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00516 Simple models for wet-snow accretion on transmission lines: snow load and liquid water content
06
Electric power generation and utilisation (scientific, technical)
9!5/00!507 Power ?? yrtsm voltage stability and security arsesammt Bian, J. and Rastgoufard, P. Electric Power Systems Rea, Sep. 1994, 30, (3), 197-201. The purpose of this investigation is to review the recent research progress
in voltage stability and security assessment of power systems. This paper presents the fundamental concepts of voltage stability, gives a shofl recall of the classical voltage theory and different criteria currently available for predicting voltage collapse problems in power systems, which have been associated with multi le power flow solutions, bifurcation, dynamics of tap changers, stochastic Poads, singular values, etc. The various methods for studying voltage collapse are compared. The application of expert system techniques to assist in the decision-making process of the reactive power/voltage control problem of power systems and future research directions towards voltage stability and security assessment are also proposed in this paper.
Robust stability in power systems with noniinrar loads using grneraiized Kharitonov’a theorem I’;4_Fti,A. et al., Electrical Power & Energy Systems, 1994, 16, (S),
95loO514
In this paper a linear model is systematically derived for an n bus m machine system with nonlinear voltage dependent loads at the network buses. The model is versatile and can be used to study different phenomena such as steady-state stability, voltage stability etc. In addition to obtaining the system A matrix, the authors also obtained a transfer function between load voltage/angles and real/reactivie powers at the network buses which is used for robust stability analysis using generalized Kharitonov’s theorem. For a given operating point and a given load model, the system A matrix and the eigenvalues can be obtained easily. Eigenvalues for different load models are investigated. 95/00515
Shajiao C: On a fast track to meet growing drmand
Modern Power Sysfems, Oct. 1994, 14, (lo), 53-63.
Practical considerations in the application of nrurai notworka to the identification of harmonic loads Varadan, S. and Makram, E. B. Electric Power Systems Res., Jul.-Aug. 1994, 30, (2), 103-106. The application of artificial neural networks to the identification of harmonic loads has been demonstrated before with gret success. In this paper, practical aspects of such an application are discussed. 95/00505
Prediction of turbulent three-dimmsionai heat transfer of heated blocks using low-Reynolds number twoequation model Faghri, M. and Asako, Y. Numerical Heat Transfer, ParrA, Applications, Jul. 1994, 26, (l), 87-101. In current electronic ackaging designs of low-power-rated electronics components on printe ! circuit boards, specific consideration is given to heat transfer analysis to achieve high heat dissipation rates and to limit peak temperature levels. This concern has generated motivation for research studies in the forced convection cooling of electronic equi ment containing a printed circuit board. The authors reported a three- %nnensional laminar heat transfer analysis of this problem under the condition where the blocks were at a prescribed uniform wall temperature. As an extension of this work, the authors computed the results of this problem under a different thermal boundary condition. 95/00505
Process automation configuration tool for Little 05/00510 Gypsy Unit No. 1 automated start-up/shut-down Ghosh, R. et aZ., Electric Power Systems Res., Sep. 1994, 30, (3), 183-190. In 1989, Lousiana Power & Light (LP&L) modernized all major control systems and computer functions at Little Gypsy Unit No. 1 (LGP-1) using the Westinghouse WDPFTMdistributed control system @SC). The new DSC had provisions for implementing a new fully automated power plant start-up and shut down capability. A process automation configuration tool (PAW has been developed to enhance and expedite the develo ment of the automatic start-up/shut-down procedures for Little Gypsy. &is computer-aided software engineering package was’used in developing automation logic for LGP-1, which led to significant savings of man ower and time, as well as in minimizing software debugging efforts. R e paper describes the philosophy and a detailed methodology adapted in the development of the automation configuration tool, and its application in the automation logic generation for LGP-1.
Report on dirtrlbution and tranrmiarion 95/00511 p4rformance 1992/93 Office of Electricity Regulation,
system
OFFER, London, 1994, 19 pp.
Provides information on the erformance of the transmission and distribution companies in England, & ales, and Scotland.
ss/oO512
A revirw of transmission security standards
National Grid Co. plc, Coventry, UK, 1994.
A review of the security standards in the UK electricity industry. Provides details of investigations made and results.
The rising star of fibre optics 95/00513 Smith, G. Energy in Buildings & Industry, Sep. 1994, 13, (8), 10, 12. Fibre optic technology has been around for many years. But now, as energy managers and lighting engineers recognise its unique benefits the future looks very bright indeed. Greg Smith, product manager for Existalite Ltd, takes a look at the technology, application and cost savings available.
