Mainly used in AC grids, resistive type superconducting fault current limiters may be still more interesting for DC systems due to their capability to reduce high short circuit currents appearing in case of DC cable fault. This limiter reduces the breaking capability, speed, and energy requirements of the required DC circuit breaker allowing the implementation of electro mechanical breakers for fault current interruption. These breakers have lower breaking capability, on load losses, and investment costs in comparison with hybrid circuit breakers based on power electronics. This paper presents a technical and economic analysis of a superconducting fault current limiter used in a radial three terminal high voltage DC grid to protect a cable link. Based on simulation studies using an electro magnetic transient program, an effective system protection will be demonstrated with special attention to the continuity of power flow through healthy parts of the grid.
High Voltage Direct Current (HVDC) is a replacement of the existing Alternating Current (HVAC) solutions for the transport of electricity using underwater cables. An example is the connexion of off-shore wind turbines to the electrical network...
Phd Ahmed ZAMA « Modeling and Control of Modular Multilevel Converters (MMCs) for HVDC applications »
Common understanding today is that the challenges to develop the SuperGrid are huge at many levels (e.g.: political, societal, economical, financial, scientific, technical…). It is also commonly accepted that the SuperGrid will require novel technologies (breakers, cables, converters…) and operating principles (e.g.: transition from a more passive essentially AC-based power system to a more active AC/DC-based one). This thesis deals with the development of a key actor for SuperGrid technology, that is, AC/DC converters.