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Protection and monitoring concept for generators and auxillaries in small power plants
06
95lQ2725 Expert system for deslgnlng transmlsslon line protectlon system Kawahara, K. et al., Int. .I. Elect. Power & Energy Systems, 1995, 17, (l), 69-78. The paper presents a powerful expert system (ES) which makes a basic design of an adequate protective relaying system based on the knowledge of skilled protectIon engineers. Following the basic design, the ES carries out the relay setting and its validation by means of the integrated power flow and fault calculation programs. Furthermore, the ES has a capability of securing coordination among separately set relays. It is very flexible in that it is able to reset the relays according to power system changes. The effectiveness has been demonstrated by using a part of the Chugoku Electric Power Company System.
95102726 A fast method for determlnlng the voltage stablllty llmlt of a power system Haque, M. H. Electric Power Systems Res., Jan. 1995, 32, (l), 35-43. The voltage stability of a power system is associated with a rapid voltage drop due to heavy system load, and it occurs because of inadequate reactive power support at some critical buses. One of the serious consequences of the voltage stability problem is a system blackout, and this problem has received much attention in recent years. The paper proposes a fast method for finding the maximum load, especially the reactive power demand, at a particular load bus before reaching the voltage stability limit. The method uses the base-case system information to find special two-bus equivalents of the system for analyzing the voltage stability problem. The method was tested on the IEEE 14-, 30-, and 118-bus systems and the results obtained were compared with those found by some other methods.
95102727 Handbook for electromagnetic compatlblllty of dlgltal equlpment In power plants, Vols. 1 snd 2 TR-102400-VI, TR-102400-V2 Final Report (RP3406-3,-7), $25,000 for set, EPRI Distribution Center, 207 Coggins Dr., PO Box 23205, Pleasant Hill, CA.94523.
Hybrld systems look good for developlng countries 95102726 Dienhart, H. and Hille, G. MPS, Modern Power Systems, Feb. 1995, 15, (2), 19, 21-22. Although interconnected grids are increasing in global importance, they are unacceptable in many thinly settled developing countries for technical and economic reasons. Decentralized electricity supply is thus of great interest in such places. Discusses how hybrid systems of 10 to 100 kW capacity comprising a combination of diesel generators and renewable energy technologies may offer a future option to the traditional diesel only systems.
Intramolecular negatlvo-U effect In the alkall-metal95102729 doped C,; A.& and A&, S?Z~ S. and Nakao, K. Fullerene Science & Technology, 1995, 3, (l), The ahthors investigated theoretically why alkali-metal-doped C A.$ is a nonmagnetic semiconductor for x=2 and 4. The authors foun $”that & is the consequence of the intramolecular negative-U effect due to the strong electronphonon interaction and the weak Hund coupling between conduction electrons.
95102730 lnvestlgatlon of the voltage stablllty reglon InvolvIng on-load tap changers Hong, Y. Y. and Wang, H. Y. Electric Power Systems Res., Jan. 1995,32, (l), 45-54. A new approach for estimating the voltage stability region of power systems is presented in this paper. This voltage stability region is conservative because it is based on ten sufficient conditions. The ower flow solution are utilized to estimate the voltage stability region o P the taps of on-load changers, voltage magnitudes, and phase angles. The coupling relation between the real and reactive powers is taken into account. The computation time is reasonable because only matrix and vector computation is involved. Two practical power systems were employed in demonstrating the capability oi the proposed approach. The test-results confirm that it ii applicable to large power systems.
Isotope effect on Intramolecular vlbratlon of C, 95102731 Tanaka, Y. er al., Fullerene Science & Technology, 1995, 3, (2), 179-223. In this paper the authors introduce the symmetry coordinates to analyze the effect of the symmetry breaking arising from the partial substitution of 13C into C , It was found that the effect of the symmetry breaking is small. An anoma p”ous isotope shift of T, and infrared spectrum of isotopically mixed C, observed by Zakhidov et al. can not be explained by the effect of the symmetry breaking when only the linear e-mv interaction is taken into account. The calculated result is, however, consistent with the small depression of T of the C superconductor measured by Chen and Lieber using isotopicalry mixed I 6.
