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Investigations of load-tap changer interaction
06
96/02748 Effects of additives on the electrolytic consumption of carbon anodes in aluminium electrolysis Kuang, Z. et al., Carbon, 1995, 33, (10), 1479-1484. The effect of impurities on the anode carbon consumption in aluminium electrolysis was studied in a closed laboratory cell, which allowed the determination of the total carbon consumption, the carbon gasification and the formation of carbon dust. 96/02749 Effects of load modeling on minimum loss, minimum emission, and multiple-obJective optimal hydrothermal power flow Mbamalu, G. A. et al., Electric Power Systems Res., Aug. 1995, 34, (2), 97-108. The effects of incorporating load models in three formulations of hydrothermal optimal power flow are considered in this paper. The formulations are transmission loss minimization, NO, minimization, and the multiple objectives of minimum NO, emission and minimum cost. The conventional algorithms and those incorporating load models were tested using a 14-bus and a 30-bus test system. 96/02750 Electric power distribution network restoration: A survey of papers and a review of the restoration problem Curcic, S. et al., Electric Power Systems Res., Nov. 1995, 35, (2), 73-86. This survey addresses the problem of supply restoration following an outage in an electric distribution system. Operator decision support for the restoration of supply after an outage is an active research area. This is significant for enhancing supply continuity and achieving better efficiency. It is important for operators to reach a feasible and speedily implementable restoration plan to restore the electricity service beyond the faulted zone. The paper provides a comprehensive survey of the conceptual aspects as well as recent algorithmic developments for distribution system restoration. 96/02751 An extended block diagram transfer function model of a synchronous machine Saidy, M. and Hughes, F. M. Elect. Power & Energy Systems, Feb. 1996, 18, (2), 139-142. The paper presents an extended transfer function block diagram model of a generator based on a standard, widely used and accepted representation, which includes field and one damper windings along the d-axis and two damper windings along the q-axis. This model can be used to explain the fundamenta l dynamic characteristicsof round rotor, as well as, salient pole machines and provides a good basis for analysis and controller design purposes. 96/02752 Fault analysis with modular neural networks Rodriguez, C. et al., Elect. Power & Energy Systems, Feb. 1996, 18, (2), 99-110. Automatic fault diagnosis in power systems presents real challenges to computing technologies. As an alternative approach to expert systems, several neural network solutions have been proposed recently. In this paper a modular, neural network-based solution to power systems alarm handling and fault diagnosis is described that overcomes the limitations of 'toy' alternatives constrained to small and fixed-topology electrical networks. 96/02753 Field performance of lead-acid batteries in photovoltaic rural electrification kits Huacuz,1. M. et al., Solar Energy, Nov. 1995,55, (4), 287-299. A field survey was carried out in 83 rural communities within seven different states in Mexico, to assess the performance of photovoltaic (PV) rural electrification systems previously installed and to sense the degree of user satisfaction with PV technology. The work reports on the performance of lead-acid batteries associated with domestic PV lighting kits. 96/02754 Foundations of electroheat. A unified approach Metaxas, A. C. John Wiley & Sons, Baffins Lane, Chichester, West Sussex, P019 IUD, UK, £45.00, Mar. 1996,400 pp. Electroheat is an extremely diverse subject area comprising many topics from laser welding to plasma furnaces for waste treatment and from induction heat for forging to radio frequency drying of textiles. The difficulty with teaching such a subject has always been its diversity and individual nature of the various topics. The book unifies three major areas: electromagnetic heating, comprising direct resistance and induction heating of metals, radio frequency and microwave heating of dielectrics. The aim of the book is to bring together the unifying theory of some topics in e1ectroheat, highlighting similarities in the equations, and any similarities of approach. 96/02755 Fuel cells - A compelling technology for the near future Glaser, S. Energy World, Feb. 1996, (236), 15-16. The article is based, in part, on a piece about fuel cells for transportation applications, prepared for the Journal of the Parliamentry Renewable and Sustainable Energy Group. The main source is a 600-page report: Fuel cells: Applications and opportunities, published by EscoVale.
