21, rue d'artois, F-75008 Paris http://www.cigre.org C1-102 Session 2004 CIGRÉ THE MEXICAN ELECTRIC SYSTEM: SYSTEM EXPANSION PLANNING AND RESTRUCTURING ACTIVITIES Miguel Angel AVILA * Luis Roberto ESCALANTE Akihito ESCOBAR Comisión Federal de Electricidad (México, D.F.) ABSTRACT The electricity sector in Mexico is undergoing a process of significant structural change. Traditional industry framework in the country has been exposed to new market structure and greater competition, and has been introduced also by changing regulations on who can generate, transmit, distribute and sell electricity. In Mexico, the electric sector has been undergoing a process of deregulation, throughout the 1990s. The sector has been opened to private participation in generation, and policy makers and participants are studying various power sector structural models that have been implemented in other countries in order to help shape the future of the Mexican power sector. Planning and operating problems will be more complex under this competitive environment; the uncertainty associated to private producer investments is a challenge in the development of planning strategies. Another area in which there is particular interest is the potential for increase cross border trade in electricity between Mexico and the United States and very recently between Mexico and Central America. Such an increase would provide economic benefits to all countries, which is of course the primary reason for engaging in trade. Although international interconnections are now in use, the total amount of energy exchanged between Mexico and the United States is relatively limited as well as between Mexico and Central America. KEYWORDS Competition Non-Utility Generation Power System Planning Regulations. * miguel.avila@cfe.gob.mx
( 3 ) ( 4 ) ( 3 ) OP.INC. 230kV KV O.I. 230 KV O.I. 230 KV DETALLE DEL AREA METROPOLITANA NOCHISTONGO OP.INC. 230kV KV KOPTE CANCUN NTE. 32MW 231MW MERIDA 343MW NIZUC MERIDA KANASIN PLAYA DEL III MAX VALLADOLID CARMEN 63MW TICUL COZUMEL 34MW TULUM 32MW OP.INI. 230 kv ( 3 ) ( 3 ) POZA RICA CAMPECHE 182 MW 110MW ( 3 ) CHAMPOTON MAZATEPEC TEZIUTLAN SABANCUY 118MW LAGUNA VERDE CD. CARMEN JALAPA VERACRUZ 53MW CHETUMAL 116MW 577MW ESCARCEGA 62MW PUEBLA610 MW VILLAHERMOSA CARDENAS 278MW MACUSPANA ORIZABA MINATITLAN 289MW 174MW COATZACOALCOS BELICE ZAPATA 330MW YAUTEPEC TECALI 547 MW 36MW CARACOL TEMASCAL 176MW MEZCALA KM. 20 INFIERNILLO ( 3 ) ( 2) PEÑITAS IXTAPA OAXACA JUILE OP. INC. 230 kv 126MW MALPASO CHICOASEN 1080MW 68MW JUCHITAN ANGOSTURA 127MW S. CRUZ TUXTLA OP. INC. 115kV 169MW POCHUTLA HUATULCO 50MW ATLACOMULCO NOPALA ALMOLOYA VICTORIA TOPILEJO APASCO TIZAYUCA (3) 37MW 1. INTRODUCTION In recent years many electric utilities in the world have started implementing important changes in their organization in order to promote efficiency and improve their financial situation. [1] Most of the changes in the power industry are related to the introduction of competition and disaggregation of electric services. [2] The unbundling of generation, transmission and distribution has altered the nature of traditional planning and operation approaches used by the vertically integrated utility. This process has started in Mexico [3] where power industry is changing to a competitive integrated model. The generation of electric energy is open to private investment for external (i.e non utility) production, through the ownership, design, construction, maintenance and