This paper proposes a power system and communication network co-simulation framework that integrates a power system dynamics simulator (PSLF) and a network simulator (NS2). The framework uses a global scheduler to run the simulation in a discrete event-driven manner, eliminating errors from separate synchronization of the simulators. As a case study, an agent-based remote backup relay system is simulated using this co-simulation framework to demonstrate its effectiveness in evaluating smart grid applications involving interactions between power and communication systems.
A SGAM-Based Architecture for Synchrophasor Applications Facilitating TSO/DSO...Luigi Vanfretti
What this presentation tries to convey:
• We need to understand all the roles and actors involved when developing/deploying/using a synchrophasor application
• This can be done with an “Architecture Model” – here we use SGAM.
• To show how this approach allows to provide a “common view and language” for engineers from multiple smart grid domains, allowing them to understand their own role in the deployment/use/etc. of PMU applications.
IRJET- Study on Hierarchical Cluster-Based Energy-Efficient Routing in Wi...IRJET Journal
This document discusses energy-efficient hierarchical cluster-based routing protocols for wireless sensor networks. It begins by introducing wireless sensor networks and explaining that energy efficiency is a key challenge due to limited battery power. It then discusses clustering structures commonly used in wireless sensor networks, including hierarchical clustering where clusters form larger clusters in a tree structure. The document goes on to describe several hierarchical cluster-based routing protocols - LEACH, PEGASIS and TEEN - and compares their approaches to routing data to extend network lifetime. It concludes that these protocols each have advantages and disadvantages depending on the network topology, and that cluster formation and communication between clusters requires further research.
IEEE ICC 2012 - Dependability Assessment of Virtualized NetworksStenio Fernandes
This document proposes a method to estimate dependability attributes (risks) in virtual network environments. It uses a hierarchical modeling approach combining reliability block diagrams and stochastic Petri nets to model large virtual networks. The method was evaluated using a case study that generated virtual network requests and assessed dependability metrics like availability and reliability. The results demonstrate how dependability measures can vary between virtual networks and be impacted by common mode failures. Future work involves improving dependability through fault tolerance and incorporating metrics into resource allocation algorithms.
AN OPTIMIZED WEIGHT BASED CLUSTERING ALGORITHM IN HETEROGENEOUS WIRELESS SENS...cscpconf
The last few years have seen an increased interest in the potential use of wireless sensor networks (WSNs) in various fields like disastermanagementbattle field surveillance, and border security surveillance. In such applications, a large number of sensor nodes are deployed, which are often unattended and work autonomously. The process of dividing the network into interconnected substructures is called clustering and the interconnected substructures are called clusters. The cluster head (CH) of each cluster act as a coordinator within the substructure. Each CH acts as a temporary base station within its zone or cluster. It also communicates with other CHs. Clustering is a key technique used to extend the lifetime of a sensor network by reducing energy consumption. It can also increase network scalability. Researchers in all fields of wireless sensor network believe that nodes are homogeneous, but
some nodes may be of different characteristics to prolong the lifetime of a WSN and its reliability. We have proposed an algorithm for better cluster head selection based on weights for different parameter that influence on energy consumption which includes distance from base station as a new parameter to reduce number of transmissions and reduce energy consumption by sensor nodes. Finally proposed algorithm compared with the WCA, IWCA algorithm in terms of number of clusters and energy consumption.
Iaetsd use of mobile communication in data-intensiveIaetsd Iaetsd
This document summarizes a research paper on using mobile communication to improve energy efficiency in data-intensive wireless sensor networks. The paper proposes using mobile relay nodes that move to optimize positions for transmitting data from sensor sources to a base station. An algorithm is presented that iteratively relocates the mobile relay nodes to minimize the total energy used for both wireless transmission and node movement. The algorithm finds optimal positions for relay nodes within a fixed routing tree topology without changing the tree structure. This approach aims to reduce energy consumption in a holistic way compared to other mobility approaches.
The document discusses several research papers related to resource allocation and control in wireless networks:
1. One paper proposes a joint access control and resource allocation mechanism for massive machine-to-machine device access in LTE networks to address performance degradation from concurrent access attempts.
2. Another models power control in dense small cell networks as a mean field game and develops an algorithm for base stations to independently adjust transmit power.
3. A third studies opportunistic relaying and jamming for secure cooperative transmission and optimizes power allocation between signals and jamming to maximize ergodic secrecy rate.
The document covers resource allocation techniques to improve performance in various wireless network settings.
Selection of Energy Efficient Clustering Algorithm upon Cluster Head Failure ...ijsrd.com
Wireless Sensor Network (WSN) applications have increased in recent times in fields such as environmental sensing, area monitoring, air pollution monitoring, forest res detection, machine health monitoring, and landslide detection. In such applications, there is a high need of secure communication among sensor nodes. There are different techniques to secure network data transmissions, but due to power constraints of WSN, group key based mechanism is the most preferred one. Hence, to implement scalable energy efficient secure group communication, the best approach would be hierarchical based like Clustering. In most of the WSN designs based on clustering, Base Station (BS) is the central point of contact to the outside world and in case of its failure; it may lead to total disconnection in the communication. Critical applications like these cannot afford to have BS failure as it is a gateway from sensor networks to the outside world. In order to provide better fault tolerant immediate action, a new BS at some other physical location will have to take the charge. This may lead to a total change in the hierarchical network topology, which in turn leads to re-clustering the entire network and in turn formation of new security keys. Therefore, there is a need to find a suitable algorithm which clusters sensor nodes in such a way that when a BS fails and a new BS takes the charge, new group key gets established with minimum computation and less energy consumption.
A SGAM-Based Architecture for Synchrophasor Applications Facilitating TSO/DSO...Luigi Vanfretti
What this presentation tries to convey:
• We need to understand all the roles and actors involved when developing/deploying/using a synchrophasor application
• This can be done with an “Architecture Model” – here we use SGAM.
• To show how this approach allows to provide a “common view and language” for engineers from multiple smart grid domains, allowing them to understand their own role in the deployment/use/etc. of PMU applications.
IRJET- Study on Hierarchical Cluster-Based Energy-Efficient Routing in Wi...IRJET Journal
This document discusses energy-efficient hierarchical cluster-based routing protocols for wireless sensor networks. It begins by introducing wireless sensor networks and explaining that energy efficiency is a key challenge due to limited battery power. It then discusses clustering structures commonly used in wireless sensor networks, including hierarchical clustering where clusters form larger clusters in a tree structure. The document goes on to describe several hierarchical cluster-based routing protocols - LEACH, PEGASIS and TEEN - and compares their approaches to routing data to extend network lifetime. It concludes that these protocols each have advantages and disadvantages depending on the network topology, and that cluster formation and communication between clusters requires further research.
IEEE ICC 2012 - Dependability Assessment of Virtualized NetworksStenio Fernandes
This document proposes a method to estimate dependability attributes (risks) in virtual network environments. It uses a hierarchical modeling approach combining reliability block diagrams and stochastic Petri nets to model large virtual networks. The method was evaluated using a case study that generated virtual network requests and assessed dependability metrics like availability and reliability. The results demonstrate how dependability measures can vary between virtual networks and be impacted by common mode failures. Future work involves improving dependability through fault tolerance and incorporating metrics into resource allocation algorithms.
AN OPTIMIZED WEIGHT BASED CLUSTERING ALGORITHM IN HETEROGENEOUS WIRELESS SENS...cscpconf
The last few years have seen an increased interest in the potential use of wireless sensor networks (WSNs) in various fields like disastermanagementbattle field surveillance, and border security surveillance. In such applications, a large number of sensor nodes are deployed, which are often unattended and work autonomously. The process of dividing the network into interconnected substructures is called clustering and the interconnected substructures are called clusters. The cluster head (CH) of each cluster act as a coordinator within the substructure. Each CH acts as a temporary base station within its zone or cluster. It also communicates with other CHs. Clustering is a key technique used to extend the lifetime of a sensor network by reducing energy consumption. It can also increase network scalability. Researchers in all fields of wireless sensor network believe that nodes are homogeneous, but
some nodes may be of different characteristics to prolong the lifetime of a WSN and its reliability. We have proposed an algorithm for better cluster head selection based on weights for different parameter that influence on energy consumption which includes distance from base station as a new parameter to reduce number of transmissions and reduce energy consumption by sensor nodes. Finally proposed algorithm compared with the WCA, IWCA algorithm in terms of number of clusters and energy consumption.
Iaetsd use of mobile communication in data-intensiveIaetsd Iaetsd
This document summarizes a research paper on using mobile communication to improve energy efficiency in data-intensive wireless sensor networks. The paper proposes using mobile relay nodes that move to optimize positions for transmitting data from sensor sources to a base station. An algorithm is presented that iteratively relocates the mobile relay nodes to minimize the total energy used for both wireless transmission and node movement. The algorithm finds optimal positions for relay nodes within a fixed routing tree topology without changing the tree structure. This approach aims to reduce energy consumption in a holistic way compared to other mobility approaches.
The document discusses several research papers related to resource allocation and control in wireless networks:
1. One paper proposes a joint access control and resource allocation mechanism for massive machine-to-machine device access in LTE networks to address performance degradation from concurrent access attempts.
