PRIORITIZATION OF REGIONAL TRANSMISSION NETWORK PROJECTS TO SUSTAIN GENERATION AND MARKET DEVELOPMENT IN SOUTH EAST EUROPE

Regija jugoistočne Europe (SEE) prolazi kroz kontinuirani proces promjena u djelatnostima proizvodnje, prijenosa i distribucije električne energije. Ove promjene se reflektiraju u svakoj državi najprije u vidu reorganizacije vertikalno integriranih elektroprivrednih kompanija, nakon čega slijedi funkcionalno razdvajanje prijenosa električne energije od proizvodnje i distribucije. Promjene u energetskom sektoru također imaju utjecaja na filozofiju planiranja proizvodne i prijenosne djelatnosti, posebno s obzirom na činjenicu da je većina zemalja jugoistočne Europe u tranziciji. U posljednjih nekoliko godina izrađene su brojne studije u cilju uspostave i harmonizacije zajedničkog regionalnog i šireg europskog tržišta električne energije. U ovom radu razmatra se interakcija između najvažnijih studija o proizvodnoj i prijenosnoj djelatnosti u regiji, a koje su predstavljene i o kojima se raspravljalo u nekoliko prilika na regionalnoj razini (Atenski forumi, konferencije, radionice, internetske stranice, itd). Glavni cilj tih studija bio je asistirati Europskoj Komisiji (EC), Svjetskoj banci (WB) i donorima pri utvrđivanju indikativne ljestvice prioriteta ulaganja u proizvodnju električne energije i financiranja odgovarajuće električne infrastrukture iz regionalne perspektive i u skladu s ciljevima tržišta električne energije u jugoistočnoj Europi. Uži cilj ovog rada je analiza regionalne prijenosne mreže za ispitane scenarije razvoja, a u skladu s informacijama i zaključcima iz ažurirane studije proizvodne djelatnosti (tzv. GIS studija [1 i [4]). Krajnji rezultat bi trebao biti ljestvica prioriteta novih interkonektivnih vodova u regiji nužnih za plasman proizvodnje električne energije iz novih objekata i održivost tržišta električne energije.The region of South East Europe (SEE) has been experiencing an ongoing process of changes in the energy sector in the areas of power generation, power transmission and power distribution. These changes are reflected in each country through reorganization of vertically integrated electric power utilities, followed by functional separation of transmission from generation and distribution. Changes in the energy sector have also affected the philosophy of generation and transmission planning since most of the SEE countries are transition countries. In order to establish and harmonize the common regional and the wider European electricity market, many study activities have been undertaken in the last few years. This paper deals with the interaction between the most important regional generation and transmission studies that were presented and discussed at different occasions at the regional level (Athens Fora, conferences, workshops, web sites etc.). The main aim of the studies was to assist the European Commission (EC), the World Bank (WB) and the donors in identifying the indicative priority list of investments in power generation and related electricity infrastructure from the regional perspective and in line with the objectives of SEE regional electricity market. The scope of work within this study was to analyze the transmission network for investigated scenarios and in accordance with the findings and conclusions from the updated GIS. The final result is supposed to be a list of new interconnection line priorities in the region necessary for new generation and future market sustainability

Multicriterial analyses and selection of the best option for revitalization and development of the southern part of Croatian 400 kV network and connection to the power system of Bosnia and Herzegovina

