PEXLINK is Hitachi ABB Power Grids concept for improving transmission line reliability and availability by providing protection of line insulation. In addition to using our well-proven polymer-housed arrester PEXLIM along with additional accessories for fixing the surge arresters across the insulators the PEXLINK concept utilizes a special disconnecting device for automatic disconnection of the arresters in the event of an overload of the arresters. The PEXLINK concept is a simple, cost-effective and proven method of increasing the performance of transmission lines.
The PEXLINK concept has traditionally employed Non-Gapped Line Arresters (NGLA) for protection of transmission lines as such solution offers several important advantages. For the system voltage of 765 kV Hitachi ABB Power Grids is now also able to offer an innovative Externally Gapped Line Arrester (EGLA) solution that provides the user with many unique benefits previously reserved for NGLA solutions only like switching control.
Using Hitachi ABB Power Grids' standard PEXLIM arrester
Hitachi ABB Power Grids' philosophy is to provide protection for line insulation at selected locations. The main element of the PEXLINK concept is the gapless silicone polymer-housed arrester PEXLIM with metal-oxide (MO) active elements. The PEXLIM surge arrester have been used for many years for protection of equipment in sub-stations and their superior protective performances are well-known.
The low weight of the PEXLIM arrester permits installation on existing structures and the polymer housing gives increased reliability of the line equipment as well as safety for people and animals which may be in the vicinity of the lines during overstress conditions
To ensure quick, safe, automatic and controlled disconnection of a failed arrester, Hitachi ABB Power Grids uses a special disconnecting device and a suitable link in the ground circuit of the surge arresters.
PEXLINK Concept Solution
To achieve optimal placement and selection for a PEXLINK installation Hitachi ABB Power Grids provides a service in which we conduct computer simulations of transmission lines to determine optimal installation strategy: e.g. installation locations, tower configuration and arrester stress level at each of the chosen locations along a transmission line. This approach will ensure that the installation strategy is cost-efficient whilst maximizing the performance improvements.