A Comprehensive Approach to Addressing the Lightning and Grounding Safety Requirements in Grid-Integrated EES Systems Per IEC 62933-5-2

This paper reviews lightning and grounding safety requirements in grid-integrated BESS systems per IEC 62933 part 5-2: Safety requirements for grid-integrated electrical energy storage (EES) systems - Electrochemical-based systems. Based on the IEC 62933-5-2 recommendations, a lightning protection risk assessment is carried out using the methodology descibed in IEC 62305–2. Lightning protection measures compliant to IEEE 998:2012 are implemented in response to the results of the risk assessment. The captured lightning current is dissipated into the earthing grid built under the EES system and nearby transformers. Grid resistivity and safety assessments are carried (step and touch hazards) out for various faults (short-circuit) scenarios using IEEE 80:2013. It is shown that modelling of the nearby HV substation and PV farm, when present, is important as it will lead to a more precise assessment of the electrocution risk on the BESS side. This assessment allows for increased safety while limiting costly over-design of safety measures.