operation of power plants. It is expected that a large portion of the generation capacity additions required to face future load demand will be met by non utility generators. [4] 2. DESCRIPTION OF CFE ELECTRIC SYSTEM Generation Structure At the end of 2002, the National Electric System (NES) had an estimated total of 166 power plants 79 hydro, 88 thermal, and 1 wind-powered with 511 units. The estimated installed generation capacity is 41,177.27 MW; 56.8 percent of this total is conventional steam units, combined-cycle units and gas turbines burning fuel oil, natural gas and diesel: 25 percent is hydro units, most of them located in the southwest of Mexico; 7.5 percent is steam units using domestic coal as fuel; 5.5 percent of the capacity is dual units burning fuel oil or imported coal; 2.2 percent is geothermal plants; and less than 1 percent is wind power stations. Electric Energy Total estimated energy production in 2002 was 201,059 terawatt hour (twh), with a maximum load demand of 28.19 gigawatts (GW); 59.8 percent of this total was sales to industrial and high voltage customers; 24.7 percent was to residential users, 8.4 percent to commercial customers, 5.8 percent for agricultural irrigation, 4.6 percent for municipal services such as street lightning and water pumping, and the remaining 1.7 percent was exports to electric utilities in the US and Belize. The average number of customers served in 2002 was 37.1 million. Transmission Structure The national grid is formed by a transmission system based on 400 kv, 230 kv and 115 kv lines that cover most of the country. Today only Baja California Peninsula remains isolated from the main electric network. Figure 1 shows a schematic diagram of the Bulk transmission system. MIGUEL IMPERIAL VALLEY (SDG & E) (SCE) MEXICALI 700MW SAN LUIS RIO COLORADO 167MW TIJUANA 500MW ROSARITO 1445.4MW ENSENADA 143MW METROPOLI SISTEMAS ELECTRICOS Y RED PRINCIPAL DE DIABLO( EPECO) AZCARATE ( EPECO) A H. CARRANZA INTERCONEXION A POZA RICA II ( PTECI ) A QUERETARO TULA CPT220MW CPC SONOYTA ( PEEECo) 1o DE ENERO DE 2002 1982MW 6930 MW CPU 100MW NOGALES 180MW AGUA PRIETA CD. JUAREZ CPD 113MW 24MW 677MW SAMALAYUCA 220MW PTO. PEÑASCO SN. VICENTE 837.7MW SASABE STA. CRUZ SN. FELIPE CANANEA 8 109MW EAGLE PASS 6 DE ABRIL NVO. CASAS SANTA ANA (CPL) A LA MANGA GRANDES SN. QUINTIN 154MW 23MW NACOZARI 148MW PTO. LOMA 200MW MOCTEZUMA A NECAXA 7 LIBERTAD 632MW HERMOSILLO III LA AMISTAD PIEDRAS NEGRAS P. E. CALLES 66MW 183MW A TUXPAN HERMO SILLO 135MW 6 750MW 250MWCC CHIHUAHUA RIO ESCONDIDO 361MW HERMOSI LLO IV HERMOSILLO V 1200MW 423MW TEXCOCO 682MW132.0MW CUAUHTEMOC CARBON II 173MW NAVA 1400MW LAREDO GUAYMAS FCO. VILLA A DONATO GUERRA A PUEBLA (CPL) 130MW 554MW AVALOS 399MW CD. OBREGON NVA. ROSITA NVO. LAREDO PRESA FALCON LA PAZ A ZOCAC 296MW HUITES CAMARGO 258MW HERCULES 67MW (CPL) A ATENCO 200MW LAMPAZOS P. NUEVO 422MW HERCULES POT. SAN BERNABE AYOTLA NAVOJOA BROWNSVILLE 130MW SANTIAGO MONCLOVA FALCON 120MW 31MW (CPL) STA. CRUZ 292MW ESCOBEDO A DONATO V. GARCIA GUERRA EL FUERTE G. PALACIO 59MW 797MW ANDALUCIA A TOLUCA STO. LORETO BACURATO 239MW REYNOSA MATAMOROS A ESTADIO DOMINGO 6MW LOS MOCHIS 92MW HUINALA340MW RIO 287MW TOPOLOBAMPO 225MW LERDO BRAVO VILLA 360MW 320MW SALTILLO MONTERREY 683.4MW CONSTITUCION GUASAVE TORREON PLAZA 458MW 2694MW1200MW 9 123MW SUR 43MW COMEDERO TECNOLOGICO P. PRIETA II 100MW 112.5MW DURANGO II SAN 5 AGUSTIN HUMAYA JERONIMO MONTE MORELOS MORELOS A ZAPATA A TECALI LA PAZ OLACHEA CULIACAN 92MW 90MW 265MW 190 MWW 65MW 417MW LA PAZ I EL TRIUNFO CD. VICTORIA V. GUERRERO 145MW ALTAMIRA BLEDALES SANTIAGO EL HABAL MATEHUALA 770MW 74MW MAZATLAN ZACATECAS TAMPICO C.D. LOS SAN JOSE 239MW RIO VERDE 415MW 344MW CABOS DEL CABO 616MW 33MW 102MW 25 MW CD. VALLES CABO SAN SN. L. POTOSI 116MW 761MW 88MW LUCAS 539MW 20 MW AGUAMILPA AGUASCALIENTES 700MW 69 MW 2.2 960MW 496MW 287MW TEPIC LEON QUERETARO 3.1 136 MW TUXPAN GUADALAJARA A. PRIETA 413MW 544MW 2100MW 52MW 14692MW 240MW SN. DEL RIO 367MW IRAPUATO EL SAUZ CELAYA TESISTAN 340MW 368MW 292MW 437MW 117MW 109MW 150MW 4 2.1 QRO.POT ZIMAPAN PTO.VALLARTA ACATLAN 220MW 125MW SALAMANCA DAÑU TAPEIXTLES ATEQUIZA 195MW866MW MORELIA 1309MW 2.3 MAZAMITLA 227MW 14MW CD. GUZMAN CARAPAN TLAXCALA 105MW 279MW 298MW 422MW 14MW AZUFRES MANZANILLO 98MW URUAPAN 175MW D. GUERRACUERNAVACA ENLACES A 400 kv 1900MW COLIMA 529 MW 1 112MW ENLACES A 230 kv COLOMO 91MW ENLACES A 115 kv LA VILLITA 3.3 ENLACES A 161 kv, 138kV, 69 kv, 34.5 kv 295MW 600MW ó 13.8 KV 354MW 1000MW 3.4 420MW L. CARDENAS 687MW ACAPULCO 1500MW 2100MW 320MW 3.2 900MW OP. INC. 115KV VALLE de MEXICO TIZIMIN Figure 2. TAPACHULA 132MW
The main transmission system consists of 38,561 kilometers of high voltage lines, and total installed substation capacity is 119,707 mega voltampers (MVA).The bulk transmission system is made up of 400 kv transmission lines (16.5 percent), 230 kv (27.8 percent) and 161 to 69 kv lines (55.7 percent). 3. CFE ELECTRIC SYSTEM PLANNING PROCEDURES CFE is the only organization responsible for the planning of electrical systems in Mexico [5]. Resources, generation, main transmission and subtransmission planning are handled by the Subdirección de Programación (SP) in central offices of CFE. The Regional Distribution Centers are responsible for distribution planning in coordination with the central office. Expansion of the system is based on an integrated scheme in geography and time. Due to the complexity of the problem, it is solved by decomposition in time hierarchy (long mid and short term) and by geographical hierarchy (generation, bulk transmission, regional subtransmission and distribution networks), complemented by global and marginal analysis. The scheme is shown in Table 1. In general, planning studies are characterized by greater uncertainties as they cannot account for unforeseen future developments, thus limiting detailed analysis. The structure of the electric system can be planned in varying degrees of detail, taking into account probable scenarios involving availability and cost of resources and technologies. Table 1. Power System Planning Procedure Scheme Network Studies Term Generation Studies Bulk Transmission Subtransmission Distribution Long - Term Year N+10 To N+30 Mid - Term Year N+5 To N+10 Short - Term Year N+3 To N+5 Guidelines for Guidelines for Site Generation Allocation Expansion of Power P lants Generation Pr ogram Site Allocation of Substations and Bulk Transmission Program Generation Decision Transmission Network Subtransmission Adjustment Design and Decision Program Adjustment Distribution Program Near - Term Year N T o N+3 N= Current Year Generati on Operation Studies and Decision Adjustments Bulk Transmission Subtransmission Operation Studies and Studies and Decision Adjustments Decision Adjustments Distribution Studies and Decision Adjustments With the locations, sizes and dates determined for the hydroelectric and thermal plants several models are used for planning the required electrical network. [6,7,8] The planning scheme is aimed at minimizing the expected investment and operational costs, which are subject to the technical and economic constraints that usually arise in large interconnected systems comprised of thermal and hydroelectric power. 