Fiber Optic Current Monitoring (CAMOS)
The Challenge of Modern Power Grids
The ongoing electrification of industry, transportation, and society, combined with the rapid integration of renewable energy sources, is driving a substantial increase in power transmission and distribution requirements. To meet these demands, utilities are expanding network capacity while simultaneously maximizing the utilization of existing cable assets.
At the same time, network operators must maintain compliance with reliability and N-1 security criteria despite increasingly dynamic power flow patterns, growing network congestion, and evolving generation portfolios. As a result, power cable systems are frequently exposed to higher load variations, increased thermal cycling, and operation for extended periods at increased load levels.
These operating conditions subject cable systems, joints, terminations, and bonding arrangements to increased thermal and mechanical stresses. Over time, such stresses can accelerate asset aging, reduce the expected service life of critical components, and increase the likelihood of developing defects and forced outages. For asset managers, maintaining network reliability while optimizing asset utilization and extending asset lifetime has therefore become a key strategic objective.
AP Sensing's Cable Advanced Management Optical System (CAMOS)* continuously monitors sheath currents, grounding behaviors, load dynamics and fault-related current signatures across the cable circuit. Advanced analytics automatically identify abnormal operating conditions, insulation degradation indicators, bonding and grounding anomalies, joint defects, and emerging fault signatures before they develop into critical failures.
The resulting insights help utilities improve asset reliability, optimize maintenance planning, reduce outage risks, and accelerate fault assessment and root-cause analysis following network events.
AP Sensing’s Fiber Optic Current Monitoring
AP Sensing's CAMOS extends our industry-leading Distributed Fiber Optic Sensing portfolio (DTS, DAS, and DTSS) with continuous electrical condition monitoring for high-voltage power cable systems. CAMOS provides utilities and asset operators with real-time visibility into the electrical condition of cable networks, complementing distributed temperature and acoustic monitoring with critical current-based diagnostics.
The system continuously monitors sheath currents and other key electrical parameters, providing early detection of developing cable issues such as bonding failures, insulation degradation, link box flooding, unintended ground contacts, sheath damage, and third party interference. These measurements provide valuable insights into cable condition and enable proactive maintenance strategies before faults impact network reliability.
CAMOS uses a centralized interrogator connected to multiple distributed current sensors installed along the cable route. The sensors can be deployed in remote locations such as link boxes, manholes, and cable pits, enabling scalable monitoring across long cable circuits while minimizing field infrastructure requirements.
Beyond real-time current monitoring, CAMOS supports advanced condition assessment through capacitive current analysis, homopolar and cross-ground current measurements, oscillography, harmonic analysis, and Total Harmonic Distortion (THD) calculations.
Integrated into our SmartVision platform, CAMOS provides operators with real-time visualization, alarm management, trend analysis, and actionable asset intelligence.
CAMOS Optical Current Transformer (OCT) Technology – How it works
CAMOS is powered by patented Optical Current Transformer (OCT) technology, delivering highly accurate current measurements for monitoring, protection, and asset management applications in high-voltage cable systems.
Key benefits include:
- Accurate current measurement from normal operating conditions up to short-circuit currents of 80 kA
- High-precision phase angle measurement for advanced diagnostics and protection
- Inherently saturation-free operation, ensuring linear measurements across the full current range
- Passive sensors requiring no local power supply
- Immunity to electromagnetic interference (EMI)
- Multiplexing of multiple sensors on a single optical fiber
- Sensor suitable for 87L, 87S, and 50S protection functions
CAMOS Fiber-based Current Monitoring (FbCM) solution
The CAMOS FbCM solution is ideally suited for projects with existing or planned acoustic monitoring using AP Sensing's Distributed Acoustic Sensing (DAS) technology. The patented FbCM system converts the current readings from conventional Current Transformers (CTs) into a readable optical information for the DAS system. No additional interrogator is required, and both systems operate on the same optical fiber infrastructure.
Key benefits include:
- Seamless integration with AP Sensing DAS systems
- No additional interrogator or communication infrastructure required
- Simple field installation with only two fiber splices per FbCM unit
- Multiple FbCM units can be daisy-chained along the same fiber route
- Designed for operating current measurements from 0 to 300 A
- Passive sensor technology requiring no local power supply
- Immune to electromagnetic interference (EMI)
By combining acoustic event detection and current monitoring on a single sensing platform, the CAMOS FbCM solution provides utilities with a cost-effective approach to enhance situational awareness, support asset management, and increase the value of existing DAS installations.
Unique Adavantages of AP Sensing’s CAMOS solution
Underground Cable Maintenance
CAMOS measures current magnitude and phase angle, providing a comprehensive view of the cable system's operating conditions. This enables the real-time detection of anomalies and deviations and supports informed operational decisions to maintain the condition and service life of the cable installation.
Underground Cable Fault Locator
The location of cable faults is a complex task, and prolonged outages can result in significant losses for utilities and their customers. The CAMOS system uses dedicated algorithms to identify the affected phase, determine the section between grounding points, and, for transposed cable systems, pinpoint the exact fault location.
Fault Discrimination in Mixed Lines
In lines with areas that work both overhead and underground, CAMOS provides protection (87L/87S/50S), which allows segregating where the fault has occurred. To do so, CAMOS uses a set of OCTs located at the terminal points of the underground sections.
Key Product Features and Highlights
AP Sensing’s CAMOS solution has broad applicability across industries and infrastructure systems that rely on high-voltage AC power cables:
Windfarms that depend on extensive underground power cables benefit from CAMOS real-time monitoring and fault detection.
CAMOS ensures the reliability of power cables by continuously monitoring for insulation failures, bonding issues, and other critical faults.
- Renewable Energy Generation:
Windfarms that depend on extensive underground power cables benefit from CAMOS real-time monitoring and fault detection. - Power Transmission and Distribution:
CAMOS ensures the reliability of power cables by continuously monitoring for insulation failures, bonding issues, and other critical fault.
Our team of application engineers will work with you to integrate CAMOS into your monitoring solution. We’ll help you optimize system performance, ensuring seamless integration with the DFOS solution while balancing cost efficiency, data accuracy, and long-term reliability for safeguarding your critical infrastructure.