Pub Date : 2008-12-16DOI: 10.1109/UPEC.2008.4651447
M. Fila, G. Taylor, J. Hiscock, M. Irving, P. Lang
Increasing penetration of Distributed Generation (DG) in distribution networks significantly changes both the real and reactive power flows in the network and can create serious voltage control problems. Furthermore, traditional Automatic Voltage Control (AVC) schemes that can normally deal with the reverse power flows, are unable to cope with the voltage problems associated with the presence of DG under certain conditions. Several techniques have been deployed to improve distribution network voltage profiles in such cases, for instance network reinforcement or active voltage control with remote voltage sensing units. Another method that has been proposed and recently implemented is the SuperTAPP n+ relay scheme that is based on locally taken measurements at the substation level combined with a state estimation technique. Such an approach enables assessment of the voltage rise at the point of connection of DG and effective control of the voltage level at the substation. The first objective of this paper is to present the fundamental principles of innovative voltage control schemes for distribution networks with DG based on locally measured signals. Secondly the functionality of the most flexible scheme will be demonstrated via software simulation for a range of distribution network case studies based upon realistic EDF Energy network scenarios. Finally, the results from the modelling and analysis of the SuperTAPP n+ relay scheme and its feasible application will be discussed and detailed conclusions are presented.
{"title":"Flexible voltage control to support Distributed Generation in distribution networks","authors":"M. Fila, G. Taylor, J. Hiscock, M. Irving, P. Lang","doi":"10.1109/UPEC.2008.4651447","DOIUrl":"https://doi.org/10.1109/UPEC.2008.4651447","url":null,"abstract":"Increasing penetration of Distributed Generation (DG) in distribution networks significantly changes both the real and reactive power flows in the network and can create serious voltage control problems. Furthermore, traditional Automatic Voltage Control (AVC) schemes that can normally deal with the reverse power flows, are unable to cope with the voltage problems associated with the presence of DG under certain conditions. Several techniques have been deployed to improve distribution network voltage profiles in such cases, for instance network reinforcement or active voltage control with remote voltage sensing units. Another method that has been proposed and recently implemented is the SuperTAPP n+ relay scheme that is based on locally taken measurements at the substation level combined with a state estimation technique. Such an approach enables assessment of the voltage rise at the point of connection of DG and effective control of the voltage level at the substation. The first objective of this paper is to present the fundamental principles of innovative voltage control schemes for distribution networks with DG based on locally measured signals. Secondly the functionality of the most flexible scheme will be demonstrated via software simulation for a range of distribution network case studies based upon realistic EDF Energy network scenarios. Finally, the results from the modelling and analysis of the SuperTAPP n+ relay scheme and its feasible application will be discussed and detailed conclusions are presented.","PeriodicalId":287461,"journal":{"name":"2008 43rd International Universities Power Engineering Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129874493","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 : 2008-12-16DOI: 10.1109/UPEC.2008.4651567
I. Makhkamova, P. Taylor, J. Bumby, K. Mahkamov
At present commercial CFD packages such as Fluent, ANSYS CFX, and Star-CD are widely used for investigation of heat and mass transfer processes in various fields of engineering. These codes can also be successfully applied to estimate the thermal state of major components of electrical distribution networks, such as overhead lines, underground cables and transformers. This paper presents some results obtained from numerical modelling of the temperature field in the Lynx overhead conductor in both cross and parallel wind conditions using 2-D and 3-D CFD models. The CFD results obtained demonstrate that for an applied load of 433 A and considering the summer rating (Lynx conductors ER P27 [1]) the maximum temperature in the conductor is considerably lower (16 degrees) than the prescribed design conductor temperature. This indicates that there is headroom for increasing the ampacity of the conductor.
