Pub Date : 1995-11-21DOI: 10.1109/EMPD.1995.500747
Shi-Lin Chen, Fu-Chien Kao, Tsung-Ming Lee
In the paper, firstly, we present an efficient computational algorithm to evaluate the short circuit capacity distribution at a substation bus, and on the basis of this distribution to specify the minimum short circuit capacity for the year under evaluation. Secondly, we estimate the maximum traction load at seven 161 kV substations of Taiwan high-speed railway system which is now under planning. Thirdly, using the maximum traction load and the minimum short circuit capacity derived, we estimate the maximum unbalance of the 3/spl phi/ voltage at these seven 161 kV substations, and compare our results with that by Taipower to demonstrate the effectiveness of our proposed algorithm.
{"title":"Specification of minimum short circuit capacity for three-phase unbalance evaluation of high-speed railway power system","authors":"Shi-Lin Chen, Fu-Chien Kao, Tsung-Ming Lee","doi":"10.1109/EMPD.1995.500747","DOIUrl":"https://doi.org/10.1109/EMPD.1995.500747","url":null,"abstract":"In the paper, firstly, we present an efficient computational algorithm to evaluate the short circuit capacity distribution at a substation bus, and on the basis of this distribution to specify the minimum short circuit capacity for the year under evaluation. Secondly, we estimate the maximum traction load at seven 161 kV substations of Taiwan high-speed railway system which is now under planning. Thirdly, using the maximum traction load and the minimum short circuit capacity derived, we estimate the maximum unbalance of the 3/spl phi/ voltage at these seven 161 kV substations, and compare our results with that by Taipower to demonstrate the effectiveness of our proposed algorithm.","PeriodicalId":447674,"journal":{"name":"Proceedings 1995 International Conference on Energy Management and Power Delivery EMPD '95","volume":"2 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120837541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-11-21DOI: 10.1109/EMPD.1995.500770
Fangzhu Ming, W. Lu, Ye Yang, Y. Ni, Hengxin Qu, Yonghua Peng
Design of a generator tripping system to enhance the transient stability of an area power network using a quasi-real-time method is presented. The Hunjiang power system in China is selected to implement the design scheme. The necessary hardware and software that are required to implement the control scheme, is outlined. The fast transient stability assessment, which uses the technology such as dynamic equivalence, state estimation and direct transient energy function method, is provided to form a control strategy table. According to this table, when a large disturbance occurs, the estimated amount of generation will be tripped to maintain the rest of the generators in stable state in the power system. The studies reveal that the generator tripping system can adapt to the changes of load and generation in the system as well as changes in the network topology. This paper also outlines the new features compared with the existing conventional control system and proposes the strategies in the event of failure of the generator tripping system.
{"title":"Transient stability control of an area network","authors":"Fangzhu Ming, W. Lu, Ye Yang, Y. Ni, Hengxin Qu, Yonghua Peng","doi":"10.1109/EMPD.1995.500770","DOIUrl":"https://doi.org/10.1109/EMPD.1995.500770","url":null,"abstract":"Design of a generator tripping system to enhance the transient stability of an area power network using a quasi-real-time method is presented. The Hunjiang power system in China is selected to implement the design scheme. The necessary hardware and software that are required to implement the control scheme, is outlined. The fast transient stability assessment, which uses the technology such as dynamic equivalence, state estimation and direct transient energy function method, is provided to form a control strategy table. According to this table, when a large disturbance occurs, the estimated amount of generation will be tripped to maintain the rest of the generators in stable state in the power system. The studies reveal that the generator tripping system can adapt to the changes of load and generation in the system as well as changes in the network topology. This paper also outlines the new features compared with the existing conventional control system and proposes the strategies in the event of failure of the generator tripping system.","PeriodicalId":447674,"journal":{"name":"Proceedings 1995 International Conference on Energy Management and Power Delivery EMPD '95","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114587131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-11-21DOI: 10.1109/EMPD.1995.500799
N. Naoe
This paper presents a demonstration of a permanent magnet generator with capacitors. In this paper, the possibility of realizing the small voltage regulation of such generators is increased. The permanent magnet generator with capacitors has a voltage compensation function. In order to determine whether this generator is feasible, the author has tested various characteristics of the machine through experiments with a prototype generator.
