Elia, the power transmission system operator in Belgium, has selected a permanent on-line partial discharge (PD) cable monitoring system from OMICRON for its Stevin project. This project is a major undertaking by Elia to reinforce the high-voltage (HV) power grid in Belgium’s Flanders region. Installation of the OMICRON cable monitoring system will start in the spring of 2016.
One part of the extensive Stevin power grid renewal project consists of laying four 380 kV power cable circuits in the ground, each over a length of 10 km between the grid substations Gezelle and Van Maerlant in Flanders. The OMICRON PD monitoring system will be permanently installed at each of the terminations and joints along these buried HV cable circuits to continuously assess PD activity and insulation condition in the cables. The monitoring system will also assess cable sheath currents during standard operation to detect fault conditions.
Customized system design
The OMICRON PD cable monitoring system consists of high-frequency current transformers for the detection of PD and data acquisition units connected via daisy chain to a data concentration unit in the substation. From there, the pre-processed PD data will be transmitted to a dedicated monitoring server in Elia headquarters for evaluation and documentation using the system’s monitoring software.
Flexible system interfaces for correlation with other monitoring data
Other types of monitoring data, including temperature points from an external distributed temperature system (DTS), can be stored in the OMICRON monitoring system’s database for correlation with the PD data. Likewise, the PD monitoring data can be transferred to an external SCADA system or asset management software applications for correlation with other types of data collected on the grid.
Complete monitoring support services
In addition to working closely with Elia on the customized design of the complete PD monitoring system, OMICRON will also install and commission the monitoring system on site and provide operators with training and data analysis support, as well as condition status reporting. These reports consist of an analysis of the current insulation condition compared with previous monitoring data, as well as a
recommendation for further action when required to ensure continued reliable operation of the cables.
PD monitoring essential for maintaining reliable operation
In defining the Stevin cable project, Elia and the Flemish government agreed to implement all technical solutions available to ensure the safe and reliable operation of the new cable system. PD monitoring was chosen as an important aspect for maintaining its HV cable system as it detects defects in cable insulation, which cause eventual failure and costly outages. Using the actionable data provided by PD monitoring systems, cable operators can make timely maintenance and repair decisions to extend service life. www.omicronenergy.com