Pub Date : 2011-03-20DOI: 10.1109/PSCE.2011.5772574
R. Horton, W. Sunderman, R. Arritt, R. Dugan
Accurate determination of neutral-to-earth voltages (NEV) in multi-grounded distribution circuits can be quite important, particularly in systems where loads are highly unbalanced or have considerable triplen harmonic current content. Some commercially-available and open source software are capable of representing distribution systems in adequate detail for performing NEV analysis. However, results can vary among programs depending on how the distribution line and associated grounding systems are modeled. This paper describes ways to model distribution lines and grounding systems to perform NEV analysis focusing on the earth return model. A simple test feeder is used to show how different distribution line and grounding system models affect NEV analysis.
{"title":"Effect of line modeling methods on neutral-to-earth voltage analysis of multi-grounded distribution feeders","authors":"R. Horton, W. Sunderman, R. Arritt, R. Dugan","doi":"10.1109/PSCE.2011.5772574","DOIUrl":"https://doi.org/10.1109/PSCE.2011.5772574","url":null,"abstract":"Accurate determination of neutral-to-earth voltages (NEV) in multi-grounded distribution circuits can be quite important, particularly in systems where loads are highly unbalanced or have considerable triplen harmonic current content. Some commercially-available and open source software are capable of representing distribution systems in adequate detail for performing NEV analysis. However, results can vary among programs depending on how the distribution line and associated grounding systems are modeled. This paper describes ways to model distribution lines and grounding systems to perform NEV analysis focusing on the earth return model. A simple test feeder is used to show how different distribution line and grounding system models affect NEV analysis.","PeriodicalId":120665,"journal":{"name":"2011 IEEE/PES Power Systems Conference and Exposition","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124925529","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 : 2011-03-20DOI: 10.1109/PSCE.2011.5772513
Ashwani Kumar, P. Srikanth, K. A. Naik
In the present paper identification of power quality events using inverse properties of Stockwell Transforms has been carried out. Identification of power quality problems using the classic Stockwell Transforms though is able to determine both sudden and gradual changes in the signal. However, for some typical cases the signatures are not unique and thereby lead to misinterpretation of the power quality problems. Consequently, a new method is proposed in the present paper to identify the various power quality problems. The technique uses the inverse properties of S-Transform for prediction and is very accurate and unique compared with the existing techniques as have been already reported in the literature. The results presented in the paper show the efficacy of the technique.
{"title":"Identification of power quality events using inverse properties of S transform","authors":"Ashwani Kumar, P. Srikanth, K. A. Naik","doi":"10.1109/PSCE.2011.5772513","DOIUrl":"https://doi.org/10.1109/PSCE.2011.5772513","url":null,"abstract":"In the present paper identification of power quality events using inverse properties of Stockwell Transforms has been carried out. Identification of power quality problems using the classic Stockwell Transforms though is able to determine both sudden and gradual changes in the signal. However, for some typical cases the signatures are not unique and thereby lead to misinterpretation of the power quality problems. Consequently, a new method is proposed in the present paper to identify the various power quality problems. The technique uses the inverse properties of S-Transform for prediction and is very accurate and unique compared with the existing techniques as have been already reported in the literature. The results presented in the paper show the efficacy of the technique.","PeriodicalId":120665,"journal":{"name":"2011 IEEE/PES Power Systems Conference and Exposition","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128798216","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 : 2011-03-20DOI: 10.1109/PSCE.2011.5772594
Ying Xiao, Hui-wen Ni, Qianli Su, P. Nieuwesteeg
The locational marginal price (LMP) is critical information provided by real-time market clearing engines. Under congestion situations, transmission constraint prices affect the LMP substantially. Usually, shadow price (SP) of a transmission constraint is considered as the constraint price. When a transmission constraint is violated, its SP will be set by the penalty price. As the penalty price is a pre-assigned high price used for penalizing constraint violations, it usually does not have monetary value to the market clearing. To prevent the LMP being contaminated by the penalty prices, it's highly desired by regional transmission organizations (RTOs) that the transmission constraint price shall be set by the physical marginal resources for constraint control. In this paper, a novel approach is proposed to calculate the price of violated transmission constraints. Case studies are conducted with PJM real-time production cases. The results demonstrate the effectiveness and high efficiency of the proposed approach. Currently, the approach has been used in PJM real-time production system for transmission constraint pricing.
