GPLK cables: challenges with aging medium-voltage cables
The Challenge: Aging GPLK Cable Networks
In many industrial sectors and grid operators, the electricity grid still consists of a mix of old GPLK cables (Armored Paper Lead Cable) and newer XLPE/EPR cables. Due to the energy transition and the increasing demands on grid reliability, investments are being made worldwide in the renewal of underground networks. But complete cable replacement is expensive and time-consuming. That is why older GPLK cables often remain in use for years.
Why extending cable life is important
For many companies, it is more attractive to invest in grid expansion rather than complete renovation. Extending the lifespan of existing cables is therefore crucial to achieve investment targets. Proper maintenance and innovative technologies make it possible to continue to use these older cables safely and reliably.
What makes GLCC cables vulnerable?
GPLK cables are made up of paper layers that are impregnated with oil and protected by a lead sheath. As the cable ages, the oil dries out due to thermal stress, ground movement and corrosion. This leads to:
- Dry and brittle paper insulation
- Formation of air holes (cavities) in the insulation
- Increase in partial discharges (PD), which further affects the cable
The solution: Lovink’s oil refill joint
The most commonly used connection technique for GLLK cables is hot shrink technology, but this does not provide a solution for drying out the insulation. Lovink therefore developed the oil refill joint: an innovative cable joint that significantly extends the lifespan of GPLK cables. This cable sleeve has an oil reservoir that constantly supplies oil.
How does it work?
- Constant oil supply: The external oil compartments ensure a continuous supply of oil to the cable.
- Restoration of insulation: The oil refills the paper layers, prevents drying out and reduces air cavities.
- Better protection: Prevents partial discharges and extends the operational life of the cable.
Benefits of LoviSil Technology
- Restores the original insulation quality
- Suitable for complex cable connections (GPLK-GPLK and GPLK-XLPE)
Want to know more about reliable cable connections?
Would you like to discover how LoviSil® Oil Refill Sleeves protects your medium-voltage network against failures and saves costs? Feel free to contact our specialists for advice without obligation.
