Pub Date : 2008-12-16DOI: 10.1109/UPEC.2008.4651452
Jae-Hong Shin, Kwang-ho Lee, Sang-Hoon Kim
Nash Equilibrium (NE) is essential to investigate a participantpsilas offer strategy in a competitive electricity market. The transmission line constraints make it difficult to compute the NE due to causing a mixed strategy NE instead of a pure strategy NE. Computing a mixed strategy is more complicated in a multi-player game. The competition among multiple participants is modeled by a two-level hierarchical optimization problem. A mathematical programming approach is widely used in finding this equilibrium. However, there are difficulties in solving a mixed strategy NE. This paper presents two heuristics applied to the mathematical programming method. The heuristics are based on empirical studies of mixed strategies in numerous sample systems. Based on the heuristics, a new formulation is provided with a set of linear and nonlinear equations, and an algorithm is suggested for using the heuristics and the newly-formulated equations. The effectiveness of the heuristics and the algorithm is illustrated through application of IEEE 30 bus system with 6 generating firms. The equilibrium is verified to satisfy the NE condition.
{"title":"A mixed strategy Nash Equilibrium of multi-player games with a transmission congestion considering PTDF","authors":"Jae-Hong Shin, Kwang-ho Lee, Sang-Hoon Kim","doi":"10.1109/UPEC.2008.4651452","DOIUrl":"https://doi.org/10.1109/UPEC.2008.4651452","url":null,"abstract":"Nash Equilibrium (NE) is essential to investigate a participantpsilas offer strategy in a competitive electricity market. The transmission line constraints make it difficult to compute the NE due to causing a mixed strategy NE instead of a pure strategy NE. Computing a mixed strategy is more complicated in a multi-player game. The competition among multiple participants is modeled by a two-level hierarchical optimization problem. A mathematical programming approach is widely used in finding this equilibrium. However, there are difficulties in solving a mixed strategy NE. This paper presents two heuristics applied to the mathematical programming method. The heuristics are based on empirical studies of mixed strategies in numerous sample systems. Based on the heuristics, a new formulation is provided with a set of linear and nonlinear equations, and an algorithm is suggested for using the heuristics and the newly-formulated equations. The effectiveness of the heuristics and the algorithm is illustrated through application of IEEE 30 bus system with 6 generating firms. The equilibrium is verified to satisfy the NE condition.","PeriodicalId":287461,"journal":{"name":"2008 43rd International Universities Power Engineering Conference","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125849022","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 : 2008-12-16DOI: 10.1109/UPEC.2008.4651467
Yu Chen, Zhao Xu, J. Ostergaard
The power system in the Danish island Bornholm is a distribution system with a high penetration of wind generation, which is representative for expected future power systems. During the period from 11th to 14th September 2007, the Distribution System Operator (DSO) Ostkraft in Bornholm conducted a planned islanding operation test. To evaluate the test and achieve useful experience for future similar operations in Bornholm or even in other similar systems, the frequency data before, during and after this period, were recorded by Phasor Measurement Units (PMUs), supplied by Centre for Electric Technology (CET), Technical University of Denmark (DTU). Statistical analysis of frequency data has been performed and the results reveal that the frequency quality during the islanding period was significantly decreased, indicating the need for enhancing frequency control of such systems in the future.
{"title":"Frequency analysis for planned islanding operation in the Danish distribution system - Bornholm","authors":"Yu Chen, Zhao Xu, J. Ostergaard","doi":"10.1109/UPEC.2008.4651467","DOIUrl":"https://doi.org/10.1109/UPEC.2008.4651467","url":null,"abstract":"The power system in the Danish island Bornholm is a distribution system with a high penetration of wind generation, which is representative for expected future power systems. During the period from 11th to 14th September 2007, the Distribution System Operator (DSO) Ostkraft in Bornholm conducted a planned islanding operation test. To evaluate the test and achieve useful experience for future similar operations in Bornholm or even in other similar systems, the frequency data before, during and after this period, were recorded by Phasor Measurement Units (PMUs), supplied by Centre for Electric Technology (CET), Technical University of Denmark (DTU). Statistical analysis of frequency data has been performed and the results reveal that the frequency quality during the islanding period was significantly decreased, indicating the need for enhancing frequency control of such systems in the future.","PeriodicalId":287461,"journal":{"name":"2008 43rd International Universities Power Engineering Conference","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125214907","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 : 2008-12-16DOI: 10.1109/UPEC.2008.4651674
A.H. Ahmed, M. Halawa, S. Moussa, E. H. Shehab Eldin, E. M. El-Refaee
This paper describes a technical method for establishment of a new compact programmable system for highly accurate AC current measurements at National Institute of Standards (NIS), Egypt. The system consists mainly of thermal current converter (TCC) associated with definite hardware and software which has been harmonized to cover a wideband of accurate AC current measurements. The new system covers a range from 5 mA to 20 A at frequencies from 10 Hz to 10 kHz. In addition, the system has been used in measuring the specific characteristics of the TCC, such as the time responses and the transfer errors at different frequencies. Many practical applications based on the reliability of this system are also stated in this paper.
