Year 2006 Report Better Managed and Controlled Transmission

Year 2006 Report “Better” Managed and Controlled Transmission Grids using Advanced Technological Concepts Aty Edris EPRI Power Delivery & Markets aedris@epri. com

Challenges • Full Use of Transmission Capacity • Maintain Power Delivery Stability, Power and Voltage Stabilities • Power Flow Control and Management, Real and “Reactive” Power © 2007 Electric Power Research Institute, Inc. All rights reserved. 2

R&D Work in 2006 • Reactive Power Management • Operator/planner training simulator for the use of advanced technological Concepts • Grid Shock Absorber Concept • Bidirectional HVDC Valve and Tripole HVDC • ETO-Based STATCOM for Wind Farm • FACTS Technology- Information and Knowledge Sharing © 2007 Electric Power Research Institute, Inc. All rights reserved. 3

EPRI Interregional Reactive Power Management Initiative Need Focused Analysis of Reactive Power and Voltage Control In Large Interconnected Transmission Grids Expected Results Demonstration of Reactive Power-Voltage Control Management Strategy for Prevention or Mitigation of Voltage Instability and Cascaded Failure Problems © 2007 Electric Power Research Institute, Inc. All rights reserved. 4

Interrgional Reactive Power Management EPRIs Interregional Reactive Power Management project aims at developing better methods for efficient use of reactive power resources and voltage control in order to improve power system operation reliability, security, and the functioning of markets. Reactive power planning is a key component. New methods are needed to help planners design systems which remain strong and robust under all conditions and contingencies. 2006 Results Development of highly automated method which identify “critical voltage control areas” in a system (for wide ranging topology, conditions, transfers and contingencies) and the required reactive power reserve solutions which will ensure system security. © 2007 Electric Power Research Institute, Inc. All rights reserved. 5

Voltage Control Area- Changing Shape and size with Load Levels and/or Transmission Contingencies Load Increase and/or Transmission Contingencies © 2007 Electric Power Research Institute, Inc. All rights reserved. 6

Planner/Operator Training Simulator CSC Schematic Structure 11 Operating Configurations Modes Marcy Convertible Static Compensator

Planner/Operator Training Simulator for Advanced Transmission Technological Concepts Technical update, Product ID#1012411 © 2007

Grid Shock Absorber SM “Grid Shock Absorber” Implementation On Eastern Interconnection (EI) The idea ! Implementation of EPRI Converter-Based BTB Technology Area 1 Area 2 Voltage supported junctions © 2007 Electric Power Research Institute, Inc. All rights reserved. 9

“Grid Shock Absorber” Implementation On Eastern Interconnection (EI) © 2007 Electric Power Research Institute,

Impact of Generation Trip on Power Flows © 2007 Electric Power Research Institute, Inc.

Impact of Generation Trip On System Dynamics AC Links DC Links © 2007 Electric

Technical Assessment of Grid Shock Absorber Impact of “Larger” Generation Trip on Power Proof of Concept Flows Product ID # 1014494 Selected bus voltages with ac ties (a) and dc links (b) in place. Voltages are not from the same buses in the two cases. © 2007 Electric Power Research Institute, Inc. All rights reserved. 13

Bidirectional HVDC Valve and Tripole Concepts Objectives • • Enabling power reverse on a DC transmission, without reversing Voltage Polarities at the transmission ends Tapping of existing HVDC lines AC to DC line conversion Providing a means for more reliable, less costly applications of Cross Link Polyethylene (XLPE) cable for submarine & underground © 2007 Electric Power Research Institute, Inc. All rights reserved. 14

Conversion of an AC Line into a Tripole DC Line • Higher $$/MW cost. Usually offset by increased transmission capacity • About 40% more capacity compared to a bipole using the same 3 -conductor system • High redundancy: Loss of a converter or pole position drops just 16% of power at peak load © 2007 Electric Power Research Institute, Inc. All rights reserved. 15

2007 Planned Activity - Tools for Assessing Conversion of AC Power Transmission Lines to Tripole DC Transmission Phase I Objective - Feasibility Assessment Tools - An assessment of alternative dc configurations and system benefits. Procedures, technical background and software references sufficient to assess conversion of specific ac transmission structures to dc Guidance in the logistics of AC to DC conversion Phase II - Applications Studies - Assessment of ac to dc adaptation of existing transmission structures, including maximum dc voltage System load flow and dynamic solutions, including modeling of detailed dc characteristics associated with various dc options Cost/benefit analysis associated with conversion alternatives including comparison with ac flow enhancement measures Phase III - AC to DC Conversion Assessment Software - Software tool for AC/Tripole DC Transmission Conversion © 2007 Electric Power Research Institute, Inc. All rights reserved. 16

Challenges (Cost of Converter-based Transmission Controllers!) (25%) 20 50 Cost Breakdown © 2007 Electric

ETO- Technical Characteristics • 5000 A Snubber-less Turn-off Capability • Low Switching losses & Conduction losses • Low Cost Device and Circuit • Easy for Series and Parallel Operation • Low Gate Drive Power • Built-in Over-Current Protection and Current Sensor • Easy for Mass-Production © 2007 Electric Power Research Institute, Inc. All rights reserved. 18

Field Demonstration of ETO-Based STATCOM • 5 -10 MVA ETO-Based STATCOM for Condon Windfarm – Currently funded by BPA, TVA and Tri. State G&T Current Objectives • Field demonstration of ETObased STATCOM, technically and economically, in mitigating voltage fluctuation due to a wind-driven induction generator © 2007 Electric Power Research Institute, Inc. All rights reserved. 19

FACTS Technology- Information and Knowledge Sharing • Annual meeting, 9 th FACTS Users Group meeting • Reference Book, EPRI Power Electronics-Based Transmission Controllers Reference Book (“The Gold Book”) • EPRIFACTS. Com © 2007 Electric Power Research Institute, Inc. All rights reserved. 20

9 th FACTS Users Group Meeting Annual meeting • Session A: Hydro Quebec’s Variable Frequency Transformer (VFT) • Session B: FACTS Controllers, Applications and Operating Experience • Session C: Power Electronics-Based Controllers, New Project Opportunities • Session D: Power Electronics-Based Controllers, Technology Development • Session E: Manufacturers Panel session © 2007 Electric Power Research Institute, Inc. All rights reserved. 21

EPRI Power Electronics-Based Transmission Controllers Reference Book The objectives of this book are to: • provide the utility members with historical perspectives • basic design considerations • factory testing, site installations, commissioning • operating performance, operation and maintenance, and • future trends © 2007 Electric Power Research Institute, Inc. All rights reserved. 22

EPRI Power Electronics-Based Transmission Controllers Reference Book Written Chapters (five) • Alternating Current (AC) Transmission Systems • Power Semiconductors and Valves • Generalized AC Transmission Controllers: Unified Power Flow Controller and Interline Power Flow Controller • Voltage Sourced Converter-Based DC Transmission • AC to Tripole DC Transmission Conversion Ten more Chapters to be written © 2007 Electric Power Research Institute, Inc. All rights reserved. 23