2. Another models power control in dense small cell networks as a mean field game and develops an algorithm for base stations to independently adjust transmit power.
3. A third studies opportunistic relaying and jamming for secure cooperative transmission and optimizes power allocation between signals and jamming to maximize ergodic secrecy rate.
The document covers resource allocation techniques to improve performance in various wireless network settings.
Selection of Energy Efficient Clustering Algorithm upon Cluster Head Failure ...ijsrd.com
Wireless Sensor Network (WSN) applications have increased in recent times in fields such as environmental sensing, area monitoring, air pollution monitoring, forest res detection, machine health monitoring, and landslide detection. In such applications, there is a high need of secure communication among sensor nodes. There are different techniques to secure network data transmissions, but due to power constraints of WSN, group key based mechanism is the most preferred one. Hence, to implement scalable energy efficient secure group communication, the best approach would be hierarchical based like Clustering. In most of the WSN designs based on clustering, Base Station (BS) is the central point of contact to the outside world and in case of its failure; it may lead to total disconnection in the communication. Critical applications like these cannot afford to have BS failure as it is a gateway from sensor networks to the outside world. In order to provide better fault tolerant immediate action, a new BS at some other physical location will have to take the charge. This may lead to a total change in the hierarchical network topology, which in turn leads to re-clustering the entire network and in turn formation of new security keys. Therefore, there is a need to find a suitable algorithm which clusters sensor nodes in such a way that when a BS fails and a new BS takes the charge, new group key gets established with minimum computation and less energy consumption.
A cross layer protocol based on mac and routing protocols for healthcare appl...ijassn
Using Wireless Sensor Networks (WSNs) in healthcare systems has had a lot of attention in recent years. In
much of this research tasks like sensor data processing, health states decision making and emergency
message sending are done by a remote server. Many patients with lots of sensor data consume a great deal
of communication resources, bring a burden to the remote server and delay the decision time and
notification time. A healthcare application for elderly people using WSN has been simulated in this paper.
A WSN designed for the proposed healthcare application needs efficient MAC and routing protocols to
provide a guarantee for the reliability of the data delivered from the patients to the medical centre. Based
on these requirements, A cross layer based on the modified versions of APTEEN and GinMAC has been
designed and implemented, with new features, such as a mobility module and routes discovery algorithms
have been added. Simulation results show that the proposed cross layer based protocol can conserve
energy for nodes and provide the required performance such as life time of the network, delay and
reliability for the proposed healthcare application.
A Survey of Fault Tolerance Methods in Wireless Sensor NetworksIRJET Journal
This document summarizes and analyzes various fault tolerance mechanisms for wireless sensor networks. It discusses mobile agent mechanisms, relay node mechanisms, and handover mechanisms. The document analyzes several existing fault tolerance methods, including Bayesian network models, probabilistic combinatorial optimization, dynamic power level adjustment, and integrated fault tolerance frameworks. Overall, the document provides an overview of important fault tolerance issues in wireless sensor networks and different approaches that have been proposed to address faults and improve reliability.
This document provides a literature review on beamforming techniques for 5G mobile communication systems. It discusses the objectives of focusing on beamforming techniques using a combination of the MUSIC and LMS algorithms in a new MLMS algorithm. It then reviews various beamforming algorithms such as LMS, TVLMS, MUSIC, and MLMS and compares their advantages and disadvantages. The document outlines future work plans to improve the MLMS algorithm by reducing iterations and convergence parameters to increase stability. It provides a work plan and references various literature on adaptive beamforming algorithms.
This document provides a review of evolutionary algorithms that have been used to optimize wireless sensor networks (WSNs). It begins with background on WSNs and discusses common issues like energy efficiency. It then reviews heuristic and metaheuristic approaches that have been used for clustering and routing in WSNs. The main part of the document focuses on four commonly used evolutionary algorithms - genetic algorithms, particle swarm optimization, harmony search algorithm, and flower pollination algorithm. For each algorithm, it provides an overview and details on how the algorithm works and pseudo-code. It concludes that these nature-inspired metaheuristic techniques can help optimize challenges in WSNs like cluster formation and energy consumption better than classical algorithms.
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology
Predicting Post Outage Transmission Line Flows using Linear Distribution FactorsDr. Amarjeet Singh
In order to design and implement preventive
and remedial actions, a continuous performance of fast
security analysis is imperative amid outages of system
components. Following the contingency of a system
component, State estimation and Load flow techniques
are the two popular techniques used to determine
system state variables leading to estimation of flows,
losses and violations in nodal voltages and transmission
line flows. But the dynamic state and complexity of the
system requires faster means of estimations which can
be achieved by linear distribution factors. The use of
Distribution factors in form of Power Transfer
Distribution Factors (PTDF) and Line Outage
Distribution Factors (LODF) which are transmission
line sensitivities with respect to active power exchanges
between buses and transmission line outages offer an
alternative to these two techniques being linear,
quicker, and non-iterative. Following the estimation of
the linear distribution factors from a reference
operating point (base case) and contingency cases
involving line outage, generator output variation and
outage of a Six bus network using Matlab programs,
the results show that by means of Linear Distribution
factors quick estimates of post outage line flows can be
made which match flow results obtained from DC load
flow analysis.
The document discusses several research papers related to wireless communications and networking. Specifically:
1) A mechanism for joint access control and resource allocation to address performance degradation from massive access attempts by M2M devices in LTE networks. It aims to maximize random access efficiency while satisfying delay requirements.
2) A mean field game approach for distributed power control in dense small cell networks underlying macrocells to minimize costs like interference.
3) An opportunistic relaying and jamming scheme with power allocation to maximize ergodic secrecy rate for secure cooperative networks against eavesdropping.
4) Several papers discuss topics like resource control in heterogeneous networks, geographical load balancing for energy efficiency, reputation systems in MANET
The document summarizes research on using mobile communication to improve the efficiency of data transmission in wireless sensor networks. It discusses three main approaches: using mobile base stations, data mules, and mobile relays. The proposed work uses low-cost mobile relay nodes that do not transport data but instead move to optimize transmission costs by reducing the distance between sensor nodes and the base station. This approach aims to lower energy consumption and transmission delays compared to other mobile approaches.
INCREASING WIRELESS SENSOR NETWORKS LIFETIME WITH NEW METHODijwmn
One of the most important issues in Wireless Sensor Networks (WSNs) is severe energy restrictions. As the
performance of Sensor Networks is strongly dependence to the network lifetime, researchers seek a way to
use node energy supply effectively and increasing network lifetime. As a consequence, it is crucial to use
routing algorithms result in decrease energy consumption and better bandwidth utilization. The purpose of
this paper is to increase Wireless Sensor Networks lifetime using LEACH-algorithm. So before clustering
Network environment, it is divided into two virtual layers (using distance between sensor nodes and base
station) and then regarding to sensors position in each of two layers, residual energy of sensor and
distance from base station is used in clustering. In this article, we compare proposed algorithm with wellknown LEACH and ELEACH algorithms in homogenous environment (with equal energy for all sensors)
and heterogeneous one (energy of half of sensors get doubled), also for static and dynamic situation of base
station. Results show that our proposed algorithm delivers improved performance.
This document summarizes a study on analyzing sensor network mobility using the OMNeT++ simulation framework and MiXiM modeling toolkit. The study models sensor node mobility and examines how various parameters affect mobility and energy consumption. The simulation involves 5 mobile sensor nodes moving randomly within a 700m x 700m area. Results show that average packet delay and energy consumption increase with higher node mobility. MiXiM provides mobility and connectivity handling in OMNeT++ and allows modeling mobile wireless networks like sensor networks.
A LOW-ENERGY DATA AGGREGATION PROTOCOL USING AN EMERGENCY EFFICIENT HYBRID ME...IJCNCJournal
Recent wireless sensor network focused on developing communication networks with minimal power and cost. To achieve this, several techniques have been developed to monitor a completely wireless sensor network. Generally, in the WSN network, communication is established between the source nodes and the destination node with an abundant number of hops, an activity which consumes much energy. The node existing between source and destination nodes consumes energy for transmission of data and maximize network lifetime. To overcome this issue, a new Emergency Efficient Hybrid Medium Access Control (EEHMAC) protocol is presented to reduce consumption of energy among a specific group of WSNs which will increase the network lifetime. The proposed model makes a residual battery is utilized for effective transmission of data with minimal power consumption. Compared with other models, the experimental results strongly showed that our model is not only able to reduce network lifetime but also to increase the overall network performance.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
IRJET- Energy Efficient Secure Communication in Wireless Sensor Networks: A S...IRJET Journal
This document summarizes research on improving energy efficiency and security in wireless sensor networks (WSNs). It discusses how WSNs have limitations like limited battery power, bandwidth, and storage in sensor nodes. Several energy efficient techniques and secure communication methods are described that aim to extend the lifetime of WSNs. This includes clustering protocols to select energy-efficient cluster heads, optimized multi-hop transmission to reduce energy consumption, and integrating routing and MAC protocols using techniques like honey bee optimization to further improve energy efficiency and security of data transmission in WSNs. The goal of these approaches is to minimize energy usage and maximize the reliable operation of resource-constrained WSNs.
