The power transmission system is increasingly dependent
on accurate time-stamping of digitally sampled values
used for protection and control. In particular, real-time
streaming of data from networked Phasor Measurement
Units (PMUs) for wide area ‘closed loop’ automated
control applications implies a critical dependence of
accurate, available, and reliable microsecond-level
timing.
While microsecond accuracy is easily met by GNSS
timing receivers, GNSS signals for open civilian use are
weak and also lack effective authentication mechanisms.
GNSS timing receivers are therefore vulnerable to
interference from malicious or inadvertent radio noise
(jamming) and susceptible to ‘spoofing’ with generated
GNSS-signals containing misleading timing and
navigation data.
The overall goal of the COSECTIME project funded by
Statnett is to demonstrate the applicability of state-of-
the art fiber-optic time transfer techniques for traceable,
secure and redundant synchronization of digital power
transmission protection and control applications. In full
deployment , the transmission system operator (TSO)
will generate redundant autonomous UTC-traceable
atomic timescales and distribute timing through
redundant fiber optic networks also under TSO control.
Here we present results from a pilot demonstration of
timing distribution to the Statnett R&D project pilot IEC
61850 digital substation.
The modern-day power grid aims at providing reliable and quality power, which requires careful monitoring of the power grid against catastrophic faults.
Therefore one promising way is to provide the system a wide protection and control named as “Wide Area Measurement and Control System” /PMU is required.
A Novel Back Up Wide Area Protection Technique for Power Transmission Grids U...Power System Operation
Current differential protection relays are widely applied
to the protection of electrical plant due to their simplicity,
sensitivity and stability for internal and external faults. The proposed
idea has the feature of unit protection relays to protect large
power transmission grids based on phasor measurement units. The
principle of the protection scheme depends on comparing positive
sequence voltage magnitudes at each bus during fault conditions
inside a system protection center to detect the nearest bus to
the fault. Then the absolute differences of positive sequence current
angles are compared for all lines connecting to this bus to
detect the faulted line. The new technique depends on synchronized
phasor measuring technology with high speed communication
system and time transfer GPS system. The simulation of the interconnecting
system is applied on 500 kV Egyptian network using
Matlab Simulink. The new technique can successfully distinguish
between internal and external faults for interconnected lines. The
new protection scheme works as unit protection system for long
transmission lines. The time of fault detection is estimated by 5
msec for all fault conditions and the relay is evaluated as a back
up relay based on the communication speed for data transferring.
Real Time and Wireless Smart Faults Detection Device for Wind Turbineschokrio
In new energy development, wind power has boomed. It is due to the proliferation of wind parks and their operation in supplying the national electric grid with low cost and clean resources. Hence, there is an increased need to establish a proactive maintenance for wind turbine machines based on remote control and monitoring. That is necessary with a real-time wireless connection in offshore or inaccessible locations while the wired method has many flaws. The objective of this strategy is to prolong wind turbine lifetime and to increase productivity. The hardware of a remote control and monitoring system for wind turbine parks is designed. It takes advantage of GPRS or Wi-Max wireless module to collect data measurements from different wind machine sensors through IP based multi-hop communication. Computer simulations with Proteus ISIS and OPNET software tools have been conducted to evaluate the performance of the studied system. Study findings show that the designed device is suitable for application in a wind park.
The modern-day power grid aims at providing reliable and quality power, which requires careful monitoring of the power grid against catastrophic faults.
Therefore one promising way is to provide the system a wide protection and control named as “Wide Area Measurement and Control System” /PMU is required.
A Novel Back Up Wide Area Protection Technique for Power Transmission Grids U...Power System Operation
Current differential protection relays are widely applied
to the protection of electrical plant due to their simplicity,
sensitivity and stability for internal and external faults. The proposed
idea has the feature of unit protection relays to protect large
power transmission grids based on phasor measurement units. The
principle of the protection scheme depends on comparing positive
sequence voltage magnitudes at each bus during fault conditions
inside a system protection center to detect the nearest bus to
the fault. Then the absolute differences of positive sequence current
angles are compared for all lines connecting to this bus to
detect the faulted line. The new technique depends on synchronized
phasor measuring technology with high speed communication
system and time transfer GPS system. The simulation of the interconnecting
system is applied on 500 kV Egyptian network using
Matlab Simulink. The new technique can successfully distinguish
between internal and external faults for interconnected lines. The
new protection scheme works as unit protection system for long
transmission lines. The time of fault detection is estimated by 5
msec for all fault conditions and the relay is evaluated as a back
up relay based on the communication speed for data transferring.
Real Time and Wireless Smart Faults Detection Device for Wind Turbineschokrio
In new energy development, wind power has boomed. It is due to the proliferation of wind parks and their operation in supplying the national electric grid with low cost and clean resources. Hence, there is an increased need to establish a proactive maintenance for wind turbine machines based on remote control and monitoring. That is necessary with a real-time wireless connection in offshore or inaccessible locations while the wired method has many flaws. The objective of this strategy is to prolong wind turbine lifetime and to increase productivity. The hardware of a remote control and monitoring system for wind turbine parks is designed. It takes advantage of GPRS or Wi-Max wireless module to collect data measurements from different wind machine sensors through IP based multi-hop communication. Computer simulations with Proteus ISIS and OPNET software tools have been conducted to evaluate the performance of the studied system. Study findings show that the designed device is suitable for application in a wind park.