Electric power generation
and utilisation
(scientfic,
technical)
95102732 Karlta 360 MWe PFBC plant will be the first P600 MPS, Modern Power Systems, Feb. 1995, 15, (2), 33, 35. Reports that the world’s first-ever 360 MWe PFBC plant -based on ABB Carbon’s PBOO module has been designed and is under manufacture for Kyushu Electric Power in southern Japan. The Kyushu Electric Power Company, one of the seven major power utilities in Japan with an installed capacity of about 15,700 MWe, has a long tradition of introducting advanced new technologies. 95102733 New slectrlcal and automatlon equlpment for a cement works Schom, D. ABE Review, 1995, 2), 24-30. Describes how ABB upgraded t6 e electrotechnical equipment to meet modem production requirements at Readymix, Dortmund, Germany. 95102734 Numerlcsl protectlon relays provlde Improved syc tern dlagnosls Pickering, S. MPS, Modern Power Systems, Feb. 1995, 15, (2), 39-41. Discusses how substantial improvements in response to system faults can be gained from system protection relays due to increased availability of fault data and disturbance records. The combined effects of fully integrated protection, contra!, monitoring and event and fault recording can offer a reduction in trip times and effective low cost busbar protection. 95102735 On-line multi-contingency preprocessln of securIty assessment for severe weather based on qualltat Bve reasonIng wlth probablllty statlstlcs classlflcatlon f-y;, R. H. et al., Int. J. Elect. Power & Energy Systems, 1995, 17, (l), A pieprocessing method to select multi-contingencies having higher probability and severity for security assessment is presented in this paper. Based upon probabilistic classification and qualitative analysis, the proposed method can quickly create and renew the multiple contingency list with probability attributes and greatly reduce the number of multi-contingencies to be asserted. The operators can concentrate on analysing multicontingency cases with higher severity and higher probability, especially for on-line aoolication durine severe weather ueriods. Thus. both the probability a&the duration 07 the loss of load &I be reduced: 95102736 Pattern analysls In power system state estlmatlon Alves de Silva, A. P. and Quintana, V. H. Int. .I. Elect. Power & Energy Systems, 1995, 17, (l), 51-60. In recent years, interest in the application of artificial intelligence technologies to power system operation, planning and design has grown rapidly. The application of non-symbolic techniques, particularly Artificial Neural Networks (ANNs), is a new area of research in this field. In this paper, intelligent systems for solving power system state estimation problems are investigated. A new framework for the solution of the topology determination, observability analysis and bad data processing tasks is proposed. 95102737 Power system security assessment using pattern recognltlon and fuzzy estlmatlon Sinha, A. K. Int. J. Elect. Power&Energy Systems, 1995, 17, (l), 11-19. A simple, fast, efficient and reliable method for power system security assessment is presented. The method is based on pattern recognition and fuzzy estimation techniques. The security status of a power system operating condition is recognized from the stored knowledge about similar operating conditions. The method is able to classify the system operating condition into secure/insecure state; and for the insecure state it provides information about pertinent contingencies which may cause insecurity. Preparatlon of barlum-contalnlng slllcon clathrate 95102736 compound Yamanada, S. et al., Fullerene Science & Technology, 1995,3, (l), 21-28. A new silicon clathrate compound containing Ba was prepared by the thermal degradation of a solid solution (Na,Ba)Si, at 500°C in vacuum. The compound has the Na,Si, clathrate type structure, which consists of silicon tetrahedral networks having two types of cages, ntagonal dodecahedra and 14-face polyhedra. The Ba atoms are place 8” only in the larger cages. 95102739 Protectlon and monltorlng concept for generators and auxlllarles In small power plants Ilar, M. and Ungrad, H. ABB Review, 1995, (1). 29-35. Generating plants in- the lower power range - l$&oelectric, wind energy, gas turbine and small industrial power stations - are usually as vital to their operators as the higher-rated units are to large electric utdities. The same attention should therefore be given to the choice of protection equipment and to its deployment, for the main plant components as well as for auxiliaries. Numerical protection devices with serial interfaces have the advantage that, by communicating with other relaying and control equipment, they allow new concepts for station protection and control. At the same time they are a low-cost means of raising plant availability, offering support in the form of continuous self-monitoring, improved disturbance recording, and a better exchange of information between the different levels in the plant control hierarchy.
