Pub Date : 2014-12-29DOI: 10.1109/RTUCON.2014.6998221
L. Grigāns, A. Sokolovs, U. Sirmelis, Laura Dzelzkaleja
The authors present the results of experimental work on a small-power direct driven permanent magnet synchronous generator reactive power compensation comparison with two methods. Particular generator is targeted for small size wind power systems, and is tested on a wind turbine emulator that consists of an AC induction motor, a frequency converter and a torque feedback. Generator output power was measured with three different setups: AC-DC converter and a DC-DC boost converter; capacitor compensated AC-DC converter and a DC-DC boost converter; frequency converter with field oriented control of synchronous generators. Simulation and experimental results of generator output power and efficiency are obtained and analyzed at different generator speed values.
{"title":"Power capability and efficiency comparison of direct drive PMSG at different power control strategies","authors":"L. Grigāns, A. Sokolovs, U. Sirmelis, Laura Dzelzkaleja","doi":"10.1109/RTUCON.2014.6998221","DOIUrl":"https://doi.org/10.1109/RTUCON.2014.6998221","url":null,"abstract":"The authors present the results of experimental work on a small-power direct driven permanent magnet synchronous generator reactive power compensation comparison with two methods. Particular generator is targeted for small size wind power systems, and is tested on a wind turbine emulator that consists of an AC induction motor, a frequency converter and a torque feedback. Generator output power was measured with three different setups: AC-DC converter and a DC-DC boost converter; capacitor compensated AC-DC converter and a DC-DC boost converter; frequency converter with field oriented control of synchronous generators. Simulation and experimental results of generator output power and efficiency are obtained and analyzed at different generator speed values.","PeriodicalId":259790,"journal":{"name":"2014 55th International Scientific Conference on Power and Electrical Engineering of Riga Technical University (RTUCON)","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132736540","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 : 2014-12-29DOI: 10.1109/RTUCON.2014.6998197
O. Ruksans, I. Oleinikova, Rodika Prohorova
In this paper several factors affecting electricity prices in Baltics are analyzed. Electricity prices vary between countries and can vary even within a single region or part of the network in the same country. In modern electricity market the electricity prices are very volatile and can be affected by several factors. It is very important to understand those factors as much as possible in order to minimize the financial risk and negative impact from buying the electricity on the market.
{"title":"Analysis of factors that are affecting electricity prices in Baltic countries","authors":"O. Ruksans, I. Oleinikova, Rodika Prohorova","doi":"10.1109/RTUCON.2014.6998197","DOIUrl":"https://doi.org/10.1109/RTUCON.2014.6998197","url":null,"abstract":"In this paper several factors affecting electricity prices in Baltics are analyzed. Electricity prices vary between countries and can vary even within a single region or part of the network in the same country. In modern electricity market the electricity prices are very volatile and can be affected by several factors. It is very important to understand those factors as much as possible in order to minimize the financial risk and negative impact from buying the electricity on the market.","PeriodicalId":259790,"journal":{"name":"2014 55th International Scientific Conference on Power and Electrical Engineering of Riga Technical University (RTUCON)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132080647","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 : 2014-12-29DOI: 10.1109/RTUCON.2014.6998195
Armands Senfelds, Arturs Paugurs
An objective to control power flow in intermediate DC link of typical induction drive converter has been introduced and respective drive setup intended for such task. Theoretical considerations and simulation results of control approach utilizing available drive controller capabilities like direct torque control and speed control, as well as introduction of additional adaptive funnel type controller has been presented. Modifications of introduced adaptive control method have been presented and evaluated by simulation. Simulation results support proposed idea of DC link power flow control.
