XXL connection and disconnection

For several years, the system of RTE has been handling a steadily rising number of requests for connecting new customers with photovoltaic or wind farms. Often, that is achieved by means of a branch connection to existing lines. Branch connections to lines reduce the cost of connection, but generate constraints in respect of the maintenance of structures, since the power supply to the customer cannot be maintained if the line is to be de-energised. Until now, maintenance was carried out using the dead line procedure on a part of the line after disconnecting a jumper at the branch connection pylon. That disconnecting operation is also possible in a live working situation, thanks to a specific piece of equipment called the AGD (arc guidance device, developed by Serect), which makes it possible to connect and disconnect installations up to 1.5 km, for example in 225 kV. In 2015, we pushed back the limits on connection and disconnection operations. An experiment was conducted with 225 kV on one of our structures, along with a customer with a branch connection. The aim was to isolate the part of the installation on which the work was done, while retaining service quality. A quick break disconnector and live work were used as the disconnecting tool. That solution allows switching up to 40 km, for de-energising links or switching them to no-load voltage. This experimental technique opens new vistas in a changing world, and reinforces the value of live work as a facilitator for the tasks of transmission system operators, who are faced with ever-increasing constraints. New outlook in terms of: • Flexibility of the maintenance schedule. • Innovation & Development of live working tools and procedures for connecting and disconnecting installations. • Exploitation & Sharing of our know-how by integrating our methods into the catalogue of RTE for national and international markets.