Fault current levels in electrical systems are rising due to natural growth in demand, the increasing presence of distributed generation (DG), and increased network interconnection. This rising trend is expected to continue in the future. Marine vessel power systems are highly power-dense and are often safety-critical. Power system protection is increasingly challenging in these systems. Superconducting fault current limiters (SFCLs) offer an attractive solution to many of the issues faced.
This thesis establishes and reviews the state of the art in resistive SFCL technology and application knowledge, and provides crucial research-based guidance for the adoption of resistive SFCLs in future power systems.
The issues associated with the application of resistive SFCLs---including location, resistance rating, the recovery period, and interaction with protection systems---are demonstrated. The relationship between several resistive SFCL design parameters is established using a generic analytical approach, hence providing a framework for validating SFCL designs. In particular, it is shown that a particular SFCL resistance rating leads to a peak in the superconductor energy dissipation, which generally should be avoided.
It is proven that resistive SFCLs have an inverse current-time characteristic, i.e., they will operate in a time that inversely depends upon the initial fault current magnitude. This knowledge is critical for underpinning the operation of a novel protection scheme using multiple resistive SFCLs. The scheme offers several advantages: very fast-acting operation in response to faults anywhere on the system under study; maximum prospective fault currents are prevented from occurring, reducing the duty on circuit breakers; inherent, fast-acting backup; and communications is not required. It is shown that the scheme is suited to highly-interconnected systems with a high presence of DG. The scheme is readily applicable to the design of future utility and marine vessel power systems.
- Electronic And Electrical Engineering
|Award date||24 Apr 2013|
|Place of Publication||Glasgow|
|Publication status||Published - Apr 2013|
- superconducting fault current limiters
- power systems