Thermal cameras in substation monitoring

Challenges


A power system consisting of electrical generation, transmission, and distribution, brings the electricity from the power plant to consumers through several substations at different voltage levels.


A large substation may have dozens of switches and other equipment. Aging and lack of continuous monitoring of the key equipment at substations and elsewhere on the grid may result in a power outage or a voltage drop causing lights to dim (blackout and brownout). For example, a disconnector breakdown or OCB oil leak causing bushing head overheating may lead to failures of a substation, which can evolve into a series of accidents in traffic, communications, security systems, banking, manufacturing, and food refrigeration. It’s estimated that the average cost of downtime across all industries could be up to $950,000 / hour.



Solution


Maintenance electricians can isolate potential failures of substations before their occurrence by identifying the heat signatures using infrared cameras, e.g. overheating or abnormal cool. Traditional spot check with handheld infrared cameras is ineffective due to the limitations of both time and workforce, not to mention the safety risk to personnel. Manual inspection has the potential to miss impending failure warning signs.


Compared to a single snapshot, a fixed-mount monitoring camera can collect thermal data continuously and analyze heat anomalies with temperature trends through live streaming based on FOTRIC open-source SDK.


Suitable product


A surveillance system consisting of FOTRIC 600 fixed-mount cameras with either auto or manual focus can provide stable and accurate 7*24h monitoring. Heat anomalies can be discovered and localized immediately in substations based on the camera features below:

  • They can see through dust, smoke, rain, and fog even in darkness at -25° to 65°C, which is practical in harsh conditions;

  • A detection range of -20°C to 2000°C for both normal and extreme temperature detections;

  • An imaging resolution up to 640 x 480 with a sensitivity of 0.03°C for detecting minute heat anomalies;

  • Lens options from 10° to 92°, enough for either distant targets or wide view purposes e.g. in substations.


Benefits


  • Complete data, events, and measured values can be archived and analyzed by FOTRIC open-source API SDK which offers versatile modular functions tailored to users’ demands;

  • Remote thermal monitoring for plant management with quantitative temperature readout and 30Hz radiometric live streaming can be recorded manually or by an automatic trigger;

  • More granular data, informed decision-making, improved reliability of electric power delivery, reduced maintenance costs, enhanced personnel safety;

  • Instant alarm for temperature beyond the pre-set parameters;

  • Easy integration into existing plant control system through SDK;

  • Some customers can report an insurance premium discount because of the increased reliability.


Applications


The key is to focus on the most critical equipment in a substation such as a transformer, circuit breaker (OCB), bushings, lightning arrestor, and surge protector, which, if it fails, will result in a major outage. FOTRIC 600 camera can help you find potential problems before they find you. Except for transformer cooling tubes, the temperature rises abnormally in the following components are usually failure warnings:

  • Transformers: cooling system failures can induce damage to the transformer rapidly. A blockage or low oil level in cooling tubes will show up as cool tubes. Also, look at the fan motor housings after they have run for 15 minutes or more to see if any of them show hotter than the others;

  • Bushings (insulator, transformer, or OCB bushings): overheating with oxidation in both external and internal connections in the bushing head or coil end caused by an increase of dielectric loss, lack of oil in the bushing or poor contact of the conductive circuit;

  • Oil-filled circuit breakers (OCB) and voltage regulators are also critical to substation operations and can suffer heat-related failures like transformers;

  • Surge protector: Look closely at segmented signatures with small rises in temperature as indicators of serious problems;

  • Lightning arrestors: degradation of metal oxide disks;

  • Capacitor: heating due to blow or poor contact of capacitor fuse or connector.