{"title":"New programmable calibration system for highly accurate AC current measurements at NIS, Egypt","authors":"A.H. Ahmed, M. Halawa, S. Moussa, E. H. Shehab Eldin, E. M. El-Refaee","doi":"10.1109/UPEC.2008.4651674","DOIUrl":"https://doi.org/10.1109/UPEC.2008.4651674","url":null,"abstract":"This paper describes a technical method for establishment of a new compact programmable system for highly accurate AC current measurements at National Institute of Standards (NIS), Egypt. The system consists mainly of thermal current converter (TCC) associated with definite hardware and software which has been harmonized to cover a wideband of accurate AC current measurements. The new system covers a range from 5 mA to 20 A at frequencies from 10 Hz to 10 kHz. In addition, the system has been used in measuring the specific characteristics of the TCC, such as the time responses and the transfer errors at different frequencies. Many practical applications based on the reliability of this system are also stated in this paper.","PeriodicalId":287461,"journal":{"name":"2008 43rd International Universities Power Engineering Conference","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123776241","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 : 2008-12-16DOI: 10.1109/UPEC.2008.4651605
M. Maksič, B. Blazic, I. Papič
In order to adequately evaluate flicker propagation in transmission networks it is essential to correctly conduct flicker measurements. This article analyzes field measurements of flicker in a part of the Slovenian transmission system that has long been under the influence of a large arc furnace. Measurements were conducted in a limited number of network nodes for two different network topologies.
{"title":"Flicker measurements in transmission network","authors":"M. Maksič, B. Blazic, I. Papič","doi":"10.1109/UPEC.2008.4651605","DOIUrl":"https://doi.org/10.1109/UPEC.2008.4651605","url":null,"abstract":"In order to adequately evaluate flicker propagation in transmission networks it is essential to correctly conduct flicker measurements. This article analyzes field measurements of flicker in a part of the Slovenian transmission system that has long been under the influence of a large arc furnace. Measurements were conducted in a limited number of network nodes for two different network topologies.","PeriodicalId":287461,"journal":{"name":"2008 43rd International Universities Power Engineering Conference","volume":"154 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122499213","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 : 2008-12-16DOI: 10.1109/UPEC.2008.4651546
F. Sulla, O. Samuelsson
This paper presents an analysis of an island-operated distribution network with distributed induction generation under different fault conditions. In the first part, the behavior of an island-operated induction generator connected to a distribution network is presented for short-circuits at different locations in the network, with varying values of fault resistance, initial loading conditions and generator rating. The second part of the paper studies the behavior of the induction generator during earth-faults on the distribution network. Unearthed, directly and resonant earthed networks are considered. The effects of the total capacitance to earth, largely due to the presence of cables, are analyzed in the case of an unearthed network. Then, the influence of a STATCOM on the fault behavior of the generator is briefly discussed and in the last part some considerations on network protection are done, under the assumption that selectivity is not required when operating the network as an island.
{"title":"Analysis of island-operated distribution networks with distributed induction generation under fault conditions","authors":"F. Sulla, O. Samuelsson","doi":"10.1109/UPEC.2008.4651546","DOIUrl":"https://doi.org/10.1109/UPEC.2008.4651546","url":null,"abstract":"This paper presents an analysis of an island-operated distribution network with distributed induction generation under different fault conditions. In the first part, the behavior of an island-operated induction generator connected to a distribution network is presented for short-circuits at different locations in the network, with varying values of fault resistance, initial loading conditions and generator rating. The second part of the paper studies the behavior of the induction generator during earth-faults on the distribution network. Unearthed, directly and resonant earthed networks are considered. The effects of the total capacitance to earth, largely due to the presence of cables, are analyzed in the case of an unearthed network. Then, the influence of a STATCOM on the fault behavior of the generator is briefly discussed and in the last part some considerations on network protection are done, under the assumption that selectivity is not required when operating the network as an island.","PeriodicalId":287461,"journal":{"name":"2008 43rd International Universities Power Engineering Conference","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126312554","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 : 2008-12-16DOI: 10.1109/UPEC.2008.4651517
Chao Zhang, Jian-Cheng Tan, B. Kirby, Z. Bo
Frequency is an important parameter for power system operation and protection. A frequency-tracking algorithm is presented for its fast and accurate measurement, which combines second derivative with linear approximation based on the sinusoidal characteristics of an AC signal and supplements a posteriori error processing. A Lagrange Polynomial-Fitting technique is used to calculate the second derivative, whilst an error compensation rate and a modifying factor are introduced to increase algorithm accuracy. The remainder of the fitting polynomial is analyzed, with the samples acquired in a half cycle data window filtered by equal ratios theorem to enhance the robustness, as well as the real time performance. Matlab simulation results show that the algorithm is suitable for instantaneous power system frequency tracking with high accuracy and a certain suppression of second harmonic interference.
