LCOE has put into service a new mobile resonant generator which enhances its capacity to attend the increasing demand from the electrical industry of AC withstand and insulation assessment tests of HV cables systems.

These tests are needed to guarantee the quality of the final construction of the cable, its accessories, and the whole process of the installation and assembly of terminations and joints. These commissioning tests are made before putting the cable system into service, applying an AC overvoltage with standardized voltage values and test durations, while performing the measurement of partial discharges in the main insulation; therefore, it is possible to detect emerging defects, which are located and solved before the operation of the line. Detection of defects while applying an overvoltage to the cable is much more effective than under normal service voltage, since partial discharges like those originated in incipient defects, usually appear and are more easily detectable in overvoltage conditions.

The new resonant system will allow to test longer cables in the new lines in power networks as well as in distribution networks. Particularly, when connected in parallel with other LCOE unit, it will be possible to test 220 kV and 400 kV cable systems with approximate lengths up to 24 km and 18 km respectively, although maximum lengths depend on the specific value of the capacitance of the cables under test.

With this unit, LCOE completes a set of four resonant generators for making the on-site tests after installation of cable systems and GIS switchgear prescribed in the corresponding standards and regulations.

More information: Sergio Ramos sramos@ffii.es