Fault current detection method

Abstract

A method for measuring the impedance of electrical distribution equipment includes: applying a voltage at a first selected frequency to electrical distribution equipment, waiting a delay time for transient effects to settle, measuring current through the electrical distribution equipment, and selecting additional frequencies to repeat the steps of applying, waiting, and measuring. The method can be implemented, for example, by a meter which includes: a control processor connected to receive and execute instructions, and to output a control signal; a frequency generator for generating a frequency signal having a frequency determined by the control signal; a power amplifier connected to receive the control signal and the frequency signal, the power amplifier outputting a voltage signal to the electrical distribution system through a voltage transformer; and an analog-to-digital converter connected to receive analog feedback voltage signals from the voltage transformer, the analog-to-digital converter outputting a digital feedback voltage signal to the processor.

Dependencies are inferred from the claim text.