30
Fuel and Energy Abstracts January 1995
The provision of electric power is a fundamental prerequisite to economic growth. Countries, seeing industrial expansion as a way of improving living standards, are therefore seekm such a rate of expansion in power supply that this demands not only t%at new power plant be rovided, but also that it be operational quickly. Describes the Shajiao C pPant in China. 95/00515 Simple models for wet-snow accretion on transmission iinsa: snow load and liquid water content i;;!21y and Skelton, P. L. Int. J. Heat & Fluid Flow, Oct. 1994, 15, (S), A simplified heat and mass transfer model is proposed for wet-snow accretion on an overhead transmission line conductor. The accretion processes near the tower and the centre of the span are formulated using the large relaxation time approximation and the cylindrical-sleeve approximation respectively. The heat and mass transfer equations governing the snow evolution process are solved analytically to yield predictions for the snow load and the liquid water content of the snow matrix as a function of the wind speed, relative humidity, air temperature, precipitation rate, and diamter and thermal properties of the conductor. uperconductin cabira 95/00517 Stabiii and AC ioaa of ?? Analysis of currentr mbaiance and inter-strand coupiPng iorws Amemiya, N. et al., Cryogenics, ICEC Supplemenl, 1994, 34, 559-562. The current imbalance and the inner-strand coupling losses are studied for the 3x3-twisted superconducting cables exposed to the temporally-changing external magnetic field or carrying the temporally-changing transportcurrent. The current distribution is calculated based on electrical circuit models. When the cable length is not the wmmon multiple of the twist pitches of the first-stage and second-stage tablings, the current imbalance among strands appears in the cables made with insulated strands. When the insulation of strand is removed, the transverse current flows across the contact resistance between strands. This results in a local current imbalance among strands and an additional inter-strand coupling loss. 95lOO515
Sun’s light boosts desktop efficiency
Energy in Buildings & Industry,
Describes the installation of cost-e new offices in Linlithgow, West 95/00519 Taking control of harmonica Newcombe, C. and Van der Werf, R. Energy in Buildings & hhstry, Sep. 1994, 13, (8), p. 40. Discusss how the failures in fluorescent lights and adjustable speed motor drives could be a result of harmonics. The authors identify ways of spot checking systems. Taking the tube to lighting savings Tirelli, J. Energy in Buildings & Indusky, Sep. 1994, 13, (8). 18, 21. The article desczbes three r&hods to exploit-the opportuiiiies energyefficient lighting can offer. 95/00520
951OOti21 Transportable, remote-controiiod MV unit for HV/MV substations Almanci, S. and Viaro, F. ABB Review, 1994, (4), 42-46. Interest in mobile HVA4V substations has prawn considerablv in recent years, and medium-voltage units in particglar have been ih; &cus of intense development activity. Use of new, compact GIS allows MV systems to be installed in standard containers, making it easier and faster to transport and set up the units. Moreover, by using microprocessor-based control and protection devices which are interfaced with a computer, local and remote control of the complete system is made extremely simple. 95100522 Working live wins Fishlock, D. New Scientist, Jul. 1994, 23-25. The author describes how the UK National Grid Company has begun working on overhead lines without turning off the power.
Electric power generation and utilisation (scientific, technical)
9!5/00!507 Power ?? yrtsm voltage stability and security arsesammt Bian, J. and Rastgoufard, P. Electric Power Systems Rea, Sep. 1994, 30, (3), 197-201. The purpose of this investigation is to review the recent research progress
in voltage stability and security assessment of power systems. This paper presents the fundamental concepts of voltage stability, gives a shofl recall of the classical voltage theory and different criteria currently available for predicting voltage collapse problems in power systems, which have been associated with multi le power flow solutions, bifurcation, dynamics of tap changers, stochastic Poads, singular values, etc. The various methods for studying voltage collapse are compared. The application of expert system techniques to assist in the decision-making process of the reactive power/voltage control problem of power systems and future research directions towards voltage stability and security assessment are also proposed in this paper.
Robust stability in power systems with noniinrar loads using grneraiized Kharitonov’a theorem I’;4_Fti,A. et al., Electrical Power & Energy Systems, 1994, 16, (S),
95loO514
In this paper a linear model is systematically derived for an n bus m machine system with nonlinear voltage dependent loads at the network buses. The model is versatile and can be used to study different phenomena such as steady-state stability, voltage stability etc. In addition to obtaining the system A matrix, the authors also obtained a transfer function between load voltage/angles and real/reactivie powers at the network buses which is used for robust stability analysis using generalized Kharitonov’s theorem. For a given operating point and a given load model, the system A matrix and the eigenvalues can be obtained easily. Eigenvalues for different load models are investigated. 95/00515
Shajiao C: On a fast track to meet growing drmand
Modern Power Sysfems, Oct. 1994, 14, (lo), 53-63.
