Project Slides REVISED 4 (1).pptx research

project

1. KYAMBOGO UNIVERSITY FACULTY OF ENGINEERING DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING PROJECT TITLE: Impact and the minimization techniques of lightning strikes on distribution power lines Supervisor: Mr. John Ssali Mbazzi 1 No Student’s Name Registration Number 1. Magoba Phina 24/U/BEL/1217/PD 2. Mubangizi Nicholas 24/U/BET/1250/PE 3. Musana Reuben 22/U/BET/3873/PE

2. Background Ever since the evolution of transmission and distribution of electric power, lightning has been a key challenge to utility company e.g. in 1880s,lightning was a main transient on distribution lines in USA and a frequent one in 1990s in Africa for which in 2020, it happened in Uganda. Usually, conductors, insulators, transformers and other electrical equipment owned by both utility companies and individuals(customers) are affected This research emphasizes lightning strikes, given their severe impact. 2

3. Problem Statement Distribution power lines are highly vulnerable to lightning strikes, which cause disruptions, equipment damage, and safety risks. Due to inadequate protection measures, frequent outages and economic losses occur. This research aimed to assess these impacts and identify effective mitigation methods to improve the reliability and safety of power distribution networks. 3

4. Research Objectives Main objective To assess the impact and minimization techniques of lightning strikes on power distribution lines. Specific objective To evaluate the impact of lightning on voltage and power frequency on distribution power lines. To assess the effectiveness of each lighting protection techniques by mathematical modeling To simulate the Lightning Protection Techniques in MATLAB R2023a and compare the results with the mathematical models. 4

5. Justification and Significance Justification Lightning strikes significantly affect distribution power lines, causing outages, damage, safety hazards, and economic losses. Existing protection methods are often inadequate, prompting this research to evaluate their impact and identify more effective mitigation strategies. Significance This study provides insights into lightning strike impacts on distribution lines, supporting the development of strategies to reduce outages, damage, and costs, and improve power network reliability and efficiency. 5

6. Research Scope This study focused on the impact of lightning strikes on Uganda’s power distribution lines (up to 33 kV). It examined protection methods like surge arresters, grounding, and shielding, and explored advanced monitoring and predictive technologies to improve lightning fault mitigation. 6

7. LITERATURE REVIEW Research scholars with similar topic and their respective gaps McGraw (2019) examined lightning strikes on distribution lines but did not assess their frequency or the resulting damage and disruption . Nucci (2020) focused on surge arresters but did not compare multiple lightning protection methods . Rakov (2024) introduced a predictive model but did not evaluate or select the most effective advanced monitoring and predictive technologies for lightning protection in a specific country context. 7

8. Methodology Addressing 1 st specific objective Step 1; data collection Data from UNMA and UEDCL about number of lighting, number of outages and number of affected transformers from 2014 to 2020 was collected and tabled as below; 8 Year Number Lightning strikes (x) Number of outages (y) (Number of TX ) , (z) Affected 2014 1603 34 9 2015 2062 30 2 2016 1983 26 3 2017 2471 14 2018 1091 7 1 2019 887 4 2020 1087 9 Step 2; Statistical Analysis Averages of lightning strike, outages and affected customers were calculated. Mean of lightning strikes: μx = = 1491 Mean of outages: μy = = 17.4 Mean of affected customers: μz = = 1.9  

9. Methodology Impact of lightening on voltages and frequency was then calculated using the collected data using the formulae below; Voltage Surge Calculation (Lightning-Induced Overvoltage) Lightning can cause temporary voltage spikes , modeled as: V surge = V nominal-high + k2.x Where: V nominal_low = 220V (minimum grid voltage in Uganda) k2= 0.03 (empirical scaling factor for surge impact) 9 Power Frequency Deviation Due to Lightning Power system disturbances often lead to frequency deviation, modeled as: f nominal −k3⋅x Where: f nominal =50Hz (standard power frequency) k3= 0.002 (scaling factor for lightning impact on frequency stability) As lightning increases, frequency dips below 50Hz .