In this paper prepared a systems to that amount the units of the fitness about structural elements within Reinforced Concrete (RC), at total times, partially atop the perfect coverage concerning sensors is provided. As a result, the records about the distances within the sensor’s near nodes and its sensing areas are the only want because concerning every sensor into the recent algorithms. Furthermore, based totally completely regarding the simulations, great improvement performs stay seen along the lifespan regarding a variety concerning existing lifespan maximization algorithms, anybody is a cease end result related to the newly proposed algorithm. The promoted sensor mark hard-ware trigger the PZT sensor and collect the responses acquires beyond the structural element. It moreover send collected information to an information middle because of similarly science yet analysis within an energy efficient manner using low power wireless verbal exchange technology. The brought ingress in conformity with and the evaluation atop the accrued information operate lie remotely executed by means of using a net interface. Performance effects showcase therefore a good deal the fractures great enough within consequence including purpose structural problems be able continue to be efficiently detected together with the promoter rule
Cluster Computing Environment for On - line Static Security Assessment of lar...IDES Editor
The increased size of modern power systems
demand faster and accurate means for the security assessment,
so that the decisions for reliable and secure operation planning
could be drawn in a systematic manner. Large computational
overhead is the major impediment in preventing the power
system security assessment (PSSA) from on-line use. To
mitigate this problem, this paper proposes, a cluster computing
based architecture for power system static security assessment,
utilizing the tools in the open source domain. A variant of the
master/slave pattern is used for deploying the cluster of
workstations (COW), which act as the computational engine
for the on-line PSSA. The security assessment is performed
utilizing the developed composite security index that can
accurately differentiate the secure and non-secure cases and
has been defined as a function of bus voltage and line flow
limit violations. Due to the inherent parallel structure of
security assessment algorithm and to exploit the potential of
distributed computing, domain decomposition is employed for
parallelizing the sequential algorithm. Extensive
experimentations were carried out on IEEE 57 bus and IEEE
145-bus 50 machine standard test systems for demonstrating
the validity of the proposed architecture.
Wide area monitoring systems (WAMS) are essentially based on the new data acquisition technology of phasor measurement and allow monitoring transmission system conditions over large areas in view of detecting and further counteracting grid instabilities.
Smart Grid
Why do we need Smart Grid?
What is Smart Grid?
Smart Grid conceptual model
Wide Area Monitoring systems
What is WAMs
WAMS Architecture
Applications of Phasor Measurement Unit (PMU)
Concluding Remarks
As the world’s electricity systems face a number of challenges
such as
New dynamics of future demand and supply
Ageing infrastructure
Complex interconnected grids
Integration of large number of renewable generation sources
Need to lower carbon emissions
New type of loads such as Electric Vehicles
A REVIEW OF SELF HEALING SMART GRIDS USING THE MULTIAGENT SYSTEMijiert bestjournal
This paper is trying review different techniques us ed for self healing of the smart grid network. A smart grid has taken a very high importance in th e last ten years or so. Then the advancement in smart grid has taken a major importance. One of the most important aspects in the field of smart grid is a self healing of fault,and this att racted the researchers. As described in many research papers,one of the main requirements of th e electrical grid is to maintain zero gap between generation and distribution [2,3,4]. Howe ver deregulation and decentralized generation has given with the information and communication te chnology (ICT). This paper will summarize latest available techniques for self healing smart grids.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Design of an Advanced Phasor Data Concentrator for Monitoring of Distributed ...Reza Pourramezan
Published in IEEE Transactions on Industrial Informatics
2017
Authors: Reza Pourramezan, Younes Seyedi, Houshang Karimi, Guchuan Zhu, and Michel Mont-Briant
DOI: 10.1109/TII.2017.2697438
The Schneider Electric MetConsole® Low Level Wind Shear Alert System (LLWAS) – a module of the company’s MetConsole Aviation Weather Suite – provides the reliable and timely information and alerting to the gust fronts, downbursts or microbursts induced by thunderstorms. It helps minimize disruptions, caused by these wind shear conditions, to aircraft flying below 1,000 feet while approaching and departing airports.
An investigation on the application and challenges for wide area monitoring a...journalBEEI
The complexity and dynamics of the modern power system are continuously changing due to the penetration of a large number of renewable energy sources and changing load patterns. These growing complexities have caused numerous outages around the world, primarily due to the lack of situational awareness about the grid operating states. Rectification of this problem requires advanced sensing technology to accurately capture the dynamics of the system for better monitoring and control. Measurement of synchrophasors is a potential solution to improve situational awareness in the grid. The synchrophasors technology is now widely accepted throughout the world and has the potential to replace the existing SCADA system in monitoring and control of the power system. Their installation enables efficient resolution to substantially improve transmission system planning, maintenance, operation, and energy trading. This paper reviews the state of the art potential applications that the PMU based WAMC offers to the power system. It also includes technical perspectives, challenges, and future possibilities.
