This paper describes a new optimization approach for planning under-frequency load shedding using a variant of a genetic algorithm (GA). The load shedding strategy consists of a given sequence of feeder disconnections, minimizing total load curtailment while taking into account load dynamic characteristics.
{"title":"Genetic algorithms in the definition of optimal load shedding strategies","authors":"J. Lopes, Wong Chan Wa, L. M. Proença","doi":"10.1109/PTC.1999.826585","DOIUrl":"https://doi.org/10.1109/PTC.1999.826585","url":null,"abstract":"This paper describes a new optimization approach for planning under-frequency load shedding using a variant of a genetic algorithm (GA). The load shedding strategy consists of a given sequence of feeder disconnections, minimizing total load curtailment while taking into account load dynamic characteristics.","PeriodicalId":101688,"journal":{"name":"PowerTech Budapest 99. Abstract Records. (Cat. No.99EX376)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123053007","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}
Fuel limitations and constraints on CO/sub 2/ emissions have an impact on the operation of the electric power system and therefore should be taken into consideration while determining the optimum operation and estimating the generation cost. In this paper a methodology is proposed, which is based on the concept of shadow prices. The methodology is incorporated into a production simulation model developed at NTUA (PROSIM) and the updated version of the model is applied to the Hellenic electroproduction system.
{"title":"Incorporation of fuel limitations and environmental constraints in production simulation models","authors":"G. Contaxis, C. Delkis, D. Papachristou","doi":"10.1109/PTC.1999.826544","DOIUrl":"https://doi.org/10.1109/PTC.1999.826544","url":null,"abstract":"Fuel limitations and constraints on CO/sub 2/ emissions have an impact on the operation of the electric power system and therefore should be taken into consideration while determining the optimum operation and estimating the generation cost. In this paper a methodology is proposed, which is based on the concept of shadow prices. The methodology is incorporated into a production simulation model developed at NTUA (PROSIM) and the updated version of the model is applied to the Hellenic electroproduction system.","PeriodicalId":101688,"journal":{"name":"PowerTech Budapest 99. Abstract Records. (Cat. No.99EX376)","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114667059","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}
A differential algorithm for phase selective detection of high impedance single-phase-to-ground faults (HIF) on high voltage lines is presented. It is based on the recognition of the fundamental frequency active power consumption of a resistive fault. In order to maximize the sensitivity of the system, a method for the approximation of the measuring system's actual uncertainties is proposed. Thus, adaptive tripping thresholds are realized. The algorithm presented relies on the superposition theorem (delta-principle).
{"title":"Active power differential algorithm for protection of transmission lines","authors":"F. Oechsle, K. Feser, N. Schuster, L. Philippot","doi":"10.1109/PTC.1999.826639","DOIUrl":"https://doi.org/10.1109/PTC.1999.826639","url":null,"abstract":"A differential algorithm for phase selective detection of high impedance single-phase-to-ground faults (HIF) on high voltage lines is presented. It is based on the recognition of the fundamental frequency active power consumption of a resistive fault. In order to maximize the sensitivity of the system, a method for the approximation of the measuring system's actual uncertainties is proposed. Thus, adaptive tripping thresholds are realized. The algorithm presented relies on the superposition theorem (delta-principle).","PeriodicalId":101688,"journal":{"name":"PowerTech Budapest 99. Abstract Records. (Cat. No.99EX376)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125222907","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 400 kV transmission line electric field was measured, and these results were compared to the guidelines. Transmission lines were measured in surroundings of Tampere, Helsinki and Paimio for 25 spans with 38 measurements. In the study, the measured electric field values did exceed the 5 kV/m guideline for general public exposure by ICNIRP in 10 measured spans. The aim of this study was to compare measured 400 kV transmission line electric fields to the guidelines.
{"title":"Electric fields in 400 kV transmission lines","authors":"T. Keikko, J. Isokorpi, L. Korpinen","doi":"10.1109/PTC.1999.826488","DOIUrl":"https://doi.org/10.1109/PTC.1999.826488","url":null,"abstract":"The 400 kV transmission line electric field was measured, and these results were compared to the guidelines. Transmission lines were measured in surroundings of Tampere, Helsinki and Paimio for 25 spans with 38 measurements. In the study, the measured electric field values did exceed the 5 kV/m guideline for general public exposure by ICNIRP in 10 measured spans. The aim of this study was to compare measured 400 kV transmission line electric fields to the guidelines.","PeriodicalId":101688,"journal":{"name":"PowerTech Budapest 99. Abstract Records. (Cat. No.99EX376)","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117195962","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 unified power flow controller (UPFC) has the possibility to damp power system oscillations more effectively than power electronics applied devices such as SVG and TCSC. In this paper, a control system design of a UPFC for power system damping enhancement based on eigenvalue control method was proposed. As a result, it was made clear that the best design method is to determine steady-state value of UPFC control variables and control parameters of UPFC such as gains and time constants simultaneously because controllability of UPFC depends on the steady-state values of UPFC and the power flow condition. A UPFC control system, taking into account the ratings of power converters, is proposed. The effectiveness of the proposed control is verified by the digital time simulation.
