Abstract: An instrument transformer includes a current transformer configured to be coupled to a load, and to generate an analog signal that is proportional to a current flowing through the load. The instrument transformer also includes a protection module and a digitizer module that is coupled to the current transformer. The digitizer module is configured to receive an input signal that is proportional to the analog signal and to convert the input signal to a digital signal. The digitizer module includes a synchronization module for generating at least one timing signal and a fiber optic interface module coupled to the protection module and to the synchronization module for transmitting the digital signal to the protection module.

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.