Vulnerability Assessment of a Protection Relay in Electrical Substation to Radiated Intentional EMI

Smart power grid has adopted digital protection relays in electrical substations, but it has also increased the vulnerability of an electrical substation should an intentional electromagnetic interference (IEMI) attack happens. Using a commercially available digital protection relay as a case study, radiated susceptibility tests are performed to investigate its susceptibility behaviors. With a known susceptibility level, the numerical model of a 22kV substation is constructed to assess the vulnerability of the protective relays deployed in the substation. It reveals that with the recent development of highpower radio frequency (RF) and microwave sources, the substation could be at risk from an IEMI attack, and thus early mitigation measures should be implemented to minimize such a risk.