Optimization of Transmission Schemes in Energy-Constrained Wireless Sensor Ne...IJEEE
This paper reviews medium access control
(MAC) in wireless sensor network (WSN),and different
management methods to save energy.MAC protocol
controls how sensors access a shared radio channel to
communicate with neighbours.
Cds based energy efficient topology control algorithm in wireless sensor net...eSAT Journals
Abstract Wireless Sensor Networks (WSNs) are a self organized network which consists of large number of sensor nodes that collects the data in a various environment [1, 2]. The sensors work on battery that have limited lifetime so it is a challenge to create an energy efficient network that can reduce the energy consumption and interference in the network graph and thereby extend the network lifetime [2]. For saving energy and extending network lifetime the topology is a well-known technique in WSNs and the widely used topology control strategy is the construction of Connected Dominating Set (CDS) [3, 4]. In this paper, we construct a CDS based energy efficient topology control algorithm i.e. GCDSTC for WSNs. The performance analysis includes the study of GCDSTC algorithm in terms of complexity and compares it with EBTC (Energy Balanced Topology Control) algorithm. The simulation results indicate that the GCDSTC algorithm reduce the energy consumption and interference in the network graph, in order to enhance the network lifetime. Keywords: Wireless Sensor Network (WSN), Connected Dominating Set (CDS), Topology Control (TC), etc.
Adequacy Analysis and Security Reliability Evaluation of Bulk Power SystemIOSR Journals
This document summarizes an article that proposes a new methodology called security-constrained adequacy evaluation (SCAE) for assessing the reliability of bulk power systems. The SCAE methodology improves on traditional techniques by incorporating major system operating practices, security constraints, and remedial actions. It performs critical contingency selection efficiently using a performance index approach. It then analyzes contingency effects using an optimal power flow algorithm that guarantees convergence. Reliability indices are computed to quantitatively indicate the system reliability level. The methodology is applied to test systems and shown to have expected advanced features.
An Adaptive Energy Aware Clustering Based Reliable Routing for in-Network Agg...Editor IJCATR
Wireless Sensor Network (WSN) consists of spatially distributed autonomous devices that cooperatively sense physical or
environmental conditions. Due to the non-uniform node deployment, the energy consumption among nodes are more
imbalanced in cluster-based wireless sensor networks this factor will affect the network life time. Cluster-based routing and EADC
algorithm through an efficient energy aware clustering algorithm is employed to avoid imbalance network distribution. Our proposed
protocol EADC aims at minimizing the overall network overhead and energy expenditure associated with the multi hop data retrieval
process while also ensuring balanced energy consumption among SNs and prolonged network life time .A optimal one-hop based
selective node in building cluster structures consisted of member nodes that route their measured data to their assigned cluster head is
identified to ensure efficient communication. The proposed routing algorithm increases forwarding tasks of the nodes in scarcely
covered areas by forcing cluster heads to choose nodes with higher energy and fewer member nodes and finally, achieves
imbalanced among cluster head and improve the network life time.
IRJET- Congestion Avoidance and Qos Improvement in Base Station with Femt...IRJET Journal
The document discusses improving quality of service in cellular base stations using femtocells. It proposes using femtocells, which are small low-power cellular base stations installed in homes or businesses, to improve coverage, capacity, and throughput. Femtocells could help reduce packet loss and congestion by closing gaps between network cells. The document reviews existing approaches like hedonic regression models and packet delivery ratio, and analyzes signal-to-noise ratios, interference, and system capacity for macro and small cells. Femtocells may enhance conventional networks by extending coverage areas and improving mobile data capacity.
design & implementation of energy effecient data collection in multiple mobil...mamtha_praksh
This document proposes an energy efficient data collection scheme called MSE2DC for wireless sensor networks with multiple mobile gateways. The key aspects are:
1) Sensor nodes are organized in a tree topology and mobile user equipments (UEs) act as mobile gateways to collect data from sensors as they move through the network.
2) When a UE stops to collect data, it activates nearby sensors and reports their addresses to the base station. The base station then selects necessary sensors for data collection/transmission and coordinates other UEs to assist in data transfer.
3) By exploiting the topological relationships between sensors activated by different UEs and coordinating their data transfer activities, the scheme aims to minimize unnecessary sensor activations
EVALUATING PERFORMANCE OF WIRELESS SENSOR NETWORK IN REALISTIC SMART GRID ENV...ijwmn
Wireless Sensor Networks (WSNs) is a strong candidate for smart grid applications, such as advanced metering infrastructure, demand response management, dynamic pricing, load control, electricity fraud detection, fault diagnostics, substation monitoring and control as well as automation of various elements of the power grid. The realization of these applications directly depends on efficiency of communication facilities among power grid elements. However, the harsh power grid environmental conditions with obstacles, noise,interference, and fading pose great challenges to reliability of these facilities to monitor and control the power grid. The purpose of this paper is to evaluate performance of WSNs in different power grid environments such as 500 kv substations, main power control room, and underground network transformer vaults. The power grid environments are modeled using a log-normal shadowing path loss model channel with realistic parameters. The network is simulated and performance is evaluated using packet delivery ratio, communication delay, and energy consumption. The simulation results have revealed that different environments have considerable impacts on performance of WSNs which make it suitable for most applications that need low data rate with low reliability requirements.
IEC 61850-9-2 based module for state estimation in co-simulated power grids IJECEIAES
This paper presents a research context on the virtualization of phasor measurement units (PMUs) and real-time power grids simulation with state estimation. In this research, real-time simulation is introduced to use powerful features for validating state estimation solutions with PMUs. Virtual and online measurement equipment are reviewed in this manuscript to develop an innovative integration of the OpenPMU incorporated with a real-time simulation power grid and additional virtualized PMUs. The implementation of the platform has useful features within the infrastructure that allows the user to reproduce a detailed modeled power grid with simulation software. The use of real-time simulation tools brings several possibilities for improving testing and prototype assessment with higher precision in different applications. In this case, 2 tests power systems are evaluated by realistic integration of IEC61850-9-2 data utilization to observe the performance of a customized state estimation approach. The study implements a versatile methodology for commissioning OpenPMU devices, interacting simultaneously with additional virtual PMUs within the same simulation through sampled values (SV) to validate the measurement frames and assess the estimation with the generated data. Finally, the proposed work identifies the potential of virtualizing PMUs and the features of the OpenPMU applied to state estimation in conjunction with real-time simulation data
On-line Power System Static Security Assessment in a Distributed Computing Fr...idescitation
The computation overhead is of major concern when
going for increased accuracy in online power system security
assessment (OPSSA). This paper proposes a scalable solution
technique based on distributed computing architecture to
mitigate the problem. A variant of the master/slave pattern is
used for deploying the cluster of workstations (COW), which
act as the computational engine for the OPSSA. Owing to the
inherent parallel structure in security analysis algorithm, to
exploit the potential of distributed computing, domain
decomposition is adopted instead of functional decomposition.
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. Validity of
proposed architecture is demonstrated by the results obtained
from an intensive experimentation using the benchmark IEEE
57 bus test system. The proposed framework, which is scalable,
can be further extended to intelligent monitoring and control
of power system
A cross layer protocol based on mac and routing protocols for healthcare appl...ijassn
Using Wireless Sensor Networks (WSNs) in healthcare systems has had a lot of attention in recent years. In
much of this research tasks like sensor data processing, health states decision making and emergency
message sending are done by a remote server. Many patients with lots of sensor data consume a great deal
of communication resources, bring a burden to the remote server and delay the decision time and
notification time. A healthcare application for elderly people using WSN has been simulated in this paper.
A WSN designed for the proposed healthcare application needs efficient MAC and routing protocols to
provide a guarantee for the reliability of the data delivered from the patients to the medical centre. Based
on these requirements, A cross layer based on the modified versions of APTEEN and GinMAC has been
designed and implemented, with new features, such as a mobility module and routes discovery algorithms
have been added. Simulation results show that the proposed cross layer based protocol can conserve
energy for nodes and provide the required performance such as life time of the network, delay and
reliability for the proposed healthcare application.
A Survey of Fault Tolerance Methods in Wireless Sensor NetworksIRJET Journal
This document summarizes and analyzes various fault tolerance mechanisms for wireless sensor networks. It discusses mobile agent mechanisms, relay node mechanisms, and handover mechanisms. The document analyzes several existing fault tolerance methods, including Bayesian network models, probabilistic combinatorial optimization, dynamic power level adjustment, and integrated fault tolerance frameworks. Overall, the document provides an overview of important fault tolerance issues in wireless sensor networks and different approaches that have been proposed to address faults and improve reliability.
This document provides a literature review on beamforming techniques for 5G mobile communication systems. It discusses the objectives of focusing on beamforming techniques using a combination of the MUSIC and LMS algorithms in a new MLMS algorithm. It then reviews various beamforming algorithms such as LMS, TVLMS, MUSIC, and MLMS and compares their advantages and disadvantages. The document outlines future work plans to improve the MLMS algorithm by reducing iterations and convergence parameters to increase stability. It provides a work plan and references various literature on adaptive beamforming algorithms.
