Microcomputer calculation of fault levels for operational interlocking

It is shown that an electrical operational interlock for a power generating station must be capable of online fault-level calculations and that conventional methods are outside the capabilities of current 8-bit microprocessors. An algorithm is then developed to calculate fault levels, which is suitable for any network whose associated graph is a tree. The approach is based on the fundamental concepts of fault level and reduction processes related to the network graph. The suitability of this algorithm to practical systems is demonstrated by means of a case study, the accuracy of the computed fault levels being shown to compare very favourably with those from a conventional program.