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Zhu Y.,North China Electrical Power University | Fan X.,State Grid Electric Power Research Institute of China
International Journal of Electrical Power and Energy Systems

As very little research on the fault location for multi-terminal transmission lines based on current traveling waves only has been done, a new fault location scheme on this is proposed. The proposed scheme is different from the traditional ones based on fundamental impedance. Fast Intrinsic Mode Decomposition (FIMD) and Teager Energy Operator (TEO) are combined (FIMD&TEO) to detect the arrival time of the traveling wave at each terminal. Fault Distance Ratio Matrix (FDRM) and rules for identifying faulted sections of a multi-terminal transmission line are proposed and the method for building FDRM is presented in this paper. After several couples of local and remote terminals connecting through the faulted section are got, their fault distances are calculated by means of a two-ended traveling wave method, and then the fault point can be located by averaging the fault distances. Many simulations under various fault conditions have been done, and the results show that the proposed scheme can locate faults more accurately than existing impedance-based methods. © 2013 Elsevier Ltd. All rights reserved. Source

Fang Y.,State Grid Electric Power Research Institute of China
Dianli Xitong Zidonghua/Automation of Electric Power Systems

A discussion is presented on the nature of highly-centralized optimization of the closed-loop adaptive stability control technology and the influence of model uncertainties on its suitability. Industrial experiences in dissolving uncertainties in security defense practices are introduced. It is pointed out that for design of security defense framework time-space conditions applicable for highly-centralized optimization system should be taken into full consideration, the conceptual design of a large complex closed-loop system control framework should not be solely based on highly-centralized optimization, other methods of not relying on system modeling accuracy should be developed besides consistently improving modeling accuracy, time-space distributed decision-making should be used to share risks of wrong decisions due to uncertainties, the role of engineers in the decision-making process should be emphasized and on-line verification of the adaptability of emergency control decisions should be widely used, flexibility of control objectives should be considered to avoid seeking simultaneous satisfaction of multi optimal man-made objectives and risk based concept should be used to coordinate on-line and off-line pre-decision-making, and further research into decision support technology of manual emergency control should be conducted. © 2011 State Grid Electric Power Research Institute Press. Source

Fang Y.,State Grid Electric Power Research Institute of China
Dianli Xitong Zidonghua/Automation of Electric Power Systems

Grid interconnection, cross-regional power transmission and intermittent energy source injection raise higher requirements for power system emergency control technology. In the light of stability problem features such as transition of stability forms during system dynamic process, complication of voltage and VAR dynamics and intensification of cross-regional impact of regional control, as well as new control equipment characteristics of fast and flexible adjustment capability, this paper presents an analysis of trends in control strategy such as use of remote regional grid information in real-time decision-making, wide-area coordination of control time sequence, coordination of stability control systems and so on. It is also pointed out that capability of control devices should be further enhanced in such aspects as countermeasures against uncertainties of control signal transmission time delay due to network communication, wide-area time sequence coordination, integration of event triggered feed-forward control and response triggered feedback control, and so on. © 2011 State Grid Electric Power Research Institute Press. Source

Gu Y.,Midwest Independent Transmission System Operator | McCalley J.D.,Iowa State University | Ni M.,State Grid Electric Power Research Institute of China
IEEE Transactions on Sustainable Energy

In this paper, a generation expansion planning model and a transmission expansion planning model are proposed to inform investment decisions from the perspectives of generation companies and ISOs, respectively. Interactions between large-scale wind integration and transmission system planning are analyzed, and a new computational procedure of system expansion planning that coordinates generation and transmission investment is presented. The cooptimization of energy and ancillary services markets is considered to capture the impacts of wind power on the operation of the electric system. Benders decomposition is employed to reduce the overall computation time. © 2010-2012 IEEE. Source

Tan S.-W.,State Grid Electric Power Research Institute of China
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control

The features of the fourth generation power dispatch automation real-time communication subsystem are analyzed in detail, such as hardware platform, operation model, communication protocol integration, PMU communication, gateway, etc. Based on application requirements, one or more real-time communication subsystems can be integrated in the unified supporting planform of the fourth generation dispatch automation system. Applications of the fourth generation front-end communication subsystem are explained. For example, it is applied to full-vision energy management system real-time communication for China southern power grid and to the EMS communication project with TASE.2 protocol for Guizhou power grid. IEC61850 protocol communication is furtherly discussed. Source

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