With power demand on the rise and new power generation sources being added, the grid has become overcrowded and vulnerable to catastrophic faults. Faults are abnormal flows of electrical current that act as a large-scale short circuit. As the grid is stressed, faults and power blackouts increase in frequency and severity.
SFCLs act like powerful surge protectors, preventing harmful faults from taking down substation equipment by reducing the fault current to a safer level (20 – 50% reduction) so that the existing switchgear can protect the grid.
Currently, electrical-utilities use massive 80kA circuit breakers, oversized transformers and fuses to prevent faults from damaging their equipment and protecting against surges. However, once a fault has occurred, standard circuit breakers suffer destructive failure and need to be replaced before service can be restored. In addition, Smart Grid and embedded alternative energy generation enhancements will increase the need for SCFLs.
Grid operators face a major challenge in moving power safely and efficiently, from generators to consumers, through several stages of voltage transformation step downs and step ups. At each stage, valuable energy is lost in the form of waste heat. Moreover, while demands are continually rising, space for transformers and substations - especially in dense urban areas - is severely limited.
Conventional oil-cooled transformers pose a fire and environmental hazard. Compact, efficient superconducting transformers, by contrast, are cooled by safe, abundant and environmentally benign liquid nitrogen. As an additional benefit, these actively-cooled devices will offer the capability of operating in overload, to twice the nameplate rating, without any loss of life to meet occasional utility peak load demands.