Voltage Stability Assessment using Phasor Measurement Units in Power Network ...Satyendra Singh
This paper presents the assessment methodology for
voltage stability using Phasor Measurement Unit (PMU) with
complete system observability. For full power system
observability, the PMU placement is considered with and without
conventional power flow as well as injection measurement such
that minimum number of PMU’s is used. Data obtained by
PMU’s are used for voltage stability assessment with the help of
L-Index. As the PMU gives real time voltage and current phasors
and L-index is dependent on voltage and admittance values, thus
the L-index so obtained can be used as real time voltage stability
indicator. The case study has been carried out on IEEE-14 bus
system.
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.
To Get any Project for CSE, IT ECE, EEE Contact Me @ 09666155510, 09849539085 or mail us - ieeefinalsemprojects@gmail.com-Visit Our Website: www.finalyearprojects.org
Design of Real-time Self Establish Wireless Sensor For Dynamic NetworkIJTET Journal
Abstract— Wireless sensor network in the recent trend engaged with high speed responsive real time system. This type of real time system requires reliable and compatible sensor to work in an environment where the sensor is dynamic in nature. Sensor network is to design to perform a set of high level information processing tasks such as detection, tracking or classification. Application of sensor networks is wide ranging and can vary significantly in application requirements, modes of deployment, sensing modality, power supply. Dynamic configuring of wireless sensor involves timing constraints to configure the sensor or to switch an adaptive sensor when working node failure due to energy, data rate, packet loss and range of the sensor. So the network, with such dynamic nature needs a background sensor which is able to be switched when the active sensor has a problem and improper functioning due to the network deploy environment. The background sensor lies inactive inside the range of the active sensor; ensure that the sensor is about to die and make sure the last data transfer successful find delay time to switch. Fault tolerance is achieved by switching the background sensor with the active sensor, where the background sensor self establish themselves in the network and perform similar routing metrics and configure them self with the network as soon they are switched. Once, the actual sensor retained back to the active condition then the background sensor will go to inactive state during this switching process the sensor will not loss data packet.
In this paper prepared a systems to that amount the units of the fitness about structural elements within Reinforced Concrete (RC), at total times, partially atop the perfect coverage concerning sensors is provided. As a result, the records about the distances within the sensor’s near nodes and its sensing areas are the only want because concerning every sensor into the recent algorithms. Furthermore, based totally completely regarding the simulations, great improvement performs stay seen along the lifespan regarding a variety concerning existing lifespan maximization algorithms, anybody is a cease end result related to the newly proposed algorithm. The promoted sensor mark hard-ware trigger the PZT sensor and collect the responses acquires beyond the structural element. It moreover send collected information to an information middle because of similarly science yet analysis within an energy efficient manner using low power wireless verbal exchange technology. The brought ingress in conformity with and the evaluation atop the accrued information operate lie remotely executed by means of using a net interface. Performance effects showcase therefore a good deal the fractures great enough within consequence including purpose structural problems be able continue to be efficiently detected together with the promoter rule
Cluster Computing Environment for On - line Static Security Assessment of lar...IDES Editor
The increased size of modern power systems
demand faster and accurate means for the security assessment,
so that the decisions for reliable and secure operation planning
could be drawn in a systematic manner. Large computational
overhead is the major impediment in preventing the power
system security assessment (PSSA) from on-line use. To
mitigate this problem, this paper proposes, a cluster computing
based architecture for power system static security assessment,
utilizing the tools in the open source domain. A variant of the
master/slave pattern is used for deploying the cluster of
workstations (COW), which act as the computational engine
for the on-line PSSA. The security assessment is performed
utilizing the developed composite security index that can
accurately differentiate the secure and non-secure cases and
has been defined as a function of bus voltage and line flow
limit violations. Due to the inherent parallel structure of
security assessment algorithm and to exploit the potential of
distributed computing, domain decomposition is employed for
parallelizing the sequential algorithm. Extensive
experimentations were carried out on IEEE 57 bus and IEEE
145-bus 50 machine standard test systems for demonstrating
the validity of the proposed architecture.
Wide area monitoring systems (WAMS) are essentially based on the new data acquisition technology of phasor measurement and allow monitoring transmission system conditions over large areas in view of detecting and further counteracting grid instabilities.
Smart Grid
Why do we need Smart Grid?
What is Smart Grid?
Smart Grid conceptual model
Wide Area Monitoring systems
What is WAMs
WAMS Architecture
Applications of Phasor Measurement Unit (PMU)
Concluding Remarks
As the world’s electricity systems face a number of challenges
such as
New dynamics of future demand and supply
Ageing infrastructure
Complex interconnected grids
Integration of large number of renewable generation sources
Need to lower carbon emissions
New type of loads such as Electric Vehicles
A REVIEW OF SELF HEALING SMART GRIDS USING THE MULTIAGENT SYSTEMijiert bestjournal
This paper is trying review different techniques us ed for self healing of the smart grid network. A smart grid has taken a very high importance in th e last ten years or so. Then the advancement in smart grid has taken a major importance. One of the most important aspects in the field of smart grid is a self healing of fault,and this att racted the researchers. As described in many research papers,one of the main requirements of th e electrical grid is to maintain zero gap between generation and distribution [2,3,4]. Howe ver deregulation and decentralized generation has given with the information and communication te chnology (ICT). This paper will summarize latest available techniques for self healing smart grids.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Design of an Advanced Phasor Data Concentrator for Monitoring of Distributed ...Reza Pourramezan
Published in IEEE Transactions on Industrial Informatics
2017
Authors: Reza Pourramezan, Younes Seyedi, Houshang Karimi, Guchuan Zhu, and Michel Mont-Briant
DOI: 10.1109/TII.2017.2697438
The Schneider Electric MetConsole® Low Level Wind Shear Alert System (LLWAS) – a module of the company’s MetConsole Aviation Weather Suite – provides the reliable and timely information and alerting to the gust fronts, downbursts or microbursts induced by thunderstorms. It helps minimize disruptions, caused by these wind shear conditions, to aircraft flying below 1,000 feet while approaching and departing airports.
