Assessing Terrorist Threats For Energy Infrastructure By Combining Historical Data And Expert Judgments

Energy systems are relatively attractive targets for terrorist attacks and should be adequately protected. The quantitative risk analysis (QRA), with the threat assessment as one of its standard components, is considered to be a promising methodological framework for optimizing such protection. This paper presents the results of the research which consisted of two parts. In the first part the statistical analysis of the terrorist attacks towards energy systems was performed. The input data were derived from the Global Terrorism Database (GTD). Within the analysis relative contributions of the attacks on energy systems to the total number of attacks were determined. Also, it was examined how those contributions are influenced by various factors related to the characteristics of the target, terrorist group and the environment in which the group operates. In the second part of the research the method for the quantitative threat assessment was developed. It is based on the results of the performed statistical analysis (i.e. on historical data) and on expert judgments. The method is applicable to the electricity, gas and oil sectors. The implementation of the Bayesian networks allows for taking the uncertainties into consideration, as well as for easy modifying and updating

THE CRITERIA AND METHOD OF DEFINING PRIORITIES FOR THE REVITALIZATION OF THE TRANSMISSION NETWORK

U radu se razmatra problematika starenja jedinica prijenosne mreže i utjecaja starenja na pouzdanost elektroenergetskog sustava, te su postavljeni kriteriji i metodologija za izradu liste prioriteta za revitalizaciju vodova i transformatora u prijenosnim elektroenergetskim mrežama. Kriteriji za revitalizaciju temelje se na stvarnom stanju jedinice, te ulozi i važnosti jedinice unutar elektroenergetskog sustava. Probabilističkim simulacijama rada sustava i mult-iscenarijskom analizom izračunavaju se očekivani godišnji operativni troškovi rada sustava, a na temelju razlike tih troškova pri različitim razinama neraspoloživosti promatranih jedinica kvantificiraju se pojedini kriteriji ovisni o ulozi i važnosti jedinica, te se izračunava indeks važnosti kandidata za revitalizaciju. Na temelju tog indeksa, te indeksa stanja pojedinačnih kandidata za revitalizaciju, izrađuje se jedinstvena lista prioriteta vodova i transformatora za revitalizaciju.The work examines the problem of the aging of transmission network units and the impact of it on the reliability of the electric power system (EPS). The criteria and methodology are defined for compiling a priority list for the revitalization of lines and transformers in transmission networks. The criteria are based on the real condition of a unit and the role and relevancy of the unit within the EPS. Through a probabilistic simulation and a multi-scenario analysis the expected annual operating costs of the system are calculated. Based on the difference of these costs at different unavailability levels of the observed units, the individual criteria, which are dependent on the role and relevance of the observed unit, are quantified and the significance index of the revitalization candidates is calculated. Based on that index, and the condition index of individual revitalization candidates, a single priority list of lines and transformers for revitalization is compiled

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

Izračun uzemljivačkih učinaka golih vodiča položenih uzduž višestrukih podzemnih kabelskih vodova korištenjem analitičkih jednadžbi

This paper presents a mathematical model to determine the fault current and voltage distribution in power cable screening conductors and bare earthing wires laid in parallel in the same cable trench. The analytical expressions for voltages and currents are derived by solving a set of differential equations. They are based on the assumption of uniformly distributed self and mutual conductances to ground of earthing wires. The earthing system under consideration includes also impedances of two adjacent substation groundings on which the earthing wires and cable screens terminate.The proposed mathematical model also takes into account mutual inductive couplings between all conductors in the trench (phases, cable screens and bare earthing wires). Particularly, in the case of a single-circuit cable line with an earthing conductor in trench, a set of generalized equations for currents and voltages along the related neutral conductors are derived in detail. An illustrative and practical example is presented too.U članku je predstavljen matematički model određivanja raspodjele struje kvara i potencijala u vodičima električne zaštite energetskih kabela i u golim uzemljivačkim užetima paralelno položenim u istom kabelskom rovu. Analitički izrazi za napone i struje su dobiveni rješavajući sustav diferencijalnih jednadžbi. Oni su temeljeni na pretpostavci o jednolikoj raspodjeli vlastite i međusobnih dozemnih konduktancija uzemljivačkih užeta. Razmatrani uzemljivački sustav uključuje također i impedancije uzemljenja dviju pridruženih transformatorskih stanica na kojima završavaju krajevi uzemljivačkih užeta i kabelskih električnih zaslona. Predloženi matematički model također uzima u obzir induktivne sprege između svih vodiča u kabelskom rovu (faznih, električnih zaštita i golih uzemljivačkih užeta). Posebno su za slučaj jednostrukog kabelskog voda s jednim uzemljivačkim užetom detaljno izvedeni opći izrazi za izračun struja i napona duž neutralnih vodiča u kabelskom rovu. Predstavljen je također i jedan ilustrativan i praktičan primjer izračuna

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

Impact of Adriatic submarine HVDC cables to South East European Electricity Market Perspectives