Fuel and Energy Abstracts
May 1995
197
95lQ2725 Expert system for deslgnlng transmlsslon line protectlon system Kawahara, K. et al., Int. .I. Elect. Power & Energy Systems, 1995, 17, (l), 69-78. The paper presents a powerful expert system (ES) which makes a basic design of an adequate protective relaying system based on the knowledge of skilled protectIon engineers. Following the basic design, the ES carries out the relay setting and its validation by means of the integrated power flow and fault calculation programs. Furthermore, the ES has a capability of securing coordination among separately set relays. It is very flexible in that it is able to reset the relays according to power system changes. The effectiveness has been demonstrated by using a part of the Chugoku Electric Power Company System.
95102726 A fast method for determlnlng the voltage stablllty llmlt of a power system Haque, M. H. Electric Power Systems Res., Jan. 1995, 32, (l), 35-43. The voltage stability of a power system is associated with a rapid voltage drop due to heavy system load, and it occurs because of inadequate reactive power support at some critical buses. One of the serious consequences of the voltage stability problem is a system blackout, and this problem has received much attention in recent years. The paper proposes a fast method for finding the maximum load, especially the reactive power demand, at a particular load bus before reaching the voltage stability limit. The method uses the base-case system information to find special two-bus equivalents of the system for analyzing the voltage stability problem. The method was tested on the IEEE 14-, 30-, and 118-bus systems and the results obtained were compared with those found by some other methods.
95102727 Handbook for electromagnetic compatlblllty of dlgltal equlpment In power plants, Vols. 1 snd 2 TR-102400-VI, TR-102400-V2 Final Report (RP3406-3,-7), $25,000 for set, EPRI Distribution Center, 207 Coggins Dr., PO Box 23205, Pleasant Hill, CA.94523.
Hybrld systems look good for developlng countries 95102726 Dienhart, H. and Hille, G. MPS, Modern Power Systems, Feb. 1995, 15, (2), 19, 21-22. Although interconnected grids are increasing in global importance, they are unacceptable in many thinly settled developing countries for technical and economic reasons. Decentralized electricity supply is thus of great interest in such places. Discusses how hybrid systems of 10 to 100 kW capacity comprising a combination of diesel generators and renewable energy technologies may offer a future option to the traditional diesel only systems.
Intramolecular negatlvo-U effect In the alkall-metal95102729 doped C,; A.& and A&, S?Z~ S. and Nakao, K. Fullerene Science & Technology, 1995, 3, (l), The ahthors investigated theoretically why alkali-metal-doped C A.$ is a nonmagnetic semiconductor for x=2 and 4. The authors foun $”that & is the consequence of the intramolecular negative-U effect due to the strong electronphonon interaction and the weak Hund coupling between conduction electrons.
95102730 lnvestlgatlon of the voltage stablllty reglon InvolvIng on-load tap changers Hong, Y. Y. and Wang, H. Y. Electric Power Systems Res., Jan. 1995,32, (l), 45-54. A new approach for estimating the voltage stability region of power systems is presented in this paper. This voltage stability region is conservative because it is based on ten sufficient conditions. The ower flow solution are utilized to estimate the voltage stability region o P the taps of on-load changers, voltage magnitudes, and phase angles. The coupling relation between the real and reactive powers is taken into account. The computation time is reasonable because only matrix and vector computation is involved. Two practical power systems were employed in demonstrating the capability oi the proposed approach. The test-results confirm that it ii applicable to large power systems.
Isotope effect on Intramolecular vlbratlon of C, 95102731 Tanaka, Y. er al., Fullerene Science & Technology, 1995, 3, (2), 179-223. In this paper the authors introduce the symmetry coordinates to analyze the effect of the symmetry breaking arising from the partial substitution of 13C into C , It was found that the effect of the symmetry breaking is small. An anoma p”ous isotope shift of T, and infrared spectrum of isotopically mixed C, observed by Zakhidov et al. can not be explained by the effect of the symmetry breaking when only the linear e-mv interaction is taken into account. The calculated result is, however, consistent with the small depression of T of the C superconductor measured by Chen and Lieber using isotopicalry mixed I 6.
