The paper presents a controller for AC motor drives with frequency converters. It controls output frequency of the converter and in such a way-rotation speed of the motor according to the sensor signals to keep the given value of some parameter of the system, e.g. water pressure in water pump outlet, constant. The suggested controller is based on comparators and an operation amplifier. It can be used for rotation speed control of pumps and fans in heating, ventilating and air conditioning or in flow applications. The controller is simple, cheap and is user friendly.
{"title":"Rotation speed controller for AC motor drives with frequency converters","authors":"A. Baskya, V. Gobia","doi":"10.1109/PTC.1999.826526","DOIUrl":"https://doi.org/10.1109/PTC.1999.826526","url":null,"abstract":"The paper presents a controller for AC motor drives with frequency converters. It controls output frequency of the converter and in such a way-rotation speed of the motor according to the sensor signals to keep the given value of some parameter of the system, e.g. water pressure in water pump outlet, constant. The suggested controller is based on comparators and an operation amplifier. It can be used for rotation speed control of pumps and fans in heating, ventilating and air conditioning or in flow applications. The controller is simple, cheap and is user friendly.","PeriodicalId":101688,"journal":{"name":"PowerTech Budapest 99. Abstract Records. (Cat. No.99EX376)","volume":"20 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":"115268715","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}
D. Popović, D. Dobrijević, N. Mijuskovic, D.J. Vlaisuvijevic
The relevant methodological and practical aspects of steady-state security assessment of Yugoslav Power System are presented in this paper. This methodology consists of a procedure for forming the unified external network equivalents, procedure for fast contingency selection and simple method for the fast assessment of dynamic change of power system frequency. Full contingency analysis is based on a specially developed method, which enables successive solution of the load-flow problem for a set of characteristic post-dynamic quasi-stationary states. The characteristics of the developed methodology are tested on the example of the existing electric power interconnection in the Balkans.
{"title":"Methodological and practical aspects of steady-state security assessment of Yugoslav Power System","authors":"D. Popović, D. Dobrijević, N. Mijuskovic, D.J. Vlaisuvijevic","doi":"10.1109/PTC.1999.826627","DOIUrl":"https://doi.org/10.1109/PTC.1999.826627","url":null,"abstract":"The relevant methodological and practical aspects of steady-state security assessment of Yugoslav Power System are presented in this paper. This methodology consists of a procedure for forming the unified external network equivalents, procedure for fast contingency selection and simple method for the fast assessment of dynamic change of power system frequency. Full contingency analysis is based on a specially developed method, which enables successive solution of the load-flow problem for a set of characteristic post-dynamic quasi-stationary states. The characteristics of the developed methodology are tested on the example of the existing electric power interconnection in the Balkans.","PeriodicalId":101688,"journal":{"name":"PowerTech Budapest 99. Abstract Records. (Cat. No.99EX376)","volume":"1 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":"122978711","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 presents efficient shielding ways for minimizing the electric field at ground surfaces resulting from the three-phase double circuit high voltage transmission lines existing in Kuwait, and in turn reducing the amount of land required as rights-of-ways. The charge simulation method (CSM) is used for field computations. Shielding is offered by two different methods. The first method is by using a vertical grid and the other uses a horizontal grid consisting of a number of grounded wires. The effect of the grid design parameters is extensively studied. The two shielding methods are also applied to reduce the right-of-way widths of two 3-phase double circuits transmission lines running in parallel in Kuwait. Good results have been obtained and shielding grid design parameters have been recommended for those systems.
{"title":"Shielding design methods for Kuwait high voltage double circuits electrical networks","authors":"H. M. Ismail","doi":"10.1109/PTC.1999.826630","DOIUrl":"https://doi.org/10.1109/PTC.1999.826630","url":null,"abstract":"This paper presents efficient shielding ways for minimizing the electric field at ground surfaces resulting from the three-phase double circuit high voltage transmission lines existing in Kuwait, and in turn reducing the amount of land required as rights-of-ways. The charge simulation method (CSM) is used for field computations. Shielding is offered by two different methods. The first method is by using a vertical grid and the other uses a horizontal grid consisting of a number of grounded wires. The effect of the grid design parameters is extensively studied. The two shielding methods are also applied to reduce the right-of-way widths of two 3-phase double circuits transmission lines running in parallel in Kuwait. Good results have been obtained and shielding grid design parameters have been recommended for those systems.","PeriodicalId":101688,"journal":{"name":"PowerTech Budapest 99. Abstract Records. (Cat. No.99EX376)","volume":"56 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":"123624644","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 paper describes a methodology for the reduction of standing phase angle (SPA) difference between two buses during restoration operations of a power system. These angles may occur across a tie line, between two systems or between two connected subsystems within a system which may causes significant delay in power system restoration. They must be within SPA limits before an attempt is made to close breakers to firm up the bulk power transmission system. To arrive at the desired SPA difference between two buses, the modified contribution at generation/load buses have been evaluated based on sensitivity factors. This methodology acts as a direct help to reduce excessive SPA difference between two buses to an acceptable limit, which otherwise requires regulation of various generation levels on a trial and error basis.
