Jacek WAŃKOWICZ, Mariusz KRUPA
45th CIGRE General Session 2014. Activity of CIGRE and PKWSE
Presented is the organizational structure of CIGRE. Discussed is the course of the 45th General Session which took place in Paris on 24-29 Aug. 2014. There was a record number of 8500 participants attending the Session and 3235 delegates taking part in the conference. During six days of the Session 196 meetings of Study Committees and Working Groups took place and the technical exhibition attracted 240 firms (amongst which there was ZAPEL S.A., the world-renowned producer of ceramic and composite insulators from Poland) and more than 4600 guests. The Polish delegation consisted of 37 persons, and 4 lectures prepared by the PKWSE members were published in the Session materials. Apart from the substantive papers there was also prepared a report concerning PKWSE activities in the years 2012-2014.
Keywords: international electrical engineers organizations, CIGRE, PKWSE, 45th CIGRE General Session
Dariusz GURAZDOWSKI, Aleksander ZIELONKA
Rotating Electrical Machines – Study Committee A1
Discussed are articles concerning improvement and development of rotating machines constructions in the range of designing, production, operation and maintenance as well as of insulation materials, reliability of cooling systems and bearings. Attention is paid to changes enabling rising of the rated output of big generators. Shown is the impact of a client’s specification and the network’s operator requirements on the construction and costs against the background of economic analysis of a network operator’s requirements influence on decisions connected with a machine modernization or rising its rated output. Additionally, when presenting the analyses of machines’ failures, not only were determined the causes and preventive measures but also discussed was the process of inspection conducting with the use of specialized robots. Presented are the distributed generation electrical machines. Taken up are the problems of development of higher efficiency constructions with special referrring to production costs, operational problems, monitoring and diagnostics. Described is the impact of failures and network disturbances on machine designing and construction strategies.
Keywords: electrical machines, modern constructions, designing and production, operation and maintenance
Janusz OSADNIK
Transformers – Study Committee A2
A review of topics concerning transformers was made during the CIGRE session but a special attention was paid to the tasks and the role that phase shifting transformers play in the system. Discussed was Italian and Brasilian experience in this field. Due to high reliability and relatively low cost the phase shifting transformers are often used elements leading to improvement of energy transmission elasticity (FACTS) of EHV networks. The required high power with a concurrent wide angle control as well as transport limitations (load gauge) restrict building of single-module constructions so it becomes indispensable to divide power between two or even more units. The Terna company experience shows that the maximum transport load is about 320 tons that means the rated power of about 400-500 MVA. Another technological restriction requiring attention is the maximum current and switchable power of an under-load tap changer. If the wide angle control is needed one should apply a symetric TPS where the best solutions are the ones of dual core and double-module construction especially when we deal with a big throughput rating, that finally gives lower transport weight and the non-zero fault impedance even with the zero shift angle. The TPF connection point is of a key importance as it enables to control the load flow and avoid overpassings in local networks. TPF also improves a network reliability, earth fault factor and voltage quality in south regions of Rio de Janeiro and reduces the load of transformers installed in Jacarepaguá and Grajaú - the most important Rio de Janeiro power supply stations. It also raises the possibilities of energy transmission to the State of Rio de Janeiro and reduces losses on transmission lines.
Keywords: transformers in a power system, operation, new electro-insulating systems, transformer equipment
Sławomir SAMEK
High Voltage Equipment – Study Committee A3
Discussed are problems referring to a high voltage equipment meeting the changing power system requirements, lifetime management and ageing of this equipment as well as the influence of extreme working conditions on it. The 2014 CIGRE Session brought many interesting and totally new informations concerning the current state of the high voltage equipment development. Undoubtedly, it will take time before all these solutions appear in our Polish power system but, looking at the recent very fast development of transmission and distribution networks, it is already worthwhile to become interested in all these novelties to be able to successfully use them in the nearest future. Also, in a short time, we can expect the publishing by the Study Committee A3 - High Voltage Equipment of the results of works concerning i.a. such problems like internal arc simulations, current-carrying capacity tests, high voltage vacuum equipment, high voltage equipment ageing and technologies slowing down this process, influence of overloads on the high voltage equipment, non-conventional high voltage transformers with digital output, acceptance procedures of installations with controlled connecting and experience in cases of phase oppositions.
