Development and qualification of a temporary supporting device for HV electrical substations

The transmission network development along with the connection of new customers and compensating systems call for extension works in existing substations. In order to address that growing need while minimising down time, Rte has acquired new Temporary Supporting Devices for High Voltage Electrical Substations. Such devices make it possible, per example, to carry out works on busbars keeping uninterrupted service on Rte network. SERECT was asked to design the new device, which was developed in about two years. It meets applicable French, European and LW regulations. These devices offer several benefits: they are versatile, and can be used in 225 kV and 400 kV substations alike. They are designed to enable the execution of works lasting up to 12 weeks (wind resistance up to 180 km/h). They are flexible in use, as they do not require preliminary civil engineering work. They are dimensioned to resist the electrodynamic forces generated by short circuit currents up to 40 kA. Their height is adjustable from 4 m to 8.2 m, allowing them to be adapted to the configuration of the substation. In particular, the device allows the realisation of extension works in HV substations, the connection of new cells, the replacement of equipments and all works on busbars. The development is fully consistent with Rte Live Working policy and its aim to continuously improve the feasibility of work without de-energising the infrastructures of the transmission network. It meets the company's objective of continually improving service quality and customer satisfaction.