US Patent 8675329 Protective device with metering and oscillography

A device, such as an intelligent electronic device (IED), provides a monitoring and protective function for a power system. The protective function uses stimulus acquired from the power system to detect power system conditions and to take one or more protective actions responsive thereto. The device may detect arc flash events in the power system based upon electro-optical and/or current stimulus measurements obtained therefrom. The stimulus measurements may be recorded to use in metering, validation, identifying detector misoperation, and/or event oscillography.