Pub Date : 2008-12-16DOI: 10.1109/UPEC.2008.4651446
Xiaoqun Ding, Ling Zhou, Li Hongliang
This paper presents that when power/voltage automatic control system (AVC) is being applied in provincial dispatching centre, in order to implement reactive power/voltage optimization control on condition of ensuring limited on-line voltage stability margin, monitoring module of on-line voltage stability should be introduced to realize the coordinated closed loop control of on-line voltage stability monitoring and AVC system. It defines the concepts of voltage lower limit of on-line voltage stability constraint and dynamic reactive power reserves of generator and considered them for AVC system as constraints to enhance the reliability and security of AVC system. The successful application in Fujian power grid indicate that the proposed method can reduce system active power loss based on ensuring limited on-line voltage stability margin.
{"title":"AVC system based on on-line voltage stability monitoring system","authors":"Xiaoqun Ding, Ling Zhou, Li Hongliang","doi":"10.1109/UPEC.2008.4651446","DOIUrl":"https://doi.org/10.1109/UPEC.2008.4651446","url":null,"abstract":"This paper presents that when power/voltage automatic control system (AVC) is being applied in provincial dispatching centre, in order to implement reactive power/voltage optimization control on condition of ensuring limited on-line voltage stability margin, monitoring module of on-line voltage stability should be introduced to realize the coordinated closed loop control of on-line voltage stability monitoring and AVC system. It defines the concepts of voltage lower limit of on-line voltage stability constraint and dynamic reactive power reserves of generator and considered them for AVC system as constraints to enhance the reliability and security of AVC system. The successful application in Fujian power grid indicate that the proposed method can reduce system active power loss based on ensuring limited on-line voltage stability margin.","PeriodicalId":287461,"journal":{"name":"2008 43rd International Universities Power Engineering Conference","volume":"31 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":"128494750","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.2008.4651575
H. Kargar, M. Sedighizadeh, A. Mosavi
In this paper a new method for grounding system of wind turbines will be proposed. The proposed method will decrease the step voltage, touch voltage and grounding resistance of the grounding system of wind turbine in compare with the traditional method. The method will be analyzed by a finite element program written in MATLAB. For analyzing and comparing the new method with the conventional method, a case study in accordance with VESTAS turbine will be explained.
{"title":"New grounding system of wind turbines","authors":"H. Kargar, M. Sedighizadeh, A. Mosavi","doi":"10.1109/UPEC.2008.4651575","DOIUrl":"https://doi.org/10.1109/UPEC.2008.4651575","url":null,"abstract":"In this paper a new method for grounding system of wind turbines will be proposed. The proposed method will decrease the step voltage, touch voltage and grounding resistance of the grounding system of wind turbine in compare with the traditional method. The method will be analyzed by a finite element program written in MATLAB. For analyzing and comparing the new method with the conventional method, a case study in accordance with VESTAS turbine will be explained.","PeriodicalId":287461,"journal":{"name":"2008 43rd International Universities Power Engineering Conference","volume":"21 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":"124656810","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.2008.4651526
Fu Ling, He Zheng-you, Bo Zhiqian
Fast and accurate fault diagnosis is the primary prerequisite for separating the faulty devices and restoring the power supply, therefore it is of great importance to develop an advanced diagnosis method to meet the power system requirements. With the perspective of information fusion, this paper proposes a novel algorithm for fault diagnosis in power system via the fusion of several different wavelet entropies. Wavelet entropy can extract the fault characteristic quickly and accurately because it combines together the advantages of Wavelet Transform and Shannon Entropy; however in some conditions it is not easy to reach a satisfying result with single wavelet because of the uncertainty and diversity of faults. Therefore, several different wavelet entropies are fused by the D-S evidence theory and the basic probability assignment is set up by a weighted average method based on norm, then a decision method based on the basic probability number is used to diagnose the faults. Simulations with EMTDC and MATLAB demonstrate that this diagnosis method can increase the supporting rate of faults and improve the accuracy and the real-time performance of fault diagnosis in power system. Results also show that the proposed algorithm is feasible and reliable for fault diagnosis.
