Transcript Document
Hurricane Hardening Commission Staff Workshop on Electric Utility Infrastructure Richard E. Brown, PhD, PE [email protected] Tallahassee, Florida January 23rd 2006 Experience you can trust. About the Presenter Richard E. Brown is a management and technical consultant for the electric power industry. He has published more than 70 technical papers related to power system reliability and infrastructure management; is a regular instructor on these topics; is author of the book Electric Power Distribution Reliability; and is a registered professional engineer. He is a senior member of the IEEE, chair of its working group on Distribution Planning and Implementation, and recipient of the Walter Fee Outstanding Young Engineer award. Richard earned his BSEE, MSEE, and PhD from the University of Washington in Seattle, and his MBA from the University of North Carolina at Chapel Hill. [email protected] Page 2 © 2006 KEMA Inc. Agenda Design criteria Hurricanes Hardening Page 3 © 2006 KEMA Inc. Power Systems Generation Plant Generation Substation Customer Service Drop Transmission Substation Distribution Transformer Distribution Substation Page 4 © 2006 KEMA Inc. Should a system be designed to withstand this? Page Page 55 © © 2006 2006 KEMA KEMA Inc. Inc. Design Criteria National Electrical Safety Code (NESC) – Grades of Construction – Extreme Wind Conditions Reliability – Sometimes set by regulators – Sometimes set by utilities Economic – Improve spending efficiency – Spend money to save money Page 6 © 2006 KEMA Inc. NESC for Distribution Poles Freeway crossings Railroad crossings Most other locations “Grade B” “Grade B” “Grade C” Grade B is 50% stronger than Grade C Page 7 © 2006 KEMA Inc. Distribution Pole Strength* 3.0 Relative Strength . 2.5 2.0 1.5 1.0 0.5 0.0 Wood Grade C Wood Grade B Wood (Extreme Wind) Concrete Grade C Concrete Grade B Concrete (Extreme Wind) * Grade C is the minimum requirement for most distribution poles. Extreme wind based on 145 mph gusts. Page 8 © 2006 KEMA Inc. Hurricanes Page Page 99 © © 2006 2006 KEMA KEMA Inc. Inc. Damage Wind only Trees Debris Flooding Page Page 10 10 © © 2006 2006 KEMA KEMA Inc. Inc. Wind Only Hurricane Wilma was strong enough to snap concrete poles Page 11 © 2006 KEMA Inc. Trees Tree damage is usually not preventable by the utility Page 12 © 2006 KEMA Inc. Debris Flying debris is usually not preventable by the utility Page 13 © 2006 KEMA Inc. Flooding Flooding can delay restoration efforts Page 14 © 2006 KEMA Inc. Hardening Page Page 15 15 © © 2006 2006 KEMA KEMA Inc. Inc. Wind Forces on a Pole Wind on Pole Wind on Conductors Wind on Attachments Page 16 © 2006 KEMA Inc. Design for Extreme Winds Based on 3-second gusts Extreme wind rating (equivalent) – Grade B – Grade C 104 mph 85 mph Florida extreme winds – Southern Coast 145 mph – North Central 95 mph Page 17 © 2006 KEMA Inc. Extreme Wind Speeds (3 second gusts) Page 18 © 2006 KEMA Inc. Hurricane Categories Wind Speed (mph) . 250 200 150 145 100 104 85 1 minute average 3 second gust 50 0 1 2 3 4 5 Huricane Category Page 19 © 2006 KEMA Inc. “Storm Hardening” Toolkit Stronger poles More guying Shorter spans Anti-cascading Conductor size Fewer attachments Undergrounding Vegetation management Page 20 © 2006 KEMA Inc. Cost of Hardening New 3-Phase Construction – Typical Overhead: – Hardened Overhead: – Underground: Typical cost 2 to 4 times typical 5 to 10 times typical Existing System – Much more expensive – Much more complicated – Could take 15 to 30 years Page 21 © 2006 KEMA Inc. Some Hardening Approaches Entire system New construction Critical customer facilities Customer-driven Targeted hardening 10-20 Years Hardening “Roadmap” Now Page 22 © 2006 KEMA Inc. Richard E. Brown, PhD, PE [email protected] 919-593-2860 Page 23 © 2006 KEMA Inc.