Fault-detection scheme for a direct digital control of a.c.-d.c. interconnections

A fault-detection scheme intended to be capable of providing the necessary information for a direct digital control of a.c.-d.c. convertors is described. The proposed scheme provides fast, safe, unique and unambiguous discrimination between the fault condition and its origin through the initial stages of the fault. It is shown that these requirements can only be achieved by sequential logic. Backup detection, based on a completely different principle, is also provided for the automatic location of possible circuit faults within the main detection scheme.