An inside look at the new world of Surveillance AutomationJanuary 25, 2024
|The new patent reinforces the novelty and utility of Power Intelligence’s Sigma Delta Tau algorithm for the preventative maintenance of utilities.
On January 16th 2024 the United States Patent and Trademark Office (USPTO) issued patent number #11,877,087 “METHODS AND SYSTEMS FOR REMOTE MONITORING OF ELECTRICAL EQUIPMENT” to Randall Thompson, inventor, CEO and owner of Power Intelligence LLC. This patent codifies Thompson’s novel approach to condition-based monitoring and automated thermography, dubbed Sigma Delta Tau (SDT) using the greek symbols SIGMA to represent standard deviation or degrees of normality and DELTA TAU to represent stability of these relationships over time.
What’s the difference between SDT automation and manual methods of thermography?
Conventional methods of infrared analysis or ‘thermography’ rely on subjective assessments of environmental factors like ambient temperature, wind speed, direction, humidity and solar effect to derive an ‘adjusted’ temperature that is used to assess equipment condition.
The inherent subjectivity of these assessments can produce large variations from one practitioner to the next, significantly reducing the predictive quality of these analyses. Not to mention the fact that manual thermographic sampling of energized equipment can expose workers to risk of electrocution.
Conversely, the newly-patented SIGMA DELTA TAU (SDT) technology enables full automation of these assessments without the need for external instruments to make adjustments due to environmental factors. The result is accurate and reliable condition assessments at distances up to 200 feet between the thermal imaging camera and the measured object, enabling fully automated station-wide measurement and assessment from a single camera and location.
“This feature alone changes the economics of condition-based maintenance, bringing affordable continuous automated assessment within the reach of every utility and equipment operator,” said Thompson.
The SDT algorithm has proven its worth in many notable high-profile installations like Atlanta’s Hartsfield-Jackson International Airport, where the technology is used to monitor the condition of hundreds of splices and dozens of switches and circuit breakers that make up the world’s busiest airport’s subterranean power delivery network. Over 100 thermal imaging cameras continuously monitor every critical connection and device and report results back to Georgia Power’s data center where the Power Intelligence software analyzes the images and reports the results to the utiliy’s SCADA system. Since installation the Power Intelligence system has detected two developing faults and averted a repeat of the 2017 11-hour outage that cost Delta Airlines alone over $50 million.
Similar detections have been made at other installations using Power Intelligence automated systems including at Entergy’s JOLIET substation which provides power to New Orleans’ levy pump system, and JOEMC, a North Carolina energy co-op who recently installed the first of these systems to be deployed in a distribution-level substation where a failing disconnect was detected within days of commissioning.
The benefits of real-time continuous monitoring of electrical assets have been clearly established both by anecdotal reports and empirical analysis by EPRI (Electric Power Research Institute), the nation’s leading authority on generation, transmission and distribution technologies and practices. In 2019 EPRI performed an exhaustive analysis and review of the SDT technology as part of Georgia Power’s due diligence into the merits of the technology in preparation for the deployment at the Atlanta airport.
The patent was assigned to North Carolina-based research and development firm NeoGenesys Inc. which has licensed the technology to Power Intelligence for use in the field of electrical equipment monitoring and diagnostics.
“With this patent and access to the underlying technology, Power Intelligence is uniquely positioned to deliver valuable products and services to owners and operators of the high-voltage equipment that makes up the nation’s electrical grid,” continued Thompson.
The patent for the Sigma Delta Tau algorithm details how this technology enables automation of infrared image processing and condition analysis in ways that extend the capability to measure, monitor and maintain critical assets like transformers, breakers, switches and disconnects without costly and potentially dangerous manual inspection methods.
The nature of the SDT algorithm is to establish a qualitative baseline of condition by observing and recording the range of nominal or “normal” differences between related groups of measurements, rather than comparison of a single measurement to a specific threshold value. This allows for the modeling of these relationships over time and the early detection of outliers, well in advance of a catastrophic failure.