{"title":"Control system design of UPFC for power system damping enhancement taking into account rating of converter during oscillation","authors":"H. Kohno, A. Yokoyama","doi":"10.1109/PTC.1999.826595","DOIUrl":"https://doi.org/10.1109/PTC.1999.826595","url":null,"abstract":"The unified power flow controller (UPFC) has the possibility to damp power system oscillations more effectively than power electronics applied devices such as SVG and TCSC. In this paper, a control system design of a UPFC for power system damping enhancement based on eigenvalue control method was proposed. As a result, it was made clear that the best design method is to determine steady-state value of UPFC control variables and control parameters of UPFC such as gains and time constants simultaneously because controllability of UPFC depends on the steady-state values of UPFC and the power flow condition. A UPFC control system, taking into account the ratings of power converters, is proposed. The effectiveness of the proposed control is verified by the digital time simulation.","PeriodicalId":101688,"journal":{"name":"PowerTech Budapest 99. Abstract Records. (Cat. No.99EX376)","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117237603","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}
Considering the new scenario of power systems, this paper points to the necessity of a new generation of energy management systems acting in open and uncertain environments. The changes in this new scenario are analyzed and the great challenges to EMS developers are discussed. Agent technology is pointed out as a promising approach to support the construction of the new generation of EMS, and an agent framework for EMS is presented and discussed.
{"title":"An agent-based approach to EMS in open environments","authors":"G.P. de Azevedo, B. Feijó, M. Costa","doi":"10.1109/PTC.1999.826445","DOIUrl":"https://doi.org/10.1109/PTC.1999.826445","url":null,"abstract":"Considering the new scenario of power systems, this paper points to the necessity of a new generation of energy management systems acting in open and uncertain environments. The changes in this new scenario are analyzed and the great challenges to EMS developers are discussed. Agent technology is pointed out as a promising approach to support the construction of the new generation of EMS, and an agent framework for EMS is presented and discussed.","PeriodicalId":101688,"journal":{"name":"PowerTech Budapest 99. Abstract Records. (Cat. No.99EX376)","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123570965","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}
Power system stabilisers (PSSs) have been employed as the first choice to improve damping and extend system transfer capabilities. However, a problem with a PSS is that its performance is strongly dependent on the power network and its interconnections. Apart from PSS, static VAr compensator (SVC) can be also used for damping improvement. This paper presents analysis performed to compare the effectiveness of PSS and SVC in damping power system oscillations under different system operating conditions. It is concluded that a SVC properly tuned for one operating condition can provide good damping of system oscillations and good voltage control over a wide range of system operating conditions. The results emphasise better effectiveness of a SVC than a PSS in damping power system oscillations and voltage control.
{"title":"Comparison of the effectiveness of PSS and SVC in damping of power system oscillations","authors":"J. Chen, J. Milanović, F. Hughes","doi":"10.1109/PTC.1999.826534","DOIUrl":"https://doi.org/10.1109/PTC.1999.826534","url":null,"abstract":"Power system stabilisers (PSSs) have been employed as the first choice to improve damping and extend system transfer capabilities. However, a problem with a PSS is that its performance is strongly dependent on the power network and its interconnections. Apart from PSS, static VAr compensator (SVC) can be also used for damping improvement. This paper presents analysis performed to compare the effectiveness of PSS and SVC in damping power system oscillations under different system operating conditions. It is concluded that a SVC properly tuned for one operating condition can provide good damping of system oscillations and good voltage control over a wide range of system operating conditions. The results emphasise better effectiveness of a SVC than a PSS in damping power system oscillations and voltage control.","PeriodicalId":101688,"journal":{"name":"PowerTech Budapest 99. Abstract Records. (Cat. No.99EX376)","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123782310","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}
A fast and efficient power flow control method incorporating the automatic adjustment of phase shifting transformers (PSTs) for specified line flows is presented. The effects of a PST are represented by the power-injection model and the corresponding extension of the conventional load flow equations is made. Load flow control by means of a PST is modeled by appropriate additional equations. A special fast decoupled algorithm is developed for the solution of the power flow control problem. The high numerical efficiency and simplicity of the fast decoupled algorithm employed is demonstrated on cases of the present state of interconnections in Balkan Electric Power Systems (EPSs) which are operating as an island with respect to UCPTE.