This document provides a review of evolutionary algorithms that have been used to optimize wireless sensor networks (WSNs). It begins with background on WSNs and discusses common issues like energy efficiency. It then reviews heuristic and metaheuristic approaches that have been used for clustering and routing in WSNs. The main part of the document focuses on four commonly used evolutionary algorithms - genetic algorithms, particle swarm optimization, harmony search algorithm, and flower pollination algorithm. For each algorithm, it provides an overview and details on how the algorithm works and pseudo-code. It concludes that these nature-inspired metaheuristic techniques can help optimize challenges in WSNs like cluster formation and energy consumption better than classical algorithms.
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology
Predicting Post Outage Transmission Line Flows using Linear Distribution FactorsDr. Amarjeet Singh
In order to design and implement preventive
and remedial actions, a continuous performance of fast
security analysis is imperative amid outages of system
components. Following the contingency of a system
component, State estimation and Load flow techniques
are the two popular techniques used to determine
system state variables leading to estimation of flows,
losses and violations in nodal voltages and transmission
line flows. But the dynamic state and complexity of the
system requires faster means of estimations which can
be achieved by linear distribution factors. The use of
Distribution factors in form of Power Transfer
Distribution Factors (PTDF) and Line Outage
Distribution Factors (LODF) which are transmission
line sensitivities with respect to active power exchanges
between buses and transmission line outages offer an
alternative to these two techniques being linear,
quicker, and non-iterative. Following the estimation of
the linear distribution factors from a reference
operating point (base case) and contingency cases
involving line outage, generator output variation and
outage of a Six bus network using Matlab programs,
the results show that by means of Linear Distribution
factors quick estimates of post outage line flows can be
made which match flow results obtained from DC load
flow analysis.
The document discusses several research papers related to wireless communications and networking. Specifically:
1) A mechanism for joint access control and resource allocation to address performance degradation from massive access attempts by M2M devices in LTE networks. It aims to maximize random access efficiency while satisfying delay requirements.
2) A mean field game approach for distributed power control in dense small cell networks underlying macrocells to minimize costs like interference.
3) An opportunistic relaying and jamming scheme with power allocation to maximize ergodic secrecy rate for secure cooperative networks against eavesdropping.
4) Several papers discuss topics like resource control in heterogeneous networks, geographical load balancing for energy efficiency, reputation systems in MANET
The document summarizes research on using mobile communication to improve the efficiency of data transmission in wireless sensor networks. It discusses three main approaches: using mobile base stations, data mules, and mobile relays. The proposed work uses low-cost mobile relay nodes that do not transport data but instead move to optimize transmission costs by reducing the distance between sensor nodes and the base station. This approach aims to lower energy consumption and transmission delays compared to other mobile approaches.
INCREASING WIRELESS SENSOR NETWORKS LIFETIME WITH NEW METHODijwmn
One of the most important issues in Wireless Sensor Networks (WSNs) is severe energy restrictions. As the
performance of Sensor Networks is strongly dependence to the network lifetime, researchers seek a way to
use node energy supply effectively and increasing network lifetime. As a consequence, it is crucial to use
routing algorithms result in decrease energy consumption and better bandwidth utilization. The purpose of
this paper is to increase Wireless Sensor Networks lifetime using LEACH-algorithm. So before clustering
Network environment, it is divided into two virtual layers (using distance between sensor nodes and base
station) and then regarding to sensors position in each of two layers, residual energy of sensor and
distance from base station is used in clustering. In this article, we compare proposed algorithm with wellknown LEACH and ELEACH algorithms in homogenous environment (with equal energy for all sensors)
and heterogeneous one (energy of half of sensors get doubled), also for static and dynamic situation of base
station. Results show that our proposed algorithm delivers improved performance.
This document summarizes a study on analyzing sensor network mobility using the OMNeT++ simulation framework and MiXiM modeling toolkit. The study models sensor node mobility and examines how various parameters affect mobility and energy consumption. The simulation involves 5 mobile sensor nodes moving randomly within a 700m x 700m area. Results show that average packet delay and energy consumption increase with higher node mobility. MiXiM provides mobility and connectivity handling in OMNeT++ and allows modeling mobile wireless networks like sensor networks.
A LOW-ENERGY DATA AGGREGATION PROTOCOL USING AN EMERGENCY EFFICIENT HYBRID ME...IJCNCJournal
Recent wireless sensor network focused on developing communication networks with minimal power and cost. To achieve this, several techniques have been developed to monitor a completely wireless sensor network. Generally, in the WSN network, communication is established between the source nodes and the destination node with an abundant number of hops, an activity which consumes much energy. The node existing between source and destination nodes consumes energy for transmission of data and maximize network lifetime. To overcome this issue, a new Emergency Efficient Hybrid Medium Access Control (EEHMAC) protocol is presented to reduce consumption of energy among a specific group of WSNs which will increase the network lifetime. The proposed model makes a residual battery is utilized for effective transmission of data with minimal power consumption. Compared with other models, the experimental results strongly showed that our model is not only able to reduce network lifetime but also to increase the overall network performance.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
IRJET- Energy Efficient Secure Communication in Wireless Sensor Networks: A S...IRJET Journal
This document summarizes research on improving energy efficiency and security in wireless sensor networks (WSNs). It discusses how WSNs have limitations like limited battery power, bandwidth, and storage in sensor nodes. Several energy efficient techniques and secure communication methods are described that aim to extend the lifetime of WSNs. This includes clustering protocols to select energy-efficient cluster heads, optimized multi-hop transmission to reduce energy consumption, and integrating routing and MAC protocols using techniques like honey bee optimization to further improve energy efficiency and security of data transmission in WSNs. The goal of these approaches is to minimize energy usage and maximize the reliable operation of resource-constrained WSNs.
Optimization of Transmission Schemes in Energy-Constrained Wireless Sensor Ne...IJEEE
This paper reviews medium access control
(MAC) in wireless sensor network (WSN),and different
management methods to save energy.MAC protocol
controls how sensors access a shared radio channel to
communicate with neighbours.
Cds based energy efficient topology control algorithm in wireless sensor net...eSAT Journals
Abstract Wireless Sensor Networks (WSNs) are a self organized network which consists of large number of sensor nodes that collects the data in a various environment [1, 2]. The sensors work on battery that have limited lifetime so it is a challenge to create an energy efficient network that can reduce the energy consumption and interference in the network graph and thereby extend the network lifetime [2]. For saving energy and extending network lifetime the topology is a well-known technique in WSNs and the widely used topology control strategy is the construction of Connected Dominating Set (CDS) [3, 4]. In this paper, we construct a CDS based energy efficient topology control algorithm i.e. GCDSTC for WSNs. The performance analysis includes the study of GCDSTC algorithm in terms of complexity and compares it with EBTC (Energy Balanced Topology Control) algorithm. The simulation results indicate that the GCDSTC algorithm reduce the energy consumption and interference in the network graph, in order to enhance the network lifetime. Keywords: Wireless Sensor Network (WSN), Connected Dominating Set (CDS), Topology Control (TC), etc.
Adequacy Analysis and Security Reliability Evaluation of Bulk Power SystemIOSR Journals
This document summarizes an article that proposes a new methodology called security-constrained adequacy evaluation (SCAE) for assessing the reliability of bulk power systems. The SCAE methodology improves on traditional techniques by incorporating major system operating practices, security constraints, and remedial actions. It performs critical contingency selection efficiently using a performance index approach. It then analyzes contingency effects using an optimal power flow algorithm that guarantees convergence. Reliability indices are computed to quantitatively indicate the system reliability level. The methodology is applied to test systems and shown to have expected advanced features.
An Adaptive Energy Aware Clustering Based Reliable Routing for in-Network Agg...Editor IJCATR
Wireless Sensor Network (WSN) consists of spatially distributed autonomous devices that cooperatively sense physical or
environmental conditions. Due to the non-uniform node deployment, the energy consumption among nodes are more
imbalanced in cluster-based wireless sensor networks this factor will affect the network life time. Cluster-based routing and EADC
algorithm through an efficient energy aware clustering algorithm is employed to avoid imbalance network distribution. Our proposed
protocol EADC aims at minimizing the overall network overhead and energy expenditure associated with the multi hop data retrieval
process while also ensuring balanced energy consumption among SNs and prolonged network life time .A optimal one-hop based
selective node in building cluster structures consisted of member nodes that route their measured data to their assigned cluster head is
identified to ensure efficient communication. The proposed routing algorithm increases forwarding tasks of the nodes in scarcely
covered areas by forcing cluster heads to choose nodes with higher energy and fewer member nodes and finally, achieves
imbalanced among cluster head and improve the network life time.
IRJET- Congestion Avoidance and Qos Improvement in Base Station with Femt...IRJET Journal
The document discusses improving quality of service in cellular base stations using femtocells. It proposes using femtocells, which are small low-power cellular base stations installed in homes or businesses, to improve coverage, capacity, and throughput. Femtocells could help reduce packet loss and congestion by closing gaps between network cells. The document reviews existing approaches like hedonic regression models and packet delivery ratio, and analyzes signal-to-noise ratios, interference, and system capacity for macro and small cells. Femtocells may enhance conventional networks by extending coverage areas and improving mobile data capacity.
design & implementation of energy effecient data collection in multiple mobil...mamtha_praksh
This document proposes an energy efficient data collection scheme called MSE2DC for wireless sensor networks with multiple mobile gateways. The key aspects are:
1) Sensor nodes are organized in a tree topology and mobile user equipments (UEs) act as mobile gateways to collect data from sensors as they move through the network.
