This webinar, hosted by T&D World and sponsored by Prismian and the Power Delivery Intelligence Initiative (PDI²), features Con Edison discussing their comprehensive approach to cable monitoring for their extensive underground transmission system. Ari Makovas from Con Edison details the utility's strategy, driven by an aging infrastructure, increasing reliability demands, and the integration of renewable energy. The presentation outlines a pilot program initiated in 2016, focusing on solid dielectric cables, which has evolved into a multi-sensor monitoring system. Key technologies include partial discharge (PD) detection, sheath current monitoring, Distributed Temperature Sensing (DTS), video and infrared cameras for vault inspections, Distributed Acoustic Sensing (DAS) for vibration and third-party interference detection, and displacement sensors for joints. The system aims to transition from reactive to proactive maintenance, enable dynamic line rating, improve fault location, and provide rich data for future AI and machine learning applications. Con Edison emphasizes robust infrastructure requirements, including dedicated fiber optic conduits, reliable power, and stringent cybersecurity measures, with the overall monitoring system cost being a small fraction (<1%) of the total cable project cost. The goal is to enhance grid reliability, resilience, and inform future cable system design and maintenance.
Con Edison's Cable Monitoring: A Comprehensive Approach to Underground Transmission Reliability
00:00:12 Introduction: Rod Walton from T&D World introduces the webinar "Cable Monitoring Insights from Con Edison's comprehensive approach," sponsored by Prismian and the Power Delivery Intelligence Initiative (PDI²).
00:01:07 PDI² Mission: Moderator Mike Beer explains PDI²'s focus on evaluating the total cost of ownership for underground versus overhead power delivery over the asset's lifespan.
00:03:29 Prismian's Role: Sergey Golastto from Prismian (EOS division) highlights their mission to help utilities transition from reactive to proactive, data-driven asset management.
00:06:39 Con Edison Overview: Ari Makovas from Con Edison begins, noting the company's 200-year history (founded 1823) and its service of gas, electricity, and steam to New York City.
00:08:21 Service Territory: Con Edison serves a dense 604 sq mile area with 3.6 million customers and a >13 GW peak load, emphasizing the critical need for reliability.
00:09:53 Transmission System Details: The focus is on the mostly underground transmission system (754 miles), with 389 feeders (mostly pipe-type), an average age of 48 years, and some feeders up to 76 years old.
00:11:16 Motivation for Monitoring: The need for a cable monitoring system is driven by aging infrastructure, managing new solid dielectric cables, the rise of renewables, and the potential for AI in data analysis.
00:13:20 Cable Failure Contributors: Past failures often occurred near heavy traffic, areas with substantial elevation differences, construction sites, or external heat sources (steam pipes, subways).
00:15:16 Pilot Project (2016): A 5.7-mile, 138 kV XLP insulated cable with 17 underground vaults was chosen. It included fiber optics in a separate duct for partial discharge (PD) and Distributed Temperature Sensing (DTS).
00:16:26 System Design Philosophy: The monitoring system combines asset health parameters (e.g., temperature, PD) with external operational parameters (e.g., vault inspection, security, fault location) to justify costs and maximize benefits.
00:18:54 Partial Discharge (PD): Crucial for early indication of insulation degradation. Baseline scans are important.
00:21:14 Sheath Current Monitoring: Ensures integrity of single-point bonding systems to prevent circulating currents and overheating.
00:22:24 Distributed Temperature Sensing (DTS): Monitors for new external heat sources, informs cable rating (potential for dynamic rating), and assesses joint thermal conditions.
00:25:05 Video & Infrared Cameras: Allows remote mandatory vault structural inspections, joint infrared scans, and security monitoring.
00:29:00 Required Infrastructure: Includes specialized electronics, sensor supports, grounding, power supply (120V AC preferred over batteries), communication channels, and cyber-secure corporate network connections.
00:30:20 Installation Requirements: Sensors and enclosures must be robust, low-maintenance, and submersible (NEMA 4 + 15ft water column), with adequate lighting and reliable power in each vault.
00:31:47 Power & Communication: Standardized 120V AC power in each vault. Two fiberglass reinforced epoxy (FRP) conduits for separate fiber optic cables (multimode for comms, single-mode for DTS/DAS).
00:32:22 Cyber Security: Rigorous hardware and software security scans are performed before commissioning, with all system access points locked and located on utility property.
00:34:33 System Installation Example: A rendering and photos show the layout in a vault, including electronics boxes, link boxes, cameras, and local vibration sensors. Fiber optic coils (25ft) are left in vaults for slack.
00:37:09 Calibration & Commissioning: Examples include IR camera views of splices, DAS calibration using a hammer drop to identify vault locations, and traffic/train vibration signatures.
00:41:14 Major Benefits: Proactive asset management, enhanced cable ratings, rapid fault location, reduced inspection costs and safety concerns, prevention of splice failures, and creation of valuable data for AI/ML to correlate parameters (e.g., vibration impact on PD).
Generation 2 is currently being installed, and Generation 3 (aiming for all-fiber optic sensors to remove electronics from vaults) is in development.
The cost of the monitoring system is less than 1% of the total cable system material and installation cost.
00:45:43 Q&A - Power Source & AI: Sensors are powered by a dedicated 120V AC circuit run from nearby distribution. AI will be used to correlate data from various sensors.
00:47:57 Q&A - Deployment Scope: The system is being installed on all new solid dielectric transmission circuits, as retrofitting existing ones is too disruptive.
00:49:17 Q&A - FRP Conduits: Fiberglass Reinforced Polymer conduits are used because polyethylene can melt and bond to cable jackets during faults, PVC degrades over time, and FRP has low friction and good thermal properties.
00:53:46 Q&A - Algorithm Development: Con Edison collaborates with vendors, providing the scope of what they want the software to analyze and achieve.
00:55:42 Q&A - Faults Detected: No major cable faults have occurred on the monitored feeders yet. However, the system did help identify some PD activity and incorrectly installed surge voltage limiters (SVLs) via sheath current monitoring during commissioning.