ACROSS&BORDERS&*&HVDC&SYSTEMS&AND&MARKET&INTEGRATION& 2.2 General System Planning

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1 PAPER C General System Planning Transmission expansion planning challenges associated to Belo Monte Power Plant s HVDC links M. V. G. da S. Farinha, M. de F. de C. Gama, T. de F. R. D. Martins Brazil LundSymposium27/28May,2015 INTRODUCTION The Brazilian electric system is characterized by its continental dimension and by the predominance of hydroelectric generation with a strong seasonal influence. Associated to this extensive transmission system, Brazil has a generation park whose actual installed capacity exceeds 130GW and is composed mainly of hydropower plants (about 70). Madeira Tapajós 4300km Belo Monte 4100km! Hydropower installed capacity is expected to increase 24GW from ! 13GW only in the North Region.! Environmental restrictions lead to run-of-the-river projects.! Main load centers are located far away. (>2000km). Load Centers LundSymposium27/28May,2015 2

2 BRAZILIAN EXPERIENCES Brazil has a good experience in using HVDC to connect remote hydroelectric plants to the AC network " Itaipu (14.000MW! 50Hz, 60Hz)! Two Bipoles, ± 600 kv, 3150 MW.! 800km long from Foz do Iguaçu to Ibiúna Converter stations.! Hybrid Solution # C A interconnection system composed of three 765kV series compensated transmission lines (900km).! P o w e r g e n e r a t e d a t 5 0 H z (Paraguay) is delivered at São Paulo at 60Hz. LundSymposium27/28May, BRAZILIAN EXPERIENCES " Santo Antônio and Jirau (6.500MW)! Madeira River Complex 2&Bipoles,&3150&MW& 2&Back*to*Backs,&400MW& Porto& Velho& Araraquara& AC&Transmission& Reinforcements&! Two Bipoles, ± 600 kv, 3150 MW.! Two 400MW Back-to-Back stations.! 2375km long from Porto Velho to Araraquara Converter stations.! Power plants completely isolated from existing system.! Asynchronous Configuration intends to provide a safe power transfer to local weak 230kV system.! AC transmission reinforcements were also necessary. LundSymposium27/28May,2015 6

3 BELO MONTE POWER PLANT The most recent project that is currently under development in Brazil is the Belo Monte Hydropower Plant. This plant is located in the Xingu River basin, in the State of Pará, and it will have an installed capacity of MW. The run-of-the-river design imposed by the environmental restrictions and the seasonal characteristics of the Xingu River, the generated power of this plant can vary from its maximum capacity to zero between wet and dry seasons. Amazon&River& Tapajós&River& Belo&Monte& Power&Plant& MW& Xingu&River& Tucuruí&Power&Plant& 8.370&MW& LundSymposium27/28May, BELO MONTE S INTEGRATION SYSTEM The definition of the best transmission expansion alternative for the integration of Belo Monte power plant to the system took into consideration a series of electrical and environmental constraints. Several different integration system alternatives were analyzed, and an hybrid connection system was chosen. 2&Bipoles,&4000&MW& Xingu& Estreit o& Terminal& Rio& AC&Transmission& Reinforcements& AC&Transmission& Reinforcements&! Two Bipoles, ± 800 kv, 4000 MW.! The first bipole was auctioned in 2013 (Starts operation by 2018). The second one will be auctioned this year (Starts operation by 2020).! First bipole # 2140km long from Xingu to Estreito Converter stations.! Second bipole # 2440km long from Xingu to Terminal Rio Converter stations.! The first embedded link in Brazil.! AC transmission reinforcements were necessary in both terminals. LundSymposium27/28May,2015 6

4 Belo Monte s planning studies were subjected to a set of additional constraints, criteria and premises that focused on ensuring a better system reliability and operational flexibility. The electrical constraints relate to physical and operational limits such as thermal capacity of the transmission lines or voltage limits in substation bus bars were taken into consideration. Among the most important premises and performance criteria adopted, the following ones had a direct impact on the study s assessment and represented additional challenges for choosing the best transmission expansion alternative: " New Voltage Level (800kV) This new voltage level was chosen based on a comparison of different possible alternatives, which include the existing configuration (600kV). However, due to the amount of energy to be transmitted and the system performance, the 800kV configuration was chosen. (The maturity of this technology was also considered). " N-1 security criterion Inordertocopewiththiscriterion,itwasdeterminedthatallpolesshouldhavea33.3 overloadcapacity,foraperiodof30minutes,sothatthelossofanypoledoesnotcause anyproblemstothesystem.(consideringbelomonte sfullinstalledcapacity). LundSymposium27/28May, " Bipole Contingency A transmission line this long is exposed to several different condinons that can cause severedisturbancesandaffecttheperformanceofthewholesystem. TheassessmentofamulNpleconNngencyinabipoleaimedtoensurethatalossoftwo poleswouldnotcauseasystemcollapse. Because of this premise, a 10 overload capacity, during& a& period& of& 4& hours, was required. " Converter locations In order to define the best locanon for the converter stanons in the Southeast region somespecificcharacterisncsweretakenintoaccountsuchas:! Proximitytoloadcenters! ProximitytogeneraNoncenters. LundSymposium27/28May,2015 8

