Pub Date : 2005-12-19DOI: 10.1109/NAPS.2005.1560509
P. Zuniga-Haro, J. Ramirez
The aim of this paper is to analyze an original detailed operation of a static synchronous series compensator (SSSC) based on 48-pulse VSC. A 48-pulse VSC configuration is fully presented. Expressions for the derivation of the current signals of the SSSC are exhibited. The procedure to charge or discharge the DC capacitor of the SSSC is explained. Deducted expressions were validated with PSCAD/EMTDC even though they are not presented here.
{"title":"Static synchronous series compensator operation based on 48-pulse VSC","authors":"P. Zuniga-Haro, J. Ramirez","doi":"10.1109/NAPS.2005.1560509","DOIUrl":"https://doi.org/10.1109/NAPS.2005.1560509","url":null,"abstract":"The aim of this paper is to analyze an original detailed operation of a static synchronous series compensator (SSSC) based on 48-pulse VSC. A 48-pulse VSC configuration is fully presented. Expressions for the derivation of the current signals of the SSSC are exhibited. The procedure to charge or discharge the DC capacitor of the SSSC is explained. Deducted expressions were validated with PSCAD/EMTDC even though they are not presented here.","PeriodicalId":101495,"journal":{"name":"Proceedings of the 37th Annual North American Power Symposium, 2005.","volume":"325 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126395005","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 : 2005-12-19DOI: 10.1109/NAPS.2005.1560503
G. Stefopoulos, Fang Yang, G. Cokkinides, A. Meliopoulos
This paper describes the development and implementation of contingency ranking and selection algorithms, as part of a power system security assessment program. The work concentrates on performance-index-based algorithms and uses a contingency control variable for precise contingency representation. The ranking is based on the value of the sensitivity of the performance index with respect to the contingency control variable for each outage. The computation of the sensitivities is performed using the very efficient co-state method. Furthermore an approach for improving the accuracy of performance-index-based contingency ranking methods is introduced. This approach is based on state rather than performance index linearization with respect to the contingency variable and it provides more accurate results in contingency ranking and selection. The effectiveness of the proposed method in identifying critical contingencies is illustrated using some small test systems. The ultimate goal is to achieve fast and accurate contingency selection, without having to solve the full load-flow problem for each contingency (as is the current utility practice).
{"title":"Advanced contingency selection methodology","authors":"G. Stefopoulos, Fang Yang, G. Cokkinides, A. Meliopoulos","doi":"10.1109/NAPS.2005.1560503","DOIUrl":"https://doi.org/10.1109/NAPS.2005.1560503","url":null,"abstract":"This paper describes the development and implementation of contingency ranking and selection algorithms, as part of a power system security assessment program. The work concentrates on performance-index-based algorithms and uses a contingency control variable for precise contingency representation. The ranking is based on the value of the sensitivity of the performance index with respect to the contingency control variable for each outage. The computation of the sensitivities is performed using the very efficient co-state method. Furthermore an approach for improving the accuracy of performance-index-based contingency ranking methods is introduced. This approach is based on state rather than performance index linearization with respect to the contingency variable and it provides more accurate results in contingency ranking and selection. The effectiveness of the proposed method in identifying critical contingencies is illustrated using some small test systems. The ultimate goal is to achieve fast and accurate contingency selection, without having to solve the full load-flow problem for each contingency (as is the current utility practice).","PeriodicalId":101495,"journal":{"name":"Proceedings of the 37th Annual North American Power Symposium, 2005.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129422051","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 : 2005-12-19DOI: 10.1109/NAPS.2005.1560562
Ashish Ahuja, Anil Pahwa
Distribution systems have to bear different loading patterns at different times. This change in load causes distribution feeders to be overloaded at sometimes and lightly loaded at others. With this load variation, operating conditions of distribution system also vary. If not compensated well, voltage at different buses goes out of nominal range and real loss on the feeders also increases, leading to high operating cost of the system. However, with the advancement in automation of distribution networks, systems like SCADA have made possible to change the topology of the distribution network in real time for minimizing real loss in the system and for improving voltage profile at the buses. The configuration of the system is changed by changing the status of switches such that load is transferred from heavily loaded feeders to lightly loaded feeders. This paper proposes using ant colony optimization (ACO) for solving reconfiguration problem for loss minimization. Ant system, one of the ACO algorithms, has been implemented in a novel hypercube framework on a 33-bus test system and the results obtained show that ACO performs as well as any other proposed method for loss minimization. In fact, this ACO algorithm found the most optimum solution found so far by any other method proposed in the literature for the 33-bus test system considered.
