Natural ester seed oil is a biodegradable fluid that is increasingly being used as a replacement for mineral oil and for high temperature flashpoint liquids, including silicone and RTEMP. Electrical contact coking in mineral oil and in silicone has been a common problem with many types of contact materials in tapchangers for de-energized operation and also the reversing switch in load tapchangers. In recent years, an accelerated aging functional life test has been developed and presented to the Transformers Committee of IEEE that has had a good correlation with field data to sort out stable versus unstable combinations. This paper presents a comparative look at natural ester fluid versus mineral oil and silicone for several popular contact pairs. In addition to its biodegradability, Natural ester is shown to have considerably better thermal stability with contact pairs that are unstable in both mineral oil and silicone
{"title":"Tapchangers for De-energized Operation in Natural Ester Fluid, Mineral Oil, and Silicone","authors":"L. Dix, P. Hopkinson","doi":"10.1109/PES.2009.5275165","DOIUrl":"https://doi.org/10.1109/PES.2009.5275165","url":null,"abstract":"Natural ester seed oil is a biodegradable fluid that is increasingly being used as a replacement for mineral oil and for high temperature flashpoint liquids, including silicone and RTEMP. Electrical contact coking in mineral oil and in silicone has been a common problem with many types of contact materials in tapchangers for de-energized operation and also the reversing switch in load tapchangers. In recent years, an accelerated aging functional life test has been developed and presented to the Transformers Committee of IEEE that has had a good correlation with field data to sort out stable versus unstable combinations. This paper presents a comparative look at natural ester fluid versus mineral oil and silicone for several popular contact pairs. In addition to its biodegradability, Natural ester is shown to have considerably better thermal stability with contact pairs that are unstable in both mineral oil and silicone","PeriodicalId":123024,"journal":{"name":"2005/2006 IEEE/PES Transmission and Distribution Conference and Exhibition","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127813989","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}
Uses of market simulation by market system operators are described. The primary distinction between simulation uses by a market system operator and simulation uses by vertically integrated utilities is that market system operators cannot assume that participants offer at marginal cost. Market system operators primarily use simulation for market monitoring and market design purposes, but have also found other uses
{"title":"Uses of Market Simulation By Market System Operators","authors":"M. DePillis","doi":"10.1109/TDC.2006.1668714","DOIUrl":"https://doi.org/10.1109/TDC.2006.1668714","url":null,"abstract":"Uses of market simulation by market system operators are described. The primary distinction between simulation uses by a market system operator and simulation uses by vertically integrated utilities is that market system operators cannot assume that participants offer at marginal cost. Market system operators primarily use simulation for market monitoring and market design purposes, but have also found other uses","PeriodicalId":123024,"journal":{"name":"2005/2006 IEEE/PES Transmission and Distribution Conference and Exhibition","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129119096","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}
In order to satisfy growing electrical demand in the San Diego, California area, San Diego Gas and Electric Company (SDG&E) is modifying existing transmission towers to maximize right of way utilization. Recent projects include modifying existing 138-kV towers to 230-kV capacity. Design considerations including construction methods, and electrical and structural requirements are discussed
{"title":"Modifying Existing 138-kV Transmission Towers to 230-kV Capacity","authors":"B. Wood, T. L. Moore","doi":"10.1109/TDC.2006.1668663","DOIUrl":"https://doi.org/10.1109/TDC.2006.1668663","url":null,"abstract":"In order to satisfy growing electrical demand in the San Diego, California area, San Diego Gas and Electric Company (SDG&E) is modifying existing transmission towers to maximize right of way utilization. Recent projects include modifying existing 138-kV towers to 230-kV capacity. Design considerations including construction methods, and electrical and structural requirements are discussed","PeriodicalId":123024,"journal":{"name":"2005/2006 IEEE/PES Transmission and Distribution Conference and Exhibition","volume":"120 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128988034","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}
Legacy substation automation protocols and architectures typically provided basic functionality for power system automation and were designed to accommodate the technical limitations of the networking technology available for implementation. There has recently been a vast improvement in networking technology that has changed dramatically what is now feasible for power system automation in the substation. Technologies such as switched Ethernet, TCP/IP, high-speed wide area networks, and high-performance low-cost computers are providing capabilities that could barely be imagined when most legacy substation automation protocols were designed. In order to take advantage of modern technology to deliver additional new benefits to users of substation automation, the International Electrotechnical Commission (IEC) has developed and released a new global standard for substation automation: IEC 61850. The paper provides a basic technical overview of IEC 61850 and discusses the benefits of each major aspect of the standard. The concept of a virtual model comprising both physical and logical device models that includes a set of standardized communications services are described along with explanations of how these standardized models, object naming conventions, and communication services bring significant benefits to the substation automation user. New services to support self-describing devices and object-orient peer-to-peer data exchange are explained with an emphasis on how these services can be applied to reduce costs for substation automation. The substation configuration language (SCL) of IEC 61850 is presented with information on how the standardization of substation configuration will impact the future of substation automation. The paper concludes with a brief introduction to the UCA International Users Group as a forum where users and suppliers cooperate in improving substation automation with testing, education, and demonstrations of IEC 61850 and other IEC standards technology
