Pub Date : 2006-07-26DOI: 10.1109/LESCPE.2006.280361
M. Abouelsaad, N. Abdel-Gawad, M. E. El Bahy, M. A. Abou El-Ata, I.M. El Shair
Rigorous assessment of uncertainties associated with capacitor installation in distribution systems is the aim of the present paper. Interval mathematics provides a powerful tool for modeling uncertainties. To account for such uncertainties, a heuristic method coupled with interval mathematics is developed with the aim of maximizing a cost saving function. The effects of uncertain inputs within the proposed model are examined for various assumed levels of overall uncertainties. To assess the relative contribution of each uncertain input, an interval sensitivity analysis is carried out. While catering for uncertainties, the proposed method offers utilities with alternatives for selecting the standard capacitor sizes to be used and the associated costs to be saved. This should enable utilities to make informed decisions regarding installing capacitors for reactive power compensation in their distribution systems. A procedure is devised in order to produce sharp bounds of the interval outcomes. Successful implementation of the proposed method is described using a nine-bus radial distribution system
{"title":"Assessment of Uncertainty in Reactive Power Compensation Analysis of Distribution Systems","authors":"M. Abouelsaad, N. Abdel-Gawad, M. E. El Bahy, M. A. Abou El-Ata, I.M. El Shair","doi":"10.1109/LESCPE.2006.280361","DOIUrl":"https://doi.org/10.1109/LESCPE.2006.280361","url":null,"abstract":"Rigorous assessment of uncertainties associated with capacitor installation in distribution systems is the aim of the present paper. Interval mathematics provides a powerful tool for modeling uncertainties. To account for such uncertainties, a heuristic method coupled with interval mathematics is developed with the aim of maximizing a cost saving function. The effects of uncertain inputs within the proposed model are examined for various assumed levels of overall uncertainties. To assess the relative contribution of each uncertain input, an interval sensitivity analysis is carried out. While catering for uncertainties, the proposed method offers utilities with alternatives for selecting the standard capacitor sizes to be used and the associated costs to be saved. This should enable utilities to make informed decisions regarding installing capacitors for reactive power compensation in their distribution systems. A procedure is devised in order to produce sharp bounds of the interval outcomes. Successful implementation of the proposed method is described using a nine-bus radial distribution system","PeriodicalId":225654,"journal":{"name":"2006 Large Engineering Systems Conference on Power Engineering","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121491341","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 : 2006-07-26DOI: 10.1109/LESCPE.2006.280351
K. Al-Tallaq
This paper presents a Hubert-transform (HT) based approach to determine apparent power components in non-sinusoidal circuits with zero instantaneous power. Instantaneous current and voltage phasors, instantaneous active power, instantaneous reactive power, and instantaneous apparent power are also, defined. The properties of the determined power related quantities are discussed. The proposed approach is applicable to sinusoidal and non-sinusoidal systems. A study case of a circuit with square wave voltage and current and zero instantaneous power is examined
{"title":"Determination of Apparent Power Components in Non-Sinusoidal Circuits","authors":"K. Al-Tallaq","doi":"10.1109/LESCPE.2006.280351","DOIUrl":"https://doi.org/10.1109/LESCPE.2006.280351","url":null,"abstract":"This paper presents a Hubert-transform (HT) based approach to determine apparent power components in non-sinusoidal circuits with zero instantaneous power. Instantaneous current and voltage phasors, instantaneous active power, instantaneous reactive power, and instantaneous apparent power are also, defined. The properties of the determined power related quantities are discussed. The proposed approach is applicable to sinusoidal and non-sinusoidal systems. A study case of a circuit with square wave voltage and current and zero instantaneous power is examined","PeriodicalId":225654,"journal":{"name":"2006 Large Engineering Systems Conference on Power Engineering","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114481718","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 : 2006-07-26DOI: 10.1109/LESCPE.2006.280371
R. Prada, L. J. de Souza
Due to real cases related about control actions that had unexpected and opposite effects in different areas of the Brazilian electric system, it was developed a program, based on the system load flow equations, which determines one sensibility matrix constituted by indexes that allows oneself to measure if a certain control action is appropriate or not. The indexes are used to verify the efficiency of the voltage control actions in steady state, and allow us to connect the grandeurs used to the voltage control with the controlled voltage, and had coherent results in comparatives studies