Electric power generation and utilisation (scientific, technical)
96/02756 A genetic algorithm for generator scheduling In power systems Orero, S. O. and Irving, M. R. Elect. Power & Energy Systems, 1996, 18, (1), 19-26. The paper presents a genetic algorithm based approach to the scheduling of l:enerators in a power system. All the usual unit commitment constraints including ramp rates are considered. An enhanced genetic algorithm incorporating a sequential decomposition logic is used to provide a faster search mechanism. The main advantage of the genetic algorithm formulation is that fairly accurate results can be obtained with a very simple algorithm. The algorithm has been tested on a power system with 26 generators. 96/02757 High speed protection relay has Increased functionality MPS, Modern Power Systems, Jan. 1996, 16, (1), 48-50. Describes an advanced digital technology principle which has been used to develop a new fully numerical five zone distance relay for HV and EHV transmission lines. The relay has an operating time of typically less than one cycle, as well as a number of protection and fault analysis features as part of an integrated scheme. 96/02758 High-speed fault detection and classification with neural nets Kezunovic, M. et al., Electric Power Systems Res., Aug. 1995, 34, (2), 109-116. The paper introduces a new neural net (NN) approach for automated fault disturbance detection and classification. The NN design and implementation are aimed at high-speed processing which can provide selective realtime detection and classification of faults. The approach is extensively tested using the Electromagnetic Transients Program (EMTP) simulations of two quite complex transmission system configurations. The results indicate that the speed and selectivity of the approach are quite adequate for a number of different transmission and distribution monitoring, control, and protection applications. 96/02759 Improved phase-coordinate Gauss-Seidel load flow algorithm Moonhy, S. et al., Electric Power Systems Res., Aug. 1995, 34, (2), 91-95. The paper provides an efficient algorithm for extendin¥ the earlier work on the application of the reduction and restoration technique of single-phase systems to three-phase network formulation based on the phase-coordinate Gauss-Seidel load flow algorithm. 96/02760 Interactions between disordered carbon and lithIum in lithium Ion rechargeable batteries Matsumura, Y. et al., Carbon, 1995, 33, (10), 1457-1462. The discharge capacity of ribbonlike carbon film with a disordered structure as an anode exceeds the theoretical capacity of graphite anode. In order to explain the phenomenon, a model for the interaction between disordered carbon and lithium in lithium ion rechargeable batteries has been proposed. The model is based on the assumptions that for the disordered carbon with a small crystallite size, Li species are not only intercalated between graphitic layers but also doped at the edge of the graphitic layers, and in additiun even more Li species are doped onto the surface of the crystallite. Investigations of load-tap changer interaction Popovic, D. et aI., Elect. Power & Energy Systems, Feb. 1996, 18, (2), 81-97. The paper explores the dynamic behaviour of loads and tap changes during the process of voltage collapse in power systems. Using an exponential recovery load model representing the dynamic behaviour of aggregate loads, the mechanism of voltage collapse is illustrated. Dynamic interaction between loads and transformers is investigated. Based on such dynamic considerations, a tap locking strategy is proposed which ensures that voltage collapse does not occur. Investigationsfocus on determining a critical value of tap position such that locking at a smaller value of tap results in stable behavour, but locking at a larger value results in voltage collapse. 96/02761
96/02762 Java-Ball link will use world's tallest towers Gheorghita, G. et al., MPS, Modern Power Systems, Dec. 1995, 15, (12), 49, 51, 53. A 500 kV overhead power line is currently planned to cross the Straits of Bali, providing a reinforcement of the existing power interconnectors between the transmission systems of East Java and Bali. The Straits, at their narrowest, are approximately 2400 m wide. In order to accomplish this interconnection it will be necessary to design and construct the tallest transmission line towers in the world, with a height of approximately 295
m.