{"title":"CFD analysis of the thermal state of an overhead line conductor","authors":"I. Makhkamova, P. Taylor, J. Bumby, K. Mahkamov","doi":"10.1109/UPEC.2008.4651567","DOIUrl":"https://doi.org/10.1109/UPEC.2008.4651567","url":null,"abstract":"At present commercial CFD packages such as Fluent, ANSYS CFX, and Star-CD are widely used for investigation of heat and mass transfer processes in various fields of engineering. These codes can also be successfully applied to estimate the thermal state of major components of electrical distribution networks, such as overhead lines, underground cables and transformers. This paper presents some results obtained from numerical modelling of the temperature field in the Lynx overhead conductor in both cross and parallel wind conditions using 2-D and 3-D CFD models. The CFD results obtained demonstrate that for an applied load of 433 A and considering the summer rating (Lynx conductors ER P27 [1]) the maximum temperature in the conductor is considerably lower (16 degrees) than the prescribed design conductor temperature. This indicates that there is headroom for increasing the ampacity of the conductor.","PeriodicalId":287461,"journal":{"name":"2008 43rd International Universities Power Engineering Conference","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130347131","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 : 2008-12-16DOI: 10.1109/UPEC.2008.4651649
G. Zafarabadi, E. A. Boroujeni
In stand still frequency response, extrapolation in low frequency will be used to calculate Ld0 (initial value of d-axes inductance), Lq0 (initial value of q-axes inductance) and Ra (stator resistance).Because of dependency of generator parameters to this parameters, accuracy of these parameters for exact identification is so important. In this paper effect of stator resistance on generator parameters identification has investigated by sensitivity analysis and then this effect has shown on practical SSFR data of Shahid Rajaei powerplant which are used for parameters identification by pattern search method.
{"title":"Investigation of effect of stator resistance on accuracy of generator parameters identification with SSFR method","authors":"G. Zafarabadi, E. A. Boroujeni","doi":"10.1109/UPEC.2008.4651649","DOIUrl":"https://doi.org/10.1109/UPEC.2008.4651649","url":null,"abstract":"In stand still frequency response, extrapolation in low frequency will be used to calculate Ld0 (initial value of d-axes inductance), Lq0 (initial value of q-axes inductance) and Ra (stator resistance).Because of dependency of generator parameters to this parameters, accuracy of these parameters for exact identification is so important. In this paper effect of stator resistance on generator parameters identification has investigated by sensitivity analysis and then this effect has shown on practical SSFR data of Shahid Rajaei powerplant which are used for parameters identification by pattern search method.","PeriodicalId":287461,"journal":{"name":"2008 43rd International Universities Power Engineering Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125678246","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 : 2008-12-16DOI: 10.1109/UPEC.2008.4651459
Youbing Zhang, Wei Chen, Xiao Zheng, Weng Guo-qing, Yijia Cao
With the impact of interruptible load (IL) to power system and the security of power grid, this paper points out that IL is one of the security providers. Then the model of power grid operation security cost is presented. The security cost consists of the generating reserve cost, the IL cost, the rescheduling cost and the expected system instability cost. A lingo program is used to optimize the model. The rationality and feasibility of the model here are demonstrated by IEEE30 bus power system.
{"title":"Study on model of power grid operation security cost in market environment","authors":"Youbing Zhang, Wei Chen, Xiao Zheng, Weng Guo-qing, Yijia Cao","doi":"10.1109/UPEC.2008.4651459","DOIUrl":"https://doi.org/10.1109/UPEC.2008.4651459","url":null,"abstract":"With the impact of interruptible load (IL) to power system and the security of power grid, this paper points out that IL is one of the security providers. Then the model of power grid operation security cost is presented. The security cost consists of the generating reserve cost, the IL cost, the rescheduling cost and the expected system instability cost. A lingo program is used to optimize the model. The rationality and feasibility of the model here are demonstrated by IEEE30 bus power system.","PeriodicalId":287461,"journal":{"name":"2008 43rd International Universities Power Engineering Conference","volume":"205 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113959149","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 : 2008-12-16DOI: 10.1109/UPEC.2008.4651581
L. McClean, L. Bryans, J. Colandairaj, B. Fox, B. O'sullivan
Governments in many countries including UK & Ireland are incentivising a higher percentage of electric power from renewable sources. In many places achieving this objective is heavily dependent on wind power. Historically, networks developed to serve load and are weak in windy areas. Network development requires permissions and therefore takes many years. This paper explores equipment and analysis to develop a set of line up-rating characteristics linked to the output of wind farms. The system and analysis is to provide an interim measure to enable power planners to connect more renewable energy sources while permission for new lines is being obtained. The equipment involves line mounted current and conductor surface temperature transducers and weather stations arranged regularly along the route. The information is transmitted by GPRS to a Web server where preliminary analysis presents information derived from the data. Further validation and analysis is carried out by downloading the raw data from the remote server. At the time of writing the paper the physical works are complete and validation/analysis is underway.
