Pub Date : 2008-03-12DOI: 10.1109/MEPCON.2008.4562315
M. Wahab, M. Hamada, A.A.A. El Tallawy, G. Ismail
The purpose of this paper is to implement non-linear multivariable regression technique (nlm) for the prediction of the residual operating time (ROT) of the transformer oil characteristics. This technique depends on non-linear models for each transformer oil characteristic and linear combination of these non-linear models. The characteristics under study are the oil breakdown voltage, total acidity and water content. The proposed technique has proved its accuracy and applicability by justifying the oil characteristics which have a strong impact on ROT and by giving more accurate predicted results than those obtained by previous modeling techniques.
{"title":"A new non-linear model for transformer oil residual operating time","authors":"M. Wahab, M. Hamada, A.A.A. El Tallawy, G. Ismail","doi":"10.1109/MEPCON.2008.4562315","DOIUrl":"https://doi.org/10.1109/MEPCON.2008.4562315","url":null,"abstract":"The purpose of this paper is to implement non-linear multivariable regression technique (nlm) for the prediction of the residual operating time (ROT) of the transformer oil characteristics. This technique depends on non-linear models for each transformer oil characteristic and linear combination of these non-linear models. The characteristics under study are the oil breakdown voltage, total acidity and water content. The proposed technique has proved its accuracy and applicability by justifying the oil characteristics which have a strong impact on ROT and by giving more accurate predicted results than those obtained by previous modeling techniques.","PeriodicalId":236620,"journal":{"name":"2008 12th International Middle-East Power System Conference","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121993107","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 : 2008-03-12DOI: 10.1109/MEPCON.2008.4562298
F. Abdel-Kader, A. El-Saadawi, A. Kalas, O.M. El-baksawi
In conventional direct torque control (DTC) has, over the years, become of the most popular methods of control for induction motors (IM) drive system. A single stator voltage vector of the inverter standard topology is selected every control sampling period, and it is maintained for the whole period. This makes the torque and stator flux reference values to be reached quickly, with a small number of inverter switching, resulting in a very good dynamic response. However, by this switching technique, based on hysteresis, large and small torque and flux errors are not distinguished, which cause an extra torque ripple in motor steady state operation.. A control is proposed to determine the reference value of the flux according to the value of the motor torque. The results of the Matlab- Simulink simulations with different algorithms such as classical DTC, SVM-DTC method and SVM-DTC with PI controller direct torque control without hysteresis band has been compared.. The average torque ripple is reduced over 60% with SVM-DTC with PI controller method compared with classical DTC and is reduced by 30% compared with SVM-DTC.
{"title":"Study in direct torque control of induction motor by using space vector modulation","authors":"F. Abdel-Kader, A. El-Saadawi, A. Kalas, O.M. El-baksawi","doi":"10.1109/MEPCON.2008.4562298","DOIUrl":"https://doi.org/10.1109/MEPCON.2008.4562298","url":null,"abstract":"In conventional direct torque control (DTC) has, over the years, become of the most popular methods of control for induction motors (IM) drive system. A single stator voltage vector of the inverter standard topology is selected every control sampling period, and it is maintained for the whole period. This makes the torque and stator flux reference values to be reached quickly, with a small number of inverter switching, resulting in a very good dynamic response. However, by this switching technique, based on hysteresis, large and small torque and flux errors are not distinguished, which cause an extra torque ripple in motor steady state operation.. A control is proposed to determine the reference value of the flux according to the value of the motor torque. The results of the Matlab- Simulink simulations with different algorithms such as classical DTC, SVM-DTC method and SVM-DTC with PI controller direct torque control without hysteresis band has been compared.. The average torque ripple is reduced over 60% with SVM-DTC with PI controller method compared with classical DTC and is reduced by 30% compared with SVM-DTC.","PeriodicalId":236620,"journal":{"name":"2008 12th International Middle-East Power System Conference","volume":"262 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117100840","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 : 2008-03-12DOI: 10.1109/MEPCON.2008.4562353
E. Azadani, S. H. Hosseinian, B. Moradzadeh, P. Divshali
Competitive bidding for energy and ancillary services is increasingly recognized as an important part of electricity markets. On the other hand, the transmission capacity limits should be considered to optimize the total market cost. In this paper, a new approach based on Constrained Particle Swarm Optimization (CPSO) is developed to address the multi-product and multi-area electricity market dispatch problem. Constraint handling is based on feasibility rules and probability distribution. CPSO method offers a new solution for optimizing the total market cost in a multi-area competitive electricity market considering system constraints. The proposed approach is verified with several cases studies with quadratic and non-smooth cost functions.
