|Title: ||Design of assets of a mixed overhead line – underground cable 400kV link –|
|Authors: ||Rimez, Johan|
Kim, Seon Gu
Engelbrecht, Chris #
|Issue Date: ||Mar-2014 |
|Conference: ||CIGRE location:Brussels date:2014|
|Article number: ||A1-102|
|Abstract: ||A new trend to develop the new assets of the modern High Voltage (HV) grid has been deployed on one of the major current investment projects of the Belgian Transmission System Operator (TSO) Elia. The new approach is a technique which is mapping the known, foreseeable and even unknown risks of a project. Starting from the impact of these risks on the installation, commissioning, operation, maintenance, emergency interventions, even decommissioning, the protection systems, lightning protection, electrical phenomena, each different topic will be treated to mitigate the corresponding risks within acceptable levels.
One of the very first projects where this new approach is applied, is the STEVIN link. This link, named after Renaissance mathematician Simon Stevin from Bruges, is a necessary step to connect electrical power from almost all wind power plants in the Belgian Territorial waters and from the NEMO HVDC link (connection the Belgian and the English grid with a rating of 1000MW) to the main 400kV grid, which is situated some 50 km inland. Close to the coastal area, only a radial 150kV grid actually exists, which is unable to absorb all the new announced offshore electrical power. The success of the wind integration program and the interconnector with the UK depends on the availability of this new grid antenna.
The rating chosen for this new link is 3000MVA, valid for any single contingency situation within this connection. This value corresponds to the highest transferred power stated by forecasting studies for wind energy production projected over 20 years in the future.
The permitting procedure, with the visual impact and the generation of electro-magnetical fields of the link in particular, made the option to have the link using only overhead line technology impossible. Several options to have the link partly underground were researched, and the choice finally fell on the use of four parallel three-phase systems of 400kV underground cable on the section closest to the historical of Bruges. As a consequence, reactive power compensation, by means of shunt reactors had to be integrated into the project.
The paper presents for each part of the final structure of the mixed-structured Stevin Link the technical choices, related identified risks and their mitigation methods: for the overhead line parts, the underground cable sections, the technical choices and motivations for the link end and intermediate substations, ratings, functions and technical characteristics of the reactive power compensation devices.
|Publication status: ||published|
|KU Leuven publication type: ||IC-p|
|Appears in Collections:||Non-KU Leuven Association publications|