Summary
As HVDC grids evolve into complex meshed networks, careful consideration is needed when introducing new test waveforms. While HVDC technology has advanced rapidly to 525 kV systems with high transmission capacities, introducing new test waveforms must be done cautiously due to the high cost, long duration, and risk of unnecessary testing requirements becoming permanent.
Read more Read lessCIGRÉ Technical Brochures 852 and 853 define several TOV wave shapes, with the long-front same-polarity waveform (LTOV-SP) being the primary reference. Using electric-field calculations for a 525 kV, 3000 mm² cable, the paper compares LTOV-SP with other waveforms such as opposite-polarity LTOV-OP and zero-crossing damped TOVs (ZCD-TOV).
Across materials and temperatures, LTOV-SP consistently produces the highest electric-field stress, while LTOV-OP and ZCD-TOV remain equal or lower. Standard tests such as AC power-frequency and lightning impulse (LI) often create higher peak stresses than ZCD-TOV.
The motivation for TOVs—longer duration—lacks experimental support. Some research shows that breakdown strength in solid insulation is governed mainly by wave-front steepness, not wave-tail duration surpassing Switching Surges, and that longer waveforms do not necessarily reduce breakdown levels. The paper calls for targeted research to better understand breakdown mechanisms and for caution before standardizing costly new test requirements.
Additional informations
| Publication type | Session Materials |
|---|---|
| Reference | B1_11389_2026 |
| Publication year | |
| Publisher | CIGRE |
| Country | Sweden |
| Study committees | |
| File size | 695 KB |
| Price for non member | 30 € |
| Price for member | 30 € |
Authors
JEROENSE Marc - MJ MarCable Consulting