{"title":"A novel approach to transmission constraint pricing","authors":"Ying Xiao, Hui-wen Ni, Qianli Su, P. Nieuwesteeg","doi":"10.1109/PSCE.2011.5772594","DOIUrl":"https://doi.org/10.1109/PSCE.2011.5772594","url":null,"abstract":"The locational marginal price (LMP) is critical information provided by real-time market clearing engines. Under congestion situations, transmission constraint prices affect the LMP substantially. Usually, shadow price (SP) of a transmission constraint is considered as the constraint price. When a transmission constraint is violated, its SP will be set by the penalty price. As the penalty price is a pre-assigned high price used for penalizing constraint violations, it usually does not have monetary value to the market clearing. To prevent the LMP being contaminated by the penalty prices, it's highly desired by regional transmission organizations (RTOs) that the transmission constraint price shall be set by the physical marginal resources for constraint control. In this paper, a novel approach is proposed to calculate the price of violated transmission constraints. Case studies are conducted with PJM real-time production cases. The results demonstrate the effectiveness and high efficiency of the proposed approach. Currently, the approach has been used in PJM real-time production system for transmission constraint pricing.","PeriodicalId":120665,"journal":{"name":"2011 IEEE/PES Power Systems Conference and Exposition","volume":"4 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128803276","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 : 2011-03-20DOI: 10.1109/PSCE.2011.5772543
D. Dolezilek
This paper describes the impact of new substation protection, control, and monitoring wiring techniques based on virtual wiring replacing traditional wiring. Special emphasis is given to the architectural implications of using digital communications between devices instead of traditional pairs of copper conductors to communicate status and measurements. Additional distinction is made regarding wiring reduction, yard construction, interoperability, and system testing. The paper also analyzes the influence of the latest best practice installation methods of pre-engineered solutions. Emphasis is placed on interoperability among generations of technology from one or more manufacturers and the physical benefits derived from the expanded use of fiber-optic network communication.
{"title":"Case study: Replace substation wiring with rugged fiber communications","authors":"D. Dolezilek","doi":"10.1109/PSCE.2011.5772543","DOIUrl":"https://doi.org/10.1109/PSCE.2011.5772543","url":null,"abstract":"This paper describes the impact of new substation protection, control, and monitoring wiring techniques based on virtual wiring replacing traditional wiring. Special emphasis is given to the architectural implications of using digital communications between devices instead of traditional pairs of copper conductors to communicate status and measurements. Additional distinction is made regarding wiring reduction, yard construction, interoperability, and system testing. The paper also analyzes the influence of the latest best practice installation methods of pre-engineered solutions. Emphasis is placed on interoperability among generations of technology from one or more manufacturers and the physical benefits derived from the expanded use of fiber-optic network communication.","PeriodicalId":120665,"journal":{"name":"2011 IEEE/PES Power Systems Conference and Exposition","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129161208","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 : 2011-03-20DOI: 10.1109/PSCE.2011.5772523
A. Rahmati
A phase angle comparison method for detection of current-transformer (CT) saturation and stability against mis-operation on heavy external faults in numerical current differential relay is presented in this paper. The proposed directional criterion is based on comparison of line currents phase angle of two sides of the power transformer. Defined criterion can differentiate saturation condition from normal condition and various internal faults. The merit of this method is demonstrated by simulation of different faults and saturation conditions on a power transformer using ATP/EMTP software.
