scholarly journals A Topology Identification Method to Enhance the Linear Estimation of Generator Rotor Speeds

2021 ◽  
Author(s):  
Davide Gotti ◽  
Pablo Ledesma ◽  
Hortensia Amaris
Keyword(s):  
New England ◽  
Network Topology ◽  
Deep Neural Networks ◽  
Test System ◽  
Rotor Speed ◽  
Generator Rotor ◽  
Distributed Approach ◽  
Topology Changes ◽  
System Operator ◽  
Measurement Units

<div>This paper proposes a methodology to avoid biased estimations of generator rotor speeds under network topology changes. The algorithm is based on deep neural networks and executes topology processing considering the relevant branches for rotor speed estimations. The proposed technique uses the measurements from the same phasor measurement units (PMUs) needed to carry out generator rotor speed estimations; thus, it does not imply an additional cost for the transmission system operator. The proposed methodology is demonstrated with a centralized and distributed approach, using a modified version of the New England test system and the IEEE 118-bus test system, respectively. The numerical results on both test systems demonstrate the reliability and the low computational burden of the proposed algorithm.</div>

scholarly journals A Topology Identification Method to Enhance the Linear Estimation of Generator Rotor Speeds

2021 ◽  
Author(s):  
Davide Gotti ◽  
Pablo Ledesma ◽  
Hortensia Amaris
Keyword(s):  
New England ◽  
Network Topology ◽  
Deep Neural Networks ◽  
Test System ◽  
Rotor Speed ◽  
Generator Rotor ◽  
Distributed Approach ◽  
Topology Changes ◽  
System Operator ◽  
Measurement Units

<div>This paper proposes a methodology to avoid biased estimations of generator rotor speeds under network topology changes. The algorithm is based on deep neural networks and executes topology processing considering the relevant branches for rotor speed estimations. The proposed technique uses the measurements from the same phasor measurement units (PMUs) needed to carry out generator rotor speed estimations; thus, it does not imply an additional cost for the transmission system operator. The proposed methodology is demonstrated with a centralized and distributed approach, using a modified version of the New England test system and the IEEE 118-bus test system, respectively. The numerical results on both test systems demonstrate the reliability and the low computational burden of the proposed algorithm.</div>

scholarly journals Power electrical network topology detection using changes of phasor measurements in transient states

2019 ◽  
Vol 139 ◽  
pp. 01063
Author(s):  
Natalja Gotman ◽  
Galina Shumilova
Keyword(s):  
Neural Networks ◽  
Artificial Neural Networks ◽  
Network Topology ◽  
Short Circuit ◽  
Transient State ◽  
Test System ◽  
Experimental Results ◽  
Electrical Network ◽  
Phasor Measurements ◽  
Measurement Units

The solution of the problem of a topology detection of an electrical network on changing voltage and current phasors obtained from the phasor measurement units (PMUs) in a transient state using artificial neural networks (ANNs) is considered. Experimental results for the 14-bus test system to detect the failed line after short circuit and the line was turned on by an auto-reclosing device are presented.

scholarly journals Optimal Coordination of Over-Current Relays in Microgrids Using Unsupervised Learning Techniques

2021 ◽  
Vol 11 (3) ◽  
pp. 1241
Author(s):  
Sergio D. Saldarriaga-Zuluaga ◽  
Jesús M. López-Lezama ◽  
Nicolás Muñoz-Galeano
Keyword(s):  
Unsupervised Learning ◽  
Distributed Generation ◽  
Network Topology ◽  
International Electrotechnical Commission ◽  
Number Of Clusters ◽  
Learning Techniques ◽  
Topology Changes ◽  
Network Topologies ◽  
Optimal Coordination ◽  
Operational Modes

Microgrids constitute complex systems that integrate distributed generation (DG) and feature different operational modes. The optimal coordination of directional over-current relays (DOCRs) in microgrids is a challenging task, especially if topology changes are taken into account. This paper proposes an adaptive protection approach that takes advantage of multiple setting groups that are available in commercial DOCRs to account for network topology changes in microgrids. Because the number of possible topologies is greater than the available setting groups, unsupervised learning techniques are explored to classify network topologies into a number of clusters that is equal to the number of setting groups. Subsequently, optimal settings are calculated for every topology cluster. Every setting is saved in the DOCRs as a different setting group that would be activated when a corresponding topology takes place. Several tests are performed on a benchmark IEC (International Electrotechnical Commission) microgrid, evidencing the applicability of the proposed approach.

