Health hazards of high-voltage cables: crises that are invisible to the naked eye
1.1 “Time bomb” inside the cable
Insulation layer bubbles (≥ 2mm bubbles in 110kV cables can cause partial discharge)
Conductor deformation (reduction of cross-sectional area by more than 15% due to construction traction)
Damaged waterproof layer (causing aging of water trees, resulting in the replacement of the entire line in a certain city)
Joint process defects (accounting for 82% of cable failures)
1.2 Limitations of Traditional Testing
Test method Discoverable issues Blind area
Infrared temperature measurement surface hotspots internal defects
Partial discharge detection partial discharge early insulation defects
Ohm test on/off fault hidden damage
X-ray detection full structure visualization none
Core technology of cable specific X-ray detection system
2.1 Three major technological innovations
Variable frequency pulse radiation source with adjustable penetration power (suitable for 35kV-500kV cables)
70% reduction in radiation dose (compliant with GBZ117-2022 standard)
Curved array detector adaptive cable curvature (diameter 50mm-200mm full coverage)
Pixel density 0.1mm/pixel
AI automatically compares historical data
Generate 3D defect model
Predicting remaining lifespan (accuracy>90%)
Actual test cases
Test object: 220kV cross-linked polyethylene cable, with a total length of 18.6km
Operating life: 12 years
Discovered issues: Poor crimping at 7 joints (maximum gap of 1.3mm) and impurities in the insulation layer at 23 joints (maximum size of 4.2mm)
Assessment of the aging degree of water trees along the entire line
Economic benefits: Avoiding potential power outage losses of approximately 27 million yuan
Extend the service life of cables by 8-10 years
Maintenance efficiency increased by 6 times
Post time: May-21-2025