An investigation on the application and challenges for wide area monitoring a...journalBEEI
The complexity and dynamics of the modern power system are continuously changing due to the penetration of a large number of renewable energy sources and changing load patterns. These growing complexities have caused numerous outages around the world, primarily due to the lack of situational awareness about the grid operating states. Rectification of this problem requires advanced sensing technology to accurately capture the dynamics of the system for better monitoring and control. Measurement of synchrophasors is a potential solution to improve situational awareness in the grid. The synchrophasors technology is now widely accepted throughout the world and has the potential to replace the existing SCADA system in monitoring and control of the power system. Their installation enables efficient resolution to substantially improve transmission system planning, maintenance, operation, and energy trading. This paper reviews the state of the art potential applications that the PMU based WAMC offers to the power system. It also includes technical perspectives, challenges, and future possibilities.
Voltage Stability Assessment using Phasor Measurement Units in Power Network ...Satyendra Singh
This paper presents the assessment methodology for
voltage stability using Phasor Measurement Unit (PMU) with
complete system observability. For full power system
observability, the PMU placement is considered with and without
conventional power flow as well as injection measurement such
that minimum number of PMU’s is used. Data obtained by
PMU’s are used for voltage stability assessment with the help of
L-Index. As the PMU gives real time voltage and current phasors
and L-index is dependent on voltage and admittance values, thus
the L-index so obtained can be used as real time voltage stability
indicator. The case study has been carried out on IEEE-14 bus
system.
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.
To Get any Project for CSE, IT ECE, EEE Contact Me @ 09666155510, 09849539085 or mail us - ieeefinalsemprojects@gmail.com-Visit Our Website: www.finalyearprojects.org
Design of Real-time Self Establish Wireless Sensor For Dynamic NetworkIJTET Journal
Abstract— Wireless sensor network in the recent trend engaged with high speed responsive real time system. This type of real time system requires reliable and compatible sensor to work in an environment where the sensor is dynamic in nature. Sensor network is to design to perform a set of high level information processing tasks such as detection, tracking or classification. Application of sensor networks is wide ranging and can vary significantly in application requirements, modes of deployment, sensing modality, power supply. Dynamic configuring of wireless sensor involves timing constraints to configure the sensor or to switch an adaptive sensor when working node failure due to energy, data rate, packet loss and range of the sensor. So the network, with such dynamic nature needs a background sensor which is able to be switched when the active sensor has a problem and improper functioning due to the network deploy environment. The background sensor lies inactive inside the range of the active sensor; ensure that the sensor is about to die and make sure the last data transfer successful find delay time to switch. Fault tolerance is achieved by switching the background sensor with the active sensor, where the background sensor self establish themselves in the network and perform similar routing metrics and configure them self with the network as soon they are switched. Once, the actual sensor retained back to the active condition then the background sensor will go to inactive state during this switching process the sensor will not loss data packet.
In-service synchronization monitoring and assuranceADVA
Smart grids, next-generation mobile networks and digital studio broadcasting all need accurate and stable synchronization for reliable and optimized operations. To ensure synchronization is kept within the expected accuracy levels, in-service monitoring and assurance is key. In his talk WSTS talk, Nir Laufer discussed solutions and best practice to enable affordable in-service synchronization monitoring. He reviewed use cases in telecoms, power utilities and broadcasting networks and demonstrated how to achieve full visibility of the synchronization network.
Satellite dish antenna control for distributed mobile telemedicine nodesIJICTJOURNAL
The positioning control of a dish antenna mounted on distributed mobile telemedicine nodes (DMTNs) within Nigeria communicating via NigComSat-1R has been presented. It was desired to improve the transient and steady performance of satellite dish antenna and reduce the effect of delay during satellite communication. In order to overcome this, the equations describing the dynamics of the antenna positioning system were obtained and transformed into state space variable equations. A full state feedback controller was developed with forward path gain and an observer. The proposed controller was introduced into the closed loop of the dish antenna positioning control system. The system was subjected to unit step forcing function in MATLAB/Simulink simulation environment considering three different cases so as to obtain time domain parameters that characterized the transient and steady state response performances. The simulation results obtained revealed that the introduction of the full state feedback controller provided improved position tracking to unit step input with a rise time of 0.42 s, settling time of 1.22 s and overshoot of 4.91%. With the addition of observer, the rise time achieved was 0.39 s, settling time of 1.31 s, and overshoot of 10.7%. The time domain performance comparison of the proposed system with existing systems revealed its superiority over them.
Contribution Of Real Time Network (NRTK) for improvement of accuracyNzar Braim
Contribution Of Real Time Network (NRTK) for improvement of accuracy in GPS.