{"title":"Economic dispatch in multi-area using particle swarm optimization in electricity market","authors":"E. Azadani, S. H. Hosseinian, B. Moradzadeh, P. Divshali","doi":"10.1109/MEPCON.2008.4562353","DOIUrl":"https://doi.org/10.1109/MEPCON.2008.4562353","url":null,"abstract":"Competitive bidding for energy and ancillary services is increasingly recognized as an important part of electricity markets. On the other hand, the transmission capacity limits should be considered to optimize the total market cost. In this paper, a new approach based on Constrained Particle Swarm Optimization (CPSO) is developed to address the multi-product and multi-area electricity market dispatch problem. Constraint handling is based on feasibility rules and probability distribution. CPSO method offers a new solution for optimizing the total market cost in a multi-area competitive electricity market considering system constraints. The proposed approach is verified with several cases studies with quadratic and non-smooth cost functions.","PeriodicalId":236620,"journal":{"name":"2008 12th International Middle-East Power System Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130801312","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 : 2008-03-12DOI: 10.1109/MEPCON.2008.4562351
Omar H. Abdalla, M. Bahgat, A. Serag, M. El-Sharkawi
Effects of modelling and aggregation of composite loads on power system dynamic performance are investigated. Interconnected induction motors and static loads are aggregated to yield a single equivalent model seen at the boundary bus. Comparison is made of the system performance in the following three cases: (i) original detailed model of the power system, (ii) reduced model with the aggregated dynamic load model, and (iii) reduced model with the load conventionally represented by constant impedance. Simulation results are presented to demonstrate the superiority of the aggregated dynamic load representation in both small and large disturbance studies. The results include system responses to sudden load changes, three phase faults, and line outage, in addition to eigenvalue analysis.
{"title":"Dynamic load modelling and aggregation in power system simulation studies","authors":"Omar H. Abdalla, M. Bahgat, A. Serag, M. El-Sharkawi","doi":"10.1109/MEPCON.2008.4562351","DOIUrl":"https://doi.org/10.1109/MEPCON.2008.4562351","url":null,"abstract":"Effects of modelling and aggregation of composite loads on power system dynamic performance are investigated. Interconnected induction motors and static loads are aggregated to yield a single equivalent model seen at the boundary bus. Comparison is made of the system performance in the following three cases: (i) original detailed model of the power system, (ii) reduced model with the aggregated dynamic load model, and (iii) reduced model with the load conventionally represented by constant impedance. Simulation results are presented to demonstrate the superiority of the aggregated dynamic load representation in both small and large disturbance studies. The results include system responses to sudden load changes, three phase faults, and line outage, in addition to eigenvalue analysis.","PeriodicalId":236620,"journal":{"name":"2008 12th International Middle-East Power System Conference","volume":"124 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123195375","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 : 2008-03-12DOI: 10.1109/MEPCON.2008.4562355
A. Masood, M. Zuberi, E. Husain
Liquid nitrogen (LN2) plays a crucial role in applying high temperature superconducting (HTSC) materials to the power apparatus. However limited literature is available pertaining to design of practical insulation for HTSC devices using LN2. This study attempts to investigate the area and the volume effects on the electrical breakdown strength in LN2 so as to obtain better design of electrical insulation for superconducting power apparatus. Measurements were made to assess the ac breakdown voltages in LN2 utilizing sphere-plane electrode configuration. Experimental results revealed that the breakdown voltage in LN2 did not increase monotonously but decreased partially as the sphere diameter increased at a constant gap length. The ac breakdown voltages in LN2 were also measured for coaxial cylindrical electrode geometry to examine the area & volume effects and the breakdown voltage showed a decrease with an increase in 90% stressed electrode area (SEA) 90 and 90% stressed liquid volume (SLV) 90.