2) When a UE stops to collect data, it activates nearby sensors and reports their addresses to the base station. The base station then selects necessary sensors for data collection/transmission and coordinates other UEs to assist in data transfer.
3) By exploiting the topological relationships between sensors activated by different UEs and coordinating their data transfer activities, the scheme aims to minimize unnecessary sensor activations
EVALUATING PERFORMANCE OF WIRELESS SENSOR NETWORK IN REALISTIC SMART GRID ENV...ijwmn
Wireless Sensor Networks (WSNs) is a strong candidate for smart grid applications, such as advanced metering infrastructure, demand response management, dynamic pricing, load control, electricity fraud detection, fault diagnostics, substation monitoring and control as well as automation of various elements of the power grid. The realization of these applications directly depends on efficiency of communication facilities among power grid elements. However, the harsh power grid environmental conditions with obstacles, noise,interference, and fading pose great challenges to reliability of these facilities to monitor and control the power grid. The purpose of this paper is to evaluate performance of WSNs in different power grid environments such as 500 kv substations, main power control room, and underground network transformer vaults. The power grid environments are modeled using a log-normal shadowing path loss model channel with realistic parameters. The network is simulated and performance is evaluated using packet delivery ratio, communication delay, and energy consumption. The simulation results have revealed that different environments have considerable impacts on performance of WSNs which make it suitable for most applications that need low data rate with low reliability requirements.
IEC 61850-9-2 based module for state estimation in co-simulated power grids IJECEIAES
This paper presents a research context on the virtualization of phasor measurement units (PMUs) and real-time power grids simulation with state estimation. In this research, real-time simulation is introduced to use powerful features for validating state estimation solutions with PMUs. Virtual and online measurement equipment are reviewed in this manuscript to develop an innovative integration of the OpenPMU incorporated with a real-time simulation power grid and additional virtualized PMUs. The implementation of the platform has useful features within the infrastructure that allows the user to reproduce a detailed modeled power grid with simulation software. The use of real-time simulation tools brings several possibilities for improving testing and prototype assessment with higher precision in different applications. In this case, 2 tests power systems are evaluated by realistic integration of IEC61850-9-2 data utilization to observe the performance of a customized state estimation approach. The study implements a versatile methodology for commissioning OpenPMU devices, interacting simultaneously with additional virtual PMUs within the same simulation through sampled values (SV) to validate the measurement frames and assess the estimation with the generated data. Finally, the proposed work identifies the potential of virtualizing PMUs and the features of the OpenPMU applied to state estimation in conjunction with real-time simulation data
On-line Power System Static Security Assessment in a Distributed Computing Fr...idescitation
The computation overhead is of major concern when
going for increased accuracy in online power system security
assessment (OPSSA). This paper proposes a scalable solution
technique based on distributed computing architecture to
mitigate the problem. A variant of the master/slave pattern is
used for deploying the cluster of workstations (COW), which
act as the computational engine for the OPSSA. Owing to the
inherent parallel structure in security analysis algorithm, to
exploit the potential of distributed computing, domain
decomposition is adopted instead of functional decomposition.
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. Validity of
proposed architecture is demonstrated by the results obtained
from an intensive experimentation using the benchmark IEEE
57 bus test system. The proposed framework, which is scalable,
can be further extended to intelligent monitoring and control
of power system
Study on the performance indicators for smart grids: a comprehensive reviewTELKOMNIKA JOURNAL
This paper presents a detailed review on performance indicators for smart grid (SG) such as voltage stability enhancement, reliability evaluation, vulnerability assessment, Supervisory Control and Data Acquisition (SCADA) and communication systems. Smart grids reliability assessment can be performed by analytically or by simulation. Analytical method utilizes the load point assessment techniques, whereas the simulation technique uses the Monte Carlo simulation (MCS) technique. The reliability index evaluations will consider the presence or absence of energy storage elements using the simulation technologies such as MCS, and the analytical methods such as systems average interruption frequency index (SAIFI), and other load point indices. This paper also presents the difference between SCADA and substation automation, and the fact that substation automation, though it uses the basic concepts of SCADA, is far more advanced in nature.
This paper describes hardware and functional features of Hybrid Real Time Simulator (HRTSim) of electrical power systems, also its application for solution of Smart Grid (SG) tasks concerned with active adaptive networks (AAN) construction. As an example of such task solution the working results of HRTSim implementation and its application for testing and setting up of active-adaptive voltage and var control system (AAVVCS) of regional Smart Grid are presented.
Supervisory control and data acquisition (SCADA) systems are crucial for ensuring power grids supply electricity safely and reliably when combined with larger energy management systems (EMS) or distribution management systems (DMS). SCADA/EMS and SCADA/DMS systems are necessary for controlling power grids, integrating renewables, and providing universal access. World Bank support is important for establishing these systems in developing countries' power networks to ensure sustainable long-term growth.
This document describes a methodology for simulating heterogeneous embedded systems that include hardware, software, and electromechanical parts. Interfaces were developed to allow a VHDL simulator to communicate with a physical systems simulator and application programs. The interfaces use the C language links of the simulators to establish communication channels and exchange commands/parameter values between the simulated parts in a chained master/slave synchronization scheme. This unified simulation environment allows designers to validate the behavior of the entire system early in the design process before implementing any of its parts.
ARTIFICIAL NEURAL NETWORK BASED POWER SYSTEM STABILIZER ON A SINGLE MACHINE ...EEIJ journal
In this paper the use of artificial neural network in power system stability is studied. A predictive
controller based on two neural networks is designed and tested on a single machine infinite bus system
which is used to replace conventional power system stabilizers. They have been used for decades in
power system to dampen small amplitude low frequency oscillation in power systems. The increases in
size and complexity of power systems have cast a shadow on efficiency of conventional method. New
control strategies have been proposed in many researches. Artificial Neural Networks have been studied
in many publications but lack of assurance of their functionality has hindered the practical usage of them
in utilities. The proposed control structure is modelled using a novel data exchange established between
MATLAB and DIgSILENT power factory. The result of simulation proves the efficiency of the proposed
structure.
ARTIFICIAL NEURAL NETWORK BASED POWER SYSTEM STABILIZER ON A SINGLE MACHINE ...EEIJ journal
In this paper the use of artificial neural network in power system stability is studied. A predictive
controller based on two neural networks is designed and tested on a single machine infinite bus system
which is used to replace conventional power system stabilizers. They have been used for decades in
power system to dampen small amplitude low frequency oscillation in power systems. The increases in
size and complexity of power systems have cast a shadow on efficiency of conventional method. New
control strategies have been proposed in many researches. Artificial Neural Networks have been studied
in many publications but lack of assurance of their functionality has hindered the practical usage of them
in utilities. The proposed control structure is modelled using a novel data exchange established between
MATLAB and DIgSILENT power factory. The result of simulation proves the efficiency of the proposed
structure.
Coupling-Based Internal Clock Synchronization for Large Scale Dynamic Distrib...Angelo Corsaro
This paper studies the problem of realizing a common software clock among a large set of nodes without an external time reference (i.e., internal clock synchronization), any centralized control and where nodes can join and leave the distributed system at their will. The paper proposes an internal clock synchronization algorithm which combines the gossip-based paradigm with a nature-inspired approach, coming from the coupled oscillators phenomenon, to cope with scale and churn. The algorithm works on the top of an overlay network and uses a uniform peer sampling service to fullfill each node’s local view. Therefore, differently from clock synchronization protocols for small scale and static distributed systems, here each node synchronizes regularly with only the neighbors in its local view and not with the whole system. Theoretical and empirical evaluations of the convergence speed and of the synchronization error of the coupled-based internal clock synchronization algorithm have been carried out, showing how convergence time and the synchronization error depends on the coupling factor and on the local view size. Moreover the variation of the synchronization error with respect to churn and the impact of a sudden variation of the number of nodes have been analyzed to show the stability of the algorithm. In all these contexts, the algorithm shows nice performance and very good self-organizing properties. Finally, we showed how the assumption on the existence of a uniform peer-sampling service is instrumental for the good behavior of the algorithm.
Improving Control Performance in DC Micro-Grids with Distributed GenerationsIJAPEJOURNAL
DC micro-grids are attracting more and more attention due to their capability to lead to more efficient integration of distributed generation compared with traditional AC micro-grids. In this paper, a hierarchical control architecture is proposed to improve the control performance of DC micro-grid with distributed generations (DGs), which utilize a global controller (GC) to optimize the overall process and a number of distributed local controllers (LCs) associated with each subsystem. The measurement reliability of each LC is guaranteed by an associated measurement validation module which is developed based on Polynomial Chaos Theory (PCT). The system efficiency and robust is counted in the design of GC, where synergetic control theory is adopted. Numerical simulations have been done to verify the proposed method, and the simulation results show good consistency with theoretical analysis.