The ultimate goal in today’s electricity business in Europe is market integration on pan-European level that will introduce transparency and competition between market players, incentives to clean energy development, as well as high quality of supply to the end-customers. To achieve these goals, in South-East Europe (SEE) there are number of barriers and uncertainties, one of which is linked with the possible new undersea HVDC connections between SEE and Italy. With the support of the United States Agency for International Development (USAID) and coordination of the United States Energy Association (USEA), within the framework of the Southeast Europe Transmission System Planning Project (SECI), a detailed analysis has been accomplished on the impact of one or more undersea HVDC cables between Italy and SEE on power system operation and electricity market development [1]. Special emphasis to this analysis is given by the fact that SECI has been one of the longest running projects in the region. It started in 2001 with active participation of all regional TSOs, including continuous updating of power system and electricity market models and its harmonization of constant changes in power system planning. It is of utmost importance in the environment of constant changes of national power system development plans and needed further steps for full market opening and integration in the region. SEE power systems and market1 were modelled using the most relevant power system and market simulation and optimization softwares. Both system and market comprehensive models have been verified by all SEE TSOs. Study analyses were divided in two parts: 1) market analysis and 2) network analysis. The market study investigated expected generation pattern, power exchanges and wholesale prices in SEE, taking into account regional market synergy, the new links with Italy, and high level of RES integration. Bulgaria and Romania are currently the main exporters in SEE. Significant power exchanges in the North-South/Southeast direction are related to the fact that the GR, MK, ME, HR and AL are mainly importing, plus the influence of Italy importing over new potential HVDC cable(s). Network analysis dealt with power flows, network bottlenecks and voltage profiles in given market scenarios. Finally, the results of this comprehensive market simulation comprised of the following: • Countries electricity balance (production, consumption and exchanges) • Electricity prices for each country • Cross-border power exchanges (MWh/h) for each border in the region on hourly basis • HVDC link loadings (MWh/h) for each HVDC submarine cable on hourly basis • Location and frequency of market congestions in SEE (NTCs full between areas with price difference) All those analyses have been performed in two different transmission network development scenarios: • Base case scenario: with planned HVDC ME-IT • Alternative scenario: with planned HVDC ME-IT, and HVDC HR-IT, and HVDC AL-IT In this way one of the most important uncertainties (new HVDC links SEE – Italy) for future power system and market operation in SEE, have been evaluated both in technical and market sense, using the most relevant inputs and model

UKLAPANJE NOVIH KOMBINIRANIH PLINSKO-PARNIH ELEKTRANA (KTE) U ELEKTROENERGETSKI SUSTAV (PRIJENOSNU MREŽU) REPUBLIKE HRVATSKE

U članku se prikazuju rezultati studija uklapanja novih kombi elektrana (KTE) u elektroenergetski sustav, odnosno prijenosnu mrežu Republike Hrvatske. Izgradnja novih kombi plinsko-parnih proizvodnih postrojenja aktualizirana je nakon izrade Master plana 1998. godine (noveliran 2001. godine) radi diversifikacije proizvodnje s obzirom na korištena goriva te ispunjavanja ekoloških i ekonomskih zahtjeva u proizvodnji električne energije. Tvrtka HEP-Proizvodnja posljednjih nekoliko godina obavlja pripremne aktivnosti na izgradnji nekoliko takvih proizvodnih postrojenja, a u sklopu tih aktivnosti određivana su i rješenja priključaka istih na visokonaponsku mrežu

Ekonomsko-tehnički pristup planiranju razvoja prijenosne mreže

U radu je izložen ekonomsko-tehnički pristup planiranju razvoja prijenosne mreže koji se zasniva na dva modela: Mexico metodi za procjenu godišnjih operativnih troškova rada elektroenergetskog sustava i očekivanog iznosa neisporučene električne energije, te modela izmjeničnih tokova snaga za određivanje naponskog profila i opterećenja vodiča u mreži za definiranu potrošnju i angažman elektrana u EES-u. Za postojeću konfiguraciju prijenosne mreže izračunavaju se godišnji operativni troškovi rada EES koji se sastoje od troškova proizvodnje elektrana i očekivanih troškova neisporučene električne energije. Određuju se slabije grane u mreži, te se ispituje profitabilnost novih grana - kandidata za pojačanje mreže. U ekonomski optimalnu konfiguraciju prijenosne mreže za promatrani vremenski presjek uključuju se samo one grane čija je izgradnja ekonomski opravdana. Tehničke analize se provode radi provjere naponskog profila u mreži i određivanja potrebe ugradnje kompenzacijskih uređaja, prijelazne i dinamičke stabilnosti sustava, razine struja kratkih spojeva i ostalih tehničkih pokazatelja pogona prijenosne mreže. U radu su prikazani rezultati opisanog pristupa na planiranje razvoja prijenosne mreže na test modelu EES-a.This book deals with transmission network planning approach based on the economical and technical calculations and two models: Mexico model for annual operational costs and unsupplied electrical energy costs estimation, and AC power flow model for voltage profile and lines loading calculation for defined power system state. For the present configuration of the electric power system, annual operational costs, which include fuel costs and unsupplied electrical energy costs, are calculated. Weak parts of transmission network are detected, and the profitability of new lines or transformers is estimated. Only economically acceptable new lines are included in a network configuration for the studied year. Technical calculations are done to optimise a voltage profile on the economically acceptable network, and to point on the nodes where condensers or reactors should be installed, to determine power system transient and small signal stability, short circuit, and to examine other technical aspects of transmission network operation. Results of the economical and technical approach to the power system test model planning are given