{"title":"Electrical drive DC link power flow control with adaptive approach","authors":"Armands Senfelds, Arturs Paugurs","doi":"10.1109/RTUCON.2014.6998195","DOIUrl":"https://doi.org/10.1109/RTUCON.2014.6998195","url":null,"abstract":"An objective to control power flow in intermediate DC link of typical induction drive converter has been introduced and respective drive setup intended for such task. Theoretical considerations and simulation results of control approach utilizing available drive controller capabilities like direct torque control and speed control, as well as introduction of additional adaptive funnel type controller has been presented. Modifications of introduced adaptive control method have been presented and evaluated by simulation. Simulation results support proposed idea of DC link power flow control.","PeriodicalId":259790,"journal":{"name":"2014 55th International Scientific Conference on Power and Electrical Engineering of Riga Technical University (RTUCON)","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130497460","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 : 2014-12-29DOI: 10.1109/RTUCON.2014.6998171
J. Survilo
To decide how to deliver electricity to cluster-like consumer, the cost of two options should be compared. In the first option, transformerless one, the cluster is connected by LV line (stem) to the central MV/LV transformer; if conductance of all conductors is the same, minimum annual cost is secured when current densities in stem and in cluster lines are equal. Cost minimization is made considering the derivative of curtailed costs observing that maximum voltage drop and current densities do not exceed admissible values. In the second option, MV/LV transformer located at the cluster is connected by MV stem to the center and cross-sections of the MV stem line and of the cluster lines are defined in a usual way. Most of the annual cost falls on the cluster transformer.
{"title":"Delivery of electricity to cluster-like consumers","authors":"J. Survilo","doi":"10.1109/RTUCON.2014.6998171","DOIUrl":"https://doi.org/10.1109/RTUCON.2014.6998171","url":null,"abstract":"To decide how to deliver electricity to cluster-like consumer, the cost of two options should be compared. In the first option, transformerless one, the cluster is connected by LV line (stem) to the central MV/LV transformer; if conductance of all conductors is the same, minimum annual cost is secured when current densities in stem and in cluster lines are equal. Cost minimization is made considering the derivative of curtailed costs observing that maximum voltage drop and current densities do not exceed admissible values. In the second option, MV/LV transformer located at the cluster is connected by MV stem to the center and cross-sections of the MV stem line and of the cluster lines are defined in a usual way. Most of the annual cost falls on the cluster transformer.","PeriodicalId":259790,"journal":{"name":"2014 55th International Scientific Conference on Power and Electrical Engineering of Riga Technical University (RTUCON)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131558615","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 : 2014-12-29DOI: 10.1109/RTUCON.2014.6998198
Y. Qiu, Min Zhang, Shuping Dang, Melanie Whitfield
Reactive power is an essential part of the power compared with active power. It is used to establish and sustain the magnetic field present in electrical equipment possessive of coils, such as transformers and electric machines. The reactive power consumption in large distribution networks can result in a huge reactive power flow, rising line current and a sub-nominal voltage. To avoid these negative impacts, an important technique called capacitive compensation is employed in most modern power systems and networks. However, the full spectrum of consequences resulting from using this technique is unclear since under some specific scenarios, it may switch to deliver a power factor that is far from unity. At the Bridgeford Street, Manchester, a monitoring system based on the cRIO platform has been installed in order to solve this problem. The research in this paper is to critically assess the performance of the capacitive compensation in the Bridgeford Street substation by processing the data which is sent by the cRIO monitoring system and to develop a control algorithm implemented into the cRIO using LabVIEW, a graphic programming language.
{"title":"Analytical methodology of smart grid-based capacitive compensation using cRIO cooperating with LabVIEW","authors":"Y. Qiu, Min Zhang, Shuping Dang, Melanie Whitfield","doi":"10.1109/RTUCON.2014.6998198","DOIUrl":"https://doi.org/10.1109/RTUCON.2014.6998198","url":null,"abstract":"Reactive power is an essential part of the power compared with active power. It is used to establish and sustain the magnetic field present in electrical equipment possessive of coils, such as transformers and electric machines. The reactive power consumption in large distribution networks can result in a huge reactive power flow, rising line current and a sub-nominal voltage. To avoid these negative impacts, an important technique called capacitive compensation is employed in most modern power systems and networks. However, the full spectrum of consequences resulting from using this technique is unclear since under some specific scenarios, it may switch to deliver a power factor that is far from unity. At the Bridgeford Street, Manchester, a monitoring system based on the cRIO platform has been installed in order to solve this problem. The research in this paper is to critically assess the performance of the capacitive compensation in the Bridgeford Street substation by processing the data which is sent by the cRIO monitoring system and to develop a control algorithm implemented into the cRIO using LabVIEW, a graphic programming language.","PeriodicalId":259790,"journal":{"name":"2014 55th International Scientific Conference on Power and Electrical Engineering of Riga Technical University (RTUCON)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129319836","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 : 2014-12-29DOI: 10.1109/RTUCON.2014.6998193
A. Kallaste, T. Vaimann, A. Kilk, A. Belahcen
This paper presents a comparative analysis between the energy efficiency of two wind generator designs. A hypothesis is presented that generators for wind applications should be designed based on their energy efficiency instead of rated efficiency. As wind generators are working with variable rotational speeds and power levels, resulting in changes in their electrical efficiency, there is a need for a method to define machine efficiency during the design process. Designing the generator based on the energy efficiency gives the opportunity to optimize the machine in a more effective way. Comparison between a slotless and a conventional directly driven wind turbine generator is given.
