Power device for preventing malfunction

Patent metadata

Field	Value
Publication number	US-9515480-B2
Application number	US-201414461770-A
Country	US
Kind code	B2
Filing date	Aug 18, 2014
Priority date	Aug 30, 2013
Publication date	Dec 6, 2016
Grant date	Dec 6, 2016

Abstract

The protecting relay may include: an input conversion unit configured to receive the analog signal and sample the analog signal according to a pre-set sampling period; a multiplexer configured to selectively output any one of a plurality of signals output from the input conversion unit; a programmable gain amplifier (PGA) configured to set different gain values according to signals output from the multiplexer, and amplify a signal output from the multiplexer with a pre-set gain value; an analog-to-digital converter (ADC) configured to convert an analog signal output from the PGA into a digital signal; and a controller configured to determine whether the analog signal received through the input conversion unit includes a surge signal based on the plurality of sampled data which have been converted into the digital signal, and determine whether to perform a relay function based on the determination results.

First claim

What is claimed is:

1. A power device configured to receive and process an analog signal generated by a certain electric power system, the power device comprising:
an input conversion unit configured to receive the analog signal and sample the analog signal according to a pre-set sampling period;
a multiplexer configured to selectively output any one of a plurality of signals output from the input conversion unit;
a programmable gain amplifier (PGA) configured to set different gain values according to signals output from the multiplexer and amplify a signal output from the multiplexer with a pre-set gain value;
an analog-to-digital converter (ADC) configured to convert analog signals output from the PGA into digital signals to obtain a plurality of sampled data; and
a controller controlling operation of a protecting device, the controller configured to:
determine whether the analog signal received through the input conversion unit includes a surge signal based on the plurality of sampled data;
determine whether to perform a relay function based on the determination results;
calculate a plurality of slopes based on two or more continued sampled data among the plurality of sampled data;
determine whether signs of the plurality of calculated slopes have been changed; and
determine that the analog signal includes a surge signal when the signs of the plurality of calculated slopes have been changed.

2. The power device of claim 1 , wherein the controller is further configured to withhold performing the relay function, generate alarm information, and output the generated alarm information when the analog signal includes a surge signal.

3. The power device of claim 1 , wherein the controller is further configured to determine that the analog signal does not include a surge signal and perform the relay function when the signs of the plurality of calculated slopes have not been changed.

4. The power device of claim 1 , wherein the power device is any one of a protecting relay, a phasor measurement unit (PMU), or a measurement device.

5. The power device of claim 2 , wherein the controller is further configured to determine that the analog signal does not include a surge signal and performs the relay function when the signs of the plurality of calculated slopes have not been changed.

Assignees

• Lsis Co Ltd

Inventors

• Park Kyung Won

Classifications

• H02H9/02

  responsive to excess current {(current limitation for voltage regulators G05F1/573; disconnection after limiting H02H3/025)} · CPC title

• G01R19/2506

  Arrangements for conditioning or analysing measured signals, e.g. for indicating peak values (G01R19/003 takes precedence); Details concerning sampling, digitizing or waveform capturing (displaying waveforms G01R13/00; analog sampling G01R19/0053) · CPC title

• H02H9/04

  responsive to excess voltage (lightning arrestors H01C7/12, H01C8/04, H01G9/18, H01T) · CPC title

• G01R19/25

  using digital measurement techniques · CPC title

• H02H9/005 Primary

  avoiding undesired transient conditions · CPC title