Keywords: power system, high voltage equipment, equipment lifetime management
Sławomir NOSKE
Insulated Cables – Study Committee B1
The activity of the B1 Study Committee (SC B1) includes all aspects of problems concerning the land and submarine AC/DC cable systems. In the range of SC B1works there are i.a. theoretical and practical problems connected with constructing and testing of cables and their accessories as well as issues referring to construction, installation and operation of cable lines. Included are also research and assessment problems as well as the ones concerning prognosing of high voltage cable line lifetime. The leading topics, according to which the papers prepared for the 2014 CIGRE General Session were accepted, were the newly installed or modernized cable systems, development trends of modern systems for assessment, testing and monitoring of cable lines as well as cable lines as a part of future networks.
Keywords: cable lines, constructing of cables and their accessories, installing and operation of cable lines
Piotr WOJCIECHOWSKI
Overhead Lines – Study Committee B2
Discussed are papers dedicated to overhead lines and concerning the increase of their acceptability, transmission capacity, reliability and accessability. Presented are possibilities of influencing the reduction of harmful effects on the environment during processes of designing (survey of line routes and their visual acceptation), construction and operation (meeting ecology requirements, reduction of lines’ influence on vegetation and natural environment management). Attention is paid to the experience gained during installation of cables on overhead lines and to the influence of various projects on a line initial and operational costs as well as to the influence of costs connected with environment, legal regulations and public opinion on total costs of a line construction. Finally, there was discussed a wide problem concerning cables including their installation and long-term efficiency, costs and methods of live line cable replacing and mechanical behaviour of cable harnesses’ new configurations as well as mastering problems like creep or material fatigue occurring in new type cables.
Keywords: overhead power lines, social acceptability of overhead lines, overhead line transmission capacity
Michał KOSMECKI
HVDC and Power Electronic – Study Committee B4
Rated parameters of power systems systematically grow e.g. in projects being under way now and concerning transmission HVDC systems (big powers, far distances) the voltage of the ±600 kV or ±800kV ranges has already become a standard while in the context of future projects the designers think even of ±1100kV. Among the rest of the lectures the prevailing ones were two inter-related issues – networks and DC circuit breakers. In both of these groups there are constructed and tested now the first demonstration installations that means a high interest in the issue and big expectations conncected with these solutions. A big part of the Session was dedicated to problems of DC networks that could link offshore wind farms with the land power systems. Discussed was the risk assessment concerning offshore wind farms investments but mainly the participants focused on financial and reliability aspects of the problem. The described task consisted in the analysis of three different topologies of networks connecting offshore wind farms with a land power system. Discussed was also module modeling of the VSC MMC type voltage converters in simulation programs reflecting the electromechanical states’ courses for a positive-sequence component.
Keywords: DC transmission systems, DC networks and circuit breakers, modeling of voltage converters
Marcin LIZER
Protection and Automation – Study Committee B5
The CIGRE Study Committee B5 focuses on problems concerning implementation of IEC 61850 standard in the power industry. As a matter of fact, this standard has already been existing for more than 10 years but only now it begins to play an increasingly important role. In the discussed papers the authors share their experience and observations gained during realization of pilot systems, then laboratory testing and finally network implementation. A big part of lectures is dedicated to the use of PMU devices in power engineering and presented are concepts of backup protection systems basing on these solutions. Such systems can especially serve to detect the loss of synchronism, load island separation and also to realize autonomic systems ensuring disturbance localization, its isolation and then a balanced network reconfiguration after removing the disturbance. Much attention was paid to the problem of cooperation of IED devices produced by various manufacturers, in the frames of one system of automation, control and protection realized according to the IEC 61850 standard. Ensuring the full cooperation is at the present moment rather difficult as a result of leaving too much room for this standard interpretation by producers. The authors show that the standard gives too much freedom in creating functional profiles of IED devices’ logic nodes that in turn leads to large differences between the IEDs of various producers. Achievement of better cooperation will only be able by further clarification of this standard as well as by elaboration of unified functional profiles and tools for configuration of these devices in the form of clear cutting off the IEDs’ functions from the equipment through which they are realized.
