US 11,754,602 B2
Frequency sensing systems and methods
Marcos A. Donolo, Pullman, WA (US); and Jay Hartshorn, Moscow, ID (US)
Assigned to Schweitzer Engineering Laboratories, Inc., Pullman, WA (US)
Filed by Schweitzer Engineering Laboratories, Inc., Pullman, WA (US)
Filed on Dec. 8, 2021, as Appl. No. 17/545,385.
Application 17/545,385 is a continuation of application No. 16/569,702, filed on Sep. 13, 2019, granted, now 11,231,449.
Claims priority of provisional application 62/734,900, filed on Sep. 21, 2018.
Prior Publication US 2022/0099717 A1, Mar. 31, 2022
Int. Cl. G01R 23/02 (2006.01); G01R 23/00 (2006.01); H03M 1/12 (2006.01)
CPC G01R 23/02 (2013.01) [G01R 23/005 (2013.01); H03M 1/12 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A system comprising:
a memory device; and
a processor operatively coupled to the memory device, wherein the processor is configured to execute instructions stored on the memory device to cause operations comprising:
obtaining a plurality of electrical values of an electrical waveform of an electric power delivery system, wherein the plurality of electrical values comprises:
a first value obtained at a first time; and
a plurality of previous values obtained at a plurality of times before the first time, wherein the plurality of previous values comprises a first previous value obtained at a second time;
determining a plurality of computed derivative values of the electrical waveform based on one or more of the plurality of previous values, wherein the plurality of computed derivative values comprises a first computed derivative value corresponding to a derivative of the first previous value;
determining, from the first computed derivative value, a first scaled derivative value that is scaled according to a first time duration between the second time and the first time;
determining a frequency of the electrical waveform based at least in part on the first time duration, the first value, and the first scaled derivative value; and
causing an operation of the electric power delivery system to be controlled based at least in part on the frequency.