4. ELECTRICITY SECTOR RESTRUCTURING DEVELOPMENTS Modernization for structural change On June 2, 1999 CFE undertook a formal corporate transformation project consisting of creating business units with greater management autonomy and technical economic results centers, as well as simulating an internal power market which would allow the company without making any amendments to the existing legal framework to operate within a competitive framework that will result in greater operational and financial effectiveness. [9]
Since August 2000, the Corporate Transformation Program (CTP) has already achieved, the following goals: To project CFE towards its transformation into a modern entity with administrative and operational processes that are transparent and cost effective, in addition to providing a more flexible structure by decentralizing its functions and strengthening its services. To foresee CFE s possible opening to investors in order to increase electric power generation, through the design of an internal power market that would in turn, assess the company s results within a market environment and to correctly assess its generation assets. Competitiveness among business divisions is necessarily reflected in better transactions prices and sales to the NES. This will insure in long run benefits for the consumers. Therefore, since August 2000, a structure was projected in which CFE would act as the corporate entity evolving into a series of divisions in charge of generation, the operations system and electric power dispatch and transfer and distribution, except for the isolated electric systems of Baja California (see Figures 1 and 2). Centralized Service Division (Coorporate) Generation Division 1 Transfer Division Distribution Division 1 Generation Division 2 Distribution Division 2 Generation Division N Distribution Division N CENACE (Power Market) Figure 2 Based on the foregoing, the following basic criteria have been established for the transformation process. Maintaining the operational stability and integrity of the NES. Ensuring technical and economical feasibility. Creating a shadow power market. 5. EXISTING BORDER INTERCONNECTIONS BETWEEN MEXICO AND THE US. There are 13 electrical interconnections between the US and Mexico, as illustrated in Figure 3. Total transfer capability is less than 900 MW, including 150 MW which is operated in a normally open mode. The two 230 kv interconnections between San Diego Gas and Electric (SDG&E) and CFE can handle 800 MW. Two interconnections between CFE and El Paso Electric Company (EPECO) are 115 kv with a combined capacity of 200 MW. Three interconnections between CFE and Central Power and Light (CPL) are 138 kv with a transfer capability of 150 MW but operated in a normally open mode. Recently CFE and Central and South West Corporation (CSW) installed an asynchronous electrical tie using HVDC light technology. [10,11] The tie is rated at 36 MVA at 138 kv and allows an interchange of power between US and Mexico in both directions under open access without interfering with the surrounding system, enabling the parties to trade electricity with each other in a mutually beneficial way.
