Integration of old PILC underground cables into smart grid environments with CSOR current sensor brackets

EWR GmbH upgrades medium-voltage cables with an innovative solution from Horstmann

EWR GmbH has further digitalised its medium-voltage grid with a modern retrofit strategy. By introducing the CSOR current sensor brackets, an innovative technology from Horstmann, old Paper-Insulated Lead-Covered (PILC) cables can be connected to modern short-circuit indicators and monitored via LoRaWAN. The monitoring of this type of cable was previously difficult to integrate into advanced network monitoring systems due to technical limitations. 

The structural integrity of traditional PILC cables remains intact as long as they rest immobile in the ground. However, mechanical shocks or vibrations due to earthworks in the vicinity, or movements caused by frost during the winter, can damage this type of cable. As a result, dangerous short-circuits can occur, leading to widespread power outages and requiring an immediate response from network operators like EWR.

Frank Aschenbroich, Head of Electricity Technology at EWR, explains: "As a grid operator, it is our job to guarantee a secure and
modern supply standard at all times. This also includes the task of digitalising our electricity grid."

The digitalisation of monitoring short-circuit indicators installed on PILC cables was previously a complex undertaking that was both time-consuming and cost-intensive. As the individual conductors above the pothead of the F&G SKV cable termination are not touch-proof, it was impossible to install short-circuit indicators with standard current sensors. Either the conductors were converted to XLPE cables which required introducing additional cable joints, or special short-circuit indicators, like fluid indicators or indicators with fibre optic connection, had to be used. However, fluid indicators have to be read locally which requires a site visit, while short-circuit indicators with fibre optic connections have to be equipped with an expensive telecontrol system for remote reading.

The current sensors are connected to a Sigma F+E 3 L short-circuit indicator, which promptly transmits detected short-circuit events directly to the control centre. This transmission occurs through a LoRaWAN network, ideal for efficiently transporting small data volumes over considerable distances. A notable advantage is the integration of the LoRaWAN transmission module within the Sigma R+D 3 L short-circuit indicators, simplifying deployment. Network managers receive comprehensive event notifications via email from the control centre.

✅ Safe application: type-tested retrofit option

✅ Cost savings: Simple, compact installation without reconstruction measures

✅ Time saving: quick installation

✅ Flexible application options for all common earth cables

✅ Universally applicable: Suitable for all ComPass and Sigma devices

Summary

EWR GmbH has implemented an innovative solution from Horstmann to digitally integrate old PILC cables in the Remscheid power grid and monitor them via LoRaWAN. Until now, it has been difficult to integrate these cables into modern smart grid monitoring systems as PILC cables are not safe to touch, and it was not possible to install short-circuit indicators with current sensors. Thanks to the special CSOR bracket, a modern short-circuit indicator can now be connected to these cables, which reports short-circuit events via LoRaWAN. This solution enables fast, safe, and cost-effective retrofitting of existing medium-voltage substations, which represents a significant step in the digitalisation and sustainable development of the urban energy infrastructure.