{"title":"Equipment and methodology for linking overhead line circuit ratings to the output of nearby windfarms","authors":"L. McClean, L. Bryans, J. Colandairaj, B. Fox, B. O'sullivan","doi":"10.1109/UPEC.2008.4651581","DOIUrl":"https://doi.org/10.1109/UPEC.2008.4651581","url":null,"abstract":"Governments in many countries including UK & Ireland are incentivising a higher percentage of electric power from renewable sources. In many places achieving this objective is heavily dependent on wind power. Historically, networks developed to serve load and are weak in windy areas. Network development requires permissions and therefore takes many years. This paper explores equipment and analysis to develop a set of line up-rating characteristics linked to the output of wind farms. The system and analysis is to provide an interim measure to enable power planners to connect more renewable energy sources while permission for new lines is being obtained. The equipment involves line mounted current and conductor surface temperature transducers and weather stations arranged regularly along the route. The information is transmitted by GPRS to a Web server where preliminary analysis presents information derived from the data. Further validation and analysis is carried out by downloading the raw data from the remote server. At the time of writing the paper the physical works are complete and validation/analysis is underway.","PeriodicalId":287461,"journal":{"name":"2008 43rd International Universities Power Engineering Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123491118","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 : 2008-12-16DOI: 10.1109/UPEC.2008.4651631
D. Desideri, M. Guarnieri, A. Maschio, F. Moro
A three-dimensional integral procedure based on the cell method and suitable for simulating non-magnetic shields has been proposed recently. Its validation against systematic measurements is here presented. A good agreement between computed and measured magnetic field RMS values confirms that the proposed integral procedure can be used confidently in designing shielding apparatuses for MV/LV substations.
{"title":"Magnetic shielding of MV/LV substations: Numerical modeling and experimental validation","authors":"D. Desideri, M. Guarnieri, A. Maschio, F. Moro","doi":"10.1109/UPEC.2008.4651631","DOIUrl":"https://doi.org/10.1109/UPEC.2008.4651631","url":null,"abstract":"A three-dimensional integral procedure based on the cell method and suitable for simulating non-magnetic shields has been proposed recently. Its validation against systematic measurements is here presented. A good agreement between computed and measured magnetic field RMS values confirms that the proposed integral procedure can be used confidently in designing shielding apparatuses for MV/LV substations.","PeriodicalId":287461,"journal":{"name":"2008 43rd International Universities Power Engineering Conference","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126443009","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 : 2008-12-16DOI: 10.1109/UPEC.2008.4651585
V. Petrović, M. Jelavic, N. Peric
The use of wind power has been increasing rapidly over last few decades and according to all predictions this trend is likely to continue. At the same time need for better cost effectiveness of wind power plants has stimulated growth in wind turbinespsila size and rated power. As wind turbines grow in size they are subject to extreme structural loads and fatigue. In order to reduce such loads advanced control methods are explored among which individual pitch control has demonstrated very promising results. To design an individual pitch controller suitable wind turbine model is required. Derivation of wind turbine model for individual pitch controller design is addressed in this paper.
{"title":"Identification of wind turbine model for individual pitch controller design","authors":"V. Petrović, M. Jelavic, N. Peric","doi":"10.1109/UPEC.2008.4651585","DOIUrl":"https://doi.org/10.1109/UPEC.2008.4651585","url":null,"abstract":"The use of wind power has been increasing rapidly over last few decades and according to all predictions this trend is likely to continue. At the same time need for better cost effectiveness of wind power plants has stimulated growth in wind turbinespsila size and rated power. As wind turbines grow in size they are subject to extreme structural loads and fatigue. In order to reduce such loads advanced control methods are explored among which individual pitch control has demonstrated very promising results. To design an individual pitch controller suitable wind turbine model is required. Derivation of wind turbine model for individual pitch controller design is addressed in this paper.","PeriodicalId":287461,"journal":{"name":"2008 43rd International Universities Power Engineering Conference","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127808871","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 : 2008-12-16DOI: 10.1109/UPEC.2008.4651680
M. M. Alamuti, A. Zare, M. Savaghebi
Reducing rail voltage and stray current corrosion all at once is one of the challenging problems in DC electrified rail transit systems. Stray current is the main reason of corrosion in the metallic parts located in the proximity of the railway. Choosing appropriate earthing scheme is an effective way to decrease corrosion intensity and providing safety for personnel. This paper discusses a possible alternative earthing scheme for Tehran Metro Line 3. A new earthing scheme entitled reversed diode earthed scheme is presented and compared with floating and diode earthed earthing schemes. A comparative simulation of the rail voltage and stray current corrosion level for the proposed scheme is presented. The results stipulate the excellence of the proposed method over the prevalent schemes.