Keywords: electrical power systems, protection and automation, substation automation
Wojciech LUBICKI, Maksymilian PRZYGRODZKI
System Development and Economics – Study Committee C1
Attention is called to the fact that the key elements in the process of a transmission line development planning become renewable energy sources due to the widespread strive for greenhouse gas emission reduction [29]. The available renewable sources potential is big enough to fulfill the task to take part in the electric energy production but usually these sources are far away from consumer centres. That is why there emerge the ideas to integrate sources that are located in numerous regions including creation of DC submarine networks linked to various continental systems. Another issue is the installation of electric energy storages in the existing power systems as well as monitoring and control systems (e.g. phase shifters, FACTS and D-FACTS). In the case of phase shifters the attention is called to the need of coordination of their working parameters with the large integrated European system. And the fundamental challenge the transmission system operators face now is the integration of renewable sources with the system in such a way as to avoid the necessity of intensive development of a network infrastructure with the utilization time counted only in hours per year. Such expansion is neither rational not accepted by regulatory offices, investors and electric energy consumers. If it comes to development planning methodology the common standard are market simulations of future power generation and network analyses conducted with the use of load-flow calculations while for the economic efficiency assessment the alternative measures are used like the market surplus, the generation cost, the cost of outages/curtailments, the cost of the not-delivered energy and so on. All these elements are usually calculated in simulation processes taking into account the probability of such conditions occurrence and are mainly used in market analyses where, depending on the time perspective, the market is either reflected in an approximate (long-term strategic analyses) or a detailed way (for terms of several years ahead). An interesting solution are initiatives aimed at connecting the European system with networks of northern Africa and the Middle East countries. Benefits from such undertaking would be on both sides because of different structure and generation costs, great renewable sources potential and differences in peak load times. A process of such integration is physically possible but requiring great investment outlays and dividing them between different investors is an open case as well as further management of these international connections and eventual sharing of potential benefits.
Keywords: power system development, energy storage, system economics
Krzysztof MADAJEWSKI
System Operation and Control – Study Committee C2
Discussed were lectures concerning new problems that emerged in the area of a power system real-time operation and control with methods to solve them like analyses, monitoring and control (including voltage control, frequency control and angle stability) and also referring to the use of dynamic network capacity or system services (including the operating reserve). The second group of problems were interactions between transmission and distribution in the system operation process that meant interfaces like transmission, distribution and consumption together with running of the system and the energy market. These interactions also include operator trainings, awareness of operational problems existence, requirements related to modeling and data exchange, distributed generation controllability, short-circuit power management or demand response.
Keywords: electric power system, real-time system operation, system services, interactions transmission distribution
Maksymilian PRZYGRODZKI
System Technical Performance – Study Committee C4
Technical issues mentioned in this article and concerning power systems refer to conditions, parameters and behaviors of a power system work in transient and steady states. Among the presented methods and analytic tools there are also some current topics on the impact of new technologies on various aspects of the power industry, from transmission and distribution systems to distributed technologies and renewable sources. The considered problems focus on interactions between a power system and its subsystems and appliances as well as on cases of exposure to external influences. These problems are often the common ones for system operators not only in Europe but also in other countries. The continuous development of equipment, installations and production technologies defines new requirements and challenges for the future power system structures so one could say that the presented content is the trendsetter for the future research directions.