This document presents a proposed self-healing control algorithm to improve the reliability of a smart grid distribution system. It begins with an introduction that outlines how smart grid solutions can help utilities quickly identify faults, shorten outage times, and restore power faster. The document then reviews literature on various approaches to self-healing control and identifies gaps in existing research. Specifically, it is proposed to develop a self-healing control algorithm using modern control theory and artificial intelligence to address voltage instability from supply-demand imbalances introduced by renewable energy sources and electric vehicles. An experiment is outlined to test the algorithm on a proposed smart grid distribution system model incorporating solar power, energy storage, and electric vehicles.
This document summarizes ongoing research in applying intelligent methods to microgrid design, modeling, simulation and control. It discusses several ongoing research projects:
1) A decentralized multi-agent system for microgrid operation being developed at Michigan State University that uses a three-step communication algorithm for distributed control of distributed generators and loads.
2) A distributed incremental cost consensus algorithm for economic dispatch being developed at North Carolina State University that allows distributed controllers to allocate power among connected buses.
3) A system developed at the University of North Carolina at Charlotte that models and controls a photovoltaic and fuel cell hybrid microgrid using a neurocontroller-based intelligent system centric controller.
4) A multi-agent based load restoration
Critical clearing time estimation of multi-machine power system transient st...IJECEIAES
This document presents a fuzzy logic method for estimating the critical clearing time (CCT) of faults in multi-machine power systems. The method involves a two-step fuzzy logic algorithm: 1) Calculate the time increment (Δt) based on maximum angle deviation (δmax) as input, 2) Classify system stability based on mechanical input power (Pm) and average acceleration (Aav) as inputs. The fuzzy logic method is tested on IEEE 9-bus and 39-bus systems and shows accuracy within 5% of time domain simulation results, while reducing computation time by about half. Tables compare estimated CCT and computation time between the two methods for different fault locations.
Designing Run-Time Environments to have Predefined Global DynamicsIJCNCJournal
The stability and the predictability of a computer network algorithm's performance are as important as the
main functional purpose of networking software. However, asserting or deriving such properties from the
finite state machine implementations of protocols is hard and, except for singular cases like TCP, is not
done today. In this paper, we propose to design and study run-time environments for networking protocols
which inherently enforce desirable, predictable global dynamics. To this end we merge two complementary
design approaches: (i) A design-time and bottom up approach that enables us to engineer algorithms based
on an analyzable (reaction) flow model. (ii) A run-time and top-down approach based on an autonomous
stack composition framework, which switches among implementation alternatives to find optimal operation
configurations. We demonstrate the feasibility of our self-optimizing system in both simulations and realworld
Internet setups
Mobile Agents based Energy Efficient Routing for Wireless Sensor NetworksEswar Publications
Energy Efficiency and prolonged network lifetime are few of the major concern areas. Energy consumption rated of sensor nodes can be reduced in various ways. Data aggregation, result sharing and filtration of aggregated data among sensor nodes deployed in the unattended regions have been few of the most researched areas in the field of wireless sensor networks. While data aggregation is concerned with minimizing the information transfer from source to sink to reduce network traffic and removing congestion in network, result sharing focuses on sharing of information among agents pertinent to the tasks at hand and filtration of aggregated data so as to remove redundant information. There exist various algorithms for data aggregation and filtration using different mobile agents. In this proposed work same mobile agent is used to perform both tasks data aggregation and data filtration. This approach advocates the sharing of resources and reducing the energy consumption level of sensor nodes.
Transient Stability Assessment and Enhancement in Power SystemIJMER
This document discusses transient stability assessment and enhancement in power systems. It first introduces transient stability and its importance. It then describes using PSAT software to analyze the IEEE 39-bus test system and calculate critical clearing times (CCTs) for different faults to assess stability. An artificial neural network is trained to predict CCTs at different operating points. Finally, particle swarm optimization is used to find the optimal placement of a thyristor controlled series capacitor to enhance stability by minimizing real power losses, increasing several CCTs above 0.1 seconds.
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.
Generalized optimal placement of PMUs considering power system observability,...IJECEIAES
This paper presents a generalized optimal placement of Phasor Measurement Units (PMUs) considering power system observability, reliability, Communication Infrastructure (CI), and latency time associated with this CI. Moreover, the economic study for additional new data transmission paths is considered as well as the availability of predefined locations of some PMUs and the preexisting communication devices (CDs) in some buses. Two cases for the location of the Control Center Base Station (CCBS) are considered; predefined case and free selected case. The PMUs placement and their required communication network topology and channel capacity are co-optimized simultaneously. In this study, two different approaches are applied to optimize the objective function; the first approach is combined from Binary Particle Swarm Optimization-Gravitational Search Algorithm (BPSOGSA) and the Minimum Spanning Tree (MST) algorithm, while the second approach is based only on BPSOGSA. The feasibility of the proposed approaches are examined by applying it to IEEE 14-bus and IEEE 118-bus systems.
Overview of State Estimation Technique for Power System ControlIOSR Journals
This document provides an overview of state estimation techniques for power system control. It discusses static, tracking, and dynamic state estimation approaches and how they differ based on whether measurements and system models are time-variant or invariant. The document also describes how state estimation processes redundant measurements to filter noise and estimate true system states like voltage magnitudes and angles at each bus. It further discusses weighted least squares estimation, the use of Jacobian matrices to iteratively estimate states, and how state estimation provides critical real-time data for power system monitoring and control functions.
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The introduction of DLAU and the CCB & CCX licensing model caused quite a stir in the HCL community. As a Notes and Domino customer, you may have faced challenges with unexpected user counts and license costs. You probably have questions on how this new licensing approach works and how to benefit from it. Most importantly, you likely have budget constraints and want to save money where possible. Don’t worry, we can help with all of this!
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Observability Concepts EVERY Developer Should Know -- DeveloperWeek Europe.pdfPaige Cruz
Monitoring and observability aren’t traditionally found in software curriculums and many of us cobble this knowledge together from whatever vendor or ecosystem we were first introduced to and whatever is a part of your current company’s observability stack.
While the dev and ops silo continues to crumble….many organizations still relegate monitoring & observability as the purview of ops, infra and SRE teams. This is a mistake - achieving a highly observable system requires collaboration up and down the stack.
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Cosa hanno in comune un mattoncino Lego e la backdoor XZ?Speck&Tech
ABSTRACT: A prima vista, un mattoncino Lego e la backdoor XZ potrebbero avere in comune il fatto di essere entrambi blocchi di costruzione, o dipendenze di progetti creativi e software. La realtà è che un mattoncino Lego e il caso della backdoor XZ hanno molto di più di tutto ciò in comune.
Partecipate alla presentazione per immergervi in una storia di interoperabilità, standard e formati aperti, per poi discutere del ruolo importante che i contributori hanno in una comunità open source sostenibile.
BIO: Sostenitrice del software libero e dei formati standard e aperti. È stata un membro attivo dei progetti Fedora e openSUSE e ha co-fondato l'Associazione LibreItalia dove è stata coinvolta in diversi eventi, migrazioni e formazione relativi a LibreOffice. In precedenza ha lavorato a migrazioni e corsi di formazione su LibreOffice per diverse amministrazioni pubbliche e privati. Da gennaio 2020 lavora in SUSE come Software Release Engineer per Uyuni e SUSE Manager e quando non segue la sua passione per i computer e per Geeko coltiva la sua curiosità per l'astronomia (da cui deriva il suo nickname deneb_alpha).
2. 2
lead to a mismatch between the real dynamics and interaction,
and the simulated one. We alleviate this problem by making
an asymmetric approach where the discrete event simulator
considers the integration time steps of the simulator of the
continuous dynamics, as events to be scheduled. It can also
adaptively adjust the granularity of its own event spacing. In a
certain sense, our approach is closer to the EPOCHS as we
also believe in federation of existing simulation frameworks as
opposed to inventing our own simulators. That is a much more
proficient way to achieve the co-simulation as the existing
simulators are developed over multiple decades, and
effectively used in the industry. The ADEVS approach does
not federate. It actually requires its own modeling of the
continuous dynamics of a power system in the DEVS
framework. The DEVS approach is to convert the continuous
dynamics into discrete events by different state event detection
mechanisms (e.g. zero crossing). Since most commercial
power system modeling and simulation tools do not use this
approach, the federated approach will not readily apply to the
ADEVS approach. We believe that our approach improves
the EPOCHS approach in accuracy while keeping intact the
idea of federation and our accuracy should be similar to
ADEVS approach while improving upon it by allowing faster
construction of co-simulation. In this paper we not only
describe our approach in detail, we show using a case study
that our approach is effective, and it is much easier to set up
the co-simulation and obtain results.
