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Model validation of power plant equipment is expected to be mandated imminently by the North American Electric Reliability Corporation. These standards will result in a great need for performing model validation for a large fleet of existing and future power plants. The historic approach to model validation of synchronous generators has typically been a battery of offline tests. In addition, the process of validation depends on a trial and error series of simulations, comparing the results of such simulations with measured test data, to gradually tend toward a validated model and its parameters. Such a method presents significant challenges for application on a large fleet of units. This paper documents a practical approach to model validation. The method is based on collecting online data from the generating unit, typically near or at base-load. Data are collected either from digital-fault recorders capturing system disturbances, or from digital excitation system for an imposed small voltage-reference step. The data are then used in a software tool to perform model validation using an automated optimization algorithm-–the entire process may be said to be semiautomated. The benefits are explained in the paper through actual examples of the application. [ABSTRACT FROM PUBLISHER]

Cellular location-based services need to use a variety of positioning methods to meet requirements on availability, response time, and accuracy. Due to the geometrical properties of the different positioning methods, the number of standardized reporting formats is large. Because the user requirements on the reporting formats are as scattered as the geometrical properties of the positioning methods, there is a need for shape conversion algorithms that transform between different formats. This paper discusses a case that transforms between a polygon and an ellipse while preserving the confidence between the two shapes. The transformation is required for emergency positioning outside North America, and when fingerprinting, localization is used in the Global System for Mobile Communications (GSM). The algorithm has a number of technically interesting properties, e.g., with regard to the selection of the optimization criterion and the fact that the solution is computed by an analytical solution of a cubic equation. [ABSTRACT FROM PUBLISHER]

Current fed parallel resonant electronic ballast (PREB) dominates the applications for the T8 fluorescent lamp in North America for its advantage of low cost, flexibility and high reliability. At fault condition, a PREB generates much heat externally, and it is difficult to provide fault protection with traditional approaches. In this paper, a digital solution is presented to detect universal fault condition in PREB without sacrificing its other advantages. Operational principal of PREB is explored to show that the load impedance disturbance in PREB leads to frequency perturbation of the inverter, which can be detected with a very simple and low cost digital device for fault detection. Experiments show that this frequency diagnostic provides very sensitive and reliable fault detection for PREB. With both end-of-life lamp and anti-arcing protections implemented with one algorithm, this technology provides a superior fault protection to one of the most widely used ballast topologies and extends the potential applications of PREB in modern lighting industry. [ABSTRACT FROM AUTHOR]