{"title":"New approach to standing phase angle reduction for power system restoration","authors":"K. Ketabi, A. Ranjbar","doi":"10.1109/PTC.1999.826509","DOIUrl":"https://doi.org/10.1109/PTC.1999.826509","url":null,"abstract":"The paper describes a methodology for the reduction of standing phase angle (SPA) difference between two buses during restoration operations of a power system. These angles may occur across a tie line, between two systems or between two connected subsystems within a system which may causes significant delay in power system restoration. They must be within SPA limits before an attempt is made to close breakers to firm up the bulk power transmission system. To arrive at the desired SPA difference between two buses, the modified contribution at generation/load buses have been evaluated based on sensitivity factors. This methodology acts as a direct help to reduce excessive SPA difference between two buses to an acceptable limit, which otherwise requires regulation of various generation levels on a trial and error basis.","PeriodicalId":101688,"journal":{"name":"PowerTech Budapest 99. Abstract Records. (Cat. No.99EX376)","volume":"26 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":"121728701","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}
M. S. Rodrigues, J. Souza, M. Do Coutto Filho, M. Schilling
Summary form only given. This paper presents a method for power systems automatic contingency selection and static security evaluation. It is possible to identify potentially harmful contingencies in a very short computational time, being the risk of false alarms and contingency misses. The method is tested for many different operating conditions and simulated with the IEEE 24 bus test system. Classification rates for contingency selection and static security evaluation are also provided.
{"title":"Automatic contingency selection based on a pattern analysis approach","authors":"M. S. Rodrigues, J. Souza, M. Do Coutto Filho, M. Schilling","doi":"10.1109/PTC.1999.826611","DOIUrl":"https://doi.org/10.1109/PTC.1999.826611","url":null,"abstract":"Summary form only given. This paper presents a method for power systems automatic contingency selection and static security evaluation. It is possible to identify potentially harmful contingencies in a very short computational time, being the risk of false alarms and contingency misses. The method is tested for many different operating conditions and simulated with the IEEE 24 bus test system. Classification rates for contingency selection and static security evaluation are also provided.","PeriodicalId":101688,"journal":{"name":"PowerTech Budapest 99. Abstract Records. (Cat. No.99EX376)","volume":"67 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":"121408442","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}
P. Georgilakis, N. Hatziargyriou, D. Paparigas, J. Bakopoulos
A new approach using neural networks and genetic algorithms to solve the transformer iron loss reduction problem is proposed in this paper. Neural networks are used to predict iron losses of wound core distribution transformers at the early stages of transformer construction. Moreover, genetic algorithms are combined with neural networks in order to improve the grouping process of the individual cores by reducing iron losses of assembled transformers. Results from the application of the proposed method on a transformer industry demonstrate the feasibility and practicality of this approach.
{"title":"On-line combined use of neural networks and genetic algorithms to the solution of transformer iron loss reduction problem","authors":"P. Georgilakis, N. Hatziargyriou, D. Paparigas, J. Bakopoulos","doi":"10.1109/PTC.1999.826586","DOIUrl":"https://doi.org/10.1109/PTC.1999.826586","url":null,"abstract":"A new approach using neural networks and genetic algorithms to solve the transformer iron loss reduction problem is proposed in this paper. Neural networks are used to predict iron losses of wound core distribution transformers at the early stages of transformer construction. Moreover, genetic algorithms are combined with neural networks in order to improve the grouping process of the individual cores by reducing iron losses of assembled transformers. Results from the application of the proposed method on a transformer industry demonstrate the feasibility and practicality of this approach.","PeriodicalId":101688,"journal":{"name":"PowerTech Budapest 99. Abstract Records. (Cat. No.99EX376)","volume":"86 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":"122677419","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}
With an actual thyristor controlled series capacitor (TCSC) in Northeast China's Yi-Feng 500 kV UHV transmission system as engineering background, this paper deals with the realization of such a compensation device in a dynamic simulation laboratory. Emphasis is laid on the TCSC controllers. Based on response time and different requirements of the power system, TCSC controllers are divided into three parts-bottom control for mitigating synchronous resonance (SSR), middle control for adjusting power flow and upper control for enhancing power system transient stability. The dynamic simulation results show that they work in a coordinated fashion. Finally, the ANN-based /spl alpha/-th order inverse system controller, used in upper control, is introduced and studied by dynamic simulation for the first time to enhance transient stability. Simulation results show that this new controller has much better operating features than conventional ones, such as of PID controllers, etc.