Finally there are four 69 kv interconnections with a total transfer capability of 120 MW, and two distribution connections with a combined capacity of only 14 MW. Minor improvements could be made to expand emergency services but a material increase in cross border trade will require significant expansion of existing transmission capacity. EXISTING BORDER INTERCONNECTIONS MIGUEL - TIJUANA 230 kv * IMPERIAL VALLEY - LA ROSITA, 230 kv * 800 MW EL PASO - CIUDAD JUAREZ (Texas), 115 kv * 200 MW EAGLE PASS- PIEDRAS NEGRAS (Texas), 138 kv 36 MW LAREDO - NUEVO LAREDO (Texas), 138 kv 100 MW FALCON - FALCON (Texas), 138 kv 80 MW BROWNSVILLE - MATAMOROS 120 MW (Texas) 138 kv SIMBOLOGIA 400 KV 230 KV 138 KV 115 KV MENOR A 115 KV * Las interconexiones mas importantes son las existentes en Baja California y Ciudad Juárez, Chih. Figure 3 BELICE - CHETUMAL 115 KV 100 MW 6. US/MEXICO BORDER GENERATION INTERCONNECTION STUDY The evolving power supply problems in California have prompted many proposals for short and mid term solutions to this growing energy crisis. In the short term, the CFE and SDG&E are evaluating opportunities for increased power and energy exports from Mexico to the US. In the mid term, several major power plants [12], most notably the Otay Mesa (558 MW) and Sempra (600 MW) projects are proposed for development in the border area (see Figure 4). US/MEXICO BORDER PROPOSED GENERATION US/MEXICO BORDER PROPOSED GENERATION PROJETS, 2003-2005 2005 PROJECTS, 2003-2005 MIGUEL IMPERIAL VALLEY PALO VERDE Otay Mesa 558 MW, June 2003 OTAY SWITCHYARD NORTH GILA AEP Resources* 250 MW, June 2003 250 MW, June 2005 TIJUANA Intergen B 600 MW, June 2003 RUMOROSA Sempra Energy Resources 600 MW, June 2003 600 MW, June 2005 PJZ AES Pacific 500 MW, June 2003 METROPOLI MEXICO Intergen A 750MW, June 2003 LA ROSITA Existing 500 kv Transmission Existing 230 kv Transmission Proposed 230 kv Transmission Under Review Not to Scale Proposed Generation *Alternate interconnection point is Miguel Substation 500 kv Substation 230 kv Substation Figure 4 CFE is cooperating with SDG&E to evaluate the ways and means to increase the rating of Path 45 so as to deliver up to 1,600 MW to California by 2005.
CUAUHTEMOC AVALOS CHIHUAHUA CAMARGO SANTIAGO FCO. VILLA Ojinaga GOMEZ PALACIO LERDO Alamito Creek Marfa Presidio HERCULES ANDALUCIA TORREON SUR Alpine HERCULES POT NAVA N. ROSITA LA AMISTAD FRONTERA V. GARCIA AMISTAD Eagle Pass Del Reo Del Rio 36 MW HVDC Piedras Negras RIO ESCONDIDO MONCLOVA SALTILLO Brackettville Eagle Pass CARBON II LAMPAZOS PV MONTERREY PLAZA TEC Uvalde Asherton LAREDO NUEVO LAREDO ESCOBEDO FALCON PRESA DAM FALCON HUINALA Hondo PEARSALL Zapata Bruni MONTE MORELOS FALCON Kendall San Marcos Skyline SAN MIGUEL Pleasantion Falfurrias J.L. BATES Stratton Edinburg Saguin SAN ANTONIO (3) SOMMERS LON C. HILL REYNOSA RIO BRAVO CD. VICTORIA AEROPUERTO Zorn Kingsville Raymondville Lytton NUECES BAY Austrop GIDEON RAYBURN VICTORIA Kennedy COLETO Coleto Creek Pawnee ANAHUAC LA PALMA PTO. ALTAMIRA ALTAMIRA Flatonia BARNEY DAVIS MATAMOROS LAURO VILLAR Hallettsville Edna Carbia FPP JOSLIN Peters Fleweller W.A. PARISH So. Lane City Columba Blessing STP S. Lane City T.H. WHARTON GREENS BAYOU VALASCO Angleton DOW 7. Potential Near-Term CFE/ERCOT Interconnections The Comisión Federal de Electricidad (CFE) and the Electric Reliability Council of Texas (ERCOT) have a long history of emergency assistance across the México/United States border. The recent study continues that tradition by performing a contemporary analysis of the CFE and ERCOT transmission systems to determine the short-term (Phase I) and long-term (Phase II) opportunities for interconnections. The study is separated into phases as follows [13] : Phase I: immediate consideration of support to the ERCOT transmission system along the Texas border where older inefficient generation is no longer economical to operate. In addition, synchronous ties may allow new block load support in remote areas where lengthy transmission additions are required. Phase 1 alternatives leverage the existing interconnections and infrastructure that do not require lengthy regulatory review. Phase II: will evaluate opportunities for long-term interconnections that can support additional economic transactions and emergency assistance between CFE and ERCOT. Phase II studies will not be constrained by infrastructure limitation, and they are likely to involve new transmission improvements for higher transfer capabilities. In both phases, both high voltage synchronous and asynchronous transmission interconnections will be considered, but the primary effort is focused on asynchronous interconnections that utilize Flexible Alternating Current Transmission Systems (FACTS) technology to allow the scheduling of power transfer between the electrical grids.