Dollands Moor AC/DC changeover is an isolation transformer based changeover scheme at the operational boundaries between Eurotunnel, HS1 and Network Rail infrastructures in Folkstone. This AC/DC changeover is part of a strategic freight link between the UK and Europe.
Phase 1 of the project renewed 3 isolation transformers, phase 2 of the project installed an additional 2 isolation transformers to re-instate the isolating sections. Navitas were engaged by Siemens to undertake the following scope of work:
- System modelling of the AC/DC changeover scheme to assess fault currents, touch voltages and induced voltages;
- Protection co-ordination assessment and protection settings;
- Transformer earth fault protection design;
- Scheme earthing and bonding design;
- Lighting and LV design;
- Isolation diagrams and instructions;
- DC stray current measurements.