RTK GPS has seen incredible mechanical advances in the course of recent years and is currently routinely utilized in a wide assortment of building type applications. RTK GPS gives a centimeter-level situation in a moment or two, permitting laborers to get the exactness. One GPS
collector is put in a control point (named the reference station) with known directions. RTK framework consolidates GPS data and information radio correspondence with cutting edge calculations to figure the exact situation of the tasks, for example, parkway and extension, GIS venture.
There is a pressing need to distribute accurate timing, i.e., frequency and/or Time of Day (ToD), across Packet Switched Networks (PSNs) for applications such as cellular backhaul. This paper reviews the main issues involved in timing over packet (ToP) demarcation and provides best practices for ToP demarcation and performance monitoring.
Stepping up to the Challenge on Tighter Time Accuracy.3G4G
By Tommy Cook & Tim Frost
Frequency synchronisation has been important in telecoms networks ever since the 1930s when techniques such as Frequency Division Multiplexing were introduced to transmit multiple voice calls over a single cable. With the advent of digitised Time Division Multiplexing in the 1960s, it became more important to avoid “slips”, where data is lost because the transmit and receive clocks are running at different frequencies.
*** Shared with Permission from ITP Journal Volume 10 | Part 1 - 2016 ***
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
Time distribution strategies in cellular networksNir Cohen
This paper reviews the various methodologies currently available for ensuring Time of Day (ToD) synchronization in cellular networks. It also introduces RAD’s revolutionary Distributed GMTM scheme, designed to deliver superb ToD accuracy at a lower cost in LTE and small cell networks, by bringing Grandmaster functionality closer to the base station in a small form factor device.
Energy-aware wireless mesh network deployment using optimization mechanismTELKOMNIKA JOURNAL
Wireless mesh networks are widely used to create network infrastructure in rural areas due to their flexible properties, such as self-healing mechanisms and associated redundant paths. For example, a wireless mesh network can suitably operate with limited battery power in wildlife monitoring applications. The locations of mobile routers to support mobile sensor nodes are essential for extending the system lifetime. This study proposes an energy-aware wireless mesh network deployment optimization mechanism. The goal is to determine a suitable location for the mesh routers with the aim of maximizing network lifetime. After the location solution is obtained from the proposed mechanism, it is then evaluated for system lifetime and network performance by the network simulator (ns-3). The proposed method outperforms the brute-force method in terms of computation time for all amounts of mesh clients. For example, for 30 mesh clients, the proposed method uses only a few minutes, while the brute-force mechanism requires more than 200 minutes to complete the process. Furthermore, compared to the brute-force method, it achieves nearly the same system lifetime and other performance parameters, such as throughput, packet delivery ratio, and packet inter-arrival time. In the real implementation, in which the sensor node placements can be changed during the installation period owing to the environmental status or the recommendation of the installers, the results can be recalculated in a short period.
The Time and Frequency Laboratory of the Hellenic Institute of Metrology (EIM)eimgreece
1. Continuous and reliable local representation of Universal Coordinated Time - UTC(EIM).
2. Contribution to Temps Atomique International (TAI).
3. Reliable and continuous distribution of reference frequencies.
4. Traceability to the international standards.
5. Broadcast of standard time and frequency signals inside and outside EIM facilities.
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SVC PLUS Frequency Stabilizer Frequency and voltage support for dynamic grid...Power System Operation
SVC PLUS
Frequency Stabilizer
Frequency and voltage support for dynamic grid stability
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Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
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Data file handling has been effectively used in the program.
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This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
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Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
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• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Redundant secure timing sources and timing distribution to digital power protection and control applications
1.
94
Summary
Thepowertransmissionsystemisincreasinglydependent
on accurate time-stamping of digitally sampled values
used for protection and control. In particular, real-time
streaming of data from networked Phasor Measurement
Units (PMUs) for wide area ‘closed loop’ automated
control applications implies a critical dependence of
accurate, available, and reliable microsecond-level
timing.
While microsecond accuracy is easily met by GNSS
timing receivers, GNSS signals for open civilian use are
weak and also lack effective authentication mechanisms.
GNSS timing receivers are therefore vulnerable to
interference from malicious or inadvertent radio noise
(jamming) and susceptible to ‘spoofing’ with generated
GNSS-signals containing misleading timing and
navigation data.
The overall goal of the COSECTIME project funded by
Statnett is to demonstrate the applicability of state-of-
the art fiber-optic time transfer techniques for traceable,
secure and redundant synchronization of digital power
transmission protection and control applications. In full
deployment , the transmission system operator (TSO)
will generate redundant autonomous UTC-traceable
atomic timescales and distribute timing through
redundant fiber optic networks also under TSO control.
Here we present results from a pilot demonstration of
timing distribution to the Statnett R&D project pilot IEC
61850 digital substation.
1. Introduction – timing
requirements in the power
system
Thepowertransmissionsystemisincreasinglydependent
on accurate time-stamping of digitally sampled values
used in protection and control. Power system uses
of timing and associated accuracy requirements are
summarizedinfigure1.Foracomprehensiveoverviewof
power sector timing issues, see references [NASPI2017]
and [GSA2018].