Keywords: electric power systems, methods and analytic tools, transient and steady states
Małgorzata BOBROWSKA-RAFAŁ, Grzegorz TOMASIK
Electricity Markets and Regulation – Study Committee C5
Two factors are the most decisive to electric enegy markets – one is the rapid development of new technologies, especially concerning renewable energy sources (RES) and energy storages, and the second is implementation of the DSR (Demand Side Response) mechanisms. They create not only the new business possibilities but also introduce considerable changes in the essence of electrical energy markets. The discussed articles refer to such main tendencies like energy market management (market models and development), integration between the demand and power supply and the energy market development as well as the integration of renewable energy sources from the energy market point of view. The period of RES prosperity has not been finished yet – new installations are built all the time and it significantly influences not only the principles of power network operation but also the aspects of energy markets. The energy storage technology which is a success factor for many RES is not yet so mature to be implemented as a standard to power systems – the works on this technology improvement and enhancing its cost-effectiveness are conducted constantly that will surely determine the success of these new market rules.
Keywords: electrical energy markets, RES technologies, demand control
Andrzej KĄKOL
Distribution Systems and Dispersed Generation – Study Committee C6
Presented is a group of lectures dedicated to problems referring to development and operation planning as well as the management of a distribution network operation with strong participation of dispersed generation. It is assumed here that the dispersed generation sources will be treated as active objects with the possibility of reactive power control while the active power control possibility will be limited as the primary energy sources are wind and sun. The unused wind and solar energy is irrecoverably lost. The ability of distributed sources to control the active power can be extended provided that energy storages are installed and their operational mode is adjusted to the current network conditions (charging and discharging). After adequate control algorithms have been applied such energy storages can be used for realization of functions unavailable to dispersed sources. A part of articles is dedicated to electric cars defining them as a new type of energy consuming objects which are characterized by high changeability both in time and space. The authors propose making use of electric cars as electric energy sources in such network conditions when it is necessary, taking into account stochastic behaviour of the car users. Observed is reduction of conventional generation share in a system energy balance due to the dispersed generation contribution into it. As the result, the abilities of conventional generation to provide system services become gradually limited so it is necessary to complement this gap with the use of developing dispersed generation sources.
Keywords: medium voltage distribution networks, dispersed generation, electric cars
Marek FLORKOWSKI
Materials and Emerging Test Techniques – Study Committee D1
Discussed were lectures dedicated to the problems of assessment and monitoring of new electrotechnical materials and modern research techniques of their operating properties, not forgetting about the fact that the problems concern both insulating and conducting materials. Apart from the properties of electrotechnical materials there were discussed problems referring to space and surface charges as well as to the potential distribution and operational hazards’ tests. Presented were also modern research techniques and diagnostic tools as well as the analysing and interpretation methods of testing results of transformation processes occurring in structures of electrotechnical materials exposed to electrical, heat, environmental and other hazards. Particular attention was paid to new research techniques used for condition assessment of the power industry facilities. Substantial space was also given to properties and applications of new materials including the environment-friendly superconductive ones and the ones for electric field shaping.
Keywords: research techniques, diagnostic tools, new electrotechnical materials
Tomasz SZUDEJKO
Information Systems and Telecommunication – Study Committee D2
Discussed were lectures concerning teleinformatic and telecommunication systems in the power sector. Presented was the creation process of an active protection system against threats to network security which key-element is the cybersecurity situation evaluation (CSSE). The CSSE includes mainly such functions like warnings (CSSAw), assessment (CSSAs) and prognosing of potential threats (CSSF) and it was built with the use of Ada-boosting algorithm. Presented are requirements ensuring proper integration of distributed energy sources with a distribution network and especially with the low-voltage one. Described is the low-voltage network characteristics as a telecommunication medium. Attention is paid to the importance of correctly functioning IT systems in the aspects of security automation and power system operation. Properly managed teleinformatics should increase the reliability of the whole power system functioning.
Keywords: informatic systems and telecommunication, new technologies, teleinformatic security