(see Figure 5). CFE and ERCOT Systems along the México and United States Border Area 6 United States Area 4 Mexico CFE AEP- TNC CPS LCRA Center Point 345/400 kv 230 kv 138/115 kv 69 kv Generation Substation Area 3 Area 5 AEP- TCC Figure 5 Area 2 CFE (3) Area 1 Gulf of Mexico Area 1 Matamoros-Brownsville Area 2 Reynosa McAllen Area 3 Nuevo Laredo Laredo Area 4 Piedras Negras Eagle Pass Area 5 Presa Falcon Falcon Area 6 Ojinaga - Presidio 8. TRANSMISSION PLANNING MODELS. The purpose of transmission planning is to identify a flexible, robust, and implementable transmission system that reliably facilitates commerce and serves loads in a cost-effective manner. [6,7,8] Meeting this planning goal requires both technical analysis of different transmission system configurations and economic analysis of different transmission projects. Different models are used by CFE for steady-state, dynamic, and short circuit analysis, and then recommend the most cost-effective projects as part of the transmission plan. [14,15]
9. KEY PLANNING ISSUES AND COMPLEXITIES. Reliability against commerce. Traditionally, vertically integrated utilities planned their transmission systems with two goals in mind: Meet reliability requirements. Ensure that the outputs from the utility s and non-utility s generation could be transported to the utility s customers. Today, transmission systems are called on to do much more. They must serve dynamic and rapidly expanding markets in which the flows of power, into, out of, and through a particular region vary substantially over time. As a consequence, it is not clear whether transmission planners should focus exclusively on the Planning Standards in assessing alternative transmission projects or whether they should also consider enabling competitions to occur over large geographic regions. Congestion Costs. Traditionally, vertically integrated utilities integrated their transmission and generation planning and operations. This coordination recognized any generation redispatch costs associated with the prevention of congestion during real-time operations. In competitive electricity markets, with generation separated from transmission and system control, congestion pricing can offer valuable information on the potential benefits of new transmission investment. Decisions on whether to build new transmission are complicated by uncertainties over the future costs of congestion. These uncertainties relate to load growth, the price responsiveness of load, fuel costs and therefore electricity prices, additions and retirements of generation capacity, and the locations of those generators. Assessment Criteria. The electricity industry and its regulators would benefit from objective assessment criteria that can be applied to the transmission planning process and to the resultant plans. Transmission plans should be low in cost, robust, and feasible to implement. To achieve these three objectives, the plan must consider a wide range of transmission and nontransmission alternatives relative to a variety of future load and generation scenarios. The assessment must consider compliance with reliability standards as well as commercial uses of the grid. Because of these many disparate factors, its unlikely that the preferred plan will be the lowest-cost solution. Instead planners should choose plans that are robust across a range of future scenarios, which means they may be least-cost for none of the scenarios. 9. CONCLUSIONS New laws and regulations have started the transformation of the electric power industry in Mexico. Two state-owned electric utilities had a monopoly in generation, transmission and distribution of electric energy in the country. Electricity market has been opened in the long term generation business and competition between CFE s generation units and private non-utility generators has been introduced. Planning and operating problems will be more complex under this competitive environment; the uncertainty associated to private producer investments is a challenge in the development of planning strategies. The evolving power supply problems in California and Texas have prompted many proposals for short-term and mid-term solutions to this growing energy crisis. In the short term CFE, and ERCOT are evaluating opportunities for increased power and energy exports from Mexico to the US.