Fuel and Energy Abstracts May 1996 193
96/02748 Effects of additives on the electrolytic consumption of carbon anodes in aluminium electrolysis Kuang, Z. et al., Carbon, 1995, 33, (10), 1479-1484. The effect of impurities on the anode carbon consumption in aluminium electrolysis was studied in a closed laboratory cell, which allowed the determination of the total carbon consumption, the carbon gasification and the formation of carbon dust. 96/02749 Effects of load modeling on minimum loss, minimum emission, and multiple-obJective optimal hydrothermal power flow Mbamalu, G. A. et al., Electric Power Systems Res., Aug. 1995, 34, (2), 97-108. The effects of incorporating load models in three formulations of hydrothermal optimal power flow are considered in this paper. The formulations are transmission loss minimization, NO, minimization, and the multiple objectives of minimum NO, emission and minimum cost. The conventional algorithms and those incorporating load models were tested using a 14-bus and a 30-bus test system. 96/02750 Electric power distribution network restoration: A survey of papers and a review of the restoration problem Curcic, S. et al., Electric Power Systems Res., Nov. 1995, 35, (2), 73-86. This survey addresses the problem of supply restoration following an outage in an electric distribution system. Operator decision support for the restoration of supply after an outage is an active research area. This is significant for enhancing supply continuity and achieving better efficiency. It is important for operators to reach a feasible and speedily implementable restoration plan to restore the electricity service beyond the faulted zone. The paper provides a comprehensive survey of the conceptual aspects as well as recent algorithmic developments for distribution system restoration. 96/02751 An extended block diagram transfer function model of a synchronous machine Saidy, M. and Hughes, F. M. Elect. Power & Energy Systems, Feb. 1996, 18, (2), 139-142. The paper presents an extended transfer function block diagram model of a generator based on a standard, widely used and accepted representation, which includes field and one damper windings along the d-axis and two damper windings along the q-axis. This model can be used to explain the fundamenta l dynamic characteristicsof round rotor, as well as, salient pole machines and provides a good basis for analysis and controller design purposes. 96/02752 Fault analysis with modular neural networks Rodriguez, C. et al., Elect. Power & Energy Systems, Feb. 1996, 18, (2), 99-110. Automatic fault diagnosis in power systems presents real challenges to computing technologies. As an alternative approach to expert systems, several neural network solutions have been proposed recently. In this paper a modular, neural network-based solution to power systems alarm handling and fault diagnosis is described that overcomes the limitations of 'toy' alternatives constrained to small and fixed-topology electrical networks. 96/02753 Field performance of lead-acid batteries in photovoltaic rural electrification kits Huacuz,1. M. et al., Solar Energy, Nov. 1995,55, (4), 287-299. A field survey was carried out in 83 rural communities within seven different states in Mexico, to assess the performance of photovoltaic (PV) rural electrification systems previously installed and to sense the degree of user satisfaction with PV technology. The work reports on the performance of lead-acid batteries associated with domestic PV lighting kits. 96/02754 Foundations of electroheat. A unified approach Metaxas, A. C. John Wiley & Sons, Baffins Lane, Chichester, West Sussex, P019 IUD, UK, £45.00, Mar. 1996,400 pp. Electroheat is an extremely diverse subject area comprising many topics from laser welding to plasma furnaces for waste treatment and from induction heat for forging to radio frequency drying of textiles. The difficulty with teaching such a subject has always been its diversity and individual nature of the various topics. The book unifies three major areas: electromagnetic heating, comprising direct resistance and induction heating of metals, radio frequency and microwave heating of dielectrics. The aim of the book is to bring together the unifying theory of some topics in e1ectroheat, highlighting similarities in the equations, and any similarities of approach. 96/02755 Fuel cells - A compelling technology for the near future Glaser, S. Energy World, Feb. 1996, (236), 15-16. The article is based, in part, on a piece about fuel cells for transportation applications, prepared for the Journal of the Parliamentry Renewable and Sustainable Energy Group. The main source is a 600-page report: Fuel cells: Applications and opportunities, published by EscoVale.