{"title":"Voltage Control Actions Adequacy in Electrical Systems Aiming Voltage Security Conditions Reinforcement","authors":"R. Prada, L. J. de Souza","doi":"10.1109/LESCPE.2006.280371","DOIUrl":"https://doi.org/10.1109/LESCPE.2006.280371","url":null,"abstract":"Due to real cases related about control actions that had unexpected and opposite effects in different areas of the Brazilian electric system, it was developed a program, based on the system load flow equations, which determines one sensibility matrix constituted by indexes that allows oneself to measure if a certain control action is appropriate or not. The indexes are used to verify the efficiency of the voltage control actions in steady state, and allow us to connect the grandeurs used to the voltage control with the controlled voltage, and had coherent results in comparatives studies","PeriodicalId":225654,"journal":{"name":"2006 Large Engineering Systems Conference on Power Engineering","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133677008","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 : 2006-07-26DOI: 10.1109/LESCPE.2006.280372
A. Al-kandari, M. Gilany, A. Shaltout
This paper presents a smart controller for optimal operation of solar systems. The controller is based on better utilization of the storage battery. In most of the commercial solar systems, the battery is charged during the daytime to be used at night or when the photovoltaic power is not available. In this project, a PLC unit continuously monitors the system status. According to the system conditions, the battery can be used to support the PV array at the period of high demand. The battery output is continuously regulated to ensure that the PV array is operated at the peak power point to extract the maximum available power. It also used to support the load during peak period in order to reduce the maximum rated capacity for the PV and consequently reduces the total cost. In all modes of operation, the controller protects the battery from being over charged or deep discharged. It also keeps the battery current within the optimum limits
{"title":"A PLC Controller Algorithm for Optimum Operation of Photovoltaic-Battery System","authors":"A. Al-kandari, M. Gilany, A. Shaltout","doi":"10.1109/LESCPE.2006.280372","DOIUrl":"https://doi.org/10.1109/LESCPE.2006.280372","url":null,"abstract":"This paper presents a smart controller for optimal operation of solar systems. The controller is based on better utilization of the storage battery. In most of the commercial solar systems, the battery is charged during the daytime to be used at night or when the photovoltaic power is not available. In this project, a PLC unit continuously monitors the system status. According to the system conditions, the battery can be used to support the PV array at the period of high demand. The battery output is continuously regulated to ensure that the PV array is operated at the peak power point to extract the maximum available power. It also used to support the load during peak period in order to reduce the maximum rated capacity for the PV and consequently reduces the total cost. In all modes of operation, the controller protects the battery from being over charged or deep discharged. It also keeps the battery current within the optimum limits","PeriodicalId":225654,"journal":{"name":"2006 Large Engineering Systems Conference on Power Engineering","volume":"446 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123042725","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 : 2006-07-26DOI: 10.1109/LESCPE.2006.280358
R. Chhetri, B. Venkatesh, E. Hill
This paper presents a method for minimizing the energy supply cost of an electricity market with multiple regions interconnected by tie lines. It optimally commits the least number of generating units through a security constrained unit commitment procedure. After deregulation of electric utilities, electricity markets have been established. The generation corporation now quote price of power in terms of a revised pricing scheme. The independent system operator is some cases (multi-region) has to act as a regional operator. The proposed method that accommodates these new features is based on a mixed integer quadratic programming solution technique that is fast and reliable. An analysis on the relation between the amount of money saved by a coordinated SCUC of the multi-regional electricity market and the inter-regional tie line flow capacities has been performed and reported
{"title":"Security Constraints Unit Commitment for a Multi-Regional Electricity Market","authors":"R. Chhetri, B. Venkatesh, E. Hill","doi":"10.1109/LESCPE.2006.280358","DOIUrl":"https://doi.org/10.1109/LESCPE.2006.280358","url":null,"abstract":"This paper presents a method for minimizing the energy supply cost of an electricity market with multiple regions interconnected by tie lines. It optimally commits the least number of generating units through a security constrained unit commitment procedure. After deregulation of electric utilities, electricity markets have been established. The generation corporation now quote price of power in terms of a revised pricing scheme. The independent system operator is some cases (multi-region) has to act as a regional operator. The proposed method that accommodates these new features is based on a mixed integer quadratic programming solution technique that is fast and reliable. An analysis on the relation between the amount of money saved by a coordinated SCUC of the multi-regional electricity market and the inter-regional tie line flow capacities has been performed and reported","PeriodicalId":225654,"journal":{"name":"2006 Large Engineering Systems Conference on Power Engineering","volume":"111 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115126894","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 : 2006-07-26DOI: 10.1109/LESCPE.2006.280375