Ekonomsko-tehnički pristup planiranju razvoja prijenosne mreže

U radu je izložen ekonomsko-tehnički pristup planiranju razvoja prijenosne mreže koji se zasniva na dva modela: Mexico metodi za procjenu godišnjih operativnih troškova rada elektroenergetskog sustava i očekivanog iznosa neisporučene električne energije, te modela izmjeničnih tokova snaga za određivanje naponskog profila i opterećenja vodiča u mreži za definiranu potrošnju i angažman elektrana u EES-u. Za postojeću konfiguraciju prijenosne mreže izračunavaju se godišnji operativni troškovi rada EES koji se sastoje od troškova proizvodnje elektrana i očekivanih troškova neisporučene električne energije. Određuju se slabije grane u mreži, te se ispituje profitabilnost novih grana - kandidata za pojačanje mreže. U ekonomski optimalnu konfiguraciju prijenosne mreže za promatrani vremenski presjek uključuju se samo one grane čija je izgradnja ekonomski opravdana. Tehničke analize se provode radi provjere naponskog profila u mreži i određivanja potrebe ugradnje kompenzacijskih uređaja, prijelazne i dinamičke stabilnosti sustava, razine struja kratkih spojeva i ostalih tehničkih pokazatelja pogona prijenosne mreže. U radu su prikazani rezultati opisanog pristupa na planiranje razvoja prijenosne mreže na test modelu EES-a.This book deals with transmission network planning approach based on the economical and technical calculations and two models: Mexico model for annual operational costs and unsupplied electrical energy costs estimation, and AC power flow model for voltage profile and lines loading calculation for defined power system state. For the present configuration of the electric power system, annual operational costs, which include fuel costs and unsupplied electrical energy costs, are calculated. Weak parts of transmission network are detected, and the profitability of new lines or transformers is estimated. Only economically acceptable new lines are included in a network configuration for the studied year. Technical calculations are done to optimise a voltage profile on the economically acceptable network, and to point on the nodes where condensers or reactors should be installed, to determine power system transient and small signal stability, short circuit, and to examine other technical aspects of transmission network operation. Results of the economical and technical approach to the power system test model planning are given

Ekonomsko-tehnički pristup planiranju razvoja prijenosne mreže

U radu je izložen ekonomsko-tehnički pristup planiranju razvoja prijenosne mreže koji se zasniva na dva modela: Mexico metodi za procjenu godišnjih operativnih troškova rada elektroenergetskog sustava i očekivanog iznosa neisporučene električne energije, te modela izmjeničnih tokova snaga za određivanje naponskog profila i opterećenja vodiča u mreži za definiranu potrošnju i angažman elektrana u EES-u. Za postojeću konfiguraciju prijenosne mreže izračunavaju se godišnji operativni troškovi rada EES koji se sastoje od troškova proizvodnje elektrana i očekivanih troškova neisporučene električne energije. Određuju se slabije grane u mreži, te se ispituje profitabilnost novih grana - kandidata za pojačanje mreže. U ekonomski optimalnu konfiguraciju prijenosne mreže za promatrani vremenski presjek uključuju se samo one grane čija je izgradnja ekonomski opravdana. Tehničke analize se provode radi provjere naponskog profila u mreži i određivanja potrebe ugradnje kompenzacijskih uređaja, prijelazne i dinamičke stabilnosti sustava, razine struja kratkih spojeva i ostalih tehničkih pokazatelja pogona prijenosne mreže. U radu su prikazani rezultati opisanog pristupa na planiranje razvoja prijenosne mreže na test modelu EES-a.This book deals with transmission network planning approach based on the economical and technical calculations and two models: Mexico model for annual operational costs and unsupplied electrical energy costs estimation, and AC power flow model for voltage profile and lines loading calculation for defined power system state. For the present configuration of the electric power system, annual operational costs, which include fuel costs and unsupplied electrical energy costs, are calculated. Weak parts of transmission network are detected, and the profitability of new lines or transformers is estimated. Only economically acceptable new lines are included in a network configuration for the studied year. Technical calculations are done to optimise a voltage profile on the economically acceptable network, and to point on the nodes where condensers or reactors should be installed, to determine power system transient and small signal stability, short circuit, and to examine other technical aspects of transmission network operation. Results of the economical and technical approach to the power system test model planning are given