{"title":"Overview of IEC 61850 and Benefits","authors":"R. Mackiewicz","doi":"10.1109/TDC.2006.1668522","DOIUrl":"https://doi.org/10.1109/TDC.2006.1668522","url":null,"abstract":"Legacy substation automation protocols and architectures typically provided basic functionality for power system automation and were designed to accommodate the technical limitations of the networking technology available for implementation. There has recently been a vast improvement in networking technology that has changed dramatically what is now feasible for power system automation in the substation. Technologies such as switched Ethernet, TCP/IP, high-speed wide area networks, and high-performance low-cost computers are providing capabilities that could barely be imagined when most legacy substation automation protocols were designed. In order to take advantage of modern technology to deliver additional new benefits to users of substation automation, the International Electrotechnical Commission (IEC) has developed and released a new global standard for substation automation: IEC 61850. The paper provides a basic technical overview of IEC 61850 and discusses the benefits of each major aspect of the standard. The concept of a virtual model comprising both physical and logical device models that includes a set of standardized communications services are described along with explanations of how these standardized models, object naming conventions, and communication services bring significant benefits to the substation automation user. New services to support self-describing devices and object-orient peer-to-peer data exchange are explained with an emphasis on how these services can be applied to reduce costs for substation automation. The substation configuration language (SCL) of IEC 61850 is presented with information on how the standardization of substation configuration will impact the future of substation automation. The paper concludes with a brief introduction to the UCA International Users Group as a forum where users and suppliers cooperate in improving substation automation with testing, education, and demonstrations of IEC 61850 and other IEC standards technology","PeriodicalId":123024,"journal":{"name":"2005/2006 IEEE/PES Transmission and Distribution Conference and Exhibition","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131086927","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}
Proper protection of distribution systems is essential to ensure high reliability and power quality. With the proposed migration to the inclusion of distributed generation in distribution systems, it is critical that the protection schemes be adapted to address these new and very different system characteristics. The authors of this paper have studied the impact of the integration of DGs in radial distribution systems on the selectivity and coordination of existing overcurrent protection schemes. Studies were conducted using the IEEE 34 node test feeder. Protective devices and distributed generators were added to the test feeder. Normal and short circuit characteristics of the feeder with and without distributed generators were analyzed. The analysis is being used to determine how overcurrent protection must be modified to properly protect distribution systems with DGs. This presentation discusses the findings of these studies
{"title":"Impact of Distributed Generators on Protective Devices in Radial Distribution Systems","authors":"K. Butler-Purry, M. Marotti","doi":"10.1109/TDC.2006.1668462","DOIUrl":"https://doi.org/10.1109/TDC.2006.1668462","url":null,"abstract":"Proper protection of distribution systems is essential to ensure high reliability and power quality. With the proposed migration to the inclusion of distributed generation in distribution systems, it is critical that the protection schemes be adapted to address these new and very different system characteristics. The authors of this paper have studied the impact of the integration of DGs in radial distribution systems on the selectivity and coordination of existing overcurrent protection schemes. Studies were conducted using the IEEE 34 node test feeder. Protective devices and distributed generators were added to the test feeder. Normal and short circuit characteristics of the feeder with and without distributed generators were analyzed. The analysis is being used to determine how overcurrent protection must be modified to properly protect distribution systems with DGs. This presentation discusses the findings of these studies","PeriodicalId":123024,"journal":{"name":"2005/2006 IEEE/PES Transmission and Distribution Conference and Exhibition","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131258590","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}
This paper describes the issue of how the implementation of automated outage management systems (OMS) can influence the accuracy of reliability indices. Approaches for analyzing the influence of the OMS implementation on the accuracy of reported reliability indices are described. An example is provided of a systematic evaluation of reliability indices calculation before and after implementation of an automated system. The paper illustrates the importance of considering these effects if reported indices are used as the basis for benchmarking of reliability performance incentives