{"title":"A directional current differential protection against CT saturation in two sides fed networks","authors":"A. Rahmati","doi":"10.1109/PSCE.2011.5772523","DOIUrl":"https://doi.org/10.1109/PSCE.2011.5772523","url":null,"abstract":"A phase angle comparison method for detection of current-transformer (CT) saturation and stability against mis-operation on heavy external faults in numerical current differential relay is presented in this paper. The proposed directional criterion is based on comparison of line currents phase angle of two sides of the power transformer. Defined criterion can differentiate saturation condition from normal condition and various internal faults. The merit of this method is demonstrated by simulation of different faults and saturation conditions on a power transformer using ATP/EMTP software.","PeriodicalId":120665,"journal":{"name":"2011 IEEE/PES Power Systems Conference and Exposition","volume":"156 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121526228","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 : 2011-03-20DOI: 10.1109/PSCE.2011.5772501
D. Gautam, V. Vittal, R. Ayyanar, T. Harbour
This work investigates the impact of increased penetration of doubly fed induction generators (DFIGs) on electromechanical modes of oscillations of a large interconnected power system. The work proposes a control mechanism aimed at designing the power system stabilizer (PSS) for a DFIG similar to the PSS of synchronous machines. The wind generator power output is taken as input to the PSS. The active power command is modulated in phase opposition to the power system oscillation and is fed to the active power control loop of the DFIG. An additional control block with the DFIG terminal voltage as the PSS input signal is fed to the reactive power control loop. The mechanism serves the purpose of improving the damping of critical mode which is validated by eigenvalue analysis. The work also compares two different control mechanisms that can be employed for damping low frequency inter area modes of oscillations. With the latter based on the idea of modifying the torque set point of the DFIG for changes in grid frequency. The proposed technique is tested on a large test system representing the Midwestern portion of the U.S. interconnection.
{"title":"Supplementary control for damping power oscillations due to increased penetration of doubly fed induction generators in large power systems","authors":"D. Gautam, V. Vittal, R. Ayyanar, T. Harbour","doi":"10.1109/PSCE.2011.5772501","DOIUrl":"https://doi.org/10.1109/PSCE.2011.5772501","url":null,"abstract":"This work investigates the impact of increased penetration of doubly fed induction generators (DFIGs) on electromechanical modes of oscillations of a large interconnected power system. The work proposes a control mechanism aimed at designing the power system stabilizer (PSS) for a DFIG similar to the PSS of synchronous machines. The wind generator power output is taken as input to the PSS. The active power command is modulated in phase opposition to the power system oscillation and is fed to the active power control loop of the DFIG. An additional control block with the DFIG terminal voltage as the PSS input signal is fed to the reactive power control loop. The mechanism serves the purpose of improving the damping of critical mode which is validated by eigenvalue analysis. The work also compares two different control mechanisms that can be employed for damping low frequency inter area modes of oscillations. With the latter based on the idea of modifying the torque set point of the DFIG for changes in grid frequency. The proposed technique is tested on a large test system representing the Midwestern portion of the U.S. interconnection.","PeriodicalId":120665,"journal":{"name":"2011 IEEE/PES Power Systems Conference and Exposition","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122859658","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 : 2011-03-20DOI: 10.1109/PSCE.2011.5772512
S. Savulescu, S. Virmani
This paper is the second paper devoted to the contributions of Glenn W. Stagg to the advancement of the state-of-the-art in power system analysis, planning and operations. It provides a critical review and assessment of his work in the fields of: computer method development; faults and short circuit analysis; load-flow and stability computation techniques; and energy management systems. Also emphasized are the far reaching consequences of Glenn W. Stagg's seminal work, which eventually opened the road for some of the advanced applications of today that were not even conceivable during those pioneering years. It is hoped that this succinct overview of his work will serve as motivation and inspirational example for students, researchers and power system professionals.