{"title":"A derivative based instantaneous frequency tracking algorithm","authors":"Chao Zhang, Jian-Cheng Tan, B. Kirby, Z. Bo","doi":"10.1109/UPEC.2008.4651517","DOIUrl":"https://doi.org/10.1109/UPEC.2008.4651517","url":null,"abstract":"Frequency is an important parameter for power system operation and protection. A frequency-tracking algorithm is presented for its fast and accurate measurement, which combines second derivative with linear approximation based on the sinusoidal characteristics of an AC signal and supplements a posteriori error processing. A Lagrange Polynomial-Fitting technique is used to calculate the second derivative, whilst an error compensation rate and a modifying factor are introduced to increase algorithm accuracy. The remainder of the fitting polynomial is analyzed, with the samples acquired in a half cycle data window filtered by equal ratios theorem to enhance the robustness, as well as the real time performance. Matlab simulation results show that the algorithm is suitable for instantaneous power system frequency tracking with high accuracy and a certain suppression of second harmonic interference.","PeriodicalId":287461,"journal":{"name":"2008 43rd International Universities Power Engineering Conference","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131783077","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 : 2008-12-16DOI: 10.1109/UPEC.2008.4651644
D. Casadei, F. Filippetti, C. Rossi, A. Stefani
This paper investigates the impact of the control system bandwidth on the detection of incipient faults in doubly fed induction generators used in wind turbines. In this application, the rotor is supplied by a static converter for the control of active and reactive power flows from the generator to the electrical grid. The Impact of the closed loop control system cannot be neglected when the detection of asymmetries in the machine are based on the signature analysis of electrical variables. An investigation of the behavior of faulty spectral components for different bandwidths of closed loop regulators is therefore necessary in order to evaluate the effectiveness of diagnostic indexes based on those variables. Simulation and experimental results are here presented to show the limits of two different approaches for fault detection. The first one based on current signature analysis and the second one based on rotor voltage signature analysis.
{"title":"Closed loop bandwidth impact on doubly fed induction machine asymmetries detection based on rotor voltage signature analysis","authors":"D. Casadei, F. Filippetti, C. Rossi, A. Stefani","doi":"10.1109/UPEC.2008.4651644","DOIUrl":"https://doi.org/10.1109/UPEC.2008.4651644","url":null,"abstract":"This paper investigates the impact of the control system bandwidth on the detection of incipient faults in doubly fed induction generators used in wind turbines. In this application, the rotor is supplied by a static converter for the control of active and reactive power flows from the generator to the electrical grid. The Impact of the closed loop control system cannot be neglected when the detection of asymmetries in the machine are based on the signature analysis of electrical variables. An investigation of the behavior of faulty spectral components for different bandwidths of closed loop regulators is therefore necessary in order to evaluate the effectiveness of diagnostic indexes based on those variables. Simulation and experimental results are here presented to show the limits of two different approaches for fault detection. The first one based on current signature analysis and the second one based on rotor voltage signature analysis.","PeriodicalId":287461,"journal":{"name":"2008 43rd International Universities Power Engineering Conference","volume":"34 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123367997","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 : 2008-12-16DOI: 10.1109/UPEC.2008.4651647
J. Zare
This paper describes the vector control of a three phase permanent magnet synchronous motor with surface magnet (PMSM) drive using artificial neural networks. After reviewing the advantages of this solution, a possible vector control schemes for PMSM drives based on the principle of rotor flux oriented control is considered. Based on motor dynamics and non-linear load characteristics, an ANN speed controller is developed and integrated with the vector control scheme of the PMSM drive. The simulation results at various operating conditions validate the efficiency of the ANN for precise speed control of the PMSM drive and the feasibility of the proposed control system. Furthermore the use of ANN makes the drive system robust, accurate and insensitive to parameter variations.