{"title":"A novel algorithm for power fault diagnosis based on wavelet entropy and D-S evidence theory","authors":"Fu Ling, He Zheng-you, Bo Zhiqian","doi":"10.1109/UPEC.2008.4651526","DOIUrl":"https://doi.org/10.1109/UPEC.2008.4651526","url":null,"abstract":"Fast and accurate fault diagnosis is the primary prerequisite for separating the faulty devices and restoring the power supply, therefore it is of great importance to develop an advanced diagnosis method to meet the power system requirements. With the perspective of information fusion, this paper proposes a novel algorithm for fault diagnosis in power system via the fusion of several different wavelet entropies. Wavelet entropy can extract the fault characteristic quickly and accurately because it combines together the advantages of Wavelet Transform and Shannon Entropy; however in some conditions it is not easy to reach a satisfying result with single wavelet because of the uncertainty and diversity of faults. Therefore, several different wavelet entropies are fused by the D-S evidence theory and the basic probability assignment is set up by a weighted average method based on norm, then a decision method based on the basic probability number is used to diagnose the faults. Simulations with EMTDC and MATLAB demonstrate that this diagnosis method can increase the supporting rate of faults and improve the accuracy and the real-time performance of fault diagnosis in power system. Results also show that the proposed algorithm is feasible and reliable for fault diagnosis.","PeriodicalId":287461,"journal":{"name":"2008 43rd International Universities Power Engineering Conference","volume":"105 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":"121393615","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.2008.4651600
Weihao Hu, Zhe Chen, Yue Wang, Zhaoan Wang
This paper presents a simulation model of a MW-level variable speed wind turbine with a permanent magnet synchronous generator (PMSG) and a full-scale converter developed in the simulation tool of PSCAD/EMTDC. Grid connected wind turbines are fluctuating power sources during continuous operation. A novel wind power fluctuations mitigation method by DC-link voltage control of variable speed wind turbines is proposed in this paper. It smoothes the active power oscillations from the wind turbine due to wind shear and tower shadow effects by varying the DC link voltage of the full-scale converter. Simulation results demonstrate the validity of the proposed method.
{"title":"Wind power fluctuations mitigation by DC-Link voltage control of variable speed wind turbines","authors":"Weihao Hu, Zhe Chen, Yue Wang, Zhaoan Wang","doi":"10.1109/UPEC.2008.4651600","DOIUrl":"https://doi.org/10.1109/UPEC.2008.4651600","url":null,"abstract":"This paper presents a simulation model of a MW-level variable speed wind turbine with a permanent magnet synchronous generator (PMSG) and a full-scale converter developed in the simulation tool of PSCAD/EMTDC. Grid connected wind turbines are fluctuating power sources during continuous operation. A novel wind power fluctuations mitigation method by DC-link voltage control of variable speed wind turbines is proposed in this paper. It smoothes the active power oscillations from the wind turbine due to wind shear and tower shadow effects by varying the DC link voltage of the full-scale converter. Simulation results demonstrate the validity of the proposed method.","PeriodicalId":287461,"journal":{"name":"2008 43rd International Universities Power Engineering Conference","volume":"256 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":"114358762","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.2008.4651501
C. Genesi, P. Marannino, M. Montagna, I. Siviero, F. Zanellini
The problem of cross border interchange and of exchange capacity allocation has gained an increasing importance because of existing price gaps between the different countries and of limited exchange capacity. The European Transmission System Operators (ETSO) committee has issued a sequence of documents illustrating the guidelines for efficient and economic assignment of the available cross border capacity. An example of successful multi-market coordination is given by the trilateral market coupling system developed by the TSOs of France, Belgium and the Netherlands. The aim of the present paper is that of finding a procedure able to make results from market coupling as close as possible to those furnished by single electricity pool.
