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01652 Power system planning - A reliability perspective
06 Optlmal contlnuatlon power flow 96/016% $j~pu, V. and Jain, N. Electric Power Systems Res., Ckt. 1995,35, (l), - . is to develop an algorithm for tracing the The objective of this inequality constrained optimal power flow as a optiml of quality amYper function of the load parameter. Although available optimixation techniques can determiae an optimal power flow solution for a fixed load, often the effects of change in load parameter on the optima for a wide range are required. The optimal continuation power fhnv approach provides a systematic way to trace the optimal for a continuous mcrease in load in the given ditection via umtlmtation techniques. This a roach also reveals the vohge stabSky limited power transfer. Results oftPRe tests on up to 1500bus networks are given to illustrate the performance of the proposed algorithm. Optimal dynamic load shedding using s Newton 86lO1649 based dynamic slgorlthm b&s% hf. A. cr aL, Electric Power Systems Res., Sep. 1995, 34, (3), - . The paper presents a reformulated optimal load shedding policy that takes into account generator control effects and voltage and frequency characteristics of loads. A dynamic problem is formulated with power generation considered as a dependent variable. The equality constraints associated with the load curtailment problem are the power flow equations in polar form utilixmg the nodal admittance matrix approach. The inequality constraints are characterized by 5exibility limits on line fhnvs, voltage magnitudes and angles, and reactive power generations. The MINOS nonlinear optimixation~package is used io implement the reformulated problem. NumericaI resuks obtained for the IEEE Wand 30-bus test power systems arc discussed. PC power play %I01850 Dawn, T. Eke. Rev.. Sep. 1995, 228, (19), 34-36. The article compares five current software packages for designing electrical power systems - EDSA, SKM Power Tools Software, Cyme (North America), Eracs (UK) and Poscodam (Switzerland). 98/01%1 Performance Improvement of a conventional power system stabilizer Said , hf. and Hughes, F. M. Electrical Power % Energy Systems, 1995, 17. r5). 313-323. A conventional power system stabilizer (PSS), based on a speed input signal, CM provide good performance over the operating power range of a generator. However, its performance deteriorates signiticantly when the connection of the generator with the grid system becomes weak. In this paper, M augmented PSS is proposed which extends pcrformancc capabilities into the weak tie-line case.
Electric
peer
penemtion
Rellablllty 96/01664 Jointly owned units
ml
of two
utilisation (scienttilic. technicel) Interconnected
systems
wlth
Ahsan, Q. Elect&al Power & Energy Systems, 1995, 17, (6), 363-370. The installation of a large size generating unit rquires a huge investment In some cases,utilities share the ownership of a unit among the nelghbourlng utilities to face the problem of this cost. The paper presents a method010 to evaluate the reliability of two interconnected systems with a ~oln * *7 y owned unit (JOU). The methodology is capable of evaluating the reliability of two interconnected systems with a multi-state JOU as well as with more than one JOU. The concept of appropriate modificrtion of transfer as well as the installed capacities to incorporate the transfer of shares from one svstem to another rs introduced in thll oaoer. The method is a plied to &tluate the reliability of two inter&t&ted systems with J&s. In the numerical evaluation, the segmentation method ls used.
%I01655 A nvlsw of the effect of voltage harmonlsatlon wlthln the bulldlng servlce industry Level& S. and Taylor, G. National Conference Papers, Oct. 1995, CIRSE, 2. _119.130. -, __ __
The paper discusses how the changes required for hrope~ harmonlsatlon of the UK’s nominal voltage from 240 volts to 230 volts means that in reality a gulf has developed between the actual average UK supply voltage of 245 volts and the now optimum design rating of new electric appliances and equipment of 230 volts. Examines the cost implications of thts voltage differenttal. Slmpls snd efflclent %/01%0 of radlsl dlstrlbutlon networks F3y3z
et al.,
Electrical
Power
method for load flow solution & Energy
Systems,
1995, 17, (5),
The pap& presents a simple and efficient method for solving radial distribution networks. The proposed method involves only the evaluation of a simple algebraic ex ression of voltage magnitudes and no trigonometric functions as oppos J to the standard load flow case.Thus, computationally the proposed method is very efficient and it re uirea less computer memory. The roposed method can easily handle d if! erent types of load characteristics. it everal Indian rural distribution networks have been successsfully solved by using the proposed method. Stablllty of large-scale MHD channels drslgned for 96lOl%7 coal-fired MHD power generatlon Ishikawa, hf. et al., Energy Convers. Mgm&, JM. 1996, 37, (l), 31-41. The stability of certain large-scale coal-fired MHD channels is studied by: (1) linear stability analysis and (2) timedependent 1D analysis. 96101858 Superfast autoconflgurlng srtlflclal neural networks and their appllcatlon to power systems Novak, B. Electric Power Systems Res., Oct. 1995.35, (1). 11-16. The paper presents the new generation of artificial neural networks (ANNs) for solving the task of power system operation planning Today the error back-propa ation ANNs are used most because of their simplicity and the possibility of parallel implementation on neuro-computers for highspeed execution. In spite of their popularity the have two major drawbacks: the learning process is time consuming andythere is no exact rule for settinu the number of neurons to avoid overfittinn or underfittinn and to achicie. hopefully! a convergin learning phase. % avoid tbese&fficulties, a new gcneratton of ANNs %as been developed based on the theory of radial basis-functions for approximation. A comparison test on an actual problem in power system operation was performed.