Electric power generation
and utilisation
(scientfic,
technical)
95102732 Karlta 360 MWe PFBC plant will be the first P600 MPS, Modern Power Systems, Feb. 1995, 15, (2), 33, 35. Reports that the world’s first-ever 360 MWe PFBC plant -based on ABB Carbon’s PBOO module has been designed and is under manufacture for Kyushu Electric Power in southern Japan. The Kyushu Electric Power Company, one of the seven major power utilities in Japan with an installed capacity of about 15,700 MWe, has a long tradition of introducting advanced new technologies. 95102733 New slectrlcal and automatlon equlpment for a cement works Schom, D. ABE Review, 1995, 2), 24-30. Describes how ABB upgraded t6 e electrotechnical equipment to meet modem production requirements at Readymix, Dortmund, Germany. 95102734 Numerlcsl protectlon relays provlde Improved syc tern dlagnosls Pickering, S. MPS, Modern Power Systems, Feb. 1995, 15, (2), 39-41. Discusses how substantial improvements in response to system faults can be gained from system protection relays due to increased availability of fault data and disturbance records. The combined effects of fully integrated protection, contra!, monitoring and event and fault recording can offer a reduction in trip times and effective low cost busbar protection. 95102735 On-line multi-contingency preprocessln of securIty assessment for severe weather based on qualltat Bve reasonIng wlth probablllty statlstlcs classlflcatlon f-y;, R. H. et al., Int. J. Elect. Power & Energy Systems, 1995, 17, (l), A pieprocessing method to select multi-contingencies having higher probability and severity for security assessment is presented in this paper. Based upon probabilistic classification and qualitative analysis, the proposed method can quickly create and renew the multiple contingency list with probability attributes and greatly reduce the number of multi-contingencies to be asserted. The operators can concentrate on analysing multicontingency cases with higher severity and higher probability, especially for on-line aoolication durine severe weather ueriods. Thus. both the probability a&the duration 07 the loss of load &I be reduced: 95102736 Pattern analysls In power system state estlmatlon Alves de Silva, A. P. and Quintana, V. H. Int. .I. Elect. Power & Energy Systems, 1995, 17, (l), 51-60. In recent years, interest in the application of artificial intelligence technologies to power system operation, planning and design has grown rapidly. The application of non-symbolic techniques, particularly Artificial Neural Networks (ANNs), is a new area of research in this field. In this paper, intelligent systems for solving power system state estimation problems are investigated. A new framework for the solution of the topology determination, observability analysis and bad data processing tasks is proposed. 95102737 Power system security assessment using pattern recognltlon and fuzzy estlmatlon Sinha, A. K. Int. J. Elect. Power&Energy Systems, 1995, 17, (l), 11-19. A simple, fast, efficient and reliable method for power system security assessment is presented. The method is based on pattern recognition and fuzzy estimation techniques. The security status of a power system operating condition is recognized from the stored knowledge about similar operating conditions. The method is able to classify the system operating condition into secure/insecure state; and for the insecure state it provides information about pertinent contingencies which may cause insecurity. Preparatlon of barlum-contalnlng slllcon clathrate 95102736 compound Yamanada, S. et al., Fullerene Science & Technology, 1995,3, (l), 21-28. A new silicon clathrate compound containing Ba was prepared by the thermal degradation of a solid solution (Na,Ba)Si, at 500°C in vacuum. The compound has the Na,Si, clathrate type structure, which consists of silicon tetrahedral networks having two types of cages, ntagonal dodecahedra and 14-face polyhedra. The Ba atoms are place 8” only in the larger cages. 95102739 Protectlon and monltorlng concept for generators and auxlllarles In small power plants Ilar, M. and Ungrad, H. ABB Review, 1995, (1). 29-35. Generating plants in- the lower power range - l$&oelectric, wind energy, gas turbine and small industrial power stations - are usually as vital to their operators as the higher-rated units are to large electric utdities. The same attention should therefore be given to the choice of protection equipment and to its deployment, for the main plant components as well as for auxiliaries. Numerical protection devices with serial interfaces have the advantage that, by communicating with other relaying and control equipment, they allow new concepts for station protection and control. At the same time they are a low-cost means of raising plant availability, offering support in the form of continuous self-monitoring, improved disturbance recording, and a better exchange of information between the different levels in the plant control hierarchy.
Fuel and Energy Abstracts
May 1995
197