The southern wing of the Croatian transmission network was constructed for 220 kV in the early 1960’s, with additional 400 kV reinforcement at the end of 1970’s. Its route of more than 200 km is quite demanding due to extreme climate, environmental specifics and related costs. However, operational experience during more than 50 years has been quite positive. Nowadays, at the end of its lifetime it is again extremely important to analyze and select the best option for network revitalization and development to serve the network users for the next 50 years, but in very different conditions of technological development, more restrictive environmental requirements, electricity market conditions and large scale RES integration. Moreover, special attention should be given to the potential opportunity and need to use this revitalization also for new interconnection to the power system of Bosnia and Herzegovina (BiH). Altogether with its length of more than 380 km this is one of the largest transmission projects in South East Europe in the last few decades. This paper presents the main findings of the multicriterial and comprehensive study covering technical, economic, financial, geographical, environmental, social and legal assessment, identifying locations of new 400 kV transmission system nodes, internal and interconnection 400 kV lines routes, together with the potential upgrade/replacement of the existing 220 kV circuits. Network analyses have been prepared on more than 180 different scenarios using PSS/E software, while market analyses were completed for 21 selected scenarios using PLEXOS software. Scenarios were based on the following criteria/uncertainties related to the power systems of Croatia and BiH: 1. analyzed time-horizons (2023 and 2028) 2. demand growth (referent, low, high) 3. analyzed operation conditions (winter/summer peak/off peak load) 4. generation scenarios (high, low, new RES, CO2 prices) 5. hydrological and climate conditions (average, extreme hydrology and wind speed) 6. power balance (import, export) 7. power transits Five main options have been initially selected as topology candidates for problem resolving. Detailed methodology and criteria for the selection of optimal option (revitalization and development scenario and topology) were developed and approved by all involved stakeholders. For selected option, based on comprehensive analyses and approved methodology , for further detailed analyses ( system reliability, technical design, investment, economics /CBA/ and environmental analyses) have been prepared, including assessment of its impact on transmission tariffs of each country. Sensitivity analyses to the most uncertain variables (investment costs and CO2 prices) were also performed. The environmental and social assessment was very demanding due to the complex governance structure and three legal frameworks to be respected (two countries, along with two entities in BiH). The Project impact was evaluated with respect to: air quality, water quality, waste management, noise, biological diversity, electromagnetic field, social measures and protected areas. This paper presents above mentioned analyses, findings and recommendations, as the most comprehensive analytical approach to the transmission line development that’s ever been applied in this region

Implementation and Perspectives of Electricity Market

Od uvođenja tržišnih odnosa u elektroenergetski sektor u Europi prošlo je desetak godina. Imajući na umu činjenicu da je cjelokupna reforma elektroenergetskog sektora pokrenuta praktično bez ikakva prethodnog iskustva i bez unaprijed sagledivih problema koji se pritom mogu javiti, zanimljivo je nakon desetogodišnjeg iskustva sagledati koji su ciljevi ostvareni i u kojoj mjeri, koji su ostali popratni rezultati i koje su ukupne perspektive daljnje reforme tog, u kapitalnom smislu intenzivnog i za gospodarstvo svake zemlje iznimno važnog sektora. U ovom radu nastojalo se na objektivan način prikazati pozitivne, ali i nedostatne segmente razvoja tržišta električne energije u Europi te iznijeti neka otvorena pitanja koja će u znatnoj mjeri odrediti daljnji razvoj elektroenergetskog sektora.More than ten years have passed since the introduction of market relations in the electricity sector in Europe. Bearing in mind the fact that reform of electricity sector was initiated with practically no previous experience and without prior understanding of all the problems that could be encountered in the process, it will be interesting to see which goals and to what extent were realized, what are the accompanying results and total perspectives for further reform in this capitally-intensive sector, important for the economy of any country. The paper aims to show in an objective manner both positive and absent segments in the development of the electricity market in Europe and to present some open issues, which will significantly determine further development of the electricity sector

Uravnoteženje opterećenja razdjelnih mreža pomoću teorije neizrazitih skupova

Uravnotežavanje opterećenja transformatora i pojnih vodova smanjuje rizik od preopterećenja zbog čestih promjena opterećenja u razdjelnim mrežama. Na taj način se smanjuje učestalost i trajanje kvarova izazvanih preopterećenjem. U ovom radu se predstavlja metoda uravnotežavanja opterećenja u razdjelnim mrežama temeljena na teoriji neizrazitih skupova. Pri tom se istovremeno razmatra uravnotežavanje ukupnog opterećenja transformatora i pojnih vodova i simetriranje faznih opterećenja. Budući da je životni vijek sklopnih uređaja definiran ukupnim brojem provedenih sklapanja, postupak uravnotežavanja i simetriranja opterećenja je potrebno provesti uz minimalni broj sklapanja. U ovom radu je ukratko predstavljena i Aokijeva metoda uravnotežavanja opterećenja u razdjelnim mrežama koja se koristi u EES-u Japana, te se uspoređuje s predstavljenom metodom teorije neizrazitih skupova. Metoda teorije neizrazitih skupova primijenjena je na općenitom primjeru razdjelne mreže, kao i na dijelu 10 kV mreže grada Pule.Transformer load balancing and feeder load balancing are used to decrease the overload risk due to load changes. According to that fault frequency and duration are also decreased as an overload consequence. This thesis deals with distribution load balancing method based on fuzzy set theory. Thereby transformer load balancing, feeder load balancing and phase balancing are analysed simultaneously. Switchgear lifetime is defined by number of switching operations. So, load balancing should be performed by the minimum number of switching operations. Fuzzy set load balancing method is compared to the Aoki’s method that is also shortly presented in this work. Aoki’s method has been widely used in Japanese power system. Proposed fuzzy set load balancing method is presented on a general example and on part of 10 kV Pula city network