{"title":"Using ant colony optimization for loss minimization in distribution networks","authors":"Ashish Ahuja, Anil Pahwa","doi":"10.1109/NAPS.2005.1560562","DOIUrl":"https://doi.org/10.1109/NAPS.2005.1560562","url":null,"abstract":"Distribution systems have to bear different loading patterns at different times. This change in load causes distribution feeders to be overloaded at sometimes and lightly loaded at others. With this load variation, operating conditions of distribution system also vary. If not compensated well, voltage at different buses goes out of nominal range and real loss on the feeders also increases, leading to high operating cost of the system. However, with the advancement in automation of distribution networks, systems like SCADA have made possible to change the topology of the distribution network in real time for minimizing real loss in the system and for improving voltage profile at the buses. The configuration of the system is changed by changing the status of switches such that load is transferred from heavily loaded feeders to lightly loaded feeders. This paper proposes using ant colony optimization (ACO) for solving reconfiguration problem for loss minimization. Ant system, one of the ACO algorithms, has been implemented in a novel hypercube framework on a 33-bus test system and the results obtained show that ACO performs as well as any other proposed method for loss minimization. In fact, this ACO algorithm found the most optimum solution found so far by any other method proposed in the literature for the 33-bus test system considered.","PeriodicalId":101495,"journal":{"name":"Proceedings of the 37th Annual North American Power Symposium, 2005.","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128500778","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 : 2005-12-19DOI: 10.1109/NAPS.2005.1560528
F. Uriarte, V. Centeno
An accurate electrical model for a HIF is implemented to investigate typical patterns in the line's current that allow for the detection of these faults. Based on the implemented model an algorithm is proposed to detect and localize the occurrence of HIFs using present recloser/sectionalizer technology. The detection algorithm is presented showing the decision criteria for HIF declaration and its discrimination against nominal behavior in distribution feeders of similar harmonic content.
{"title":"High-impedance fault detection and localization in distribution feeders with microprocessor based devices","authors":"F. Uriarte, V. Centeno","doi":"10.1109/NAPS.2005.1560528","DOIUrl":"https://doi.org/10.1109/NAPS.2005.1560528","url":null,"abstract":"An accurate electrical model for a HIF is implemented to investigate typical patterns in the line's current that allow for the detection of these faults. Based on the implemented model an algorithm is proposed to detect and localize the occurrence of HIFs using present recloser/sectionalizer technology. The detection algorithm is presented showing the decision criteria for HIF declaration and its discrimination against nominal behavior in distribution feeders of similar harmonic content.","PeriodicalId":101495,"journal":{"name":"Proceedings of the 37th Annual North American Power Symposium, 2005.","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121819328","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 : 2005-12-19DOI: 10.1109/NAPS.2005.1560507
F. Noor, R. Arumugam, M. Vaziri
When one or more distributed resources (DR) become isolated from the rest of the power system and inadvertently continue to serve loads separately from the utility system, the condition is known as "unintentional islanding". Utility engineers are seriously concerned about unintentional formation of islands. This is because the utility looses control of the voltage and the frequency during the islanding condition. Frequency deviation and out of limit voltage conditions can have severe consequences on utility loads. In this paper, various type of islanding is discussed. The focus is on the methods and special equipment used to detect and prevent islanding. Examples, advantages and disadvantages of each technique are also discussed.
