example, Dynamics
e
During the disturbance the form of P ( ) changes,
altering the power system dynamics:
1
sin
a th
M
th
E V
P
M X