Uravnoteženje opterećenja razdjelnih mreža pomoću teorije neizrazitih skupova

Uravnotežavanje opterećenja transformatora i pojnih vodova smanjuje rizik od preopterećenja zbog čestih promjena opterećenja u razdjelnim mrežama. Na taj način se smanjuje učestalost i trajanje kvarova izazvanih preopterećenjem. U ovom radu se predstavlja metoda uravnotežavanja opterećenja u razdjelnim mrežama temeljena na teoriji neizrazitih skupova. Pri tom se istovremeno razmatra uravnotežavanje ukupnog opterećenja transformatora i pojnih vodova i simetriranje faznih opterećenja. Budući da je životni vijek sklopnih uređaja definiran ukupnim brojem provedenih sklapanja, postupak uravnotežavanja i simetriranja opterećenja je potrebno provesti uz minimalni broj sklapanja. U ovom radu je ukratko predstavljena i Aokijeva metoda uravnotežavanja opterećenja u razdjelnim mrežama koja se koristi u EES-u Japana, te se uspoređuje s predstavljenom metodom teorije neizrazitih skupova. Metoda teorije neizrazitih skupova primijenjena je na općenitom primjeru razdjelne mreže, kao i na dijelu 10 kV mreže grada Pule.Transformer load balancing and feeder load balancing are used to decrease the overload risk due to load changes. According to that fault frequency and duration are also decreased as an overload consequence. This thesis deals with distribution load balancing method based on fuzzy set theory. Thereby transformer load balancing, feeder load balancing and phase balancing are analysed simultaneously. Switchgear lifetime is defined by number of switching operations. So, load balancing should be performed by the minimum number of switching operations. Fuzzy set load balancing method is compared to the Aoki’s method that is also shortly presented in this work. Aoki’s method has been widely used in Japanese power system. Proposed fuzzy set load balancing method is presented on a general example and on part of 10 kV Pula city network

Uravnoteženje opterećenja razdjelnih mreža pomoću teorije neizrazitih skupova

Uravnotežavanje opterećenja transformatora i pojnih vodova smanjuje rizik od preopterećenja zbog čestih promjena opterećenja u razdjelnim mrežama. Na taj način se smanjuje učestalost i trajanje kvarova izazvanih preopterećenjem. U ovom radu se predstavlja metoda uravnotežavanja opterećenja u razdjelnim mrežama temeljena na teoriji neizrazitih skupova. Pri tom se istovremeno razmatra uravnotežavanje ukupnog opterećenja transformatora i pojnih vodova i simetriranje faznih opterećenja. Budući da je životni vijek sklopnih uređaja definiran ukupnim brojem provedenih sklapanja, postupak uravnotežavanja i simetriranja opterećenja je potrebno provesti uz minimalni broj sklapanja. U ovom radu je ukratko predstavljena i Aokijeva metoda uravnotežavanja opterećenja u razdjelnim mrežama koja se koristi u EES-u Japana, te se uspoređuje s predstavljenom metodom teorije neizrazitih skupova. Metoda teorije neizrazitih skupova primijenjena je na općenitom primjeru razdjelne mreže, kao i na dijelu 10 kV mreže grada Pule.Transformer load balancing and feeder load balancing are used to decrease the overload risk due to load changes. According to that fault frequency and duration are also decreased as an overload consequence. This thesis deals with distribution load balancing method based on fuzzy set theory. Thereby transformer load balancing, feeder load balancing and phase balancing are analysed simultaneously. Switchgear lifetime is defined by number of switching operations. So, load balancing should be performed by the minimum number of switching operations. Fuzzy set load balancing method is compared to the Aoki’s method that is also shortly presented in this work. Aoki’s method has been widely used in Japanese power system. Proposed fuzzy set load balancing method is presented on a general example and on part of 10 kV Pula city network