{"title":"Fundamental characteristics of voltage compensation type permanent-magnet generator","authors":"N. Naoe","doi":"10.1109/EMPD.1995.500799","DOIUrl":"https://doi.org/10.1109/EMPD.1995.500799","url":null,"abstract":"This paper presents a demonstration of a permanent magnet generator with capacitors. In this paper, the possibility of realizing the small voltage regulation of such generators is increased. The permanent magnet generator with capacitors has a voltage compensation function. In order to determine whether this generator is feasible, the author has tested various characteristics of the machine through experiments with a prototype generator.","PeriodicalId":447674,"journal":{"name":"Proceedings 1995 International Conference on Energy Management and Power Delivery EMPD '95","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126653533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-11-21DOI: 10.1109/EMPD.1995.500810
Li Yongli, H. Jiali, Duan Yuqian
A neural network method used to identify the operating states of transformers has been proposed and established. It is superior to the traditional transformer protective relays and can correctly identify, within half cycle from the fault inception, the internal faults, magnetizing inrush current state, external faults and switching on internal faults of a no-load transformer. In addition, this method has broad availability and high fault-tolerant ability. A lot of simulations have demonstrated its superiority.
{"title":"Application of neural network to microprocessor-based transformer protective relaying","authors":"Li Yongli, H. Jiali, Duan Yuqian","doi":"10.1109/EMPD.1995.500810","DOIUrl":"https://doi.org/10.1109/EMPD.1995.500810","url":null,"abstract":"A neural network method used to identify the operating states of transformers has been proposed and established. It is superior to the traditional transformer protective relays and can correctly identify, within half cycle from the fault inception, the internal faults, magnetizing inrush current state, external faults and switching on internal faults of a no-load transformer. In addition, this method has broad availability and high fault-tolerant ability. A lot of simulations have demonstrated its superiority.","PeriodicalId":447674,"journal":{"name":"Proceedings 1995 International Conference on Energy Management and Power Delivery EMPD '95","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127976661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-11-21DOI: 10.1109/EMPD.1995.500776
K. Yoshinaga, H. Hisha, S. Sakabe
Contribution to the society with excellent technology and creativity is the objective of Mitsubishi Electric Corporation. In order to realize this commitment covering a range of ever advanced products, continual stimuli and integrated efforts are a must in the competitive arena in corporate-wide engineer training and education. The continuing education system has been therefore evolved over several decades, which is briefly dealt with. In the area of power and energy-related engineer education, practical and comprehensive in-depth engineering seminars and workshops are organized based on the Corporation's key technologies such as electromagnetics and its software implementation. A development in this category emphasizes two fronts, namely, computer based "skill" training and education, and corporate-wide distance engineer education using satellite communications, as described in this paper.
{"title":"Power engineering education utilizing satellite communications and computer networks","authors":"K. Yoshinaga, H. Hisha, S. Sakabe","doi":"10.1109/EMPD.1995.500776","DOIUrl":"https://doi.org/10.1109/EMPD.1995.500776","url":null,"abstract":"Contribution to the society with excellent technology and creativity is the objective of Mitsubishi Electric Corporation. In order to realize this commitment covering a range of ever advanced products, continual stimuli and integrated efforts are a must in the competitive arena in corporate-wide engineer training and education. The continuing education system has been therefore evolved over several decades, which is briefly dealt with. In the area of power and energy-related engineer education, practical and comprehensive in-depth engineering seminars and workshops are organized based on the Corporation's key technologies such as electromagnetics and its software implementation. A development in this category emphasizes two fronts, namely, computer based \"skill\" training and education, and corporate-wide distance engineer education using satellite communications, as described in this paper.","PeriodicalId":447674,"journal":{"name":"Proceedings 1995 International Conference on Energy Management and Power Delivery EMPD '95","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126916555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-11-21DOI: 10.1109/EMPD.1995.500724
S. Kaneko, M. Hisatome, M. Hishida
Mitsubishi Heavy Industries Ltd. (MHI), the world largest power plant manufacturer, has been leading the development of technologies to meet the requirements special to the Japanese utility power industry. Mitsubishi supplied a number of supercritical sliding pressure units for firing fuels such as oil, gas and coal, with successful operating performance. In this paper, design features of a supercritical sliding pressure operation boiler are reported, considering points for a dual fuel firing boiler, low NOx firing technologies and the experience of oil and gas-firing supercritical sliding pressure operation boiler represented by the ultrasupercritical pressure gas firing units with a steam condition of 31 MPa (316 kgf/cm/sup 2/ g), 566/566/566/spl deg/C.