%I01 %2 Power system planning - A rellablllty perspective y;iyg? K. and C&l, L,. Electric Power Systems Res., Sep. 1995,34, (3), - . One of the basic objectives of power system planners is to determine the necessary generating capacity to satisfy the system demand in the presence of scheduled and unscheduled outages and unforcsccn variations in the system load. A second important objective is the development of a suitable transmission network to transport the generated electrical energy to the bulk load centres. This aspect is dealt with in conjunction with the available and planned generation facilities. Lastly, adequate distribution facilities must be constructed in order to deliver the available energy from the bulk load centres to the actual customer premises. The reliability at which these three subsystems (namely, generation, transmission and distribution) will function is of utmost importance.
%I01659 Switched reluctance drives: A comparatlvs evaluation Poh~2 C. and Michaelides, A. Power Engng. J., Dec. 1995, 9, (6). - . Provides an overview of switched reluctance drive technology to date. The operation of the switched reluctance motor is briefly descrtbcd and basic niodelling considerations are presented. Power converter topologies that have been developed for the switched reluctance drive are reviewed.
Probabllistlc steady-state security analysis including (sub)statlon generated contingencies Nahman, J. and Babic, B. Electric Power SystemsRes., Oct. 1995, 35, (1) 31-37. A method is suggested for modeling (sub)station generation commoncause outages for properly ranking contingencies affecting power system steady-state security. The method and the security indices proposed are based upon the Markov state transition model of the power system which makes it possible to include probability weighted impact factors for appropriate contingency ranking and selection. An illustrative real-life example is also included, demonstrating the relevance of (sub)station associated contingencies for a proper security analysis.
Technlcal vlewpolnt. Plasma generatlon urlng an 90lO1660 alternatlng current plasma generator Chew, R. Energy & Environmenr, 1995, 6, (4). 391-395. The use of an electric discharge in a working gas to create a plasma is a basic technique that has been researched for many years. Several plasma systems were developed and are in use today in applications such as the plasma metal cutting torch. Plasma is defined as a state of matter which exhibits the properties of a gas, contains about equal numbers of positive and negative charges, and is a good conductor of electricity; thus, its flow can be effected by a magnetic field. The bulk of previous work has been oerformcd with a direct current svstcm because the alternatinn current iystem (ac) was inherently unstabh. It is recognized early on tht an ac system would be more efficient and less expensive but the stability issue irihibited its development.
96/01%3
Fuel and Energy Abstracts
March 1996
111
Electric
peer
penemtion
Rellablllty 96/01664 Jointly owned units
ml
of two
utilisation (scienttilic. technicel) Interconnected
systems
wlth
Ahsan, Q. Elect&al Power & Energy Systems, 1995, 17, (6), 363-370. The installation of a large size generating unit rquires a huge investment In some cases,utilities share the ownership of a unit among the nelghbourlng utilities to face the problem of this cost. The paper presents a method010 to evaluate the reliability of two interconnected systems with a ~oln * *7 y owned unit (JOU). The methodology is capable of evaluating the reliability of two interconnected systems with a multi-state JOU as well as with more than one JOU. The concept of appropriate modificrtion of transfer as well as the installed capacities to incorporate the transfer of shares from one svstem to another rs introduced in thll oaoer. The method is a plied to &tluate the reliability of two inter&t&ted systems with J&s. In the numerical evaluation, the segmentation method ls used.