这篇论文是第二篇致力于Glenn W. Stagg对电力系统分析、规划和运行的先进技术的贡献的论文。它对他在以下领域的工作进行了批判性的回顾和评估:计算机方法开发;故障及短路分析;潮流与稳定计算技术;能源管理系统。还强调了格伦·w·斯塔格开创性工作的深远影响，它最终为今天的一些先进应用开辟了道路，这些应用在那些开创性的年代甚至是不可想象的。希望这篇对他的工作的简要概述将为学生、研究人员和电力系统专业人员提供激励和鼓舞人心的榜样。
{"title":"Half a century of computer methods in power system analysis, planning and operations: Part II: Glenn W. Stagg and his contributions to advancing the technology","authors":"S. Savulescu, S. Virmani","doi":"10.1109/PSCE.2011.5772512","DOIUrl":"https://doi.org/10.1109/PSCE.2011.5772512","url":null,"abstract":"This paper is the second paper devoted to the contributions of Glenn W. Stagg to the advancement of the state-of-the-art in power system analysis, planning and operations. It provides a critical review and assessment of his work in the fields of: computer method development; faults and short circuit analysis; load-flow and stability computation techniques; and energy management systems. Also emphasized are the far reaching consequences of Glenn W. Stagg's seminal work, which eventually opened the road for some of the advanced applications of today that were not even conceivable during those pioneering years. It is hoped that this succinct overview of his work will serve as motivation and inspirational example for students, researchers and power system professionals.","PeriodicalId":120665,"journal":{"name":"2011 IEEE/PES Power Systems Conference and Exposition","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117113718","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 : 2011-03-20DOI: 10.1109/PSCE.2011.5772521
S. Dutta, T. Overbye
Incorporation of energy storage units with wind farms is being considered critical for wind farms to address variability in wind power generation and meeting committed generation schedules. However, operational constraints such as limited energy of storage units, in addition to the inherent variability of wind power, limit the maximum generation commitment that can be met reliably by a wind farm operating in combination with a storage plant. This paper presents a method for computing an optimal storage dispatch for a storage unit coupled with a wind farm over the period of one hour with the objective of minimizing generation schedule deviations and taking into consideration the uncertainties involved in wind power predictions. The optimization uses a stochastic dynamic programming framework in discrete time. The algorithm minimizes the total expected deviations from a steady power delivery schedule of the combined wind farm-energy storage plant. Tests on a simplified model of a wind-storage plant connected to a load verify the desired objectives. The deviations when generated wind power is known accurately are also presented as a special case. Results provide insights about the maximum generation commitment the combined wind-storage unit can meet without deviations over the scheduling horizon given the probabilities of power generation from wind.
{"title":"Optimal storage scheduling for minimizing schedule deviations considering variability of generated wind power","authors":"S. Dutta, T. Overbye","doi":"10.1109/PSCE.2011.5772521","DOIUrl":"https://doi.org/10.1109/PSCE.2011.5772521","url":null,"abstract":"Incorporation of energy storage units with wind farms is being considered critical for wind farms to address variability in wind power generation and meeting committed generation schedules. However, operational constraints such as limited energy of storage units, in addition to the inherent variability of wind power, limit the maximum generation commitment that can be met reliably by a wind farm operating in combination with a storage plant. This paper presents a method for computing an optimal storage dispatch for a storage unit coupled with a wind farm over the period of one hour with the objective of minimizing generation schedule deviations and taking into consideration the uncertainties involved in wind power predictions. The optimization uses a stochastic dynamic programming framework in discrete time. The algorithm minimizes the total expected deviations from a steady power delivery schedule of the combined wind farm-energy storage plant. Tests on a simplified model of a wind-storage plant connected to a load verify the desired objectives. The deviations when generated wind power is known accurately are also presented as a special case. Results provide insights about the maximum generation commitment the combined wind-storage unit can meet without deviations over the scheduling horizon given the probabilities of power generation from wind.","PeriodicalId":120665,"journal":{"name":"2011 IEEE/PES Power Systems Conference and Exposition","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117150291","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 : 2011-03-20DOI: 10.1109/PSCE.2011.5772555
V. Ramachandran, S. K. Solanki, J. Solanki
With the deregulation of the electric power industry and the advancement of new technologies, the attention of the utilities has been drawn towards adapting Distributed Generation (DG) into their existing infrastructure. In this paper photovoltaic (PV) systems are modeled to study the effects of their interconnection in a distribution system. The system is a combination of the PV array, DC-DC boost converter with Maximum Power Point Tracking (MPPT) control and DC-AC inverter. With increasing penetration of PV, reverse power may flow on the grid which is associated with voltage rise that may lead to violation of various standards. The impact depends upon the size and location of the PV system. Studies are conducted on the real time data obtained from DTE Energy utility. Voltages of the feeder, two way flow of power and the voltage regulation under various levels of PV penetration are analyzed for an IEEE test system utilizing unbalanced power flow solution.