Analysis of Wireless Mesh Network Routing

2014 ◽  
Vol 989-994 ◽  
pp. 4629-4632
Author(s):  
Xiao Long Tan ◽  
Jia Zhou ◽  
Wen Bin Wang
Keyword(s):  
Network Topology ◽  
Routing Protocol ◽  
Wireless Mesh Network ◽  
Network Routing ◽  
Mesh Network ◽  
Mac Layer ◽  
Key Factors ◽  
Wireless Mesh ◽  
Topology Changes ◽  
Communication Links

Since the wireless mesh network topology dynamics and the radio channels instable, the design of wireless mesh network routing protocol become one of the key factors to determine the performance. This paper mainly studied the existing several kinds of typical three-layer mesh network routing protocol (DSDV and AODV), aimed at the defects of three-layer routing limited to the network topology changes, the paper proposed a network model based on two-layer routing. Forwarding the packet, establishing and maintaining the communication links are accomplished on the Mac layer. Simulation tests showed that two-layer routing has a big improvement on the efficiency of packet forwarding, and it effectively reduced the routing overhead and end-to-end delay simultaneously.

scholarly journals A New Indicator of Transient Stability for Controlled Islanding of Power Systems: Critical Islanding Time

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2975 ◽  
Author(s):  
Zhenzhi Lin ◽  
Yuxuan Zhao ◽  
Shengyuan Liu ◽  
Fushuan Wen ◽  
Yi Ding ◽  
...  
Keyword(s):  
New York ◽  
Power Systems ◽  
New England ◽  
Transient Stability ◽  
Time Frame ◽  
Test System ◽  
Crucial Importance ◽  
Interconnected System ◽  
Controlled Islanding ◽  
Simulation Results

Transient stability after islanding is of crucial importance because a controlled islanding strategy is not feasible if transient stability cannot be maintained in the islands created. A new indicator of transient stability for controlled islanding strategies, defined as the critical islanding time (CIT), is presented for slow coherency-based controlled islanding strategies to determine whether all the islands created are transiently stable. Then, the stable islanding interval (SII) is also defined to determine the appropriate time frame for stable islanding. Simulations were conducted on the New England test system–New York interconnected system to demonstrate the characteristics of the critical islanding time and stable islanding interval. Simulation results showed that the answer for when to island could be easily reflected by the proposed CIT and SII indicators. These two indicators are beneficial to power dispatchers to keep the power systems transiently stable and prevent widespread blackouts.

scholarly journals Impact of emission trading and renewable energy support scheme on the optimality of generator side bidding

2020 ◽  
Vol 167 ◽  
pp. 05008 ◽  
Author(s):  
A Arya ◽  
SPS Mathur ◽  
M Dubey
Keyword(s):  
Renewable Energy ◽  
Ghg Emissions ◽  
Profit Maximization ◽  
Emission Trading ◽  
Pso Algorithm ◽  
Optimization Method ◽  
Developed Countries ◽  
Test System ◽  
For Profit ◽  
System Operator

As a major Green House Gases (GHG) producer, CO2 in particular, the electricity industry’s emissions have turned in to a matter of immense concern in many countries, especially in India. India’s economy and fast economic development has attracts the attention of the world. Emission trading schemes (ETS) and renewable energy support schemes (RESS) are implemented by the various developed countries to alleviate the affect of GHG emissions. In this paper, an optimization based market simulation approach is proposed with the consideration of emission trading schemes and renewable support schemes. To simulate the bidding strategy and for profit maximization, a particle swarm optimization (PSO) algorithm is used. As above problem is a multi-objective optimization problem, Where, in the first level each Genco submit the bid to the independent system operator and in the next level a optimization method is used for the determination of optimal bidding with the implementation of emission trading schemes and renewable support schemes. It is assumed that each generator should submit bid as a price taker’s in sealed auction based on pay-as-bid market clearing price mechanism. The practicability of proposed optimization method is checked by an IEEE-30 bus test system consists of six suppliers.

