Abstract: A system suppresses extreme voltage surges induced on electric power lines due to transient electromagnetic energy disturbance from detonation of a nuclear weapon at high altitude generating an electromagnetic pulse (EMP) comprising E1, E2, and E3 pulses, geomagnetic disturbance, and intentional electromagnetic interference. Low voltage (LV) surge protection (SP) assemblies mounted at medium voltage (MV) inputs and LV outputs of the stacked converter cells of a solid-state transformer (SST) form SP of MV and LV electrical power grids interfaced by the SST. The SP assemblies utilize LV components to provide MV grid protection, shunting overcurrent to ground without interfering with the SST MV/LV grid segments isolation. The SP components are selected and coordinated to achieve predefined response at protection threshold voltage levels with current capacity mitigating complex components of HEMP. The hybrid SP communicates with SST control to react to a prolonged overvoltage/overcurrent fault condition.

Abstract: A method and system for status monitoring of transient surge protection devices may display operational status and instantaneously a fault condition of a surge protection device (SPD) induced by transient electromagnetic energy disturbance from high altitude nuclear weapon detonation generating an electromagnetic pulse (EMP), Geo-magnetic disturbance (GMD), solar corona mass ejection (CME), intentional electromagnetic interference (IEMI), natural lightning strikes, or other transient surges due to radiated and conducted EMI. The system monitors operational status and readiness of SPDs installed on electric power networks to protect devices powered by the networks. The status monitoring of SPD has local display and cybersecure, over-the-power-lines communication (OPLC), implemented with analog circuits and instantaneous response.