{"title":"A multilateral market coupling approach for the allocation of cross border transmission capacity","authors":"C. Genesi, P. Marannino, M. Montagna, I. Siviero, F. Zanellini","doi":"10.1109/UPEC.2008.4651501","DOIUrl":"https://doi.org/10.1109/UPEC.2008.4651501","url":null,"abstract":"The problem of cross border interchange and of exchange capacity allocation has gained an increasing importance because of existing price gaps between the different countries and of limited exchange capacity. The European Transmission System Operators (ETSO) committee has issued a sequence of documents illustrating the guidelines for efficient and economic assignment of the available cross border capacity. An example of successful multi-market coordination is given by the trilateral market coupling system developed by the TSOs of France, Belgium and the Netherlands. The aim of the present paper is that of finding a procedure able to make results from market coupling as close as possible to those furnished by single electricity pool.","PeriodicalId":287461,"journal":{"name":"2008 43rd International Universities Power Engineering Conference","volume":"42 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":"116216725","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.2008.4651598
Lasantha Gunaruwan Meegahapola, D. Flynn, T. Littler
This paper presents transient stability analysis for a power system with high wind penetration. The transient stability has been evaluated based on two stability criteria: rotor angle stability and voltage stability. A modified IEEE-14 bus system has been used as the main study network and simulations have been conducted at several wind power penetration levels, defined as a fraction of total system generation. A wide range of scenarios have been presented based on the wind farm voltage at the point of connection, i.e. low voltage (LV) distribution level and high voltage (HV) transmission level, and the type of wind generator technology, i.e. fixed speed induction generator (FSIG) and doubly-fed induction generator (DFIG).
{"title":"Transient stability analysis of a power system with high wind penetration","authors":"Lasantha Gunaruwan Meegahapola, D. Flynn, T. Littler","doi":"10.1109/UPEC.2008.4651598","DOIUrl":"https://doi.org/10.1109/UPEC.2008.4651598","url":null,"abstract":"This paper presents transient stability analysis for a power system with high wind penetration. The transient stability has been evaluated based on two stability criteria: rotor angle stability and voltage stability. A modified IEEE-14 bus system has been used as the main study network and simulations have been conducted at several wind power penetration levels, defined as a fraction of total system generation. A wide range of scenarios have been presented based on the wind farm voltage at the point of connection, i.e. low voltage (LV) distribution level and high voltage (HV) transmission level, and the type of wind generator technology, i.e. fixed speed induction generator (FSIG) and doubly-fed induction generator (DFIG).","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":"116222378","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.2008.4651651
G. Cvetkovski, L. Petkovska
In this paper a torque calculation of a permanent magnet DC commutator motor (PMDCCM) by using FEM data is performed. For the FEM calculation of the torque a 2D FEM magnetic field calculation, as very suitable for this type of geometry, is performed. Therefore a proper modelling of the motor is required. The method used for the torque calculation using FEM data is the Weighted Stress Tensor (WST) method. The necessary data for the calculation of the electromagnetic torque and the cogging torque is provided by calculating the magnetic vector potential for rated current load, as well as for no load for different rotor displacements. The values of the electromagnetic torque for rated load calculated by the weighted stress tensor method show good agreement compared to the measured ones.
{"title":"Torque evaluation of permanent magnet DC commutator motor using FEM data","authors":"G. Cvetkovski, L. Petkovska","doi":"10.1109/UPEC.2008.4651651","DOIUrl":"https://doi.org/10.1109/UPEC.2008.4651651","url":null,"abstract":"In this paper a torque calculation of a permanent magnet DC commutator motor (PMDCCM) by using FEM data is performed. For the FEM calculation of the torque a 2D FEM magnetic field calculation, as very suitable for this type of geometry, is performed. Therefore a proper modelling of the motor is required. The method used for the torque calculation using FEM data is the Weighted Stress Tensor (WST) method. The necessary data for the calculation of the electromagnetic torque and the cogging torque is provided by calculating the magnetic vector potential for rated current load, as well as for no load for different rotor displacements. The values of the electromagnetic torque for rated load calculated by the weighted stress tensor method show good agreement compared to the measured ones.","PeriodicalId":287461,"journal":{"name":"2008 43rd International Universities Power Engineering Conference","volume":"35 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":"127767588","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.2008.4651606
Iman Ziari, Alireza Jalilian
In this paper, a new ant colony system (ACS) based-method is proposed for the implementation of optimal harmonic power flow in power systems. In this algorithm, allocating and sizing of active power filters (APFs) are performed in order to minimize the voltage total harmonic distortion (VTHD) as well as total current injecting of the APFs. The VTHD limit standard is also satisfied as a constraint. The execution of proposed approach on a distorted 6-bus power system represents promising results.