The IEC 61850 requirement of microsecond accuracy
with respect to UTC can be met by properly installed and
characterized GNSS timing receivers [EURAMET2016]
in combination with timing distribution using the IEEE
1588 PTP precision timing protocol on the substation
process bus. However, GNSS signals for open civilian
use are weak and also lack effective authentication
mechanisms. GNSS timing receivers may therefore be
vulnerable to interference from malicious or inadvertent
radio noise (jamming) and susceptible to ‘spoofing’ with
generatedGNSS-signalscontainingmisleadingtimingand
navigationdata[Shepard2012].Malicioustimingattacksor
simplyinadvertenttimingerrorsmayhaveadverseimpact
on monitoring and control applications [Almas2018].
Applications studied in [Almas2018] illustrate the role of
precision timing as a valuable cyber-asset in power sector
control systems. For critical applications timing accuracy
requirements need to be complemented by requirements
on availability and integrity.
Redundant secure timing sources and
timing distribution to digital power
protection and control applications
H. HAUGLIN¤
, T. DUNKER¤
, A. WALLIN+, O. TUNGLAND*, N. HURZUK*, R. LØKEN*
¤
JUSTERVESENET, +VTT MIKES,*STATNETT,
¤
* Norway, *Finland
KEYWORDS
UTC, traceability, secure timing, redundant timing, IEEE 1588 PTP, cesium clocks
* hha@justervesenet.no
2.
95
Figure 2. Conceptual sketch of redundant traceable timescale generation and
distribution to digital power applications. UTC-traceability of TSO timescales
is maintained by fiber-optic time transfer to a national timing laboratory
participating in the realization of UTC [BIPM2013].
2. COSECTIME: Generation of
traceable atomic timing and
distribution through optical
networks
The COSECTIME (COordinated SECureTIME) project
is funded by the Norwegian TSO Statnett. The goal is
to demonstrate how synchronization requirements of
power system applications may be met independent of
GNSS. The project uses state-of-the-art fiber-optic time
transfer techniques for traceable, secure and redundant
synchronization. In full deployment (see figure 2), the
transmissionsystemoperator(TSO)generatesredundant
semi-autonomous UTC-traceable atomic timescales
and distributes timing through redundant fiber-optic
networks also under TSO control.
Figure 1: Power system uses of time-dependent data. Reproduced from [NASPI2017] Table 2.
3.
96
3. Setup of pilot demonstration
timing distribution to an IEC
61580 digital substation
The COSECTIME project pilot demonstration is
integrated into another Statnett R&D project building
and evaluating a pilot IEC 61850 Process Bus compliant
digital substation. See [Hurzuk2019] for a description.
The pilot demonstration setup is outlined in figure 3.
Substation clocks
Substation clocks (Meinberg M3000) were chosen
because they handle multiple external reference inputs
(GNSS, PPS, IRIG-B, 10 MHz, PTP), support a number
of different timing distribution modules, and incorporate
a multi-channel measurement system. See figure 4 for
a sketch of the substation clock configuration. A multi-
channel measurement system monitors the timing offset
of available external references against the substation
clock timescale. The reference selection algorithm
chooses among external references based on availability
and configured priority, with an additional option of
excluding ‘unacceptable’ external sources with timing
offsets outside a selectable threshold. The local rubidium
oscillator (Rb) is steered to follow the substation clock
timescale and may be used for extended holdover when
no other acceptable external references are available. The
substation clock timescale is distributed to the various
output modules.All PTP-GM (Grandmaster) modules for
the substation buses get timing from the substation clock
timescale, but run separate CPUs and network stacks.
Redundant Statnett master timescales are generated
by industrial cesium clocks (Microsemi 5071A) at
separate locations. The accuracy and traceability of
Statnett clocks with respect to UTC is maintained
by time transfer to the timescale UTC(JV) generated
by the Norwegian national timing laboratory at
Justervesenet (JV). We have established continuously
running clock comparisons via dedicated high-accuracy
IEEE 1588-2019 PTP-WR (Precision Time Protocol;
‘White Rabbit’) fiber-optic links between Statnett and
Justervesenet. PTP-WR links have been demonstrated to
maintainhighstabilityovermorethan1000kmofoptical
transport networks [Dierikx2016], suitable for running
direct sensitive comparisons of stable atomic clocks at
separate geographic locations. Clock comparison data
are the basis for occasional steering of Statnett cesium
clocks. The cesium clocks have to be steered a few
times per year to stay within a target of 100 ns offset
from UTC. The required frequency of steering depends
partly on the stability of the clock environment at
Statnett (temperature, humidity and magnetic fields) and
has been evaluated in the COSECTIME project. Fully
deployed, Statnett will have autonomous control over
timing sources and timing distribution to critical power
system control and monitoring applications. The role of
the national timing laboratory is to provide traceability
of Statnett timescale(s) to UTC and a running indirect
verification and supervision of Statnett timing. See
the telecom sector.
Figure 3. Setup of pilot demonstration of optical network timing distribution to an IEC 61850 digital substation. Timescales are generated by cesium
clocksattwoseparatelocations.Onecesiumclockislocatedatclocksite1whereitisthetimingsourceforaPTPGrandmaster(MeinbergM500with
MRS input card).Timing links use IEEE 1588-2008 PTP(default profile) over a combination of CWDM/DWDM optical transport network.Another
cesium clock is located at the digital substation with its PPS output connected directly to the substation clocks. Substation clock#1 is configured to
use timing over PTPfrom Cs clock#1 as the preferred external reference.
4.
97
well within a target 100 ns deviation over 100 days.
