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Abstract: In order to enhance power system reliability and manage network congestions, many power utilities around the world have deployed various forms of system protection schemes (SPS) in their systems. In a deregulated environment, SPS could offer immediate solutions to network congestion that are beneficial to both utilities and customers. This paper presents a framework for quantitative risk and benefit assessments of SPS operations. The risk of SPS operations and its effect to the system security are evaluated by a probabilistic risk assessment approach. The benefits obtainable from power market and the customer interruption costs resulting from SPS operations are appraised. The proposed methodology can be used by power system operators and planners to assess the applications of SPS for system reliability enhancement and compare different alternatives for managing network congestion. Numerical results obtained from an actual event-based SPS example are presented. [ABSTRACT FROM AUTHOR]

The rapid growth of data exchange on the Internet has created many critical problems that require an answer. Traditional data exchange systems based on client/server communication models are less scalable and incur especially high maintenance cost in the data exchange domain. For these reasons, many researchers have switched their interest to asynchronous communication models. Although Message-Oriented Middleware (MOM) is a middle-tier infrastructure that links operating systems and applications, such asynchronous communication APIs supported by middleware vendors are usually hard to use. For these reasons, in this study, we present a new development environment for asynchronous communication platforms which we term Ghostwriter. The keyword for our development environment is ‘easy’, that is, easy to use, easy to develop, and easy to deploy. Therefore, many researchers have switched their interest to asynchronous communication models. In addition, learning about and implementing the functions of the asynchronous communication''s clients in Ghostwriter environment is simple. Other benefits are a lower technical learning curve, help for concentrate on system design, has easily reusable components, and easily integrated applications. [Copyright &y& Elsevier]

This letter introduces a dual-master synchronous operation scheme (DMSOS) of control center implemented in a high density longitudinal power system. A fully redundant peer-to-peer scheme with multi-site operations of advanced energy management system (EMS) located at northern and southern parts is presented. [ABSTRACT FROM PUBLISHER]

This paper presents an enhanced differential evolution algorithm (DE) for solving the directional overcurrent relay (DOCR) coordination problem. Comparisons among different versions of DE for coordination of DOCRs in larger and interconnected power systems are presented. The evaluation criteria consist of fitness value, number of violation and standard deviation. The outstanding DE algorithm has been enhanced in four aspects: dial reduction scheme, elitism and mediocrity scheme, mutation index renew scheme, and population reduction scheme. The enhanced-DE (eDE) shown best result in terms of execution time, result quality, robustness and convergence ability compared to the others analyzed in this research. The IEEE 14 and 57 bus systems are used to validate the proposed algorithm. A significant comparison result between eDE and DE on the IEEE 57 bus network are: execution time in seconds 364 vs. 2040, fitness value 1.933 vs. 7.91, and standard deviation of fitness value 0.018 vs. 5.52. Results are averaged values in 50 runs. [ABSTRACT FROM AUTHOR]

Due to the growth of electricity demands and transactions in power markets, existing power networks need to be enhanced in order to increase their loadability. The problem of determining the best locations for network reinforcement can be formulated as a mixed discrete-continuous nonlinear optimization problem (MDCP). The complexity of the problem makes extensive simulations necessary and the computational requirement is high. An ordinal optimization (OO) technique is proposed in this paper to solve the MDCP involving two types of flexible ac transmission systems (FACTS) devices, namely static var compensator (SVC) and thyristor controlled series compensator (TCSC), for system loadability enhancement. In this approach, crude models are proposed to cope with the complexity of the problem and speed up the simulations with high alignment confidence. Test results based on a practical power system confirm that the proposed models permit the use of OO-based approach for finding good enough solutions with less computational efforts. [ABSTRACT FROM AUTHOR]