{"title":"High efficiency supercritical sliding pressure units for oil/gas firing","authors":"S. Kaneko, M. Hisatome, M. Hishida","doi":"10.1109/EMPD.1995.500724","DOIUrl":"https://doi.org/10.1109/EMPD.1995.500724","url":null,"abstract":"Mitsubishi Heavy Industries Ltd. (MHI), the world largest power plant manufacturer, has been leading the development of technologies to meet the requirements special to the Japanese utility power industry. Mitsubishi supplied a number of supercritical sliding pressure units for firing fuels such as oil, gas and coal, with successful operating performance. In this paper, design features of a supercritical sliding pressure operation boiler are reported, considering points for a dual fuel firing boiler, low NOx firing technologies and the experience of oil and gas-firing supercritical sliding pressure operation boiler represented by the ultrasupercritical pressure gas firing units with a steam condition of 31 MPa (316 kgf/cm/sup 2/ g), 566/566/566/spl deg/C.","PeriodicalId":447674,"journal":{"name":"Proceedings 1995 International Conference on Energy Management and Power Delivery EMPD '95","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131913191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-11-21DOI: 10.1109/EMPD.1995.500735
Hong-Tzer Yang, Kun-Yuan Huang, C. Huang
This paper presents a constraint logic programming (CLP) algorithm to solve the thermal unit commitment (UC) problem. The CLP algorithm provides an efficient and flexible solution method for the UC problem. Constraints satisfaction techniques are used to prune the search space a priori. The solutions that can not appear as a feasible one are removed from further evaluation. These techniques propagate the constraints as much as possible, and assume the values of some variables of the unit on/off schedule until the infeasible solutions are excluded. After pruning the infeasible solutions, branch and bound approach is then employed to find the minimum operation cost from the feasible domains. The algorithm has been implemented to solve the practical Taiwan power 38-unit thermal system UC problem. Results are compared to those of the Lagrangian relaxation (LR) method to demonstrate the feasibility and effectiveness of the proposed approach to solving the thermal UC problem.
{"title":"A constraint logic programming algorithm for solving thermal unit commitment problem","authors":"Hong-Tzer Yang, Kun-Yuan Huang, C. Huang","doi":"10.1109/EMPD.1995.500735","DOIUrl":"https://doi.org/10.1109/EMPD.1995.500735","url":null,"abstract":"This paper presents a constraint logic programming (CLP) algorithm to solve the thermal unit commitment (UC) problem. The CLP algorithm provides an efficient and flexible solution method for the UC problem. Constraints satisfaction techniques are used to prune the search space a priori. The solutions that can not appear as a feasible one are removed from further evaluation. These techniques propagate the constraints as much as possible, and assume the values of some variables of the unit on/off schedule until the infeasible solutions are excluded. After pruning the infeasible solutions, branch and bound approach is then employed to find the minimum operation cost from the feasible domains. The algorithm has been implemented to solve the practical Taiwan power 38-unit thermal system UC problem. Results are compared to those of the Lagrangian relaxation (LR) method to demonstrate the feasibility and effectiveness of the proposed approach to solving the thermal UC problem.","PeriodicalId":447674,"journal":{"name":"Proceedings 1995 International Conference on Energy Management and Power Delivery EMPD '95","volume":"122 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133175463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-11-21DOI: 10.1109/EMPD.1995.500726
K. Karunakara, P. Nambudiri, S. Arabhya, E. Kumar, Channakeshava
In a complex network, the connected loads may be of single phase or three phase. The increased trend of traction loads, arc furnace loads and thyristor devices necessitates checks for voltage quality. Harmonics, flicker and unbalance are some of the factors influencing the voltage quality. Evaluation of voltage quality and applying correction, if required, are to be made depending upon the situation prevailing in the system. Under certain load conditions like an arc furnace, traction and thyristor devices, the unbalance factor may vary every few cycles and for the unbalance correction, devices like static VAr compensators (SVC) have to be used. These correcting devices have some time lag when effecting corrections, thus measurement based on short time information will not give the true picture. To avoid erroneous conclusions from the short term data, an instrument based on an integrated value over fairly long duration was designed and fabricated by CPRI. This paper discusses the design and calibration of the instrument and presents typical measured data on an electrical system using this instrument.