{"title":"Effect of Outage Management System Implementation on Reliability Indices","authors":"M. McGranaghan, A. Maitra, C. Perry, A. Gaikwad","doi":"10.1109/TDC.2006.1668677","DOIUrl":"https://doi.org/10.1109/TDC.2006.1668677","url":null,"abstract":"This paper describes the issue of how the implementation of automated outage management systems (OMS) can influence the accuracy of reliability indices. Approaches for analyzing the influence of the OMS implementation on the accuracy of reported reliability indices are described. An example is provided of a systematic evaluation of reliability indices calculation before and after implementation of an automated system. The paper illustrates the importance of considering these effects if reported indices are used as the basis for benchmarking of reliability performance incentives","PeriodicalId":123024,"journal":{"name":"2005/2006 IEEE/PES Transmission and Distribution Conference and Exhibition","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128413318","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}
When such severe contingency as double pole block fault arouses instability in the South China interconnected power system (SCIPS), selective tripping of generating units in the sending end has to be used as a method to maintain system stability. In case the tripped units go through a shutdown and cold start cycle for long duration, it is desirable that they should be hot started and resynchronized to the system as soon as possible to make a quick recovery of the system after fault. Under conditions where the DC fault is permanent, however, such objective is difficult to achieve. This paper presents a control strategy that power generation of some running units be reduced during this process to permit the tripped units to be resynchronized to the system without changing the power level at the sending end, which enables the tripped units to be restored to load rapidly without disturbing system stability. With user models developed in PSS/E, simulations were performed on the SCIPS to investigate the system behavior during reloading process of those thermal units which had been tripped following DC block fault. The results show that power generation at the sending end can be maintained at a reasonable steady level when output of some running units are appropriately reduced during the reloading process of the thermal units, thus having little impact on the system stability, which demonstrates the feasibility and effectiveness of the proposed scheme
{"title":"Restoration Strategies for the South China Interconnected Power System after Generator Tripping following DC System Fault","authors":"G. Cheng, Z. Xu, J. Chao","doi":"10.1109/TDC.2006.1668656","DOIUrl":"https://doi.org/10.1109/TDC.2006.1668656","url":null,"abstract":"When such severe contingency as double pole block fault arouses instability in the South China interconnected power system (SCIPS), selective tripping of generating units in the sending end has to be used as a method to maintain system stability. In case the tripped units go through a shutdown and cold start cycle for long duration, it is desirable that they should be hot started and resynchronized to the system as soon as possible to make a quick recovery of the system after fault. Under conditions where the DC fault is permanent, however, such objective is difficult to achieve. This paper presents a control strategy that power generation of some running units be reduced during this process to permit the tripped units to be resynchronized to the system without changing the power level at the sending end, which enables the tripped units to be restored to load rapidly without disturbing system stability. With user models developed in PSS/E, simulations were performed on the SCIPS to investigate the system behavior during reloading process of those thermal units which had been tripped following DC block fault. The results show that power generation at the sending end can be maintained at a reasonable steady level when output of some running units are appropriately reduced during the reloading process of the thermal units, thus having little impact on the system stability, which demonstrates the feasibility and effectiveness of the proposed scheme","PeriodicalId":123024,"journal":{"name":"2005/2006 IEEE/PES Transmission and Distribution Conference and Exhibition","volume":"95 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131683750","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}
The use of a DSP with peripherals, such as PWM modules, in the control of voltage source converters (VSC) is widely used in our days in FACTS. These peripherals allow some concurrent operation, the control and modulation algorithms can be executed at the same time, they have internal hardware which can be dedicated to producing the most common technique of space vector modulation (SVM) for VSC. Anyway, these simultaneous tasks cannot be executed when a current source converter (CSC) is controlled because the modulation algorithm cannot be implemented in the DSP peripherals. The algorithm must be executed in a sequential mode and most computation resources of the DSP must be devoted to generating the modulation algorithm. As a result, the bandwidth is reduced due to the increasing in the sampling time. This paper presents a field programmable gate array (FPGA) based algorithm for adapting any VSC modulation strategy to control a CSC. Many engineers know the VSC and its modulation strategies, but they do not know so deeply the strategies for controlling the CSC. The main advantage of this proposal is that the wealth of knowledge and experience associated with series VAR compensators based on VSC can be immediately applied to a series VAR compensator based on CSC without requiring further analysis. Experimental results confirm the feasibility of the proposed structure