In the mid-term several major power plants, are proposed for development in the border area. CFE is cooperating with ERCOT to evaluate the ways and means to increase the existing rating of 138 kv paths so as to deliver up to 300 MW to Texas by 2005. The introduction of the electricity market has resulted in new frames and considerations in transmission network planning. As more and more countries are liberalizing the electricity sector, a number of questions have been raised regarding the transmission network planning. A number of key issues have been listed and classified as the most important due to the changed conditions. The most important ones are: Uncertainties in electricity prices (market prices). Uncertainties in regulation and transmission pricing. Possibility of financing new interconnections. Uncertainties in development in international markets. These uncertainties calls for a new planning approach. BIBLIOGRAPHY [1] D.S. Kirschen, R. Bacher, G.T. Heydt. The Technology of Power System Competition. Special Issue. Proceeding IEEE. February 2000. [2] M. Ilic, F. Galiana, L.H. Fink. Power System Restructuring. Engineering and Economics. Kluwer Academic Publishers. 1998. [3] F. Aboytes, R. Cristerna. Planning and Operation Challenges for the Electric Power Industry in Mexico Under a Competitive Environment. CIGRE 1996. Paper 37-109. [4] Prospectiva del Sector Eléctrico 2002 2011. Dirección General de Política y Desarrollo de Energéticos. Secretaría de Energía. México. 2002 [5] Ley del Servicio Público de Energía Eléctrica. Secretaría de Energía, Minas e Industria Paraestatal. México 1993. [6] R.R. Austria, R. Nadira, L. Consenza, C. Fuentes, M.A. Avila, J. Ramírez. Least Cost Transmission Planning Considering Power Industry Restructuring. International Conference IASTED, Orlando, Florida, USA. October 1997. [7] R. Nadira, R.R. Austria, L. Cosenza, F. Lecaros, C. Fuentes. M.A. Avila, J. Ramírez. Planificación de Sistemas de Transmisión de Energía Eléctrica en el Futuro: Son válidas las premisas tradicionales?. Latin American Power Conference 1997, Conference and Exhibition. Caracas, Venezuela, April 1997. [8] R. Nadira, R.R. Austria, C. Dortolina, F. Lecaros. Transmission Planning in the Presence of Uncertainties. 2003 PES General Meeting July, 13-20. Toronto, Ontario, Canada. [9] Informe Anual 1999. Comisión Federal de Electricidad. [10] Eagle Pass/Piedras Negras B t B Light. ABB Power Transmission. March 1999. [11] D. Kidd, B. Mehraban, B. Ekehov, T. Larsson, J. Ulleryd, A. Edris. Eagle Pass Back to Back VSC Installation. 2003 PES General Meeting July, 13-17. Toronto, Ontario, Canada.. [12] US/Mexico Border Proposed Generation Projects 2003 2005. Joint Interconnection & System Upgrade Study. May 2003. Draft Report. SDG&E. [13] ERCOT-CFE Interconnection Study. Draft Report. October 2003. ERCOT/CFE [14] Power System Simulator, PSS/E. Power Technologies Inc. 2002. [15] GE Power System Analysis Software. General Electric Co. 2002.