{"title":"Steady state analysis of three phase unbalanced distribution systems with interconnection of photovoltaic cells","authors":"V. Ramachandran, S. K. Solanki, J. Solanki","doi":"10.1109/PSCE.2011.5772555","DOIUrl":"https://doi.org/10.1109/PSCE.2011.5772555","url":null,"abstract":"With the deregulation of the electric power industry and the advancement of new technologies, the attention of the utilities has been drawn towards adapting Distributed Generation (DG) into their existing infrastructure. In this paper photovoltaic (PV) systems are modeled to study the effects of their interconnection in a distribution system. The system is a combination of the PV array, DC-DC boost converter with Maximum Power Point Tracking (MPPT) control and DC-AC inverter. With increasing penetration of PV, reverse power may flow on the grid which is associated with voltage rise that may lead to violation of various standards. The impact depends upon the size and location of the PV system. Studies are conducted on the real time data obtained from DTE Energy utility. Voltages of the feeder, two way flow of power and the voltage regulation under various levels of PV penetration are analyzed for an IEEE test system utilizing unbalanced power flow solution.","PeriodicalId":120665,"journal":{"name":"2011 IEEE/PES Power Systems Conference and Exposition","volume":"103 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115342934","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 : 2011-03-20DOI: 10.1109/PSCE.2011.5772540
T. Kumano
Economic load dispatch among thermal units is one of the most important problems in power systems operation. Usually so called equal marginal cost criterion is adopted to this calculation. Recently global trend of utilizing more and more renewable energy makes this problem more important than ever. In case of large penetration of fluctuating power sources such as PV or wind, thermal units might be more often required a severe operation pattern because the outputs from PV and wind power generators are affected by uncertain change of weather condition. In a sense the large scale utilization of natural energy depends on the flexible and adaptive operation of thermal units. In such a situation it is easily imagined that thermal units would be required to change their output faster than before sometimes almost violating the limitation due to the physical constraints of the plant. We will need a load dispatch calculation method which maximally utilizes their output change capability within the upper limits of the ramp rate. Dynamic economic load dispatch has been studied for a long time to give appropriate load dispatch among generators considering the above stated constraints. However the existing methods are not enough in case of the scenario of very steep demand change. Some more sophisticated calculation scheme is highly needed today which gives us feasible solution in severer situations. This paper proposes a new calculation scheme for the above stated dynamic economic load dispatch problem based on functional optimization which numerically solves Euler's differential equation in the field of calculus of variations. The constraints related to unit output and output ramp rate are readily considered by the logarithmic penalty function terms in the objective function together with the equality constraint regarding the total demand/supply balance. Numerical examples show that the proposed method can solve the above stated severe situation which has been difficult to treat by the existing methods. Convergence performance is also discussed.
{"title":"A functional optimization based dynamic economic load dispatch considering ramping rate of thermal units output","authors":"T. Kumano","doi":"10.1109/PSCE.2011.5772540","DOIUrl":"https://doi.org/10.1109/PSCE.2011.5772540","url":null,"abstract":"Economic load dispatch among thermal units is one of the most important problems in power systems operation. Usually so called equal marginal cost criterion is adopted to this calculation. Recently global trend of utilizing more and more renewable energy makes this problem more important than ever. In case of large penetration of fluctuating power sources such as PV or wind, thermal units might be more often required a severe operation pattern because the outputs from PV and wind power generators are affected by uncertain change of weather condition. In a sense the large scale utilization of natural energy depends on the flexible and adaptive operation of thermal units. In such a situation it is easily imagined that thermal units would be required to change their output faster than before sometimes almost violating the limitation due to the physical constraints of the plant. We will need a load dispatch calculation method which maximally utilizes their output change capability within the upper limits of the ramp rate. Dynamic economic load dispatch has been studied for a long time to give appropriate load dispatch among generators considering the above stated constraints. However the existing methods are not enough in case of the scenario of very steep demand change. Some more sophisticated calculation scheme is highly needed today which gives us feasible solution in severer situations. This paper proposes a new calculation scheme for the above stated dynamic economic load dispatch problem based on functional optimization which numerically solves Euler's differential equation in the field of calculus of variations. The constraints related to unit output and output ramp rate are readily considered by the logarithmic penalty function terms in the objective function together with the equality constraint regarding the total demand/supply balance. Numerical examples show that the proposed method can solve the above stated severe situation which has been difficult to treat by the existing methods. Convergence performance is also discussed.","PeriodicalId":120665,"journal":{"name":"2011 IEEE/PES Power Systems Conference and Exposition","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132493849","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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