A study of the dielectric properties of some phosphonitrilic fluorides, chlorides and chloride-fluorides in cyclohexane solutions was carried out and evidence was found to support the hypothesis that these compounds all have a non-negligible atom polarization caused by low frequency vibrations of the molecules. The distortion polarization of one of the geminally substituted isomers of the compound N₄P₄F₄Cl₄ was measured and this datum was used as support for assigning the 1,1,3,3-isomer structure to the compound. / Science, Faculty of / Chemistry, Department of / Graduate

The thesis analyzes internationalization strategies and processes that were used by major German electricity companies during their transition from purely national companies to some of the world's largest electricity corporations with operations in many different countries. The paper starts out by outlining theoretical elements that are available to companies in general and then provides an in-depth analysis of the internationalization that Germany's major Electricity companies went through after the liberalization of German and European electricity markets. Based on this, the thesis then identifies key internationalization patterns in the German electricity industry and, by taking into account future developments, provides factors that will influence further internationalization strategies in the segment.

In 1927 the Central Electricity Board began to oversee the building of the national grid. In the early development of electricity, electrical power was consumed by those privileged enough to be able to afford their own generators. A small number of local undertakings were established in urban centres during the 1920s but it was the nationalisation of electricity supply that gradually made electric power available to the masses. The electrical supply industry marketed electrical appliances as economical, efficient and clean alternatives to gas and coal, and, as time and labour saving appliances to the housewife. This thesis employs an interdisciplinary approach to the consumption of electricity and electrical technologies within the domestic environment, drawing upon the methodology of social construction of technology, historical geography, material culture studies and oral histories. It aims to compare and contrast constructions of the ideal modern electric home and electrical appliances with the lived reality of experiences of electricity in different homes across Britain to draw out the tensions between the two and explore how they mutually constructed and shaped each other. Using case studies of electric cookers, refrigerators, electric irons, vacuum cleaners, electric toys, radios, electric razors and hairdryers, it explores how the electrical industry constructed modernity and the ideal modern home in advertising material, the construction of the ‘housewife consumer’ and other users in the home, and the fluid nature of domestic space and its relationship with electricity.

The impedances of cables are some of the parameters needed for various studies in cable systems. In this work, the impedances of cables are calculated using the subdivisions of the conductors (including ground) in the system. Use is also made of analytically derived ground return formulae to speed up the calculations. The impedances of most linear materials are calculated with a good degree of accuracy but materials with highly nonlinear properties, like steel pipes, give large deviations in the results when they are represented by the linear model used. The method is used to study a test case of induced sheath currents in bonded sheaths and it gives very good results when compared with the measured values. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Unknown

Techniques for modelling of synchronous generators in the simulation of electromagnetic transients are described. First of all, an adequate mathematical model of the generator is established. It uses the conventional set of generator data only, which are readily available, but it is flexible enough to accommodate additional data, if and when such become available. The resulting differential equations of the generator are then transformed into linear algebraic equations, with a time varying coefficient matrix, by using the numerically stable trapezoidal rule of integration. These equations can be interfaced with the equations of an electromagnetic transients program in one of two ways: (a) Solve the equations of the generator simultaneously with the equations of a three-phase Thevenin equivalent circuit of the transmission network seen from the generator terminals. (b) Replace the generator model with a modified Thevenin equivalent circuit and solve the network equations with the generator treated as known voltage sources e[sup red][sub ph] (t-Δt) behind constant resistances [R [sup red][sub ph]]. After the network solution at each time step, the stator quantities are known and used to solve the equations for the rotor windings. These two methods cover, in principle, all possible interfacing techniques. They are not tied to the trapezoidal rule of integration, but can be used with any other implicit integration technique. The results obtained with these two techniques are practically identical. Interfacing by method (b), however, is more general since it does not require a Thevenin equivalent circuit of the network seen from the generator terminals. The numerical examples used in this thesis contain comparisons with field test results in order to verify the adequacy of the generator model as well as the correctness of the numerical procedures. A short discussion of nonlinear saturation effects is also presented. A method of including these effects into the model of the generator is then proposed. Typical applications of the developed numerical procedures include dynamic overvoltages, torsional vibrations of the turbine-generator shaft system, resynchronization of the generator after pole slipping and detailed assessment of generator damping terms in transient stability simulations. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

Midwest Independent Transmission System Operator, Inc. (MISO) is a non-profit regional transmission organization (RTO) that oversees electricity production and transmission across thirteen states and one Canadian province. MISO also operates an electronic exchange for buying and selling electricity for each of its five regional hubs. MISO oversees two types of markets. The forward market, which is referred to as the day-ahead (DA) market, allows market participants to place demand bids and supply offers on electricity to be delivered at a specified hour the following day. The equilibrium price, known as the locational marginal price (LMP), is determined by MISO after receiving sale offers and purchase bids from market participants. MISO also coordinates a spot market, which is known as the real-time (RT) market. Traders in the real-time market must submit bids and offers by thirty minutes prior to the hour for which the trade will be executed. After receiving purchase and sale offers for a given hour in the real time market, MISO then determines the LMP for that particular hour. The existence of the DA and RT markets allows producers and retailers to hedge against the large fluctuations that are common in electricity prices. Hedge ratios on the MISO exchange are estimated using various techniques. No hedge ratio technique examined consistently outperforms the unhedged portfolio in terms of variance reduction. Consequently, none of the hedge ratio methods in this study meet the general interpretation of FASB guidelines for a highly effective hedge. One of the major goals of deregulation is to bring about competition and increased efficiency in electricity markets. Previous research suggests that electricity exchanges may not be weak-form market efficient. A simple moving average trading rule is found to produce statistically and economically significant profits on the MISO exchange. This could call the long-term survivability of the MISO exchange into question.

No description available.

No description available.

No description available.

No description available.