At the end of characterization at Justervesenet, both
clocks were nominally synchronized (frequency and
phase) to UTC using the ‘rapid UTC’ product from
BIPM [Petit2014]. Cesium clock#1 was deployed at
clock site 1 and placed in a server rack with forced air
(18 oC) convection cooling through the rack. Cesium
clock#2 was used as a portable clock for calibration of
link asymmetries and for on-site calibration of clock#1
at clock site 1. Cesium clock#2 was eventually placed at
the digital substation pilot to provide a redundant stable
time reference.
The influence of the clock environment was evident
for cesium clock#1. Through on-site calibration, we
found that the clock had gained a systematic rate change
of +4 ns/day compared to the calibration value in
Justervesenet’s laboratory. This change is mostly due to
a significantly lower operating temperature.
Cesium clock#2 deployed at the digital substation
was evaluated by comparison to the substation clock
GNSS timing (figure 6). Over 100 days, the average
clock rate error corresponds to 0.2 ns/day with respect
to the GNSS clock, and the long-term stability (> 10
days) is comparable to the stability measured in the lab
environment.
In conclusion: Cesium clocks are suitable for stable
timescale generation in an industrial environment, but
to maintain timing within 100 ns of UTC, clocks need
initial synchronization and sporadic steering based on
repeated on-site calibration or running verification.
Timing links
Timing links to the substation were established using
IEEE 1588-2008 PTP (default profile). The PTP link
to the digital substation is carried over a combination
of coarse (CWDM) and dense wavelength division
multiplexing (DWDM) optical transport networks.
Optical-to-electrical-to-optical transponder cards in the
DWDM system are used to convert between CWDM
and DWDM optical channels. See figure 3 for details.
Measurements and data archiving
Multi-reference source measurement data from both
substation clocks are logged every 12 s and automatically
archived daily at a central data repository for off-line
analysis.Additional measurements are performed using a
high-resolution time-interval counter (Keysight 53230A).
4. Results and operational
experiences from the pilot
demonstration
Suitability of cesium clocks for timescale generation
Clocks (Microsemi 5071A standard performance)
were initially calibrated at Justervesenet in a stable lab
environment, with strictly controlled temperature and
humidity. Clocks were also characterized in a climate
chamber to determine the influence of temperature
changes on the clock rate. Between 12 oC and 32
oC, cesium clock#2 showed a systematic rate change
correspondingto-0.5ns/day/K.Figure5leftpanelshows
the time deviation of cesium clock#1 and #2, indicating
that timing errors due to random clock noise should stay
Figure 4. Redundant digital substation clock configuration.
5.
98
convert between CWDM and DWDM optical channels.
Recently, WR links have been established using alien
wavelength (i.e. without transponders) in the Statnett
DWDM lab network, but not yet implemented in the
production network.Asimilar alien wavelength link has
been described by [Dierikx2016].
Standard PTPlinks
Currently operating links are between clock site 1 and
the digital substation and between clock site 1 and
Justervesenet. The links use the default profile IEEE
1588-2008 PTP. Clock comparison data of cesium
clock#1andcesiumclock#2throughthePTPlink(figure
3) is shown in figure 7.With the exception of a particular
200 ns dip of unknown cause, the PTP link itself does
not contribute to the variation observed for , which is
dominated by random timing noise of the cesium clocks.
The pilot link (figure 3) was found to have delay
asymmetry resulting in a systematic offset of 340
ns for timing received at the substation clock. This
asymmetry was calibrated using cesium clock#2 as a
mobile time transfer reference. Such asymmetries may
be compensated in the substation clock multi-reference
source measurement system.
Figure 6. Timing offset between cesium clock#2 and substation clock GNSS
timing over 100 days (October ‘18 – January’19). Timing offsets have been
smoothed by a 1 day wide moving average filter.
PTP-WR links
High accuracy IEEE 1588 PTP-WR [IEEE2019] was
initially intended to be used for the network timing
links in the COSECTIME project. The inability of WR
equipment to achieve stable timing lock for the link
shown in figure 3 and a similar link set up between
Statnett and JV is likely due to excess jitter in the
optical-to-electrical-to-optical transponders used to
Figure 5. Cesium clock frequency stability (left panel) and timing stability (right panel) in climate-controlled lab environment measured against
UTCr. The time deviation (right panel) indicate projected timing errors due to random clock noise. Blue lines indicate factory specifications for
standard and high-performance clocks
Figure 7. Comparison of cesium clocks
#1 and #2 by timing distribution over
IEEE 1588 PTP. Clock measurement
data are taken from the multi-channel
measurement system of substation
clock#1. Short-term noise is dominated by
the limited resolution of the measurement
system. Long-term (>1 day) variation is
consistent with fundamental clock noise
of 5071ACs clocks. The cause of the ‘dip’
at day 58427 (also shown in the inset) is
unknown.
6.
99
10 ns and will be evaluated during the COSECTIME
project. However, for any country-wide deployment of
network timing, using a mobile clock is labor-intensive
and logistically challenging. Calibration of network
delay asymmetries would benefit greatly if substations
were equipped with properly calibrated GNSS timing
reception chains (antenna/cable/lightning arrestor/
timing receiver) [EURAMET2016].