{"title":"Dynamic simulator of thyristor controlled series capacitor in a UHV transmission system","authors":"Y. Tang, H.F. Wang, A. Johns, H. Chen, N.H. Li","doi":"10.1109/PTC.1999.826697","DOIUrl":"https://doi.org/10.1109/PTC.1999.826697","url":null,"abstract":"With an actual thyristor controlled series capacitor (TCSC) in Northeast China's Yi-Feng 500 kV UHV transmission system as engineering background, this paper deals with the realization of such a compensation device in a dynamic simulation laboratory. Emphasis is laid on the TCSC controllers. Based on response time and different requirements of the power system, TCSC controllers are divided into three parts-bottom control for mitigating synchronous resonance (SSR), middle control for adjusting power flow and upper control for enhancing power system transient stability. The dynamic simulation results show that they work in a coordinated fashion. Finally, the ANN-based /spl alpha/-th order inverse system controller, used in upper control, is introduced and studied by dynamic simulation for the first time to enhance transient stability. Simulation results show that this new controller has much better operating features than conventional ones, such as of PID controllers, etc.","PeriodicalId":101688,"journal":{"name":"PowerTech Budapest 99. Abstract Records. (Cat. No.99EX376)","volume":"32 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":"125564184","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}
Approaches to developing a virtual environment for design and study of complex electromagnetic systems are presented. Development results of decision making methods, mathematical simulation of electric machines and devices, and numerical methods of nonlinear electromagnetic field problem solving are reflected in this paper.
{"title":"Virtual Design Studio: new approach to computer aided design of power electromagnetic devices","authors":"H. Terzyan, A. Mkrtchyan","doi":"10.1109/PTC.1999.826520","DOIUrl":"https://doi.org/10.1109/PTC.1999.826520","url":null,"abstract":"Approaches to developing a virtual environment for design and study of complex electromagnetic systems are presented. Development results of decision making methods, mathematical simulation of electric machines and devices, and numerical methods of nonlinear electromagnetic field problem solving are reflected in this paper.","PeriodicalId":101688,"journal":{"name":"PowerTech Budapest 99. Abstract Records. (Cat. No.99EX376)","volume":"117 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":"125758597","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. This paper presents the adjustable speed hydro (ASH) machine concept as an alternative for obtaining better utilisation of power networks. Transmission lines appearing as bottlenecks with respect to power demand may increase their transfer capacity as ASH machines are introduced in the network. This is achieved by a quick and precise regulation of rotor currents and thereby active and reactive power out of the machine. During faults in the network, these properties map be utilised to maintain near constant power production and torque equilibrium. This in turn gives less speed deviation and better ability to control the network behaviour. Hence, the ASH machine can give a considerable contribution to the network both during and after serious conditions in the power system.
{"title":"Assessing the benefits of adjustable speed hydro machines","authors":"T. Gjengedal, J. Gjerde, R. Sporild","doi":"10.1109/PTC.1999.826536","DOIUrl":"https://doi.org/10.1109/PTC.1999.826536","url":null,"abstract":"Summary form only given. This paper presents the adjustable speed hydro (ASH) machine concept as an alternative for obtaining better utilisation of power networks. Transmission lines appearing as bottlenecks with respect to power demand may increase their transfer capacity as ASH machines are introduced in the network. This is achieved by a quick and precise regulation of rotor currents and thereby active and reactive power out of the machine. During faults in the network, these properties map be utilised to maintain near constant power production and torque equilibrium. This in turn gives less speed deviation and better ability to control the network behaviour. Hence, the ASH machine can give a considerable contribution to the network both during and after serious conditions in the power system.","PeriodicalId":101688,"journal":{"name":"PowerTech Budapest 99. Abstract Records. (Cat. No.99EX376)","volume":"66 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":"129243540","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 examines the impact of a thyristor controlled series capacitor (TCSC) on power system reliability. In this application, the TCSC is employed to adjust the natural power sharing of two different parallel transmission lines and, therefore, enable the maximum transmission capacity to be utilized. The improvement is measured using the two reliability risk indices of loss of load expectation (LOLE) and loss of energy expectation (LOEE).
{"title":"Impact of thyristor controlled series capacitor on power system reliability","authors":"S. Faried, R. Billinton, M. Fotuhi‐Firuzabad","doi":"10.1109/PTC.1999.826582","DOIUrl":"https://doi.org/10.1109/PTC.1999.826582","url":null,"abstract":"This paper examines the impact of a thyristor controlled series capacitor (TCSC) on power system reliability. In this application, the TCSC is employed to adjust the natural power sharing of two different parallel transmission lines and, therefore, enable the maximum transmission capacity to be utilized. The improvement is measured using the two reliability risk indices of loss of load expectation (LOLE) and loss of energy expectation (LOEE).","PeriodicalId":101688,"journal":{"name":"PowerTech Budapest 99. Abstract Records. (Cat. No.99EX376)","volume":"57 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":"128654791","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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