{"title":"Comparative analysis of wind generator energy efficiency based on machine design","authors":"A. Kallaste, T. Vaimann, A. Kilk, A. Belahcen","doi":"10.1109/RTUCON.2014.6998193","DOIUrl":"https://doi.org/10.1109/RTUCON.2014.6998193","url":null,"abstract":"This paper presents a comparative analysis between the energy efficiency of two wind generator designs. A hypothesis is presented that generators for wind applications should be designed based on their energy efficiency instead of rated efficiency. As wind generators are working with variable rotational speeds and power levels, resulting in changes in their electrical efficiency, there is a need for a method to define machine efficiency during the design process. Designing the generator based on the energy efficiency gives the opportunity to optimize the machine in a more effective way. Comparison between a slotless and a conventional directly driven wind turbine generator is given.","PeriodicalId":259790,"journal":{"name":"2014 55th International Scientific Conference on Power and Electrical Engineering of Riga Technical University (RTUCON)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126166222","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 : 2014-12-29DOI: 10.1109/RTUCON.2014.6998182
I. Zicmane, S. Kovalenko, Aleksejs Soboļevskis, A. Sauhats
The market economy dictates the terms of unification of the energy systems of the countries that leads to a change in number of interconnections, the increase of the transmitted power, and therefore, it is necessary to reconfigure the networks and, consequently, the recalculation of their normal modes, as well as the project assessment of static stability is required. Stability is an important constraint in power system operation and control. Power system stability is understood as the ability to regain an equilibrium state after being subjected to a physical disturbance. A key method among those of static stability analysis is the determination of system stability on the consideration of eigenvalues in steady state condition. This provides appropriate strategy to have a quick decision on the system's steady state behavior. The configuration of the electrical systems should be often changed in terms of market relations. The research is aimed to overcome the difficulties while dealing with the characteristic polynomial of a higher degree. Latvian power systems static stability is evaluated applying the methods of localization of the roots of the CP and isolines.
{"title":"Localization of the roots of the characteristic polynomial (CP) and isolines to analyze static stability","authors":"I. Zicmane, S. Kovalenko, Aleksejs Soboļevskis, A. Sauhats","doi":"10.1109/RTUCON.2014.6998182","DOIUrl":"https://doi.org/10.1109/RTUCON.2014.6998182","url":null,"abstract":"The market economy dictates the terms of unification of the energy systems of the countries that leads to a change in number of interconnections, the increase of the transmitted power, and therefore, it is necessary to reconfigure the networks and, consequently, the recalculation of their normal modes, as well as the project assessment of static stability is required. Stability is an important constraint in power system operation and control. Power system stability is understood as the ability to regain an equilibrium state after being subjected to a physical disturbance. A key method among those of static stability analysis is the determination of system stability on the consideration of eigenvalues in steady state condition. This provides appropriate strategy to have a quick decision on the system's steady state behavior. The configuration of the electrical systems should be often changed in terms of market relations. The research is aimed to overcome the difficulties while dealing with the characteristic polynomial of a higher degree. Latvian power systems static stability is evaluated applying the methods of localization of the roots of the CP and isolines.","PeriodicalId":259790,"journal":{"name":"2014 55th International Scientific Conference on Power and Electrical Engineering of Riga Technical University (RTUCON)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125872461","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 : 2014-12-29DOI: 10.1109/RTUCON.2014.6998181
L. Petrichenko, S. Guseva, N. Jankovskis
The paper focuses on the development strategies in Latvian largest city (Riga), analysis of its existing infrastructure and complex approach to formation of load density at city. Well-founded the future loads' definition on early stages of long-term planning and medium-term design is offered. The development process at districts and microdistricts of large city is mainly provided by growth of loads and according to load density. Reliable information about such an important parameter as load density can be used to help with the future loads of new districts, preliminary selection of loads' elements of electrical systems, installed powers of transformers and placement of new transformer substations (TS). In this paper the question of formation, determination and update of load density on different voltage levels in large city is presented.
