Thank you for your question regarding the protection of power substations from the effects of lightning. It is our pleasure to help.
There are a number of factors that must be considered when designing a lightning protection system for a substation. What Lightning Protection Standard is one using? NFPA 780 or BS EN 62305? Does the substation have existing infrastructure of sufficient height? What are the soil conditions? What other structures are nearby that could impact the site( other tall buildings, gas pipelines, etc.)? Where are the incoming and outgoing power lines and how tall are the transmission towers? Do the towers have overhead ground wires and are they bonded to the substations ground grid? What is the ground grids configuration at the substation? What materials are used? These are but a few of the questions that need to be asked and analyzed.
The best way to protect an electrical substation from the effects of lightning, is to get a properly designed and analyzed Lighting Protection System (LPS). This design should include at a minimum an engineering and scientific analysis of the following:
- Soil Resistivity Modeling of the earth at the site
- Ground Potential Rise (GPR)
- Frequency Spectrum & Time Domain of the Lightning Strike
- Step & Touch Voltage Hazards
- Current Distribution Analysis of the Ground Grid
The above five (5) analysis’ will make up the basis for designing the Lightning Protection System (LPS) and will ensure that the designed system is able to safely and efficiently protect both personnel and equipment at the substation.
E&S Grounding Solutions is more than happy to help you with this mandatory and important design process. But if not us, please get someone with the proper expertise to conduct these critical and life saving analysis’ and designs. We recommend and use the CDEGS Engineering and Simulation Software by Safe Engineering Services Ltd. Whoever conducts these study’s should have the CDEGS software with at least the modules: RESAP, MALZ, HIFREQ, FFTSES & FCDIST. If you should have any further questions, please do not hesitate to call one of our engineers and they will gladly speak with you about your project, free of charge.
The Engineering Team at E&S Grounding Solutions