5. Discussion
The results presented above indicate that industrial
cesium clocks in combination with fiber-optic timing
distribution using IEEE 1588 PTP (standard and/
or high accuracy ‘White Rabbit’) is an alternative to
GNSS timing for power application sync requirements.
The clear benefit of this approach is that GNSS-timing
is only used as a secondary backup, thus eliminating
adverseimpactsofpotentialGNSSjammingorspoofing.
However, deploying redundant cesium clock timescale
systems and associated sync distribution networks
comes with additional challenges: (1) Maintaining
robust timescales, i.e. how to steer clocks and detect
failing individual clocks and still be able to provide an
accurate timescale; (2) Deploying a sync distribution
network with 100s of user sites and calibrating network
timing asymmetries; (3) Monitoring the overall integrity
of the timing distribution chains, including anomaly
detection. Such timing anomalies may be due to failing
equipment or changes in the sync distribution network
paths that affect timing asymmetries.
Disclaimer
Commercial products are identified for the sake of
completeness. No particular endorsements are implied.
Described apparent strengths or weaknesses may not be
characteristic of current equipment versions.
Bibliography
[Almas2018] Almas MS et al, Vulnerability of Synchrophasor-
based WAMPAC Applications to Time Synchronization Spoofing,
IEEE Transactions on Smart Grid 9(5) 2018. DOI: 10.1109/
TSG.2017.2665461
In conclusion: The established point-to-point links using
standard IEEE 1588-2008 PTPare sufficiently stable for
timing distribution to the digital substation. However, a
sensitive comparison of cesium clocks may benefit from
the high accuracy IEEE 1588 PTP-WR in combination
with high-resolution time interval measurements.
Cesium clock failure
Cesium clock #1 located at remote clock site 1 failed
after 482 days of continuous operation. While the clock
controller reported fatal loss of lock on the cesium
resonance, the clock continued operating on its internal
crystal oscillator. In normal operation, the crystal
oscillator is continuously disciplined to follow the long-
term accuracy and stability of the cesium resonance.
A system for detection of cesium clock alarms had
not been implemented, nor had a direct running link
between clock site 1 and Justervesenet been established.
However, PTP timing from cesium clock#1 was
distributed to substation clock#1 and used as the selected
synchronization source. Archived multi-reference data
show the effect of the clock failure on substation clock
timing (figure 8).
The clock failure could have been detected at several
layers of a timing chain as depicted in figure 2: (1) By
detecting ‘fatal error’alarms raised by the clock itself; (2)
By real time analysis of cesium clock comparison data,
either with another clock at the same site and/or through
high stability timing links to other sites with cesium
clocks; (3) At the substation clock, the PTP timing from
Cs#1 could be rapidly flagged ‘erroneous’and deselected
as the preferred sync source by a majority vote among
the available external synchronization sources (figure 8).
However, such a logic is not currently implemented in the
source selection algorithm of the substation clocks.
Calibration
Calibration of link delay asymmetries were carried out
using a cesium clock as a mobile timing reference. This
is convenient and accurate on short (< 1 day) calibration
campaigns. The calibration uncertainty is of magnitude
Figure 8. Failure of the remote cesium clock as measured by substation clock#1. Left panel: Time offset between PTP slave referenced to Cs#1 and PPS from Cs#2
(located at the substation). Middle panel: Timing offset between PTPslave referenced to Cs#1 and timing from the local Rb oscillator. Right panel: Multi-reference data
from all available external sources at the onset of failure.
7.
100
Synchronization Protocol for Networked Measurement and Control
Systems. URL: https://standards.ieee.org/standard/1588-2019.html
[NASPI2017] Time Synchronization in the Electric Power System,
North American Synchrophasor Initiative 2017. URL: https://www.
naspi.org/node/608
[Petit2014] Petit G et al, UTCr: a rapid realization of UTC, Metrologia
51, 33-9 2014
[Shepard2012] D.P. Shepard, T.E. Humphreys, A.A. Fansler,
“Evaluation of the Vulnerability of Phasor Measurement Units to GPS
Spoofing Attacks,” International Journal of Critical Infrastructure
Protection, Vol. 5, 2012. Downloaded from http://radionavlab.
ae.utexas.edu
[Śliwczyński2019] Śliwczyński et al, Calibrated optical time transfer
of UTC(k) for supervision of telecom networks, Metrologia 56 015006
2019. DOI: https://doi.org/10.1088/1681-7575/aaef57
[BIPM2013] Practical realization of the unit of time, International
Bureau of Weights and Measures, Paris 2013. Available at: https://
www.bipm.org/utils/en/pdf/SIApp2_s_en.pdf
[Dierikx2016] Dierikx E et al, White rabbit precision time protocol
on long-distance fiber links, IEEE Trans. Ultrason. Ferroelectr Freq.
Control 63 945–52 2016
[EURAMET2016] Use of GPS disciplined Oscillators for Frequency or
Time Traceablility, Euramet technical guide no 3 2016. Downloaded
from www.euramet.org
[GSA2018] Report on Time & Synchronization User Needs and
Requirements, European Global Satellite Systems Agency 2018.
Downloaded from www.gsc-europa.eu
[Hurzuk2019] N Hurzuk et al, paper contribution to Cigre B5
Colloquium, Tromsø 2019
[IEEE2019] IEEE Approved Draft Standard for a Precision Clock