Schweitzer Engineering Laboratories, Inc.

Daniel P Dwyer

Veselin Skendzic

Bai-Lin Qin

Chandrasekaran Swaminathan

Carl V Mattoon

Max B Ryan

A method includes obtaining electrical measurements of an input signal of a power system. The electrical measurements are obtained at a sampling frequency and the input signal is indicative of an operating frequency of the power system. The method includes generating an intermediate signal from the input signal. The intermediate signal has a direct current (DC) component indicative of a magnitude and a phase of the input signal. The method includes filtering the intermediate signal using an adjustable length filter to obtain the magnitude and the phase of the input signal. The length of the adjustable length filter varies based at least in part on a period measurement of the power system.

Processing sinewave signals of variable frequency in a device with fixed processing rates

An apparatus and method for compensating digital input delay in an intelligent electronic device is provided. A method is provided which provides for accurate SER data recording while facilitating the reduction of processing burden on the IED and optimization of system performance during the processing of SER data flow. An apparatus is further provided which generally includes a time delay element coupled to a sequential events recorder for compensating for delay in communication of a data signal such that the sequential events recorder records a compensated time for a select event based on the clock and the time delay. An apparatus is provided which includes an edge detection element for detecting either a rising or falling edge from the data signal.

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Bothell, WA, United States of America

Daniel P Dwyer