The following paper is organized as: Section II presents the
co-simulation framework with an accurate synchronization
mechanism between continuous time and discrete event
simulation. Section III describes the co-simulation
construction using a transient power simulator and a network
simulator. An agent-based remote backup relay scheme which
benefits from communication infrastructure is studied and
discussed in Section IV. This scheme is further simulated
using our co-simulation tool in Section V to demonstrate the
effectiveness of our method. In the end the whole paper is
concluded in Section VI.
time, then integrating small variations of state variables to
approximate the system trajectory. The discretized time step is
often very small so that the system variables do not have an
abrupt transition within the time step. The discretization and
integration process can be represented as:
S : System State Variables
S n : Sample of S at t n
X :System Input Variables
F : Discretized Equations
Y : System Output Variables
G : Output Functions
S (t0 ) = S 0 ;
ΔS n = F ( S n , X n , Δt n );
S n +1 = S n + ΔS n ;
Yn = G ( S n , X n , Δtn );
Especially in power system analysis, dynamic simulation
runs in a step by step manner which can be seen in Fig. 1.
After the system initialization by solving system power flow,
the simulation enters a loop. Within this loop, first the network
boundary variables for dynamic models connected directly to
the system network are calculated. For example, the generator
internal voltage is calculated from source current. Then
dynamic models’ secondary variables are calculated from
system state variables. This includes models that are not
directly connected to the system. For example some internal
control devices such as excitation systems and governors are
processed in this step. One round in the loop is completed by
calculating state variable derivatives and integrations. The
loop continues until the simulation reaches a preset stop time.
II. CO-SIMULATION FRAMEWORK
Power system dynamic simulation is commonly modeled as
a continuous time simulation. A typical case is transient
stability simulation. Communication networks are usually
modeled as discrete events systems to account for the
stochastic nature of packet generation and transmissions.
Hybrid models [6-8] integrating those two have been applied
in the area of computer engineering which aimed at mixed
signal circuit designs but still rarely seen for power system
except the ADEVS [5] approach.
A. Continuous System Simulation
In a continuous time system, the system state variables
change in a continuous manner with respect to time. Typically
the system is represented by sets of differential equations in
which the relationship between continuous state variables’
changing rates are defined. For simple cases, the differential
equations can be solved analytically to get closed form results.
However for most cases in the real world such closed form
results are not available. The solution for this is to numerically
solve the problem by discretizing differential equations and
Figure. 1. Step by step simulation of power system dynamics
B. Discrete Event Simulation
Discrete event-driven simulation is suitable for systems
whose state is subject to change due to discrete events. The
occurrences of events are usually unevenly distributed on a
timeline. For instance, the arrival time of cars to a toll booth
may follow Poisson distribution. Hence time discretization
into steady small time intervals as done in continuous time
systems cannot be appropriately applied to discrete event
system since the time step is difficult to determine. If the time
step is selected too small then it will waste simulation times
since system state remains unchanged during many
3. 3
consecutive time steps. If the time step is selected too long,
then many events could be missed during a single time step.
In an event-driven simulation, instead of doing integration
of discretized time, the time hops between events. A event
scheduler is designed to record current system time and also
maintain an event list. Event list is a queue that stores system
events with timestamps in chronological sequence. Before a
simulation starts the scheduler initializes the system state and
the event list. When the simulation starts, the scheduler
proceeds with the first event from the list and sorts out the
processes attached to this event. The processes can generate
new events to and remove existing events from the event list.
New events are placed to the right places in the list by the
scheduler. Then the scheduler switches the system time
directly to the time when next event is going to happen. The
whole simulation stops when system time reaches a certain
stop time or the system reaches a certain state.
Communication networks simulation is an example that
uses discrete event-driven simulation. The system consists of
network hardware devices as well as software agents. The
events in communication network could be receiving or
sending a packet as shown in Fig. 2. The network protocols
receive packets and send new packets to the network.
Figure. 2. Event-driven simulation for communication network
C. Co-Simulation Framework
Under the smart grid scenario, the power system interacts
with its communication network infrastructure at widely
distributed locations. Software agents collect power system
data through Advanced Metering Infrastructure (AMI) and
send them to corresponding receivers through communication
network. Analyzing the systems together is a natural outcome
and hybrid simulation tools combining power system and
communication network simulation are needed to cover new
design areas. A precise synchronization mechanism is the key
to fulfill this requirement.
When researchers first made efforts to integrate power
system and communication network simulation an intuitive
synchronization is adopted as shown in Fig. 3 [4]. In this
mechanism power system simulation and communication
network simulation runs independently until both simulators’
simulation time reaches a synchronization point, as denoted in
Fig.3 by red dashed lines. At this point both simulators halt
themselves and the overall control is taken over by an external
mediator which has access to internal data of both simulators.
The mediator imitates the behavior of agents in the smart grid,
exchanges data between two simulations and executes
necessary modifications to them. The control will be returned
to two simulators after the coordination and the two simulators
will continue their independent simulations until the next
synchronization point. If the power system simulation time
step is steady then there will be equal number of simulation
rounds between synchronization points. However there can be
any number of network events that happene between
synchronization points due to their uneven distribution.
Figure. 3. Synchronization mechanism with accumulating errors
This synchronization mechanism can introduce time
accumulating errors owing to difficulty for selecting a perfect
synchronization boundary. For instance, between two
synchronization points if there is a fault that happened in the
power system, the simulator has to store its fault report
temporarily and wait to the synchronization point to pass the
report to mediator and components in network simulator. This
is indicated by “Error 1” in Fig. 3. On the other hand, if a
control message is received by an agent in network simulator,
it as well has to wait until synchronization to take action in the
power system. This is also presented by “Error 2” in Fig. 3.
We propose a new co-simulation framework which removes
the accumulating errors described in the preceding paragraphs.
Since the disadvantage of that synchronization is very similar
to the one that using continuous time simulation methods to
simulate a discrete event system, we run the simulation
globally in a discrete event-driven manner as shown in Fig. 4.
In this framework we remove those explicit synchronization
points and make the simulators implicitly synchronized. We
adopt a global scheduler for co-simulation and two simulators
share the same timeline instead of running independently. The
repeating rounds in power system dynamic simulation are
broken into individuals and expanded over the timeline as
discrete events for the global scheduler. The global scheduler
recognizes the expanded rounds as its initialization events and
combines them with normal communication network events to
form a global event list. When the simulation starts the global
scheduler processes, either a power system dynamic
simulation round or a communication network event according
to their timestamp orders. When a power system dynamic
simulation round is finished, the power simulator is suspended
until next round is processed by the global scheduler. In this
framework whenever an interaction between power system
and communication network is needed, the request can be
processed immediately by the global scheduler without
unnecessary wait time. Both errors in Fig.3 are eliminated in
this framework.
4. 4
Figure. 4. Co-Simulation framework adopting a global scheduler without
synchronization errors
We need to clarify that our co-simulation framework only
removes accumulating errors introduced by synchronization
between two running processes. It doesn’t help to remove
errors introduced by simulators themselves. If a big time step
is selected for power system dynamic simulation it is still
possible to have multiple network events happening during
that interval and induce simulation errors. Also, if people use a
very small synchronization interval in Fig.3 it converges to
our co-simulation framework but with more simulation cost
and limited time scale.
III. CO-SIMULATION IMPLEMENTATION
We implement the preceding co-simulation framework by
integrating two acknowledged simulators: Positive Sequence
Load Flow (PSLF) software for power system dynamic
simulation and Network Simulator 2 (NS2) for communication
network simulation. The reason we choose these two
simulators is that both of them are of proven simulation
capabilities in their respective research domains, and have
good supports for user defined extensions. It is better than
writing simulation codes from the scratch as long as the
selected software can be appropriately allocated in the cosimulation framework.
PSLF is a power system software package designed by GE
which provides both steady-state and dynamic power system
simulations. PSLF can simulate a system with up to 60000
buses and is equipped with a rich library of electromechanical
dynamic models. The software suite is written in Java and
provides application programming interfaces (APIs) for user
for further development. User can interact with the simulator
through a graphical user interface (GUI) or from a command
line console. The software also comes with a script language
EPCL which can configure user-customized simulation and
add new dynamic models to the model library.
NS2 is an open source communication network simulation
software developed by the academia, aiming at network
performance evaluation. It is a well-known and widely used
simulator in networking research domain because of its
comprehensive support of network models. NS2 can simulates
four layers in the Open Systems Interconnection (OSI)
reference model for computer network protocols which
include application layer, transport layer, network layer and
data link layer. NS2 support most of the network protocols
used in today’s computer network and substantially covers
wired, wireless and hybrid communication simulations. NS2 is
mainly written in C++ and also provides a script language
OTcl for simple and fast simulation configuration. A
framework called “OTcl linkage” is realized in NS2 to
cooperate the simulation written in C++ and OTcl. OTcl
linkage establishes a class hierarchy mapping between C++
and OTcl so that whenever an object is instantiated in OTcl, a
corresponding shadow object is created in C++. Both OTcl
classes and C++ classes derive from the same father class
TclObject. Through OTcl linkage, a user can write and
compile new network protocols or models in C++ and
configure the simulation by OTcl without repeating
compilation for each simulation case. In this manner NS2 is
nothing but an OTcl language translator.
