LIGHTNING PROTECTION OF TRANSMISSION AND DISTRIBUTION LINES Team Members Eric Nelson, EE – Project LeaderDavid Dieterich, EE Tim Conrad, EE – Com. CoordinatorSam Muhindo, EE Client Marlon Vogt – PE & Senior Civil Engineer Alliant Energy, Cedar Rapids, IA Faculty Advisor Dr. Vijay Vittal – ECpE Department Iowa State University Introduction Project Requirements Project Team – Dec04-04 Estimated Resources Conclusion Project Schedule Summary Each year, thousands of brief outages caused by lightning strikes occur on electric transmission and distribution lines across the country. While most of these momentary outages are caused by the operation of protection equipment, even a short interruption in service becomes a nuisance and a source for customer dissatisfaction. To meet an increasing customer demand for highly reliable electric power, Alliant Energy is seeking to validate or improve their current lightning protection practices. The group’s main goal, through various research activities, is to establish a benchmark for good lightning performance of transmission and distribution lines. Alliant’s pursuit of exceptional lightning protection practices will demonstrate their continued commitment to their electric service customers. References Intended Users and Uses Users – Managers, engineers, drafters, design technicians Uses – Serve as a guide for updating and improving current design standards as well as aid in decisions regarding future line replacement or retrofit Assumptions Standards from other representative local utilities will be accessible Additional unavailable information can be provided by the client as necessary, or suitable alternatives can be established Limitations The scope of this project will examine only line designs for 69 kV and below Practices and standards examined will be limited to Midwest utilities for geographical and meteorological considerations End Product and Deliverables The end product will be a written report compiling the results of the group’s work Abstract In today’s technology-driven society, the need for reliable electric power for thousands of consumer electronic products and sensitive manufacturing processes is growing more today than ever before. Minimizing the effects of lightning strikes to power transmission and distribution lines is a key goal for every utility. Alliant Energy has asked for review and recommendations regarding the ability of their existing lines to withstand lightning strikes and advice as to whether or not they are in line with prevailing industry practices. The group’s findings will provide credibility of Alliant’s practices to their customers. Acknowledgements Alliant Energy – Marlon Vogt – Provide group with construction standards, outage data, and most of the financial resources, as required Iowa State University – Dr. Vijay Vittal – Provide direction, resources, and advice Design Objectives Provide practical suggestions for revising standards or updating system equipment Demonstrate credibility of Alliant Energy’s current practices to their customers Functional Requirements Provide analysis of the lightning performance of current design standards Justify evaluation criteria or reliability benchmarks Supply feasible changes to current practices to bring Alliant Energy in line with other utilities Design Constraints Suggested changes must adhere to all safety regulations and practices Project must be completed on a very limited budget in a limited amount of time Measurable Milestones Problem Definition Research and Development End Product Development End Product Demonstration Project Reporting Proposed Approach Research current line design practices of other Midwest utilities Establish performance criteria for evaluating multiple designs Analytically compare designs and examine feasibility/economics Submit final recommendations to client Technologies Considered Analytical software or mathematical modeling software such as Matlab ® Data manipulation software Testing Considerations Because the end product is a report, no testing will be required. Validation of the end product will come from advisor review and client satisfaction with the results rather than from actually performing tests. Problem Statement General Problem Lightning strikes cause momentary outages and power quality degradation Service disruptions result from momentary outages and lead to customer dissatisfaction Like many other utilities, Alliant Energy is looking to improve lightning performance on electric transmission and distribution facilities Solution Approach Group will research state-of-the-art line design practices Feedback will be given to Alliant Energy for making necessary system changes Operating Environment Subjected to multiple reviews by the client Used as a standard for future line design changes Financial Resources Labor (799 hrs.) x $10/hr = $7, Poster= $70.00 Document Printing= $20.00 Total = $8, Other Resources No other resources required Sample Ground Flash Density Map for the United States Lightning Strike Near a Rural Distribution Line Personnel Effort