{"title":"Load density formation in largest cities","authors":"L. Petrichenko, S. Guseva, N. Jankovskis","doi":"10.1109/RTUCON.2014.6998181","DOIUrl":"https://doi.org/10.1109/RTUCON.2014.6998181","url":null,"abstract":"The paper focuses on the development strategies in Latvian largest city (Riga), analysis of its existing infrastructure and complex approach to formation of load density at city. Well-founded the future loads' definition on early stages of long-term planning and medium-term design is offered. The development process at districts and microdistricts of large city is mainly provided by growth of loads and according to load density. Reliable information about such an important parameter as load density can be used to help with the future loads of new districts, preliminary selection of loads' elements of electrical systems, installed powers of transformers and placement of new transformer substations (TS). In this paper the question of formation, determination and update of load density on different voltage levels in large city is presented.","PeriodicalId":259790,"journal":{"name":"2014 55th International Scientific Conference on Power and Electrical Engineering of Riga Technical University (RTUCON)","volume":"153 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123086834","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 : 2014-12-29DOI: 10.1109/RTUCON.2014.6998172
N. Kunicina, A. Zabasta, K. Kondratjevs, A. Galkina
This article deals with a case study of application of wireless sensor networks for control of emergency situations in an automated manufacturing. The control design approach of manufacture, which is using as self-energy production solutions and municipal utility services, is discussed. The correlation of manufacturing processes with emergency situations in critical infrastructure is taken in the account. The development of novel methods of power supply control in critical infrastructure and its integration in autonomous manufacturing system are offered. The evaluation of system complex reliability and formal approach for power cut off emergencies impact on autonomous production line are proposed.
{"title":"Power-off alarming in control of small manufactures in rural regions","authors":"N. Kunicina, A. Zabasta, K. Kondratjevs, A. Galkina","doi":"10.1109/RTUCON.2014.6998172","DOIUrl":"https://doi.org/10.1109/RTUCON.2014.6998172","url":null,"abstract":"This article deals with a case study of application of wireless sensor networks for control of emergency situations in an automated manufacturing. The control design approach of manufacture, which is using as self-energy production solutions and municipal utility services, is discussed. The correlation of manufacturing processes with emergency situations in critical infrastructure is taken in the account. The development of novel methods of power supply control in critical infrastructure and its integration in autonomous manufacturing system are offered. The evaluation of system complex reliability and formal approach for power cut off emergencies impact on autonomous production line are proposed.","PeriodicalId":259790,"journal":{"name":"2014 55th International Scientific Conference on Power and Electrical Engineering of Riga Technical University (RTUCON)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133797338","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 : 2014-12-29DOI: 10.1109/RTUCON.2014.6998218
O. Linkevičs, A. Mahņitko, Karina Mjadjuta, M. Balodis
Liberalization and restructuring of power sector changes the task of power system control substantially. Efficient control of operating regimes becomes especially important in competitive markets. This paper provides a formulation of optimal control task, describes a simplified model for simulation of four different energy sources, consider a solution for optimization task in the numerical example and evaluates the impact of key parameters for selection of optimal regime. For determination of optimal solution, the following methods of mathematical programming are applied: dynamic programming - for efficient use of hydroelectric resources, linear programming - for optimization of other power plants and import. Utilization of mentioned methods guarantees the acquisition of global optimum.
{"title":"Modelling of wind, hydroelectric and thermal power plant coordinated dispatch in Latvian power system","authors":"O. Linkevičs, A. Mahņitko, Karina Mjadjuta, M. Balodis","doi":"10.1109/RTUCON.2014.6998218","DOIUrl":"https://doi.org/10.1109/RTUCON.2014.6998218","url":null,"abstract":"Liberalization and restructuring of power sector changes the task of power system control substantially. Efficient control of operating regimes becomes especially important in competitive markets. This paper provides a formulation of optimal control task, describes a simplified model for simulation of four different energy sources, consider a solution for optimization task in the numerical example and evaluates the impact of key parameters for selection of optimal regime. For determination of optimal solution, the following methods of mathematical programming are applied: dynamic programming - for efficient use of hydroelectric resources, linear programming - for optimization of other power plants and import. Utilization of mentioned methods guarantees the acquisition of global optimum.","PeriodicalId":259790,"journal":{"name":"2014 55th International Scientific Conference on Power and Electrical Engineering of Riga Technical University (RTUCON)","volume":"125 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122078026","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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