{"title":"Electrical breakdown of Liquid Nitrogen viewed from area & volume effects","authors":"A. Masood, M. Zuberi, E. Husain","doi":"10.1109/MEPCON.2008.4562355","DOIUrl":"https://doi.org/10.1109/MEPCON.2008.4562355","url":null,"abstract":"Liquid nitrogen (LN2) plays a crucial role in applying high temperature superconducting (HTSC) materials to the power apparatus. However limited literature is available pertaining to design of practical insulation for HTSC devices using LN2. This study attempts to investigate the area and the volume effects on the electrical breakdown strength in LN2 so as to obtain better design of electrical insulation for superconducting power apparatus. Measurements were made to assess the ac breakdown voltages in LN2 utilizing sphere-plane electrode configuration. Experimental results revealed that the breakdown voltage in LN2 did not increase monotonously but decreased partially as the sphere diameter increased at a constant gap length. The ac breakdown voltages in LN2 were also measured for coaxial cylindrical electrode geometry to examine the area & volume effects and the breakdown voltage showed a decrease with an increase in 90% stressed electrode area (SEA) 90 and 90% stressed liquid volume (SLV) 90.","PeriodicalId":236620,"journal":{"name":"2008 12th International Middle-East Power System Conference","volume":"126 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115177207","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 : 2008-03-12DOI: 10.1109/MEPCON.2008.4562391
H. Attia
The primary function of the power system is to satisfy load and energy requirements for customers with a reasonable assurance of continuity and quality of supply. The electricity sector in all countries is interested in improving system quality not only to achieve legal obligations and standard regulation but also to increase the revenue. Improving system quality leads to increasing electricity sales, which represent a profit to the utility, and contract damage. The appliances and equipments will operate more efficiency during its lifetime which is a return to the customer. Two main items identifying the quality of service were considered that directly affect the system operation besides the utility revenue and also customer satisfaction. Voltage profile control and losses minimization were the two items considered. Owing to the load growth, the utility lies in a criticality due to the increasing voltage drop and losses in addition to the capabilities of the distribution network. This paper introduces a new method to find out the optimal location and quantity of capacitor banks for reactive power compensation. There before a step voltage regulator for voltage profile control is assigned and allocated to achieve the highest benefits for customer load patterns and utility loss reduction. The compensation problem under study is an optimization problem solved using nonlinear programming technique. Appropriate voltage profile control and regulator allocation depends on the sight of the operation engineer and distribution feeder.
{"title":"Optimal voltage profile control and losses minimization of radial distribution feeders","authors":"H. Attia","doi":"10.1109/MEPCON.2008.4562391","DOIUrl":"https://doi.org/10.1109/MEPCON.2008.4562391","url":null,"abstract":"The primary function of the power system is to satisfy load and energy requirements for customers with a reasonable assurance of continuity and quality of supply. The electricity sector in all countries is interested in improving system quality not only to achieve legal obligations and standard regulation but also to increase the revenue. Improving system quality leads to increasing electricity sales, which represent a profit to the utility, and contract damage. The appliances and equipments will operate more efficiency during its lifetime which is a return to the customer. Two main items identifying the quality of service were considered that directly affect the system operation besides the utility revenue and also customer satisfaction. Voltage profile control and losses minimization were the two items considered. Owing to the load growth, the utility lies in a criticality due to the increasing voltage drop and losses in addition to the capabilities of the distribution network. This paper introduces a new method to find out the optimal location and quantity of capacitor banks for reactive power compensation. There before a step voltage regulator for voltage profile control is assigned and allocated to achieve the highest benefits for customer load patterns and utility loss reduction. The compensation problem under study is an optimization problem solved using nonlinear programming technique. Appropriate voltage profile control and regulator allocation depends on the sight of the operation engineer and distribution feeder.","PeriodicalId":236620,"journal":{"name":"2008 12th International Middle-East Power System Conference","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133952164","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 : 2008-03-12DOI: 10.1109/MEPCON.2008.4562405
A. Thabet, J. Fothergill
To improve the manufacturing of multi- composites of solid insulation materials, this paper has studied the space charge distribution in pure, micro- and nano-filled composites of solid dielectric materials at various high impulse voltages. The pulsed electro-acoustic (PEA) method has been used as one of the most effective techniques for the measurement of the space charge distribution in insulating materials. This can measure the space charge profiles every 10 musec so, the effect of stressing on impulse breakdown voltage has been investigated. Results of PEA measurements performed on various kinds of multi-dielectrics are presented and discussed.
{"title":"Space-charge measurement in composite dielectrics","authors":"A. Thabet, J. Fothergill","doi":"10.1109/MEPCON.2008.4562405","DOIUrl":"https://doi.org/10.1109/MEPCON.2008.4562405","url":null,"abstract":"To improve the manufacturing of multi- composites of solid insulation materials, this paper has studied the space charge distribution in pure, micro- and nano-filled composites of solid dielectric materials at various high impulse voltages. The pulsed electro-acoustic (PEA) method has been used as one of the most effective techniques for the measurement of the space charge distribution in insulating materials. This can measure the space charge profiles every 10 musec so, the effect of stressing on impulse breakdown voltage has been investigated. Results of PEA measurements performed on various kinds of multi-dielectrics are presented and discussed.","PeriodicalId":236620,"journal":{"name":"2008 12th International Middle-East Power System Conference","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114351453","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 : 2008-03-12DOI: 10.1109/MEPCON.2008.4562344
A. El-Halim, M. Ashraf, I.F. Al-Arabawy
This paper introduces a review of the two basic designs of linear induction motor (LIM). Two designs (single side and double sided) are introduced. The modeling of the LIM is given as relations between the variables and the motor parameters. The control techniques for the motor are given. The problems from which the motor suffers due to the construction and applications are demonstrated. The design concept of LIM based on computer aid will be introduced. Finally, we present our new model design of two degree of linear motion in X-Y plane and therefore a multi- axis motion.