10. Methodology… Addressing 2 nd specific objective Rating based on 11kV line according to IEEE Surge arrester failure probability , where But the residual voltage after surge discharge ( 6kV assumed for 11kV systems ). V SA = Surge arrester rating ( 15kV for 11kV systems). = = 0.40   10 Grounding system failure probability = RG = Earth resistance (assumed 12Ω for 11kV grounding systems). y, x = Outages and lightning strikes . Mean value of = μ = 0.1264   Techniques Rating Surge arrester 15kV – 18kV Grounding system 10 Ω -20 Ω, 16mm grounding conductor diameter Shielding method Shielding wire height is 2m – 3m above conductors Year 2014 =0.2547 2015 =0.1746 2016 =0.1573 2017 =0.0679 2018 =0.0770 2019 =0.0542 2020 =0.0994 Year 2014 2015 2016 2017 2018 2019 2020

11. Methodology… Shielding Method Failure Probability Shielding effectiveness for 11kV lines is lower, given shorter shielding wire heights: = 1 – Ps hield Assuming a 55% shielding effectiveness for 11kV systems as commonly referred [6], [7], = 1 – 0.55 = 0.45 Addressing third specific objective Prior to simulation, mathematical models were developed to quantify failure probabilities for three protection techniques: All these were implemented in Matlab code for simulation purposes to address the third specific objective.   11

12. Results 12 The impact of lightning on voltage and frequency was done in M atlab and for voltage it can cause a surge while o n frequency it showed a complete reduction from 45 to 48.23Hz deviating from 50Hz as in the screen screenshot from M atlab below Lightning Protection Technique Failure Probability Grounding System 0.1264 (Best) Surge Arrester 0.40 (Second Best) Shielding Method 0.45 (Least Effective) The failure probabilities for each technique were computed using established formulas and historical outage data. The average failure probabilities were determined as follows: Based on the failure probability method of analysis, the above table summarized the best and the worst method

13. Results 13

14. Results 14

15. Recommendation 15 To enhance grounding effectiveness, utilities should conduct soil resistivity studies, perform regular maintenance, and use deeper electrodes. Real-time lightning monitoring, including sensor installation and automated response systems, should be adopted. Regulatory bodies should update lightning protection guidelines by mandating audits. offering incentives for advanced technologies . and setting outage benchmarks.

16. Conclusion 16 The study evaluated the frequency and impact of lightning strikes on Uganda’s distribution lines, developing a linear regression model that showed a direct link between lightning activity and power outages . Grounding systems proved most effective among protection methods, followed by surge arresters and shielding . MATLAB simulations confirmed their role in reducing voltage and frequency disturbances. Future research should integrate machine learning and enhance model accuracy.

17. References 17 Millen, S. L. J., & Murphy, A. (2021). Modelling and analysis of simulated lightning strike tests: A review. Composite Structures, Article 114347. Pereira dos Reis, T., & Raizer , A. (2024). Modeling and simulation of distribution networks under lightning transients: A comparative study of accuracy and complexity. Zhang, Y., & Liu, J. (2023). Precise lightning strike detection in overhead lines using KL divergence. He, J., & Chen, X. (2022). Simulation of lightning-induced voltages on medium voltage distribution lines. IEEE Transactions on Power Delivery, 37(4), 1234-1242. Kumar, S., & Singh, R. (2021). Design and implementation of a lightning detection system for power distribution networks. International Journal of Electrical Power & Energy Systems, 129, 106837. Wang, L., & Gao, F. (2023). Monitoring and analysis of lightning strikes on medium voltage lines using advanced simulation techniques. Journal of Electrical Engineering & Technology, 18(3), 567-578.

18. Appendix 18 Work plan In order to make this research, the following steps were followed;

19. Appendix 19 Research budget During the research, some money was used as shown in the table below;