Electric power generation and utilisation (scientific, technical)
96/02756 A genetic algorithm for generator scheduling In power systems Orero, S. O. and Irving, M. R. Elect. Power & Energy Systems, 1996, 18, (1), 19-26. The paper presents a genetic algorithm based approach to the scheduling of l:enerators in a power system. All the usual unit commitment constraints including ramp rates are considered. An enhanced genetic algorithm incorporating a sequential decomposition logic is used to provide a faster search mechanism. The main advantage of the genetic algorithm formulation is that fairly accurate results can be obtained with a very simple algorithm. The algorithm has been tested on a power system with 26 generators. 96/02757 High speed protection relay has Increased functionality MPS, Modern Power Systems, Jan. 1996, 16, (1), 48-50. Describes an advanced digital technology principle which has been used to develop a new fully numerical five zone distance relay for HV and EHV transmission lines. The relay has an operating time of typically less than one cycle, as well as a number of protection and fault analysis features as part of an integrated scheme. 96/02758 High-speed fault detection and classification with neural nets Kezunovic, M. et al., Electric Power Systems Res., Aug. 1995, 34, (2), 109-116. The paper introduces a new neural net (NN) approach for automated fault disturbance detection and classification. The NN design and implementation are aimed at high-speed processing which can provide selective realtime detection and classification of faults. The approach is extensively tested using the Electromagnetic Transients Program (EMTP) simulations of two quite complex transmission system configurations. The results indicate that the speed and selectivity of the approach are quite adequate for a number of different transmission and distribution monitoring, control, and protection applications. 96/02759 Improved phase-coordinate Gauss-Seidel load flow algorithm Moonhy, S. et al., Electric Power Systems Res., Aug. 1995, 34, (2), 91-95. The paper provides an efficient algorithm for extendin¥ the earlier work on the application of the reduction and restoration technique of single-phase systems to three-phase network formulation based on the phase-coordinate Gauss-Seidel load flow algorithm. 96/02760 Interactions between disordered carbon and lithIum in lithium Ion rechargeable batteries Matsumura, Y. et al., Carbon, 1995, 33, (10), 1457-1462. The discharge capacity of ribbonlike carbon film with a disordered structure as an anode exceeds the theoretical capacity of graphite anode. In order to explain the phenomenon, a model for the interaction between disordered carbon and lithium in lithium ion rechargeable batteries has been proposed. The model is based on the assumptions that for the disordered carbon with a small crystallite size, Li species are not only intercalated between graphitic layers but also doped at the edge of the graphitic layers, and in additiun even more Li species are doped onto the surface of the crystallite. Investigations of load-tap changer interaction Popovic, D. et aI., Elect. Power & Energy Systems, Feb. 1996, 18, (2), 81-97. The paper explores the dynamic behaviour of loads and tap changes during the process of voltage collapse in power systems. Using an exponential recovery load model representing the dynamic behaviour of aggregate loads, the mechanism of voltage collapse is illustrated. Dynamic interaction between loads and transformers is investigated. Based on such dynamic considerations, a tap locking strategy is proposed which ensures that voltage collapse does not occur. Investigationsfocus on determining a critical value of tap position such that locking at a smaller value of tap results in stable behavour, but locking at a larger value results in voltage collapse. 96/02761
96/02762 Java-Ball link will use world's tallest towers Gheorghita, G. et al., MPS, Modern Power Systems, Dec. 1995, 15, (12), 49, 51, 53. A 500 kV overhead power line is currently planned to cross the Straits of Bali, providing a reinforcement of the existing power interconnectors between the transmission systems of East Java and Bali. The Straits, at their narrowest, are approximately 2400 m wide. In order to accomplish this interconnection it will be necessary to design and construct the tallest transmission line towers in the world, with a height of approximately 295
m.
Fuel and Energy Abstracts May 1996 193