{"title":"Optimal harmonic power flow using an ant colony system-based algorithm","authors":"Iman Ziari, Alireza Jalilian","doi":"10.1109/UPEC.2008.4651606","DOIUrl":"https://doi.org/10.1109/UPEC.2008.4651606","url":null,"abstract":"In this paper, a new ant colony system (ACS) based-method is proposed for the implementation of optimal harmonic power flow in power systems. In this algorithm, allocating and sizing of active power filters (APFs) are performed in order to minimize the voltage total harmonic distortion (VTHD) as well as total current injecting of the APFs. The VTHD limit standard is also satisfied as a constraint. The execution of proposed approach on a distorted 6-bus power system represents promising results.","PeriodicalId":287461,"journal":{"name":"2008 43rd International Universities Power Engineering Conference","volume":"104 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":"126369875","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.2008.4651468
Amir A. A. Eisa, K. Ramar
This paper presents a new method for the removal of decaying dc offset from current signals in digital protective devices. The method is based on the fact that a purely sinusoidal signal has a zero average over a full cycle or multiples of the full cycle of its fundamental frequency, whereas an exponential signal has a nonzero average over that same interval. A full cycle plus one sample of post fault data are required to calculate the parameters of the decaying dc offset in order to completely eliminate it from the current signal. Decaying dc offset removal is carried out before applying the current signal to the digital filter used for phasor estimation. The method has been tested by applying it to a fault current signal generated by computer simulation. Results obtained indicate that the method has greatly improved the performance of the full-cycle DFT algorithm. The new method can be applied in real time on digital protective devices because of its simplicity and computational efficiency.
{"title":"Removal of decaying DC offset in current signals for power system phasor estimation","authors":"Amir A. A. Eisa, K. Ramar","doi":"10.1109/UPEC.2008.4651468","DOIUrl":"https://doi.org/10.1109/UPEC.2008.4651468","url":null,"abstract":"This paper presents a new method for the removal of decaying dc offset from current signals in digital protective devices. The method is based on the fact that a purely sinusoidal signal has a zero average over a full cycle or multiples of the full cycle of its fundamental frequency, whereas an exponential signal has a nonzero average over that same interval. A full cycle plus one sample of post fault data are required to calculate the parameters of the decaying dc offset in order to completely eliminate it from the current signal. Decaying dc offset removal is carried out before applying the current signal to the digital filter used for phasor estimation. The method has been tested by applying it to a fault current signal generated by computer simulation. Results obtained indicate that the method has greatly improved the performance of the full-cycle DFT algorithm. The new method can be applied in real time on digital protective devices because of its simplicity and computational efficiency.","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":"130478866","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.2008.4651465
S. J. Kazempour, A. Yousefi, K. Zare, M. P. Moghaddam, M. Haghifam, G. Yousefi
This paper addresses the problem of optimal operation scheduling of an individual pumped-storage plant to participate in the energy and regulation markets simultaneously. The goal is achieving of the maximum expected profit when the plant participates in a day-ahead (DA) energy and regulation markets while all of the technical constraints are satisfied. This optimal operation scheduling problem is formulated and solved as a mixed integer programming (MIP) problem. Numerical results for a case study are discussed.
{"title":"A MIP-based optimal operation scheduling of pumped-storage plant in the energy and regulation markets","authors":"S. J. Kazempour, A. Yousefi, K. Zare, M. P. Moghaddam, M. Haghifam, G. Yousefi","doi":"10.1109/UPEC.2008.4651465","DOIUrl":"https://doi.org/10.1109/UPEC.2008.4651465","url":null,"abstract":"This paper addresses the problem of optimal operation scheduling of an individual pumped-storage plant to participate in the energy and regulation markets simultaneously. The goal is achieving of the maximum expected profit when the plant participates in a day-ahead (DA) energy and regulation markets while all of the technical constraints are satisfied. This optimal operation scheduling problem is formulated and solved as a mixed integer programming (MIP) problem. Numerical results for a case study are discussed.","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":"131026219","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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