{"title":"Vector control of permanent magnet synchronous motor with surface magnet using artificial neural networks","authors":"J. Zare","doi":"10.1109/UPEC.2008.4651647","DOIUrl":"https://doi.org/10.1109/UPEC.2008.4651647","url":null,"abstract":"This paper describes the vector control of a three phase permanent magnet synchronous motor with surface magnet (PMSM) drive using artificial neural networks. After reviewing the advantages of this solution, a possible vector control schemes for PMSM drives based on the principle of rotor flux oriented control is considered. Based on motor dynamics and non-linear load characteristics, an ANN speed controller is developed and integrated with the vector control scheme of the PMSM drive. The simulation results at various operating conditions validate the efficiency of the ANN for precise speed control of the PMSM drive and the feasibility of the proposed control system. Furthermore the use of ANN makes the drive system robust, accurate and insensitive to parameter variations.","PeriodicalId":287461,"journal":{"name":"2008 43rd International Universities Power Engineering Conference","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116458076","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 : 2008-12-16DOI: 10.1109/UPEC.2008.4651453
Jae-Hong Shin, Sang-Hoon Kim, Kwang-ho Lee
This paper looks at the influence of Financial Transmission Rights (FTRs) on the market value(Social Welfare; SW) in the competitive electricity market. The transmission line constraints make it difficult to compute the Nash Equilibrium (NE) due to causing a mixed strategy NE instead of a pure strategy NE. Computing a mixed strategy is more complicated in a multi-player game. The aim of this paper are to compute a mixed strategy NE and analyze SW in power transaction with FTRs. This paper introduces a formula and a technique for solving NE of multi-player game with FTRs. A formula based on two heuristics is introduced for finding a mixed strategy NE in a multiplayer game depending on the network configuration. The heuristics are based on empirical studies of mixed strategies in numerous sample systems. Also, to verify that the solution of the numerical results is a NE, we show numerical results for the marginal profits of the electricity market. Finally, this paper proposed that SW is the smallest when generation company with the smallest PTDF holds the transmission rights.
{"title":"Analysis of power transaction by solving Nash Equilibrium in electricity markets with Financial Transmission Rights","authors":"Jae-Hong Shin, Sang-Hoon Kim, Kwang-ho Lee","doi":"10.1109/UPEC.2008.4651453","DOIUrl":"https://doi.org/10.1109/UPEC.2008.4651453","url":null,"abstract":"This paper looks at the influence of Financial Transmission Rights (FTRs) on the market value(Social Welfare; SW) in the competitive electricity market. The transmission line constraints make it difficult to compute the Nash Equilibrium (NE) due to causing a mixed strategy NE instead of a pure strategy NE. Computing a mixed strategy is more complicated in a multi-player game. The aim of this paper are to compute a mixed strategy NE and analyze SW in power transaction with FTRs. This paper introduces a formula and a technique for solving NE of multi-player game with FTRs. A formula based on two heuristics is introduced for finding a mixed strategy NE in a multiplayer game depending on the network configuration. The heuristics are based on empirical studies of mixed strategies in numerous sample systems. Also, to verify that the solution of the numerical results is a NE, we show numerical results for the marginal profits of the electricity market. Finally, this paper proposed that SW is the smallest when generation company with the smallest PTDF holds the transmission rights.","PeriodicalId":287461,"journal":{"name":"2008 43rd International Universities Power Engineering Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130310658","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 : 2008-12-16DOI: 10.1109/UPEC.2008.4651675
M. Sarvi, N. NamazyPour
In this paper a PID-fuzzy controller is proposed in order to control of a Buck DC/DC converter. A fuzzy system is used to tune the PID controller gains in real time. This fuzzy system is constructed from a set of fuzzy IF-THEN rules that describe how to choose the PID gains under certain operation conditions. The simulation results are presented for line and load regulations, i.e. the effects of input voltage and load variation on the proposed controller.
{"title":"A new PID-Fuzzy controller for DC/DC converters","authors":"M. Sarvi, N. NamazyPour","doi":"10.1109/UPEC.2008.4651675","DOIUrl":"https://doi.org/10.1109/UPEC.2008.4651675","url":null,"abstract":"In this paper a PID-fuzzy controller is proposed in order to control of a Buck DC/DC converter. A fuzzy system is used to tune the PID controller gains in real time. This fuzzy system is constructed from a set of fuzzy IF-THEN rules that describe how to choose the PID gains under certain operation conditions. The simulation results are presented for line and load regulations, i.e. the effects of input voltage and load variation on the proposed controller.","PeriodicalId":287461,"journal":{"name":"2008 43rd International Universities Power Engineering Conference","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132763496","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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