• Title, Summary, Keyword: Congestion Management

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Optimal Relocating of Compensators for Real-Reactive Power Management in Distributed Systems

  • Chintam, Jagadeeswar Reddy;Geetha, V.;Mary, D.
    • Journal of Electrical Engineering and Technology
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    • v.13 no.6
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    • pp.2145-2157
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    • 2018
  • Congestion Management (CM) is an attractive research area in the electrical power transmission with the power compensation abilities. Reconfiguration and the Flexible Alternating Current Transmission Systems (FACTS) devices utilization relieve the congestion in transmission lines. The lack of optimal power (real and reactive) usage with the better transfer capability and minimum cost is still challenging issue in the CM. The prediction of suitable place for the energy resources to control the power flow is the major requirement for power handling scenario. This paper proposes the novel optimization principle to select the best location for the energy resources to achieve the real-reactive power compensation. The parameters estimation and the selection of values with the best fitness through the Symmetrical Distance Travelling Optimization (SDTO) algorithm establishes the proper controlling of optimal power flow in the transmission lines. The modified fitness function formulation based on the bus parameters, index estimation correspond to the optimal reactive power usage enhances the power transfer capability with the minimum cost. The comparative analysis between the proposed method with the existing power management techniques regarding the parameters of power loss, cost value, load power and energy loss confirms the effectiveness of proposed work in the distributed renewable energy systems.

A Resource Management Scheme for Reliable Multimedia Data Transmission in Ship Area Networks (선박 네트워크에서 신뢰성있는 멀티미디어 데이터 전송을 위한 자원 관리 기법)

  • Kim, Jin-Woo;Lee, Seong Ro
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.7
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    • pp.1377-1384
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    • 2015
  • In this paper, a resource management scheme for preventing the video frame loss in the presence of network congestion is proposed. WiMedia protocol is suitable for the application that supports the real-time multimedia service in the ship area network since it supports high speed data transfer. However, network congestion causes the degradation of video quality, since WiMedia standard discards video frames regardless of importance of video frame. Therefore, a resource management scheme for WiMedia network is proposed in this paper. The proposed technique can intelligently treat the network congestion, and solve the degradation of video quality.

Adaptive Nonlinear RED Algorithm for TCP Congestion Control

  • Park, Kyung-Joon;Park, Eun-Chan;Lim, Hyuk;Cho, Chong-Ho
    • 제어로봇시스템학회:학술대회논문집
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    • pp.121.1-121
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    • 2001
  • Congestion control is a critical issue in TCP networks, Recently, active queue management (AQM) was proposed for congestion control at routers. The random early detection RED algorithm is widely known in the AQM algorithms, We present an adaptive nonlinear RED (NRED) algorithm, which has nonlinear drop probability profile. The proposed algorithm enhanced the performance of the RED algorithm by the self-parameterization based on the traffic load Furthermore, the proposed algorithm can effectively adapt itself between he RED and the drop-tail queue management by adopting proper nonlinearity in the drop probability profile. Through simulation, we show the effectiveness of the proposed algorithm comparing with the drop-tail and the original RED algorithm.

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Assessment of Total Transfer Capability for Congestion Management using Linear Programming (선형계획기반 선로혼잡처리에 대한 총송전용량 평가)

  • Kim, Kyu-Ho;Song, Kyung-Bin
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.55 no.11
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    • pp.447-452
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    • 2006
  • This paper presents a scheme to solve the congestion problem with phase-shifting transformer(PST) controls and power generation controls using linear programming method. A good design of PST and power generation control can improve total transfer capability(TTC) in interconnected systems. This paper deals with an application of optimization technique for TTC calculation. Linear programming method is used to maximize power flow of tie line subject to security constraints such as voltage magnitude and real power flow in interconnected systems. The results are compared with that of repeat power flow(RPF) and sequential quadratic programming(SQP). The proposed method is applied to 10 machines 39 buses model systems to show its effectiveness.

A Variable Demand Traffic Assignment Model Based on Stable Dynamics (안정동력학에 의한 가변수요 통행배정모형)

  • Park, Koo-Hyun
    • Journal of the Korean Operations Research and Management Science Society
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    • v.34 no.1
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    • pp.61-83
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    • 2009
  • This study developed a variable demand traffic assignment model by stable dynamics. Stable dynamics, suggested by Nesterov and do Palma[19], is a new model which describes and provides a stable state of congestion in urban transportation networks. In comparison with the user equilibrium model, which is based on the arc travel time function in analyzing transportation networks, stable dynamics requires few parameters and is coincident with intuitions and observations on congestion. It is therefore expected to be a useful analysis tool for transportation planners. In this study, we generalize the stable dynamics into the model with variable demands. We suggest a three stage optimization model. In the first stage, we introduce critical travel times and dummy links and determine variable demands and link flows by applying an optimization problem to an extended network with the dummy links. Then we determine link travel times and path flows in the following stages. We present a numerical example of the application of the model to a given network.

Development of Traffic Congestion Prediction Module Using Vehicle Detection System for Intelligent Transportation System (ITS를 위한 차량검지시스템을 기반으로 한 교통 정체 예측 모듈 개발)

  • Sin, Won-Sik;Oh, Se-Do;Kim, Young-Jin
    • IE interfaces
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    • v.23 no.4
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    • pp.349-356
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    • 2010
  • The role of Intelligent Transportation System (ITS) is to efficiently manipulate the traffic flow and reduce the cost in logistics by using the state of the art technologies which combine telecommunication, sensor, and control technology. Especially, the hardware part of ITS is rapidly adapting to the up-to-date techniques in GPS and telematics to provide essential raw data to the controllers. However, the software part of ITS needs more sophisticated techniques to take care of vast amount of on-line data to be analyzed by the controller for their decision makings. In this paper, the authors develop a traffic congestion prediction model based on several different parameters from the sensory data captured in the Vehicle Detection System (VDS). This model uses the neural network technology in analyzing the traffic flow and predicting the traffic congestion in the designated area. This model also validates the results by analyzing the errors between actual traffic data and prediction program.