5 " Converter locations! The Estreito converter stanon, located in the State of Minas Gerais, is strategically locatednearsãopauloloadcenterandsomeexisnnghydroelectricpowerplantsin theparanáriver,parnaíbariverandgranderiverbasins. SS&Estreito&(Belo&Monte)& SS&Araraquara& (Madeira)& SS&Ibiúna&(Itaipu)& SS&Terminal&Rio& LundSymposium27/28May,2015 (Belo&Monte)&! The Estreito substanon is located in a strong part of the system, and no significant transmission reinforcements arerequired.! The Terminal Rio converter stanon is located near Rio de Janeiromainloadcenterandit does not require significant AC reinforcementseither. 9 " Reversal Transmission operation! BeloMonte sreducedgeneranonduringdryseasonsandtheprojectedloadgrowth for the northern region required that the bipoles could operate transmi^ng energy inbothnorth*south&and&south*north&direc_ons. LundSymposium27/28May, ! Strong seasonal variability! Energy surplus d u r i n g w e t season! Wet to dry season in just a fewmonths

6 " Reversal Transmission operation! Most of the Nme the bipoles are expected to operate expornng energy to the SoutheastregionduetotheexisNngenergysurplusinnorthernareas.! ThereversaloperaNonmodehasledtotherecommendaNonofhavingthreeofBelo Monte sgeneratorsoperanngas&synchronous&condenser&duringdryseasoninorder tosupplyanadequateshortcircuitpowerlevel. " Energy Transfer Requirements Year Load Level N SE N SE Transfer Capacity (MW) Light Heavy Light Heavy " By2018,whenthefirstbipolestartsoperaNng,theenergy transfercapacityneedstoreach8200mwinthenorth/ southdirecnonand6000mwintheoppositedirecnon. " By2020,thistransfercapacityneedstoincreaseeven morereaching12500mwinthenorth/southdirecnon. LundSymposium27/28May, " Benefits of the planned links FUTURE TRENDS " Byincreasingtheenergyexchangelevels,differentoperaNonaleffectsareexpected:! The energy transfer in Belo Monte s bipoles can occur in either direcnon. This characterisnc will give full flexibility for the System Operator to choose an opnmal configuranon for the system, improving both AC and DC systems performance,especiallywhenhighlevelsofenergytransferarerequired.! ItwillallowtheHVDCsystemtocoveroutagesintheparallelHVACsystemand viceversa.! During dry seasons, there is generally an increase in other renewable energy sources availability such as wind power in the Northeast area. The new HVDC links can be used for expornng any renewable energy surplus to the main load centers. LundSymposium27/28May,

7 FUTURE TRENDS " New possibilities for embedded links " MostoftheunexploitedgeneraNonpotenNalinBrazilisconcentratedintheNorth andnortheastregions.brazilhasmorethan mwofhydropowergeneranon potennal,and70ofthispotennalislocatedinthenorthregion. Tapajós " The North region will have more than 10GW& increase in its installed capacity by 2021 taking into consideranon new generanon projects. This generanon expansion is associated to São Luís do T a p a j ó s ( M W ) a n d J a t o b á (2300MW)hydropowerplants. Load Centers LundSymposium27/28May, FUTURE TRENDS " TheNortheastregionisalsobecominganimportantrenewablegeneraNonpoleinthe country. " Since2009,whenBrazilstartedsNmulaNngwindpowerviaPowerPurchaseAgreement AucNons,morethan15GWofwindpowerinstalledcapacitywascontracted. Wind&Power& Belo& >&15GW& Monte& Tapajós&River& >&10GW& Madeira& Itaipu& " EPE has already started studying different alternanves for increasing the system transfer capacity in the NorthandNortheastnetworks. " The high capacity long/length transmission corridors required to deliver the energy surplus to the SoutheastregionrepresentpotenNal applicanonsforfutureembeddeddc linksinbrazil. LundSymposium27/28May,

8 CONCLUSIONS " Belo Monte s interconnecnon system consists of several AC reinforcements in the exisnnggridandtwo±800kv4000mwhvdclinks,whicharegoingtobethefirst completelyembeddedonesinthecountry. " These links will play an important role in increasing the transfer capacity between differentregions. " SomeinnovaNonscanbeassignedtothisprojectsuchastheinserNonofnewvoltage level(±800kv)andtherecommendanonofsomeofthelongesttransmissionlinesin theworld. " ThecriteriaadoptedforchoosingtheconverterstaNonssites,theassessmentofthe necessaryoperanonmodes,andtheconsequencesofassumingspecificcriteriawere alsodiscussed. LundSymposium27/28May, CONCLUSIONS " The experience acquired in Belo Monte s integranon study also provided an insight intothefutureperspecnvesofusingembeddedhvdclinksinbrazil. " There s a great probability that the future recommended links be associated to the exploitanonoftheremaininghydropowerpotennalinthenorthregion,especiallyif hugeprojectsthathavethesamecharacterisncsofbelomonteorsantoantônioand JirauaretakenintoconsideraNon. " The unlizanon of such links for bulk power transmission of the renewable energy surplusfromthenortheastregionisalsoapossibletendency. LundSymposium27/28May,