{"title":"Unintentional islanding and comparison of prevention techniques","authors":"F. Noor, R. Arumugam, M. Vaziri","doi":"10.1109/NAPS.2005.1560507","DOIUrl":"https://doi.org/10.1109/NAPS.2005.1560507","url":null,"abstract":"When one or more distributed resources (DR) become isolated from the rest of the power system and inadvertently continue to serve loads separately from the utility system, the condition is known as \"unintentional islanding\". Utility engineers are seriously concerned about unintentional formation of islands. This is because the utility looses control of the voltage and the frequency during the islanding condition. Frequency deviation and out of limit voltage conditions can have severe consequences on utility loads. In this paper, various type of islanding is discussed. The focus is on the methods and special equipment used to detect and prevent islanding. Examples, advantages and disadvantages of each technique are also discussed.","PeriodicalId":101495,"journal":{"name":"Proceedings of the 37th Annual North American Power Symposium, 2005.","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126366467","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 : 2005-12-19DOI: 10.1109/NAPS.2005.1560506
P. M. Hogan, J. Rettkowski, J. L. Bala
Optimal capacitor placement (OCP) determines the sizing, siting, and switching of capacitors that are added to a radial distribution feeder. OCP seeks to maximize the net dollar savings resulting from the reduction in power and energy losses less the total costs of capacitors. The distribution feeder typically consists of a main branch, some lateral branches, and nodes. Nodes are points on the feeder where segment characteristics change and where electrical loads are connected. This paper presents a new OCP method that employs a branch-and-bound algorithm, which seeks to reduce the total number of possible alternative sizes and sites to test. The proposed method automatically generates combinations of capacitor banks and feeder nodes, it performs power flow analysis to determine the effectiveness of each combination, and it stores the optimal and near-optimal solutions. The switching of capacitors is based on a user-specified power level. The proposed method has been applied successfully to a test distribution feeder. The proposed method has a fast computational time because it does not require evaluating all possible alternative combinations.
{"title":"Optimal capacitor placement using branch and bound","authors":"P. M. Hogan, J. Rettkowski, J. L. Bala","doi":"10.1109/NAPS.2005.1560506","DOIUrl":"https://doi.org/10.1109/NAPS.2005.1560506","url":null,"abstract":"Optimal capacitor placement (OCP) determines the sizing, siting, and switching of capacitors that are added to a radial distribution feeder. OCP seeks to maximize the net dollar savings resulting from the reduction in power and energy losses less the total costs of capacitors. The distribution feeder typically consists of a main branch, some lateral branches, and nodes. Nodes are points on the feeder where segment characteristics change and where electrical loads are connected. This paper presents a new OCP method that employs a branch-and-bound algorithm, which seeks to reduce the total number of possible alternative sizes and sites to test. The proposed method automatically generates combinations of capacitor banks and feeder nodes, it performs power flow analysis to determine the effectiveness of each combination, and it stores the optimal and near-optimal solutions. The switching of capacitors is based on a user-specified power level. The proposed method has been applied successfully to a test distribution feeder. The proposed method has a fast computational time because it does not require evaluating all possible alternative combinations.","PeriodicalId":101495,"journal":{"name":"Proceedings of the 37th Annual North American Power Symposium, 2005.","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121545008","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 : 2005-12-19DOI: 10.1109/NAPS.2005.1560594
H. R. Zamot, E. O’Neill-Carrillo, Senior Member, A. Irizarry-Rivera
Nowadays, we arc confronting many different problems and limitations associated with conventional electricity generation. People are concerned about the pollution emitted by energy sources like coal, oil and natural gas. Wind power is one of the most rapidly growing technologies for renewable power generation, and is taking an important role as an accepted utility generation technology. It is important to consider the direct and indirect environmental impacts associated with wind energy. Some of them are related to the visual impact, noise, use of lands, electromagnetic interferences, the impact on birds and the impact of construction in terrestrial ecosystems. This paper focuses on the perception of the public about wind energy, and potential environmental impacts. The paper also presents an example of the analysis for a wind project in the island of Puerto Rico, considering impact on bird mortality.
{"title":"Analysis of wind projects considering public perception and environmental impact","authors":"H. R. Zamot, E. O’Neill-Carrillo, Senior Member, A. Irizarry-Rivera","doi":"10.1109/NAPS.2005.1560594","DOIUrl":"https://doi.org/10.1109/NAPS.2005.1560594","url":null,"abstract":"Nowadays, we arc confronting many different problems and limitations associated with conventional electricity generation. People are concerned about the pollution emitted by energy sources like coal, oil and natural gas. Wind power is one of the most rapidly growing technologies for renewable power generation, and is taking an important role as an accepted utility generation technology. It is important to consider the direct and indirect environmental impacts associated with wind energy. Some of them are related to the visual impact, noise, use of lands, electromagnetic interferences, the impact on birds and the impact of construction in terrestrial ecosystems. This paper focuses on the perception of the public about wind energy, and potential environmental impacts. The paper also presents an example of the analysis for a wind project in the island of Puerto Rico, considering impact on bird mortality.","PeriodicalId":101495,"journal":{"name":"Proceedings of the 37th Annual North American Power Symposium, 2005.","volume":"14 70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134050576","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 : 2005-12-19DOI: 10.1109/NAPS.2005.1560542
J. Smith, J. Speakes, M. Rashid
The light dimmer is a specialized circuit that utilizes switching techniques to control the brightness of a light fixture. Thyristors (unidirectional semiconductor device) and triacs (bidirectional semiconductor device) are the basic power electronic devices used to control the switching. Once the current crosses the zero-crossing of AC power, the brightness is determined. The sine wave is cut in accordance to the zero-crossing to determine the output power. The light dimmer is an efficient and practical application of power electronic devices in an industrial or consumer product.