{"title":"Reversed diode earthing scheme in DC traction power system","authors":"M. M. Alamuti, A. Zare, M. Savaghebi","doi":"10.1109/UPEC.2008.4651680","DOIUrl":"https://doi.org/10.1109/UPEC.2008.4651680","url":null,"abstract":"Reducing rail voltage and stray current corrosion all at once is one of the challenging problems in DC electrified rail transit systems. Stray current is the main reason of corrosion in the metallic parts located in the proximity of the railway. Choosing appropriate earthing scheme is an effective way to decrease corrosion intensity and providing safety for personnel. This paper discusses a possible alternative earthing scheme for Tehran Metro Line 3. A new earthing scheme entitled reversed diode earthed scheme is presented and compared with floating and diode earthed earthing schemes. A comparative simulation of the rail voltage and stray current corrosion level for the proposed scheme is presented. The results stipulate the excellence of the proposed method over the prevalent schemes.","PeriodicalId":287461,"journal":{"name":"2008 43rd International Universities Power Engineering Conference","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129008023","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 : 2008-12-16DOI: 10.1109/UPEC.2008.4651572
H. Livani, J. Rouhi, H. Karimi-Davijani
This paper investigates possible improvements of grid voltage stability in connection of 40 MW wind farm to transmission network using VSC-HVDC. The 40 MW wind farm comprises 20 individual 2 MW permanent magnet synchronous generators. The voltage at the transmission network terminal should be re-established with minimized power losses during wind speed fluctuations and after the clearance of grid side short-circuit faults. This paper highlights a modified decoupling control strategy which is applied to VSC-HVDC converters to achieve variable speed operation and voltage stabilization in wind farm network and transmission network respectively. Simulations using PSCAD/EMTDC are performed to study behavior of wind farm, transmission network and dc link for various changes in wind speed and fault on ac grid. The simulation results validate the connection method and the modified decoupling control strategy.
{"title":"Voltage stabilization in connection of wind farms to transmission network using VSC-HVDC","authors":"H. Livani, J. Rouhi, H. Karimi-Davijani","doi":"10.1109/UPEC.2008.4651572","DOIUrl":"https://doi.org/10.1109/UPEC.2008.4651572","url":null,"abstract":"This paper investigates possible improvements of grid voltage stability in connection of 40 MW wind farm to transmission network using VSC-HVDC. The 40 MW wind farm comprises 20 individual 2 MW permanent magnet synchronous generators. The voltage at the transmission network terminal should be re-established with minimized power losses during wind speed fluctuations and after the clearance of grid side short-circuit faults. This paper highlights a modified decoupling control strategy which is applied to VSC-HVDC converters to achieve variable speed operation and voltage stabilization in wind farm network and transmission network respectively. Simulations using PSCAD/EMTDC are performed to study behavior of wind farm, transmission network and dc link for various changes in wind speed and fault on ac grid. The simulation results validate the connection method and the modified decoupling control strategy.","PeriodicalId":287461,"journal":{"name":"2008 43rd International Universities Power Engineering Conference","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116874819","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 : 2008-12-16DOI: 10.1109/UPEC.2008.4651462
T. T. Nguyen, M. F. Kandlawala, A. Rahim, M. Alam
Dynamic model of a variable speed wind generation system connected to grid is developed, and its steady state and dynamic performance is explored. The performance under wind gust and three-phase fault has been studied and the amount of transient injection to the grid is also investigated. A control scheme that minimizes the transient injection through a thyristor controlled variable capacitance at the generator terminal is proposed and developed. Fuzzy logic based controller is included in its control loop. Simulation results confirmed the effectiveness of the fuzzy logic controlled variable capacitance compensation scheme.
{"title":"Power generation redispatching to improve transient stability in power systems using controllability and observability gramians","authors":"T. T. Nguyen, M. F. Kandlawala, A. Rahim, M. Alam","doi":"10.1109/UPEC.2008.4651462","DOIUrl":"https://doi.org/10.1109/UPEC.2008.4651462","url":null,"abstract":"Dynamic model of a variable speed wind generation system connected to grid is developed, and its steady state and dynamic performance is explored. The performance under wind gust and three-phase fault has been studied and the amount of transient injection to the grid is also investigated. A control scheme that minimizes the transient injection through a thyristor controlled variable capacitance at the generator terminal is proposed and developed. Fuzzy logic based controller is included in its control loop. Simulation results confirmed the effectiveness of the fuzzy logic controlled variable capacitance compensation scheme.","PeriodicalId":287461,"journal":{"name":"2008 43rd International Universities Power Engineering Conference","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114888154","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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