Browse Prior Art Database

Analog Monitor for Power Line

IP.com Disclosure Number: IPCOM000075579D
Original Publication Date: 1971-Oct-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 43K

Publishing Venue

IBM

Related People

Kaminsky, CJ: AUTHOR [+3]

Abstract

This device monitors threephase power lines on a continuous, unattended basis, and provides a permanent record of power deviations in excess of a preset tolerance. A permanent photograph of the waveform permits detailed analysis of the characteristics of the deviation.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 57% of the total text.

Page 1 of 2

Analog Monitor for Power Line

This device monitors threephase power lines on a continuous, unattended basis, and provides a permanent record of power deviations in excess of a preset tolerance. A permanent photograph of the waveform permits detailed analysis of the characteristics of the deviation.

Amplitude deviation detector 10 continuously compares the instantaneous value of each of the three line-to-line voltages in a three-phase power system 12 against a built-in standard. Any deviation from a preset tolerance (e.g. + 15%) will result in a display of the voltage on the oscilloscope 14. The 35 mm camera 16 records this display and advances to the next frame. For purposes of resolution, two superimposed sweeps are executed for each phase in each photograph. The first trace is recorded at a sweep frequency of 1 millisecond per centimeter; the second trace at 50 milliseconds per centimeter. This method allows high-frequency disturbances to be easily observed on the first trace (approximately 1/2 of a power cycle) and longer term disturbances on the second trace (approximately 30 power cycles).

When a disturbance is detected, as indicated by an output from 10, the following sequence of events is initiated:.

A) Oscilloscope 14 is triggered via 18 causing the first trace to be recorded at 1 millisecond per centimeter.

B) Completion of the first sweep is signaled via 19 and control 20 resets 14, without erasure.

C) Control circuit 20 also changes the sweep speed of...