{"title":"Design two degree of linear motion X-Y plane machine using linear induction motor","authors":"A. El-Halim, M. Ashraf, I.F. Al-Arabawy","doi":"10.1109/MEPCON.2008.4562344","DOIUrl":"https://doi.org/10.1109/MEPCON.2008.4562344","url":null,"abstract":"This paper introduces a review of the two basic designs of linear induction motor (LIM). Two designs (single side and double sided) are introduced. The modeling of the LIM is given as relations between the variables and the motor parameters. The control techniques for the motor are given. The problems from which the motor suffers due to the construction and applications are demonstrated. The design concept of LIM based on computer aid will be introduced. Finally, we present our new model design of two degree of linear motion in X-Y plane and therefore a multi- axis motion.","PeriodicalId":236620,"journal":{"name":"2008 12th International Middle-East Power System Conference","volume":"166 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114433986","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 : 2008-03-12DOI: 10.1109/MEPCON.2008.4562367
M. Shaaban
Simulation software is a very effective tool for in- class demonstrations and can be readily incorporated in electronic courses. This paper presents an interactive simulation tool to assist instructors for explaining power system stability phenomena. The underlying computational engine is Matlab/Simulaink, whereas the graphical user interface (GUI) is constructed using C#. The GUI provides the capability to modify system parameters/operating conditions interactively. Simulation of a five bus power system model has showed the potentials of the developed tool.
{"title":"A graphical medium for demonstrating power system stability concepts","authors":"M. Shaaban","doi":"10.1109/MEPCON.2008.4562367","DOIUrl":"https://doi.org/10.1109/MEPCON.2008.4562367","url":null,"abstract":"Simulation software is a very effective tool for in- class demonstrations and can be readily incorporated in electronic courses. This paper presents an interactive simulation tool to assist instructors for explaining power system stability phenomena. The underlying computational engine is Matlab/Simulaink, whereas the graphical user interface (GUI) is constructed using C#. The GUI provides the capability to modify system parameters/operating conditions interactively. Simulation of a five bus power system model has showed the potentials of the developed tool.","PeriodicalId":236620,"journal":{"name":"2008 12th International Middle-East Power System Conference","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115004835","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 : 2008-03-12DOI: 10.1109/MEPCON.2008.4562381
S. E. El Safty, Majid Nasr, M. Mansour
Application of PMU for fault location is conducted through a driven algorithm and is applied to different study systems through computer numerical simulation.The algorithm estimates the fault location based on synchronized phasors from both ends of the transmission line whether phase measurement units are installed to both ends or to only one end and the other end is calculated from synchronized phasors from another side. This algorithm allows for accurate estimation of fault location irrespective of fault resistance, load currents, and source impedance. A computer simulation using PSCAD program of the transmission line under study with various fault types and different locations is carried out. A transformation modal is used in the algorithm. Different fault types are simulated with different fault locations to more than one line in the Egyptian network, which has phase measurement units installed according to a selected allocating technique. The results obtained from applying the considered technique shows high levels of accuracy in locating the fault of different faults types. Hence, it is strongly recommended to use the PMU in the Egyptian Network.
{"title":"New technique for fault location in interconnected networks using phasor measurement unit","authors":"S. E. El Safty, Majid Nasr, M. Mansour","doi":"10.1109/MEPCON.2008.4562381","DOIUrl":"https://doi.org/10.1109/MEPCON.2008.4562381","url":null,"abstract":"Application of PMU for fault location is conducted through a driven algorithm and is applied to different study systems through computer numerical simulation.The algorithm estimates the fault location based on synchronized phasors from both ends of the transmission line whether phase measurement units are installed to both ends or to only one end and the other end is calculated from synchronized phasors from another side. This algorithm allows for accurate estimation of fault location irrespective of fault resistance, load currents, and source impedance. A computer simulation using PSCAD program of the transmission line under study with various fault types and different locations is carried out. A transformation modal is used in the algorithm. Different fault types are simulated with different fault locations to more than one line in the Egyptian network, which has phase measurement units installed according to a selected allocating technique. The results obtained from applying the considered technique shows high levels of accuracy in locating the fault of different faults types. Hence, it is strongly recommended to use the PMU in the Egyptian Network.","PeriodicalId":236620,"journal":{"name":"2008 12th International Middle-East Power System Conference","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123953535","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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