M. Rashidi-nejad, A. Gharaveisi, A. Khajehzadeh, M. Salehizadeh
Under competitive electricity markets, various long-term and short-term contracts based on spot price are implemented by independent market operator (IMO). An accurate forecasting technique for spot price facilitates the market participants to develop bidding strategies in order to maximize their benefit. Neural-wavelet is a powerful method for forecasting problems under the condition of nonlinearity as well as uncertainty. In this paper, a new methodology based upon radial basis function (RBF) network is proposed to the forecasting spot price problem. To train the network, in order to apply historical information of the price behavior, some other effective parameters are used. Load level, fuel price, generation and transmission location as well as conditions are the effective parameters which are associated with general well known parameters. All these parameters are applied for learning process to an assumed neural wavelet network (NWN). Simulation results are presented in details in this paper, where these results indicate the effectiveness of the proposed forecasting tool as an accurate technique
{"title":"Eelctricity Price Forecasting Using WaveNet","authors":"M. Rashidi-nejad, A. Gharaveisi, A. Khajehzadeh, M. Salehizadeh","doi":"10.1109/LESCPE.2006.280375","DOIUrl":"https://doi.org/10.1109/LESCPE.2006.280375","url":null,"abstract":"Under competitive electricity markets, various long-term and short-term contracts based on spot price are implemented by independent market operator (IMO). An accurate forecasting technique for spot price facilitates the market participants to develop bidding strategies in order to maximize their benefit. Neural-wavelet is a powerful method for forecasting problems under the condition of nonlinearity as well as uncertainty. In this paper, a new methodology based upon radial basis function (RBF) network is proposed to the forecasting spot price problem. To train the network, in order to apply historical information of the price behavior, some other effective parameters are used. Load level, fuel price, generation and transmission location as well as conditions are the effective parameters which are associated with general well known parameters. All these parameters are applied for learning process to an assumed neural wavelet network (NWN). Simulation results are presented in details in this paper, where these results indicate the effectiveness of the proposed forecasting tool as an accurate technique","PeriodicalId":225654,"journal":{"name":"2006 Large Engineering Systems Conference on Power Engineering","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130197287","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 : 2006-07-26DOI: 10.1109/LESCPE.2006.280382
A.K. Al-Khalifah, E. El-Saadany
Transformer inrush currents are high-magnitude, harmonic rich currents generated when transformer cores are driven into saturation during energization. These currents have undesirable effects, including potential damage or loss-of-life of transformer, protective relay miss operation, and reduced power quality on the system. This paper explores the theoretical explanations of inrush currents and explores different factors that have influences on the shape and magnitude of those inrush currents. PSCAD/EMTDC is used to investigate inrush currents phenomena by modeling a practical power system circuit for single phase transformer
{"title":"Investigation of Magnetizing Inrush Current in a Single-Phase Transformer","authors":"A.K. Al-Khalifah, E. El-Saadany","doi":"10.1109/LESCPE.2006.280382","DOIUrl":"https://doi.org/10.1109/LESCPE.2006.280382","url":null,"abstract":"Transformer inrush currents are high-magnitude, harmonic rich currents generated when transformer cores are driven into saturation during energization. These currents have undesirable effects, including potential damage or loss-of-life of transformer, protective relay miss operation, and reduced power quality on the system. This paper explores the theoretical explanations of inrush currents and explores different factors that have influences on the shape and magnitude of those inrush currents. PSCAD/EMTDC is used to investigate inrush currents phenomena by modeling a practical power system circuit for single phase transformer","PeriodicalId":225654,"journal":{"name":"2006 Large Engineering Systems Conference on Power Engineering","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125132732","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 : 2006-07-26DOI: 10.1109/LESCPE.2006.280370
Hengxu Zhang, Zhihao Yun, Yuanyuan Sun, Yutian Liu
