The Measurement Outage Table and State Estimation

State estimation uses measurements to obtain important power system operating information ("states"). This paper uses a tabular representation to quantify the effects of measurement failure (i.e., sensor failure or measurement communications failure). The concept of a measurement outage table is introduced to evaluate the state estimator performance under measurement failure conditions. The concept of a condition indicator is used and this includes a study of certain elements of the singular spectrum of the state estimator process matrix. Examples are shown to illustrate the concept. The analysis also shows that using condition indicators for measurement placement may improve the response of the state estimator under measurement failure conditions.     

Increasing student interest and comprehension in power engineeringat the graduate and undergraduate levels

This paper reports on new efforts in the modernization of the basic undergraduate courses and a graduate curriculum in electric power engineering. The main focus of the paper is the modernization of the way power engineering is portrayed to students. The motivation is the recognition of the new deregulated and restructured environment in power engineering and the broadening of the area in general. At the undergraduate level, a multimedia approach is described in which renovation of the curriculum is done in such a way as to allow broadening of the subject material. At the graduate level, new efforts in power electronics and electric power quality are described. The implementations of changes as those reported here were made at several universities including Arizona State University     

An algebraic approach for identifying operating point dependentparameters of synchronous machines using orthogonal series expansions

This paper presents a method for identifying armature and field parameters of synchronous machines from digital fault recorder (DFR) data. The method uses operational properties of orthogonal series expansions such as the Hartley, Walsh and Fourier series to transform a set of differential equations into linear algebraic equations. The algebraic formulation and use of operational calculus reduce the problem of identifying parameters to the manipulation of matrices that may be easily performed in such computational packages as Matlab. The variation of machine parameters with operating point is considered     

Synchronous machine parameter estimation using the Hartley series

This paper presents a novel alternative to estimate armature circuit parameters of large utility generators using real time operating data. The proposed approach uses the Hartley series for fitting operating data (voltage and currents measurements). The essence of the method is the use of linear state estimation to identify the coefficients of the Hartley series. The approach is tested for noise corruption likely to be found in measurements. The method is found to be suitable for the processing of digital fault recorder data to identify synchronous machine parameters     

Latency Viewed as a Stochastic Process and its Impact on Wide Area Power System Control Signals

A method of calculating the communication delay (latency) for measurements and control signals in a power system is shown. The basis of the calculation is a dedicated communication channel for control signals. The time delay calculation is examined using a dynamic equivalent of the Western Electricity Coordinating Council transmission system. The impact on control system response is discussed. The application given is a wide area control system for interarea mode damping. Results demonstrate that control signal latency can degrade the performance of controls in a wide area control system.     

Optical transmission of 16 digitised TV channels over 21 km fibre at a bit rate of 1.12 Gbit/s

The letter describes an optical transmission system which carries 16 digitised TV channels over a distance of 21 km without repeater at a bit rate of 1.12 Gbit/s.     

Geräuschuntersuchungen und Maßnahmen zur Geräuschminderung an mehrseitigen Hobel- und Fräsmaschinen für die Holzbearbeitung

Ohne Zusammenfassung     

Present and Future Trends and Needs in Electric Power Quality Sensors and Instrumentation

Sensors and instrumentation systems form an important part of power quality assessment and preservation. In this paper, the present and future trends in power quality instrumentation are discussed and the present capabilities are identified (e.g., bandwidth, dynamic range, quantities measured). Innovative methods of instrumenting nonsinusoidal voltages and currents are described, including applications of the Global Positioning System (GPS), solid state sensors, sensors that involve light and video, advanced data compression techniques, and advanced state estimation. The cost-to-benefit ratio of sensor development is evaluated in the context of the deregulated electric utility business environment.