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Utilities frequently use ADSS (All Dielectric Self-Supporting) fiber-optic cables installed on transmission lines 3-6 m below the high voltage conductors. Dry-band arcing occurs on the fiber-optic cables when the cables are polluted and wet. This has been assumed to cause cable failures. An equivalent circuit has been developed to represent the polluted fiber-optic cable in the high voltage environment. The objective of this paper is to present a novel numerical method that can be used to predict dry-band arcing in fiber-optic cables. KCL (Kirchoffs Current Law) is used to derive node point equations for the equivalent circuit. Forward elimination and backward substitution of node voltage is used to solve the equations. The effect of pollution, tower arrangement, and conductor sag is analyzed. The numerical method has speed advantages over circuit simulation methods. This method includes conductor sag, non uniform pollution, and variable capacitance. This algorithm can be used to predict dry band arcing in fiber-optic cables. Index Terms--ADSS, circuit simulation, dry-band arcing, optical fiber cables, power transmission lines.

Due to technological advancements, the flywheel energy storage system is becoming a viable alternative to electrochemical batteries. Two potential applications of flywheel systems are for voltage support and as an uninterruptible power supply. The two applications are both useful to protect critical loads on distribution feeders. Therefore, it may be useful to look at the possibility of combining both functions into one system. This paper considers a flywheel energy storage system which performs both functions and presents a novel control scheme using both sinusoidal pulse width modulation as well as a boost converter to regulate the critical load voltage on the feeder. Dynamic voltage compensation is achieved by injecting voltage through series transformers rather than by connecting the system in shunt, to minimize the amount of kVA required by the flywheel system. Simulations are provided using the Electromagnetic Transients Program to validate the concept.

In order to better simulate the natural pollution accumulation on composite insulators, a new artificial contamination method has been developed. It is based on mixing dry contamination particles with a low amount of atomized salt solution by means of a specially designed mixing nozzle. Unlike most of the other contamination methods developed for composite insulators, no pretreatment of the surface is needed. The pollution process takes no longer than a few minutes and requires no special training. ESDD and NSDD of the artificial pollution can be controlled accurately.

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. Index Terms--Education, energy conversion, power electronics.

This paper discusses the effect of external low frequency magnetic field interference on cathode ray tube (CRT) computer monitors. The paper describes a new test facility and presents a quantitative measuring method which has been developed to characterize the field effects. A total of 21 monitors from major manufacturers were tested. It was found that larger monitors are more sensitive and that the relationship between the magnitude of jitter and the magnetic flux density is linear and independent of the refresh rate and the frequency of the interfering magnetic field. The monitors are most sensitive to magnetic fields parallel to the screen. Monitor sensitivity is specified and presented for the tested monitors. A statistical survey was carried out to determine the human perceptibility level of jitter. It was found that 12 mG may cause detectable jitter for the common 14' monitor. This value drops to around 7 mG for a 21' monitor. Index Terms--CRT, EMI, flicker, jitter, perceptibility, refresh rate, sensitivity, VDU.

The contamination performance of non-ceramic (NC) insulators is better than porcelain insulators. The paper describes the pollution collection mechanism and concludes that silicone rubber insulators collect more pollution than porcelain insulators. Long term exposure of silicone rubber insulators produces a thin layer of pollution, which is a mixture of dust, salt and silicone oil. Fog or morning dew produces droplets on the flat surfaces and forms conductive regions. Spot discharge starts between the regions, which reduces hydrophobicity. Simultaneously, dry-band arcing starts on the shank of the insulator The two arcs join together, which leads to flashover. The flashover voltage of polluted NC insulators is significantly higher than porcelain ones. Insulator performance is measured with laboratory tests. However, salt-fog and clean-fog tests can give different flashover values.

This letter presents a new concept for circuit breakers (CBs) using microelectromechanical switches (MEMS). The building block is a switching unit, including a micro-switch shunted by a diode. Several switching units are connected in series and in parallel to form a switching string assembly. The opening of the mechanical switches transfers the current to the diodes. The diodes interrupt the current at the first zero crossing. The use of micro-switches miniaturizes the CB and assures arc less current interruption by the end of the first half cycle. Index Terms--Circuit breaker, current interruption, microelectro-mechanical switch, switching string, zero current switching.