Transient security assessment (TSA) is becoming an essential requirement for security control of power systems in the new utility environment. At present, detailed time numerical simulation is still the most reliable security assessment approach. Step-size is one of the important factors affecting speed and veracity of TSA. In this paper, some studies on selecting a proper step-size in TSA are presented with a compound simulation index aiming to reach a compromise between speed and veracity. Key issues of selecting a proper simulation step-size in TSA are discussed
{"title":"Studies on Selecting Proper Step-Size in Transient Security Assessment","authors":"Hengxu Zhang, Zhihao Yun, Yuanyuan Sun, Yutian Liu","doi":"10.1109/LESCPE.2006.280370","DOIUrl":"https://doi.org/10.1109/LESCPE.2006.280370","url":null,"abstract":"Transient security assessment (TSA) is becoming an essential requirement for security control of power systems in the new utility environment. At present, detailed time numerical simulation is still the most reliable security assessment approach. Step-size is one of the important factors affecting speed and veracity of TSA. In this paper, some studies on selecting a proper step-size in TSA are presented with a compound simulation index aiming to reach a compromise between speed and veracity. Key issues of selecting a proper simulation step-size in TSA are discussed","PeriodicalId":225654,"journal":{"name":"2006 Large Engineering Systems Conference on Power Engineering","volume":"96 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128761982","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 : 2006-07-26DOI: 10.1109/LESCPE.2006.280381
S. Soliman, M. Mostafa, A. Alkandari
αβ-Transformation is a dc transformation used to transfer the three-phase ac system of voltage or current to a dc system. This paper presents the application of this transformation to identifying the power quality events, such as harmonics, voltage sage, voltage flicker, voltage swell and voltage transients. This transformation can be implemented for a single phase or three- phase system of voltage. The phasor voltage resulting from the combination of Vα and Vβ has a magnitude that proportional to the system operating voltage and rotates with a speed of the frequency of the system voltage.
{"title":"αβ-Transformation Based Algorithm for Identifying the Power Quality Events in an Electric Distribution Network","authors":"S. Soliman, M. Mostafa, A. Alkandari","doi":"10.1109/LESCPE.2006.280381","DOIUrl":"https://doi.org/10.1109/LESCPE.2006.280381","url":null,"abstract":"αβ-Transformation is a dc transformation used to transfer the three-phase ac system of voltage or current to a dc system. This paper presents the application of this transformation to identifying the power quality events, such as harmonics, voltage sage, voltage flicker, voltage swell and voltage transients. This transformation can be implemented for a single phase or three- phase system of voltage. The phasor voltage resulting from the combination of Vα and Vβ has a magnitude that proportional to the system operating voltage and rotates with a speed of the frequency of the system voltage.","PeriodicalId":225654,"journal":{"name":"2006 Large Engineering Systems Conference on Power Engineering","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126210494","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 : 2006-07-26DOI: 10.1109/LESCPE.2006.280374
H. Farahmand, M. Rashidinejad, A.A. Gharaveici, M. Shojaee
Under new re-regulated environment an open access to transmission systems is required. Transmission system operators (TSOs) are encouraged to use the existing facilities more efficiently. This paper focuses on the application of FACTS devices to improve voltage profile as well as maximum available transfer capability (ATC) considering lower prices. Real genetic algorithm (RGA) is used for optimization process and analytical hierarchy process (AHP) with fuzzy sets is used as a hybrid approach to evaluate the fitness function in an accurate fashion. Results show the effectiveness of the proposed methodology that are implemented via case studies
{"title":"An Application of Hybrid Heuristic Approach for ATC Enhancement","authors":"H. Farahmand, M. Rashidinejad, A.A. Gharaveici, M. Shojaee","doi":"10.1109/LESCPE.2006.280374","DOIUrl":"https://doi.org/10.1109/LESCPE.2006.280374","url":null,"abstract":"Under new re-regulated environment an open access to transmission systems is required. Transmission system operators (TSOs) are encouraged to use the existing facilities more efficiently. This paper focuses on the application of FACTS devices to improve voltage profile as well as maximum available transfer capability (ATC) considering lower prices. Real genetic algorithm (RGA) is used for optimization process and analytical hierarchy process (AHP) with fuzzy sets is used as a hybrid approach to evaluate the fitness function in an accurate fashion. Results show the effectiveness of the proposed methodology that are implemented via case studies","PeriodicalId":225654,"journal":{"name":"2006 Large Engineering Systems Conference on Power Engineering","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128123909","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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