{"title":"An overview of the modern light dimmer: design, operation, and application","authors":"J. Smith, J. Speakes, M. Rashid","doi":"10.1109/NAPS.2005.1560542","DOIUrl":"https://doi.org/10.1109/NAPS.2005.1560542","url":null,"abstract":"The light dimmer is a specialized circuit that utilizes switching techniques to control the brightness of a light fixture. Thyristors (unidirectional semiconductor device) and triacs (bidirectional semiconductor device) are the basic power electronic devices used to control the switching. Once the current crosses the zero-crossing of AC power, the brightness is determined. The sine wave is cut in accordance to the zero-crossing to determine the output power. The light dimmer is an efficient and practical application of power electronic devices in an industrial or consumer product.","PeriodicalId":101495,"journal":{"name":"Proceedings of the 37th Annual North American Power Symposium, 2005.","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124008867","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 : 2005-12-19DOI: 10.1109/NAPS.2005.1560502
V. Donde, V. López, B. Lesieutre, Ali Pinar, Chao Yang, J. Meza
In this paper we propose a two-stage screening and analysis process for identifying multiple contingencies that may result in very severe disturbances and blackouts. In a screening stage we form an optimization problem to find the minimum change in the network to move the power flow feasibility boundary to the present operating point and that will cause the system to separate with a user-specified power imbalance. The lines identified by the optimization program are used in a subsequent analysis stage to find combinations that may lead to a blackout. This approach is applied to a 30-bus system with encouraging results.
{"title":"Identification of severe multiple contingencies in electric power networks","authors":"V. Donde, V. López, B. Lesieutre, Ali Pinar, Chao Yang, J. Meza","doi":"10.1109/NAPS.2005.1560502","DOIUrl":"https://doi.org/10.1109/NAPS.2005.1560502","url":null,"abstract":"In this paper we propose a two-stage screening and analysis process for identifying multiple contingencies that may result in very severe disturbances and blackouts. In a screening stage we form an optimization problem to find the minimum change in the network to move the power flow feasibility boundary to the present operating point and that will cause the system to separate with a user-specified power imbalance. The lines identified by the optimization program are used in a subsequent analysis stage to find combinations that may lead to a blackout. This approach is applied to a 30-bus system with encouraging results.","PeriodicalId":101495,"journal":{"name":"Proceedings of the 37th Annual North American Power Symposium, 2005.","volume":"86 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127143566","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 : 2005-12-19DOI: 10.1109/NAPS.2005.1560514
Bhavesh Dalela, G. Radman
This paper deals with the design of an auxiliary controller using linear quadratic regulator (LQR) and linear quadratic Gaussian (LQG) techniques. A three machine three bus power system equipped with conventional controllers is considered. The system is supplemented with the proposed auxiliary controllers. Using computer simulation it is shown that the proposed controller has increased stability and reliability of the system.
{"title":"A study of multivariable supplementary power system stabilizers","authors":"Bhavesh Dalela, G. Radman","doi":"10.1109/NAPS.2005.1560514","DOIUrl":"https://doi.org/10.1109/NAPS.2005.1560514","url":null,"abstract":"This paper deals with the design of an auxiliary controller using linear quadratic regulator (LQR) and linear quadratic Gaussian (LQG) techniques. A three machine three bus power system equipped with conventional controllers is considered. The system is supplemented with the proposed auxiliary controllers. Using computer simulation it is shown that the proposed controller has increased stability and reliability of the system.","PeriodicalId":101495,"journal":{"name":"Proceedings of the 37th Annual North American Power Symposium, 2005.","volume":"195 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122522751","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}