{"title":"Phase shifting transformers in an efficient power flow control method","authors":"T. Papazoglou, D. Popović, S. Mijailović","doi":"10.1109/PTC.1999.826439","DOIUrl":"https://doi.org/10.1109/PTC.1999.826439","url":null,"abstract":"A fast and efficient power flow control method incorporating the automatic adjustment of phase shifting transformers (PSTs) for specified line flows is presented. The effects of a PST are represented by the power-injection model and the corresponding extension of the conventional load flow equations is made. Load flow control by means of a PST is modeled by appropriate additional equations. A special fast decoupled algorithm is developed for the solution of the power flow control problem. The high numerical efficiency and simplicity of the fast decoupled algorithm employed is demonstrated on cases of the present state of interconnections in Balkan Electric Power Systems (EPSs) which are operating as an island with respect to UCPTE.","PeriodicalId":101688,"journal":{"name":"PowerTech Budapest 99. Abstract Records. (Cat. No.99EX376)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125273111","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 investigates the existence of multiple branches of the bifurcation surface of a power system. At points where such branches intersect we identify singular points of the bifurcation surface. Analyzing two simple power systems, we identify a cusp, a "pure fold" and a codimension 3 bifurcation.
{"title":"Multiple bifurcation branches and cusp bifurcation in power systems","authors":"C. Vournas, B. Nomikos, M.E. Karystian","doi":"10.1109/PTC.1999.826521","DOIUrl":"https://doi.org/10.1109/PTC.1999.826521","url":null,"abstract":"This paper investigates the existence of multiple branches of the bifurcation surface of a power system. At points where such branches intersect we identify singular points of the bifurcation surface. Analyzing two simple power systems, we identify a cusp, a \"pure fold\" and a codimension 3 bifurcation.","PeriodicalId":101688,"journal":{"name":"PowerTech Budapest 99. Abstract Records. (Cat. No.99EX376)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126611758","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}
Summary form only given. The potential for subsynchronous torsional interaction (SSTI) with static VAr compensators (SVCs) and other FACTS devices has been considered in simulation studies as well as in real applications. System studies suggest that large SVCs could have a noticeable impact on torsional vibration modes of nearby generators especially under high-stress conditions. The SSTI sensitivity to SVCs appears from these investigations, mainly related to the dimension and location of SVCs as well as the effect of the voltage control loop and supplemental modulation controls at subsynchronous frequencies. Analysis of SSTI requires complete characterisation of both, the electromechanical dynamics and the electromagnetic dynamics of the network including representation of power system controls in the subsynchronous frequency range. As pointed out by several researchers, SSTI involving FACTS devices is a rather complicated phenomenon, which depends on several factors such as power flow and the interaction with other control devices and control actions. This paper presents some recent advances on the development of analytical techniques for the analysis of subsynchronous resonance (SSR) with AC transmission lines and SSTI with power system controls, namely SVCs and thyristor-controlled series capacitors (TCSCs). Emphasis is being placed on the analysis of the combined effect of series capacitor-compensated transmission lines and SVCs on torsional vibrations. An advanced linear state model of the power system that includes the representation of several FACTS devices is presented.
{"title":"Development of advanced analytical techniques for the analysis of subsynchronous torsional interaction with FACTS devices","authors":"A. R. Messina, S. Rivera, S.D. Olguin, V.D. Ruiz","doi":"10.1109/PTC.1999.826707","DOIUrl":"https://doi.org/10.1109/PTC.1999.826707","url":null,"abstract":"Summary form only given. The potential for subsynchronous torsional interaction (SSTI) with static VAr compensators (SVCs) and other FACTS devices has been considered in simulation studies as well as in real applications. System studies suggest that large SVCs could have a noticeable impact on torsional vibration modes of nearby generators especially under high-stress conditions. The SSTI sensitivity to SVCs appears from these investigations, mainly related to the dimension and location of SVCs as well as the effect of the voltage control loop and supplemental modulation controls at subsynchronous frequencies. Analysis of SSTI requires complete characterisation of both, the electromechanical dynamics and the electromagnetic dynamics of the network including representation of power system controls in the subsynchronous frequency range. As pointed out by several researchers, SSTI involving FACTS devices is a rather complicated phenomenon, which depends on several factors such as power flow and the interaction with other control devices and control actions. This paper presents some recent advances on the development of analytical techniques for the analysis of subsynchronous resonance (SSR) with AC transmission lines and SSTI with power system controls, namely SVCs and thyristor-controlled series capacitors (TCSCs). Emphasis is being placed on the analysis of the combined effect of series capacitor-compensated transmission lines and SVCs on torsional vibrations. An advanced linear state model of the power system that includes the representation of several FACTS devices is presented.","PeriodicalId":101688,"journal":{"name":"PowerTech Budapest 99. Abstract Records. (Cat. No.99EX376)","volume":"325 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122463302","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：