Figure. 5. Integration of PSLF and NS2
The co-simulation is realized by designing interface code on
both sides as shown in Fig. 5. In NS2, its build-in network
event scheduler is adopted as the global scheduler. A new
class “PSLF_Tcl” derived from TclObject is designed in C++
as an interface to PSLF and initializes power system dynamic
simulation rounds in NS2 for the global scheduler. This class
sends command to PSLF interface model to collect power
system data from PSLF after each dynamic round and stores
them in NS2 for fast access by other network components. In
PSLF, a new user-written dynamic model “epcmod” is
attached to the simulated system. This model is designed as a
stand-alone component in the power system and does affect
the regular simulation. Its function is twofold: one is to
explain commands from NS2 interface model and report back
power system state data and another one is to suspend PSLF’s
simulation after each dynamic round and wait for NS2
commands to continue. The second function is crucial in our
implementation. Without it the co-simulation cannot be
scheduled by a global scheduler.
Other than the interface codes on both sides, a group of new
network components are designed in NS2 to facilitate power
system applications. A slave agent class is designed at the
application layer in NS2. It stands for software or hardware
agents interacting with power system and communication
infrastructure in the real world. Typical instances of them
could be the intelligent electronic devices (IEDs) or digital
relays. The slave agents share a uniform design format so that
they can be configured as different type of agents like bus
agent, generator agent, relay agent etc., upon simulation
requirements. A master agent is also implemented in
application layer as a coordinator on top of all the slave
agents. The master agent can stand for a central control
module or an operation center. Furthermore several classic
network transport protocols like User Datagram Protocol
(UDP) and Transmission Control Protocol (TCP) are modified
so as to recognize and transmit power system data.
5. 5
IV. AGENT-BASED REMOTE RELAY BACKUP PROTECTION
A recently proposed agent-based supervisory remote
backup relay protection scheme to prevent hidden failure
based tripping is one example [9] whose validation requires a
power system and networking co-simulation. Traditional
relays monitor local system state and make autonomous
decision. Even though current digital relays have been
designed and equipped with comprehensive functionality and
computation ability, in practice they are usually working on
the lowest profile and most of the functions are not fully
utilized. Hence there is great potential to upgrade the relay
protection system without too much intrusion on their current
structures.
In the agent-based supervisory remote backup relay
protection scheme, instead of working individually, relays are
connected with each other and co-operate their protection
through extensive communication. Within the interested area,
each distance relay has a software agent (slave) associated
with it. This software agent works as an interface to other
relays for information exchange. There is also a master agent
in locale working as a global coordinator for other slave
agents. In this form the system is able to provide better
protection on the system and avoid hidden failure induced
false tripping [10]. For example, whenever a relay picks up for
a fault in its back up zone of protection or senses a change in
the breaker status, the corresponding agent records it and
sends the information to the master agent through the network.
The master agent queries the other slaves in the vicinity of the
reporting slave. Based on the responses from the other slaves,
the master agent decides if there is a real fault or the reporting
slave is picking up falsely. Accordingly, the master agent
allows or blocks the tripping of that relay.
Fig.6 shows the typical communication between the master
agent and slave agents. There are four steps in total before a
decision is made for the backup relay: (1) Slave picks up a
fault and submits a query to the Master; (2) The master
collects information from other slaves; (3) Other slaves report
back (4) Master sends decision back to the slave who
submitted the query. It is necessary to study the total time
delay consumed in these four steps to make sure the fault can
be dealt with in time since protection is a time-critical
application [11]. We show how to validate this scheme using
our co-simulation framework.
protection may take place: primary relay failure and remote
backup relay false tripping. As shown in Fig.7 we construct
the power system in PSLF and build a communication
network in NS2 which has the same topology with the power
system. The communication link is configured to have a
bandwidth of 100Mbytes and 3ms communication delay on
each link. Coaxial and microwave communication media
usually has this representative settings.
A. Case 1: Primary Relay Failure
We first assume a primary relay failure in the 39-bus
system. A short circuit fault is created at 0.01s between bus 4
and bus 14. We also assume that the relay at bus 4 can
normally see the fault and trip the breaker on its side but on
the other side, the primary relay at bus 14 did not see the fault
due to a failure or wrong relay settings. In this condition, the
remote backup relay at bus 15 and 13 see the remote fault and
request the master agent at bus 16 to make a decision. The
master agent polls other relays and concludes that there is
something wrong with the primary relay at bus 14. The
command is then sent back to relays at bus 13 and bus 15.
Here our decision making is simple: as long as there is another
relay seeing the fault the remote backup relay should take
action to protect the system since the chance that two relays
have simultaneous malfunction is low.
Figure. 7. Primary relay at bus 14 does not see the fault [12]
Figure. 6. Remote backup relay communication
V. CO-SIMULATION CASES
We apply the agent-based remote relay protection scheme
to the New England 39-bus system benchmark and simulate it
on our co-simulation platform. The simulation case is studied
not only to validate our co-simulation but also to evaluate the
performance of the agent-based remote relay protection. We
consider two conditions when the agent-based remote relay
Figure. 8. Voltage magnitude at bus 13 in case 1
6. 6
The simulated voltage magnitude at bus 13 is plotted in Fig.
8 from which we can see that after the fault happened the
voltage drops and comes back after the fault is cleared at both
sides. It roughly takes 25ms for the agent-based remote
backup relay to clear the fault which is good enough to protect
the system.
B. Case 2: Remote Backup Relay Failure
We also consider a case of remote backup relay false
tripping. A remote backup relay could see a false fault due to
hidden failure. Without agent-based relay communication the
backup relay could trip its circuit breaker and generate
unwanted loss to the system. In our case, also in the 39-bus
system we assume the remote backup relay at bus 13 sees a
false fault owing to wrong relay settings. Then it sends a
request to the master agent to collect information from others.
The master agent checks other relays and cannot find anything
wrong. Thereby the master sends a message to the relay at bus
13 telling that it is a false fault. Then the relay should stay still
and report for maintenance. The voltage magnitude at bus 13
is again plotted in Fig.10 from which we can see that nothing
has been changed in the system.
Figure. 10. Voltage magnitude at bus 13 in case 2
VII. ACKNOWLEDGMENT
We would like to thank EPOCHS’s author Dr. Kenneth
Hopkinson for his advices on the co-simulation
implementation.
VIII. REFERENCES
Figure. 9. Remote relay at bus 13 sees a false fault [12]
VI. CONCLUSION
In this paper we propose a co-simulation framework which
combines power system simulation and communication
network simulation together. We analyze the continuous time
model used in power system simulation and the discrete eventdriven model used in communication network simulation.
However, we leverage existing simulators for both the
continuous state and discrete-event simulation by federating
them. The previous federated simulators for the same purpose
can be shown to have coarser grain synchronization induced
inaccuracies. In this paper we show how to alleviate this
problem by proposing an errorless implicit synchronization
mechanism for the co-simulation framework. We further
implement this co-simulation framework by integrating PSLF
and NS2 software. An agent-based supervisory remote backup
relay protection scheme is studied on this platform. Both the
protection scheme and the co-simulation framework are
validated this way.
[1] U.S Department of Homeland Security, "National Power Grid Simulator
Workshop Report," December 2008.
[2] C. M. Davis, et al., "SCADA Cyber Security Testbed Development," in
Power Symposium, 2006. NAPS 2006. 38th North American, 2006, pp.
483-488.
[3] N. Higgins, et al., "Distributed Power System Automation With IEC
61850, IEC 61499, and Intelligent Control," Systems, Man, and
Cybernetics, Part C: Applications and Reviews, IEEE Transactions on,
vol. PP, pp. 1-12, 2010.
[4] K. Hopkinson, et al., "EPOCHS: a platform for agent-based electric
power and communication simulation built from commercial off-the-shelf
components," Power Systems, IEEE Transactions on, vol. 21, pp. 548558, 2006.
[5] J. Nutaro, et al., "Integrated Hybrid-Simulation of Electric Power and
Communications Systems," in Power Engineering Society General
Meeting, 2007. IEEE, 2007, pp. 1-8.
[6] F. Bouchhima, et al., "A SystemC/Simulink Co-Simulation Framework
for Continuous/Discrete-Events Simulation," in Behavioral Modeling and
Simulation Workshop, Proceedings of the 2006 IEEE International, 2006,
pp. 1-6.
[7] J. H. Taylor and Z. Jie, "Rigorous hybrid systems simulation with
continuous-time discontinuities and discrete-time components," in
Control & Automation, 2007. MED '07. Mediterranean Conference on,
2007, pp. 1-6.
[8] M. C. D'Abreu and G. A. Wainer, "Models for continuous and hybrid
system simulation," in Simulation Conference, 2003. Proceedings of the
2003 Winter, 2003, pp. 641-649 Vol.1.
[9] S. Garlapati, et al., "Agent Based Supervision of Zone 3 Relays to
Prevent Hidden Failure Based Tripping," presented at the First IEEE
International Conference on Smart Grid Communications, 2010.
[10] H. Wang and J. S. Thorp, "Optimal locations for protection system
enhancement: a simulation of cascading outages," Power Delivery, IEEE
Transactions on, vol. 16, pp. 528-533, 2001.
[11] J. W. Stahlhut, et al., "Latency Viewed as a Stochastic Process and its
Impact on Wide Area Power System Control Signals," Power Systems,
IEEE Transactions on, vol. 23, pp. 84-91, 2008.
[12] I. Hiskens, "Significance of Load Modeling in Power System dynamics,"
presented at the x symposium of specialists in electric operational and
expansion planning, 2006.