Use of Lightning Data for Electricity Transmission Operations Juha Paldanius, 28.5.2014 IV International Conference of Lightning Protection St.Petersburg,Russia

Presentation Outline NLDN Introduction Lightning Data Applications in Electricity Transmission Ops. Operations Management Transmission line engineering Transmission line analysis Technology upgrades 2013 upgrade 2014 improvements 12/8/2018 [Name]

NLDN Introduction Continuous CONUS Data Since 1989 The Vaisala operated U.S. National Lightning Detection Network (NLDN) has been providing real-time, continental-scale lightning data since 1989. Continuous and Quantified Improvement Upgrades in 1995, 2003-4, and 2010-12 were coupled with detailed performance analyses. Cloud-to-Ground Lightning Tower studies - Cramer and Cummins (2014) Rocket triggered lighting studies - Mallick et al. (2014) Cloud Lightning Video camera studies - Cummins et al. (2014) Comparison against Lightning Mapping Array - Murphy and Nag (2014) In this paper, we discuss the results expected from the current network-wide upgrade on the performance characteristics of the U.S. NLDN. We also examine the peak current distributions of cloud and cloud-to-ground lightning reported by the network.

NLDN – CG Flash Detection Efficiency & Accuracy

User Case – Operations Management Customer has built an real time weather information system to manage maintenance crews Mobile application for crews on the field Automatic alarm function 30/60 mile radius 15/30 min time delay Storm mitigation On-duty calls On-hand spare part inventory Active on-call location 12/8/2018 [Name]

User Case – Transmission Line Engineering FALLS software Reliability Analysis for fault investigation Regional Analysis by Substation & Line Design Claims Support Small Area Analysis for Distribution network monthly reports Small Area Analysis for Maintenance prioritization A FALLS® 5.0 Regional Analysis displaying lightning discharges by amplitude. The yellow and red circles represent cloud-to-ground strokes with amplitudes greater than +/- 165 kA that are likely associated with faults. 12/8/2018 [Name]

FALLS® 5.0 Exposure Analysis - 115kV Line 21 operations (2000) 46.43 Miles = 74.7km 60% operations are lightning induced Considerations included: Budget – how much improvements would cost? Reliability Targets – How much the reliability would increase Other Externals A FALLS® 5.0 Exposure Analysis showing a segment of transmission line that has been exposed to an above average number of lightning challenges. This information can provide an electric utility guidance for further inspection or protection investments.

115kV Line – Improvement Project 6 out of 10 line sections were noticed to be vulnerable to lightning Improvement of 20 – 40 spans per year (2 – 5 miles) Alumoweld shielding overhead ground wire (2003 – 2011) and optical ground fiber shielding (2012)

115kV Line – Results Performance as expected showed improvement year 2 – 3 Lightning outages from 12 (2000) to 4 (2011) Approach used as a general road map Asset Sections used to monitor program performance

User Case – Transmission Line Analysis Lightning density maps Lightning events along the transmission line Comparison to IEEE Flash tool Statistics of whole transmission network 12/8/2018 [Name]

IEEE Flash Tool Estimates frequency of failures based on CG lightning density and transmission line parameters 12/8/2018 [Name]

Analysis Results 12/8/2018 [Name]

Technology Upgrades NLDN updated in 2013, results in performance improvements. Vaisala’s LS7002 sensors have been deployed, replacing the older generation LS7001 and IMPACT sensors. The cloud flash detection efficiency in the NLDN is expected to be about 40-50%. These performance characteristics continue to be validated by triggered lightning, tower strikes, network inter-comparison, and camera studies. A new NLDN central processor is expected to be operational in April 2014. Burst processing, new classification algorithm location accuracy improvements. Future developments will be included in Vaisala’s lightning detection technology offering In this paper, we discuss the results expected from the current network-wide upgrade on the performance characteristics of the U.S. NLDN. We also examine the peak current distributions of cloud and cloud-to-ground lightning reported by the network.