Defects Defection. Smarter Inspection.

Transformers are among the most critical assets in substations. Components such as bushings, transformer tanks, radiators, conservators, and high- and low-voltage terminals operate continuously under high-voltage and high-current conditions. Localized overheating may occur due to overload, loose electrical connections, or internal insulation aging. If left undetected, these thermal anomalies can lead to insulation breakdown, transformer fires, or even explosions.

• Traditional spot thermometers measure only a single point, making it difficult to detect localized hotspots.
• Energized bushings are installed at elevated positions, making close-range inspection hazardous.
• Sudden temperature rises cannot be captured in real time, leaving significant gaps in routine inspections.

Gas-insulated switchgear (GIS) integrates high-voltage components such as circuit breakers, disconnectors, and busbars within a sealed metal enclosure, offering advantages such as a compact footprint and high operational reliability. However, internal issues such as gas leakage, poor contact at switching points, and insulator defects are difficult to detect through visual inspection. Once a failure occurs, it can lead to severe consequences and significant system disruptions.

• Sealed enclosure design makes internal defects impossible to identify through visual inspection.
• Conventional leak detectors cannot identify electrical defects such as overheating at contact points.
• Sudden internal faults cannot be detected in advance or effectively warned against.

Busbars serve as the main pathways for power collection and distribution within substations. Their connection points carry high currents continuously and are susceptible to increased contact resistance caused by loose bolts, oxidation of contact surfaces, or improper installation. These issues can result in abnormal heating at the connection points. If overheating is not addressed promptly, it may trigger a busbar fault, leading to a total substation power outage.

• A large number of connection points make individual inspections time-consuming and labor-intensive.
• Overheating can escalate into a vicious cycle, increasing the risk of equipment failure.<br>
• Energized busbars make close-range inspection hazardous.

Current transformers play a critical role in reducing high primary currents to proportional secondary currents. During long-term operation, issues such as moisture ingress into the insulation, loose electrical connections, and core deterioration can lead to localized overheating. Failure to detect this in time will compromise the accuracy of relay protection and metering, and in severe cases, could lead to equipment explosion.

• Continuous full-load operation increases the risk of internal defects.
• Early-stage overheating shows only slight temperature rise, making faults difficult to detect.
• Conventional diagnostic methods may miss or misinterpret voltage-induced thermal faults.

Voltage transformers are used to step down high voltages proportionally for use by measuring instruments and protective devices. During long-term operation, faults such as internal insulation degradation, core overheating, and loose terminals can easily lead to abnormal temperature rises, thereby affecting equipment lifespan and system safety.

• Internal defects in the core and insulation cannot be visually identified.
• Voltage-induced thermal faults are difficult to diagnose.
• Special insulation structures make diagnostic analysis more complex.

High-voltage bushings are critical external insulation components used in transformers, circuit breakers, and GIS equipment. They are subjected to both high voltage and heavy current stress during operation. Defects such as internal insulation moisture ingress, low oil level, and aging of the capacitive core can manifest as abnormal thermal patterns, making bushings one of the most common sources of heating faults in substation equipment.

• Bushings are installed at elevated positions, making close-range inspection hazardous.
• Early-stage moisture ingress and insulation aging produce subtle temperature rises that are easily overlooked.
• Single-point temperature measurement cannot reflect the overall thermal distribution.