Online Prediction of Transient Instability by Wide Area Measurement System

2016 ◽  
Vol 1 (1) ◽  
pp. 31
Author(s):  
Farhad Namdari ◽  
Maryam Nourizadeh ◽  
Mahmoodreza Shakarami
Keyword(s):  
New England ◽  
Prediction Method ◽  
Test System ◽  
Least Square ◽  
Area Measurement ◽  
Wide Area ◽  
Small Scale ◽  
Unknown Parameters ◽  
Wide Area Measurement System ◽  
Real Time Simulations

<p>In this paper an online accurate prediction method is proposed to enhance the speed of Transactionient stability assessment. This method is the measurement basis technique resulted from wide area measurement systems (WAMS). In the proposed method, the generators with same dynamic behavior, referred as to coherent generators, are clustered as a same group and they can be considered as an equivalent bus. So the system will be reduced into a small scale system. The admittance matrix parameters of the reduced system can be identified with the least square algorithm. Then the trajectory prediction is performed by real-time simulations. Obtained results from simulations on New England test system show the high noticeable efficiency for performance of the proposed method, capable in predicting of the disturbed trajectory under existence of unknown parameters in grid structure.. </p>

scholarly journals The (T, L)-Path Model and Algorithms for Information Dissemination in Dynamic Networks

Information ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 212
Author(s):  
Zhiwei Yang ◽  
Weigang Wu
Keyword(s):  
Network Topology ◽  
Information Dissemination ◽  
Dynamic Networks ◽  
Dynamic Network ◽  
Network Models ◽  
Point Of View ◽  
Path Model ◽  
Dynamic Network Models ◽  
Topology Changes ◽  
Practical Design

A dynamic network is the abstraction of distributed systems with frequent network topology changes. With such dynamic network models, fundamental distributed computing problems can be formally studied with rigorous correctness. Although quite a number of models have been proposed and studied for dynamic networks, the existing models are usually defined from the point of view of connectivity properties. In this paper, instead, we examine the dynamicity of network topology according to the procedure of changes, i.e., how the topology or links change. Following such an approach, we propose the notion of the “instant path” and define two dynamic network models based on the instant path. Based on these two models, we design distributed algorithms for the problem of information dissemination respectively, one of the fundamental distributing computing problems. The correctness of our algorithms is formally proved and their performance in time cost and communication cost is analyzed. Compared with existing connectivity based dynamic network models and algorithms, our procedure based ones are definitely easier to be instantiated in the practical design and deployment of dynamic networks.

scholarly journals SDN-based Handover Scheme in Cellular/IEEE 802.11p Hybrid Vehicular Networks

Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1082 ◽  
Author(s):  
Ran Duo ◽  
Celimuge Wu ◽  
Tsutomu Yoshinaga ◽  
Jiefang Zhang ◽  
Yusheng Ji
Keyword(s):  
Network Topology ◽  
Network Performance ◽  
Vehicular Networks ◽  
Ieee 802.11P ◽  
Centralized Control ◽  
Topology Changes ◽  
Dynamic Topology ◽  
Stable Transmission ◽  
Transmission Layer ◽  
Handover Scheme

With the arrival of 5G, the wireless network will be provided with abundant spectrum resources, massive data transmissions and low latency communications, which makes Vehicle-to-Everything applications possible. However, VANETs always accompany with frequent network topology changes due to the highly mobile feature of vehicles. As a result, the network performance will be affected by the frequent handover. In this paper, a seamless handover scheme is proposed where the Software-Defined Networking (SDN) and Mobile Edge Computing (MEC) technologies are employed to adapt to the dynamic topology change in VANETs. The introduction of SDN provides a global view of network topology and centralized control, which enables a stable transmission layer connection when a handover takes place, so that the upper layer performance is not influenced by the network changes. By employing MEC server, the data are cached in advance before a handover happens, so that the vehicle can restore normal communication faster. In order to confirm the superiority of our proposal, computer simulations are conducted from different aspects. The results show that our proposal can significantly improve the network performance when a handover happens.

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