%I01655 A nvlsw of the effect of voltage harmonlsatlon wlthln the bulldlng servlce industry Level& S. and Taylor, G. National Conference Papers, Oct. 1995, CIRSE, 2. _119.130. -, __ __
The paper discusses how the changes required for hrope~ harmonlsatlon of the UK’s nominal voltage from 240 volts to 230 volts means that in reality a gulf has developed between the actual average UK supply voltage of 245 volts and the now optimum design rating of new electric appliances and equipment of 230 volts. Examines the cost implications of thts voltage differenttal. Slmpls snd efflclent %/01%0 of radlsl dlstrlbutlon networks F3y3z
et al.,
Electrical
Power
method for load flow solution & Energy
Systems,
1995, 17, (5),
The pap& presents a simple and efficient method for solving radial distribution networks. The proposed method involves only the evaluation of a simple algebraic ex ression of voltage magnitudes and no trigonometric functions as oppos J to the standard load flow case.Thus, computationally the proposed method is very efficient and it re uirea less computer memory. The roposed method can easily handle d if! erent types of load characteristics. it everal Indian rural distribution networks have been successsfully solved by using the proposed method. Stablllty of large-scale MHD channels drslgned for 96lOl%7 coal-fired MHD power generatlon Ishikawa, hf. et al., Energy Convers. Mgm&, JM. 1996, 37, (l), 31-41. The stability of certain large-scale coal-fired MHD channels is studied by: (1) linear stability analysis and (2) timedependent 1D analysis. 96101858 Superfast autoconflgurlng srtlflclal neural networks and their appllcatlon to power systems Novak, B. Electric Power Systems Res., Oct. 1995.35, (1). 11-16. The paper presents the new generation of artificial neural networks (ANNs) for solving the task of power system operation planning Today the error back-propa ation ANNs are used most because of their simplicity and the possibility of parallel implementation on neuro-computers for highspeed execution. In spite of their popularity the have two major drawbacks: the learning process is time consuming andythere is no exact rule for settinu the number of neurons to avoid overfittinn or underfittinn and to achicie. hopefully! a convergin learning phase. % avoid tbese&fficulties, a new gcneratton of ANNs %as been developed based on the theory of radial basis-functions for approximation. A comparison test on an actual problem in power system operation was performed.
%I01 %2 Power system planning - A rellablllty perspective y;iyg? K. and C&l, L,. Electric Power Systems Res., Sep. 1995,34, (3), - . One of the basic objectives of power system planners is to determine the necessary generating capacity to satisfy the system demand in the presence of scheduled and unscheduled outages and unforcsccn variations in the system load. A second important objective is the development of a suitable transmission network to transport the generated electrical energy to the bulk load centres. This aspect is dealt with in conjunction with the available and planned generation facilities. Lastly, adequate distribution facilities must be constructed in order to deliver the available energy from the bulk load centres to the actual customer premises. The reliability at which these three subsystems (namely, generation, transmission and distribution) will function is of utmost importance.
%I01659 Switched reluctance drives: A comparatlvs evaluation Poh~2 C. and Michaelides, A. Power Engng. J., Dec. 1995, 9, (6). - . Provides an overview of switched reluctance drive technology to date. The operation of the switched reluctance motor is briefly descrtbcd and basic niodelling considerations are presented. Power converter topologies that have been developed for the switched reluctance drive are reviewed.
Probabllistlc steady-state security analysis including (sub)statlon generated contingencies Nahman, J. and Babic, B. Electric Power SystemsRes., Oct. 1995, 35, (1) 31-37. A method is suggested for modeling (sub)station generation commoncause outages for properly ranking contingencies affecting power system steady-state security. The method and the security indices proposed are based upon the Markov state transition model of the power system which makes it possible to include probability weighted impact factors for appropriate contingency ranking and selection. An illustrative real-life example is also included, demonstrating the relevance of (sub)station associated contingencies for a proper security analysis.
Technlcal vlewpolnt. Plasma generatlon urlng an 90lO1660 alternatlng current plasma generator Chew, R. Energy & Environmenr, 1995, 6, (4). 391-395. The use of an electric discharge in a working gas to create a plasma is a basic technique that has been researched for many years. Several plasma systems were developed and are in use today in applications such as the plasma metal cutting torch. Plasma is defined as a state of matter which exhibits the properties of a gas, contains about equal numbers of positive and negative charges, and is a good conductor of electricity; thus, its flow can be effected by a magnetic field. The bulk of previous work has been oerformcd with a direct current svstcm because the alternatinn current iystem (ac) was inherently unstabh. It is recognized early on tht an ac system would be more efficient and less expensive but the stability issue irihibited its development.
96/01%3
Fuel and Energy Abstracts
March 1996
111