{"title":"Modulation System for a Series VAR Compensator Based on a Current Source Converter","authors":"J. Doval‐Gandoy, J. Rey, F. Sanchez, Ó. López, C. Peñalver","doi":"10.1109/TDC.2006.1668583","DOIUrl":"https://doi.org/10.1109/TDC.2006.1668583","url":null,"abstract":"The use of a DSP with peripherals, such as PWM modules, in the control of voltage source converters (VSC) is widely used in our days in FACTS. These peripherals allow some concurrent operation, the control and modulation algorithms can be executed at the same time, they have internal hardware which can be dedicated to producing the most common technique of space vector modulation (SVM) for VSC. Anyway, these simultaneous tasks cannot be executed when a current source converter (CSC) is controlled because the modulation algorithm cannot be implemented in the DSP peripherals. The algorithm must be executed in a sequential mode and most computation resources of the DSP must be devoted to generating the modulation algorithm. As a result, the bandwidth is reduced due to the increasing in the sampling time. This paper presents a field programmable gate array (FPGA) based algorithm for adapting any VSC modulation strategy to control a CSC. Many engineers know the VSC and its modulation strategies, but they do not know so deeply the strategies for controlling the CSC. The main advantage of this proposal is that the wealth of knowledge and experience associated with series VAR compensators based on VSC can be immediately applied to a series VAR compensator based on CSC without requiring further analysis. Experimental results confirm the feasibility of the proposed structure","PeriodicalId":123024,"journal":{"name":"2005/2006 IEEE/PES Transmission and Distribution Conference and Exhibition","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134590077","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}
Natural ester seed oil is a biodegradable fluid that is increasingly being used as a replacement for mineral oil and for high temperature flashpoint liquids, including silicone and RTEMP. This paper addresses technical issues that need to be answered in introducing a new dielectric insulating and cooling fluid for distribution and power transformers. The author's experience and training in large power high voltage transformers gives him particular insight into the dielectric, thermal, and physical issues that must be addressed
{"title":"Requirements and Expectations of Natural Ester Fluids for Application in Power Transformers","authors":"H. Moore","doi":"10.1109/TDC.2006.1668446","DOIUrl":"https://doi.org/10.1109/TDC.2006.1668446","url":null,"abstract":"Natural ester seed oil is a biodegradable fluid that is increasingly being used as a replacement for mineral oil and for high temperature flashpoint liquids, including silicone and RTEMP. This paper addresses technical issues that need to be answered in introducing a new dielectric insulating and cooling fluid for distribution and power transformers. The author's experience and training in large power high voltage transformers gives him particular insight into the dielectric, thermal, and physical issues that must be addressed","PeriodicalId":123024,"journal":{"name":"2005/2006 IEEE/PES Transmission and Distribution Conference and Exhibition","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122463251","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}
Modern single-phase loads contain significant harmonic components, particularly triplen harmonics. These harmonics are generated by the proliferation of electronic devices as well as electromagnetic devices (e.g., single-phase induction motors) that operate somewhat saturated. The growth of these non-linear loads has caused an increase of neutral current in the utility system at harmonic frequencies. Since the neutral conductor is grounded to the earth at multiple points, neutral currents flow in the power system neutral, the earth, and other parallel utilities. In a simple system with no parallel utilities, the return currents flow in both the neutral and the earth. Any disparity in the voltage drops caused by these currents results in a voltage difference between the neutral conductor and earth. Attempts to predict the NEV through modeling have proven difficult due to lack of parallel earth and neutral conductor models and representative interconnection between the two circuits. This paper has presented a model of a feeder that incorporates both return paths as well as a more accurate representation of the interconnection between the two systems
{"title":"Elevated NEV due to Triplen Harmonics: Modeling and Results","authors":"E. R. Collins, Jian Jiang","doi":"10.1109/TDC.2006.1668501","DOIUrl":"https://doi.org/10.1109/TDC.2006.1668501","url":null,"abstract":"Modern single-phase loads contain significant harmonic components, particularly triplen harmonics. These harmonics are generated by the proliferation of electronic devices as well as electromagnetic devices (e.g., single-phase induction motors) that operate somewhat saturated. The growth of these non-linear loads has caused an increase of neutral current in the utility system at harmonic frequencies. Since the neutral conductor is grounded to the earth at multiple points, neutral currents flow in the power system neutral, the earth, and other parallel utilities. In a simple system with no parallel utilities, the return currents flow in both the neutral and the earth. Any disparity in the voltage drops caused by these currents results in a voltage difference between the neutral conductor and earth. Attempts to predict the NEV through modeling have proven difficult due to lack of parallel earth and neutral conductor models and representative interconnection between the two circuits. This paper has presented a model of a feeder that incorporates both return paths as well as a more accurate representation of the interconnection between the two systems","PeriodicalId":123024,"journal":{"name":"2005/2006 IEEE/PES Transmission and Distribution Conference and Exhibition","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122967914","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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