Pluggable high-voltage connections by PFISTERER
CONNEX turns power transformers into compact all-rounders
Network structures are changing dynamically while substations are becoming increasingly space-saving. These trends see power transformers and gas-insulated switchgear (GIS) face new challenges. They need to be quickly installable and replaceable, and support outdoor, indoor, offshore and variable use well into the future. Transformers can meet these exacting requirements with the universal, dry and pluggable CONNEX connection system by PFISTERER. With its wide range of cable terminations and connections, surge arresters, bushings, joints and voltage testing systems, it provides the most comprehensive dry and pluggable product range for voltages between 12 and 550 kV available on the market.
The CONNEX plug-in principle guarantees maximum flexibility for power transformers. This is based on the technical philosophy of installing the CONNEX device connection permanently in the system so that the two form a self-contained unit. This means that the socket becomes a device-side integrated interface via which various components such as bushings or surge arresters can simply be plugged in – without the need to intervene in the sensitive inner workings of the system. This significantly facilitates work on site and reduces the installation time by up to 75 %. High-voltage networks and offshore applications benefit in particular because the cable or bushing connection compartment no longer needs to be opened when connecting with HV-CONNEX during the installation and commissioning of transformers and gas-insulated switchgear (GIS). The time- and cost-intensive oil and gas work typical of conventional systems is, therefore, no longer required.
To ensure that the power transformers always operate reliably, the integrated components must meet specific requirements. CONNEX is tested in accordance with all international standards relating to its three system connection areas. It is type approved in accordance with IEC 60840 for conventional cable assemblies, and additionally as per IEC 62271-203 for GIS and as per IEC 60137 for bushings. Since this standard focuses on conventional solutions, PFISTERER expanded its requirements profile. All device connectors have proven in more than one hundred development tests that they achieve far more than the IEC 60137 calls for, and practical experience anticipates, with respect to AC voltage, partial discharge and overload operation. In addition, power transformers equipped with CONNEX have functioned perfectly for many years and with a high degree of user-friendliness.