Practical considerations in the application of nrurai notworka to the identification of harmonic loads Varadan, S. and Makram, E. B. Electric Power Systems Res., Jul.-Aug. 1994, 30, (2), 103-106. The application of artificial neural networks to the identification of harmonic loads has been demonstrated before with gret success. In this paper, practical aspects of such an application are discussed. 95/00505
Prediction of turbulent three-dimmsionai heat transfer of heated blocks using low-Reynolds number twoequation model Faghri, M. and Asako, Y. Numerical Heat Transfer, ParrA, Applications, Jul. 1994, 26, (l), 87-101. In current electronic ackaging designs of low-power-rated electronics components on printe ! circuit boards, specific consideration is given to heat transfer analysis to achieve high heat dissipation rates and to limit peak temperature levels. This concern has generated motivation for research studies in the forced convection cooling of electronic equi ment containing a printed circuit board. The authors reported a three- %nnensional laminar heat transfer analysis of this problem under the condition where the blocks were at a prescribed uniform wall temperature. As an extension of this work, the authors computed the results of this problem under a different thermal boundary condition. 95/00505
Process automation configuration tool for Little 05/00510 Gypsy Unit No. 1 automated start-up/shut-down Ghosh, R. et aZ., Electric Power Systems Res., Sep. 1994, 30, (3), 183-190. In 1989, Lousiana Power & Light (LP&L) modernized all major control systems and computer functions at Little Gypsy Unit No. 1 (LGP-1) using the Westinghouse WDPFTMdistributed control system @SC). The new DSC had provisions for implementing a new fully automated power plant start-up and shut down capability. A process automation configuration tool (PAW has been developed to enhance and expedite the develo ment of the automatic start-up/shut-down procedures for Little Gypsy. &is computer-aided software engineering package was’used in developing automation logic for LGP-1, which led to significant savings of man ower and time, as well as in minimizing software debugging efforts. R e paper describes the philosophy and a detailed methodology adapted in the development of the automation configuration tool, and its application in the automation logic generation for LGP-1.
Report on dirtrlbution and tranrmiarion 95/00511 p4rformance 1992/93 Office of Electricity Regulation,
system
OFFER, London, 1994, 19 pp.
Provides information on the erformance of the transmission and distribution companies in England, & ales, and Scotland.
ss/oO512
A revirw of transmission security standards
National Grid Co. plc, Coventry, UK, 1994.
A review of the security standards in the UK electricity industry. Provides details of investigations made and results.
The rising star of fibre optics 95/00513 Smith, G. Energy in Buildings & Industry, Sep. 1994, 13, (8), 10, 12. Fibre optic technology has been around for many years. But now, as energy managers and lighting engineers recognise its unique benefits the future looks very bright indeed. Greg Smith, product manager for Existalite Ltd, takes a look at the technology, application and cost savings available.
30
Fuel and Energy Abstracts January 1995
The provision of electric power is a fundamental prerequisite to economic growth. Countries, seeing industrial expansion as a way of improving living standards, are therefore seekm such a rate of expansion in power supply that this demands not only t%at new power plant be rovided, but also that it be operational quickly. Describes the Shajiao C pPant in China. 95/00515 Simple models for wet-snow accretion on transmission iinsa: snow load and liquid water content i;;!21y and Skelton, P. L. Int. J. Heat & Fluid Flow, Oct. 1994, 15, (S), A simplified heat and mass transfer model is proposed for wet-snow accretion on an overhead transmission line conductor. The accretion processes near the tower and the centre of the span are formulated using the large relaxation time approximation and the cylindrical-sleeve approximation respectively. The heat and mass transfer equations governing the snow evolution process are solved analytically to yield predictions for the snow load and the liquid water content of the snow matrix as a function of the wind speed, relative humidity, air temperature, precipitation rate, and diamter and thermal properties of the conductor. uperconductin cabira 95/00517 Stabiii and AC ioaa of ?? Analysis of currentr mbaiance and inter-strand coupiPng iorws Amemiya, N. et al., Cryogenics, ICEC Supplemenl, 1994, 34, 559-562. The current imbalance and the inner-strand coupling losses are studied for the 3x3-twisted superconducting cables exposed to the temporally-changing external magnetic field or carrying the temporally-changing transportcurrent. The current distribution is calculated based on electrical circuit models. When the cable length is not the wmmon multiple of the twist pitches of the first-stage and second-stage tablings, the current imbalance among strands appears in the cables made with insulated strands. When the insulation of strand is removed, the transverse current flows across the contact resistance between strands. This results in a local current imbalance among strands and an additional inter-strand coupling loss. 95lOO515
Sun’s light boosts desktop efficiency
Energy in Buildings & Industry,
Describes the installation of cost-e new offices in Linlithgow, West 95/00519 Taking control of harmonica Newcombe, C. and Van der Werf, R. Energy in Buildings & hhstry, Sep. 1994, 13, (8), p. 40. Discusss how the failures in fluorescent lights and adjustable speed motor drives could be a result of harmonics. The authors identify ways of spot checking systems. Taking the tube to lighting savings Tirelli, J. Energy in Buildings & Indusky, Sep. 1994, 13, (8). 18, 21. The article desczbes three r&hods to exploit-the opportuiiiies energyefficient lighting can offer. 95/00520
951OOti21 Transportable, remote-controiiod MV unit for HV/MV substations Almanci, S. and Viaro, F. ABB Review, 1994, (4), 42-46. Interest in mobile HVA4V substations has prawn considerablv in recent years, and medium-voltage units in particglar have been ih; &cus of intense development activity. Use of new, compact GIS allows MV systems to be installed in standard containers, making it easier and faster to transport and set up the units. Moreover, by using microprocessor-based control and protection devices which are interfaced with a computer, local and remote control of the complete system is made extremely simple. 95100522 Working live wins Fishlock, D. New Scientist, Jul. 1994, 23-25. The author describes how the UK National Grid Company has begun working on overhead lines without turning off the power.