Implementation and Perspectives of Electricity Market

Od uvođenja tržišnih odnosa u elektroenergetski sektor u Europi prošlo je desetak godina. Imajući na umu činjenicu da je cjelokupna reforma elektroenergetskog sektora pokrenuta praktično bez ikakva prethodnog iskustva i bez unaprijed sagledivih problema koji se pritom mogu javiti, zanimljivo je nakon desetogodišnjeg iskustva sagledati koji su ciljevi ostvareni i u kojoj mjeri, koji su ostali popratni rezultati i koje su ukupne perspektive daljnje reforme tog, u kapitalnom smislu intenzivnog i za gospodarstvo svake zemlje iznimno važnog sektora. U ovom radu nastojalo se na objektivan način prikazati pozitivne, ali i nedostatne segmente razvoja tržišta električne energije u Europi te iznijeti neka otvorena pitanja koja će u znatnoj mjeri odrediti daljnji razvoj elektroenergetskog sektora.More than ten years have passed since the introduction of market relations in the electricity sector in Europe. Bearing in mind the fact that reform of electricity sector was initiated with practically no previous experience and without prior understanding of all the problems that could be encountered in the process, it will be interesting to see which goals and to what extent were realized, what are the accompanying results and total perspectives for further reform in this capitally-intensive sector, important for the economy of any country. The paper aims to show in an objective manner both positive and absent segments in the development of the electricity market in Europe and to present some open issues, which will significantly determine further development of the electricity sector

THE FEASIBILITY OF THE INTEGRATION OF WIND POWER PLANTS INTO THE ELECTRIC POWER SYSTEM OF THE REPUBLIC OF CROATIA

U članku se prezentiraju rezultati analiza provedenih radi određivanja mogućnosti prihvata proizvodnje vjetroelektrana u elektroenergetski sustav Republike Hrvatske i njihovog priključka na postojeću prijenosnu mrežu, koje su poslužile kao podloge HEP Operatoru prijenosnog sustava d.o.o. za postavljanje gornje veličine izgradnje vjetroelektrana u iznosu od 360 MW koje sustav u ovom trenutku može prihvatiti.This article presents the results of an analysis performed in order to determine the feasibility of integrating the generation of wind power plants into the electric power system of the Republic of Croatia and their connection to the existing transmission network, for the purpose of providing a basis for the HEP Transmission System Operator (HEP Operator prijenosnog sustava d.o.o.) to establish the upper limits for the construction of wind power plants of 360 MW, which the system is currently capable of integrating

Aspects Referring Wind Energy Integration from the Power System Point of View in the Region of Southeast Europe. Study Case of Romania

Wind energy integration is a complex target that could refer to different aspects such as: grid capacity; power system; support scheme; environmental; social issues; etc. It is probably the less predictable renewable energy sources (RES) due to its high volatility being difficult to be securely integrated into the power systems. This paper will focus on the wind energy integration from the power system point of view, emphasizing the case of Romania. Before going into the Romanian case, the paper analyzes the potential benefits of the regional approach in terms of power system integration, revealing that it can bring significant advantages by reducing the required power reserves or increasing wind power plants (WPP) generation. Currently, the power system integration is one of the major obstacle to large scale wind energy penetration in the region of Southeast (SE) Europe with high wind energy potential. The results of our research consist in proposing a model for estimating the balancing reserves sharing at regional level, comparing regional to country-by-country approach in terms of the power reserve requirements for balancing the operation of WPP. It definitely reveals that by regional Transmission System Operators (TSO) coordination; less reserves are needed; therefore, the space for RES enlarges. We also propose a model for Romanian power system that is able to calculate the installed power of WPP that could operate without considerable interruptions. Also, the model estimates the additional power reserves required for larger wind energy integration. This perspective can provide interesting insights on what should be foreseen as reasonable behavior of the policy makers and investors