Congestion Management in Deregulated Power System by Optimal Choice and Allocation of FACTS Controllers Using Multi-Objective Genetic Algorithm

  • Reddy, S. Surender;Kumari, M. Sailaja;Sydulu, M.
    • Journal of Electrical Engineering and Technology
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    • v.4 no.4
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    • pp.467-475
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    • 2009
  • Congestion management is one of the technical challenges in power system deregulation. This paper presents single objective and multi-objective optimization approaches for optimal choice, location and size of Static Var Compensators (SVC) and Thyristor Controlled Series Capacitors (TCSC) in deregulated power system to improve branch loading (minimize congestion), improve voltage stability and reduce line losses. Though FACTS controllers offer many advantages, their installation cost is very high. Hence Independent System Operator (ISO) has to locate them optimally to satisfy a desired objective. This paper presents optimal location of FACTS controllers considering branch loading (BL), voltage stability (VS) and loss minimization (LM) as objectives at once using GA. It is observed that the locations that are most favorable with respect to one objective are not suitable locations with respect to other two objectives. Later these competing objectives are optimized simultaneously considering two and three objectives at a time using multi-objective Strength Pareto Evolutionary Algorithms (SPEA). The developed algorithms are tested on IEEE 30 bus system. Various cases like i) uniform line loading ii) line outage iii) bilateral and multilateral transactions between source and sink nodes have been considered to create congestion in the system. The developed algorithms show effective locations for all the cases considered for both single and multiobjective optimization studies.

Active Congestion Control Using Active Router′s Feedback Mechanism (액티브 라우터의 피드백 메커니즘을 이용한 혼잡제어 기법)

  • Choe, Gi-Hyeon;Jang, Gyeong-Su;Sin, Ho-Jin;Sin, Dong-Ryeol
    • The KIPS Transactions:PartC
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    • v.9C no.4
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    • pp.513-522
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    • 2002
  • Current end-to-end congestion control depends only on the information of end points (using three duplicate ACK packets) and generally responds slowly to the network congestion. This mechanism can't avoid TCP global synchronization which TCP congestion window size is fluctuated during congestion occurred and if RTT (Round Trip Time) is increased, three duplicate ACK packets is not a correct congestion signal because congestion maybe already disappeared and the host may send more packets until receive the three duplicate ACK packets. Recently there is increasing interest in solving end-to-end congestion control using active network frameworks to improve the performance of TCP protocols. ACC (Active congestion control) is a variation of TCP-based congestion control with queue management In addition traffic modifications nay begin at the congested router (active router) so that ACC will respond more quickly to congestion than TCP variants. The advantage of this method is that the host uses the information provided by the active routers as well as the end points in order to relieve congestion and improve throughput. In this paper, we model enhanced ACC, provide its algorithm which control the congestion by using information in core networks and communications between active routers, and finally demonstrate enhanced performance by simulation.

A Statistical Method for Predicting Recurrent Congestion Time in Urban Freeway (도시고속도로 반복정체 시점의 통계학적 분석방법)

  • Han, Yeong-Jun;Son, Bong-Su;Kim, Won-Gil
    • Journal of Korean Society of Transportation
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    • v.24 no.3
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    • pp.29-37
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    • 2006
  • As a recurrent congestion of urban freeway occurs in almost same time and section, it is possible to manage the congestion effectively by the expectation and advance correspondence. In the existing traffic management system. we have used pattern data to manage a recurrent congestion. But it is not applicable to an urban freeway which kas various traffic circumstance. In this study, the probability by travel speed using a statistical distribution method will be used to predict the probability of recurrent congestion. It is expected that we can get the point of time and the duration of recurrent congestion, and we can devise an effective advance correspondence and a transportation operation.

A real-time multiple vehicle tracking method for traffic congestion identification

  • Zhang, Xiaoyu;Hu, Shiqiang;Zhang, Huanlong;Hu, Xing
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.6
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    • pp.2483-2503
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    • 2016
  • Traffic congestion is a severe problem in many modern cities around the world. Real-time and accurate traffic congestion identification can provide the advanced traffic management systems with a reliable basis to take measurements. The most used data sources for traffic congestion are loop detector, GPS data, and video surveillance. Video based traffic monitoring systems have gained much attention due to their enormous advantages, such as low cost, flexibility to redesign the system and providing a rich information source for human understanding. In general, most existing video based systems for monitoring road traffic rely on stationary cameras and multiple vehicle tracking method. However, most commonly used multiple vehicle tracking methods are lack of effective track initiation schemes. Based on the motion of the vehicle usually obeys constant velocity model, a novel vehicle recognition method is proposed. The state of recognized vehicle is sent to the GM-PHD filter as birth target. In this way, we relieve the insensitive of GM-PHD filter for new entering vehicle. Combining with the advanced vehicle detection and data association techniques, this multiple vehicle tracking method is used to identify traffic congestion. It can be implemented in real-time with high accuracy and robustness. The advantages of our proposed method are validated on four real traffic data.