Manav Energy Private Limited in association with SPARK (Ignited to share) – A Power Engineers group, organized a virtual panel discussion on “Role of Lightning arrester for electrical safety” on 4th July 2020. The panel experts were Mr.Sonjib Banerjee, President, Manav Group, and Mr.Naveenkumar, Head- Electrical Design, Manav Energy with Mr. P K Pattanaik, DGM OPTCL as moderator of the session. Over 300 participants from esteemed organizations around the country were part of the live session to understand the principles behind lightning protection and the role of a lightning arrester.
The concepts discussed in the session are as follows:
- Events of lightning: Major lightning incidents in recent times caused damage to infrastructures and posed a threat to human life. This interrupted the performance of power systems, where the high transient voltages caused flashover across the terminals of electrical equipment. The causes of equipment break down were also elaborated using case studies.
- Structure of lightning: Protection radius and attachment distances of various types of lightning involving current magnitude and polarity were explained. The choice of protection mechanism to be implemented for application-specific needs was discussed.
- Selection and installation of lightning arrester: Technical concepts, for selection of the appropriate surge arrester, were discussed. Clearances and distances necessary between adjacent equipment and lightning arrester for protection of the equipment were deliberated. Discussions put a light on myths and misconceptions regarding the selection and installation of lightning arresters. The positioning of lightning arresters in close vicinity to the equipment under protection and reflections leading to voltage doubling was clarified.
- Design and maintenance: Design and maintenance aspects of Lightning arrester was explained with some unique real-time projects carried out by MEPL across the world such as Burj Khalifa, Ain Dubai, Creek Tower using EMTP-RV simulation platform. Basic maintenance procedures and their importance were also discussed among the experts.
- THRC: Performance and health of the surge arresters depend on the property of the metal oxide(ZnO) and integrity of hygroscopic sealing. However, deterioration due to aging or anomaly increases 3rd harmonic leakage current, the magnitude of the resistive current, and degree of non-linearity of voltage/current characteristics of metal oxide. Limits of THRC values and other major nuances in the testing of Lightning arrester were also discussed.
A satisfactory technical clarification based on MEPL experience was provided for multiple queries put forth by participants during the Q&A session. It gave a clear understanding of concepts and highlighted the importance of lightning arresters.