{"title":"Design of computerised unbalance measuring system","authors":"K. Karunakara, P. Nambudiri, S. Arabhya, E. Kumar, Channakeshava","doi":"10.1109/EMPD.1995.500726","DOIUrl":"https://doi.org/10.1109/EMPD.1995.500726","url":null,"abstract":"In a complex network, the connected loads may be of single phase or three phase. The increased trend of traction loads, arc furnace loads and thyristor devices necessitates checks for voltage quality. Harmonics, flicker and unbalance are some of the factors influencing the voltage quality. Evaluation of voltage quality and applying correction, if required, are to be made depending upon the situation prevailing in the system. Under certain load conditions like an arc furnace, traction and thyristor devices, the unbalance factor may vary every few cycles and for the unbalance correction, devices like static VAr compensators (SVC) have to be used. These correcting devices have some time lag when effecting corrections, thus measurement based on short time information will not give the true picture. To avoid erroneous conclusions from the short term data, an instrument based on an integrated value over fairly long duration was designed and fabricated by CPRI. This paper discusses the design and calibration of the instrument and presents typical measured data on an electrical system using this instrument.","PeriodicalId":447674,"journal":{"name":"Proceedings 1995 International Conference on Energy Management and Power Delivery EMPD '95","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130768549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-11-21DOI: 10.1109/EMPD.1995.500739
D. Valenza, G. Cipollini
The paper begins with an introduction on the reasons that lead to the use of HVDC submarine cable links. The main aspects for the choice of direct current are presented as well as the advantages deriving from the utilization of submarine cables. The second part is dedicated to a discussion on the various type of insulation that could be used in power cables and their possible application to HVDC submarine cables. There is a description of the main characteristics and technical details of two projects. The first is Spain-Morocco link, a 26 km long interconnection for the transmission, in a first phase, of 700 MW from Spain to Morocco at 400 kV AC by means of three cables, plus one spare, of the fluid filled type. The cables are designed for a future change to 450 kV DC, allowing a transmission of 500 MW each (i.e. 2 GW total). One of the peculiarities of the link is the maximum water depth of 615 m (world record for submarine power cables at the time of installation). The second is the Italy-Greece link, a 160 km long interconnection for the transmission of 500 MW (bi-directional) by means of one paper insulated mass impregnated cable having 1250 mm/sup 2/ conductor size and insulated for a rated voltage of 400 kV. This link will attain the world record for the maximum water depth for submarine power cables: 1000 m. The last part deals with the future development expected in this field, in terms of conductor size and voltage leading to an increase in transmissible capacity.
{"title":"HVDC submarine power cable systems-state of the art and future developments","authors":"D. Valenza, G. Cipollini","doi":"10.1109/EMPD.1995.500739","DOIUrl":"https://doi.org/10.1109/EMPD.1995.500739","url":null,"abstract":"The paper begins with an introduction on the reasons that lead to the use of HVDC submarine cable links. The main aspects for the choice of direct current are presented as well as the advantages deriving from the utilization of submarine cables. The second part is dedicated to a discussion on the various type of insulation that could be used in power cables and their possible application to HVDC submarine cables. There is a description of the main characteristics and technical details of two projects. The first is Spain-Morocco link, a 26 km long interconnection for the transmission, in a first phase, of 700 MW from Spain to Morocco at 400 kV AC by means of three cables, plus one spare, of the fluid filled type. The cables are designed for a future change to 450 kV DC, allowing a transmission of 500 MW each (i.e. 2 GW total). One of the peculiarities of the link is the maximum water depth of 615 m (world record for submarine power cables at the time of installation). The second is the Italy-Greece link, a 160 km long interconnection for the transmission of 500 MW (bi-directional) by means of one paper insulated mass impregnated cable having 1250 mm/sup 2/ conductor size and insulated for a rated voltage of 400 kV. This link will attain the world record for the maximum water depth for submarine power cables: 1000 m. The last part deals with the future development expected in this field, in terms of conductor size and voltage leading to an increase in transmissible capacity.","PeriodicalId":447674,"journal":{"name":"Proceedings 1995 International Conference on Energy Management and Power Delivery EMPD '95","volume":"299 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133610571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-11-21DOI: 10.1109/EMPD.1995.500784
Y. Yamagata, K. Tanaka, Y. Terasawa, H. Aoyagi, K. Nojima, I. Hioki, H. Murase, T. Yokota
Very fast transients (VFTs) in a grounding circuit of a 1000 kV class high speed grounding switch (HSGS) were investigated. Referring to the VFT voltage levels estimated by the investigation, the structure of their grounding circuit was designed. The suitability of the design was confirmed by a low voltage test and a high voltage test, which were carried out using the HSGS for a field test.
{"title":"Very fast transients in 1000 kV HSGS grounding circuit","authors":"Y. Yamagata, K. Tanaka, Y. Terasawa, H. Aoyagi, K. Nojima, I. Hioki, H. Murase, T. Yokota","doi":"10.1109/EMPD.1995.500784","DOIUrl":"https://doi.org/10.1109/EMPD.1995.500784","url":null,"abstract":"Very fast transients (VFTs) in a grounding circuit of a 1000 kV class high speed grounding switch (HSGS) were investigated. Referring to the VFT voltage levels estimated by the investigation, the structure of their grounding circuit was designed. The suitability of the design was confirmed by a low voltage test and a high voltage test, which were carried out using the HSGS for a field test.","PeriodicalId":447674,"journal":{"name":"Proceedings 1995 International Conference on Energy Management and Power Delivery EMPD '95","volume":"258 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125794721","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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