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Digital Monitor for Power Lines

IP.com Disclosure Number: IPCOM000075511D
Original Publication Date: 1971-Sep-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 51K

Publishing Venue

IBM

Related People

Felton, BC: AUTHOR [+5]

Abstract

This monitor provides a permanent record in decimal format which identifies power line disturbances by amplitude and duration thresholds. It is a three-phase, line-to-line connected device which has the ability to separately record low-frequency disturbances (one-half power cycle or greater duration), switching disturbances (300 Hz to 3,500 Hz), high-frequency disturbances (4 KHz to 30 KHz), and date and time of the disturbance. Disturbance Separation.

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Digital Monitor for Power Lines

This monitor provides a permanent record in decimal format which identifies power line disturbances by amplitude and duration thresholds. It is a three- phase, line-to-line connected device which has the ability to separately record low-frequency disturbances (one-half power cycle or greater duration), switching disturbances (300 Hz to 3,500 Hz), high-frequency disturbances (4 KHz to 30 KHz), and date and time of the disturbance. Disturbance Separation.

Disturbances are separated in the power line monitor 10 through the use of an isolation transformer and three pass filters for each of the three phases. The disturbances are placed in three separate categories: high frequency, switching, and low frequency. From this point on, they are monitored separately and recorded separately. Strobe Generation.

Low-frequency disturbance sampling is performed at the peak point of the power cycle. This is accomplished by generating a strobe (sample) pulse 12 which is synchronized with the preceding zero voltage point on the power waveform and then delayed to the peak point. There is a strobe generation circuit for each of the three phases. Amplitude Deviation Detection.

The low-frequency Amplitude Deviation Detector 14 for each phase is a gated, over/under voltage detector which can be preset to any desired level. The detector is gated on by 12. Duration Accumulation

Output of 14 steps a duration counter 16 one position for each 1/2 cycle, until the disturbance ends. Output of 16 and categorization (amplitude and phase) of the disturbance are utilized by logic to opera...