COORDINATION OF AUTOMATIC-CONTROL FUNCTIONS IN TRANSMISSION SUBSTATIONS, USING PETRI NETS

A coordination scheme for a set of computer-based control functions for line automation in transmission substations is defined, keeping the stand-alone properties of each one and still reaching a reliable and consistent behavior for the set of all functions. To preserve the stand-alone features of each function, namely timings, data verifications and intrinsic sequences, maximum freedom is allowed in concurrent operations. To reach an overall reliable and consistent behavior, communication links are defined between the functions. These functional inter-relations have a clear meaning. Petri Nets are applied to specify the integrated system. Computer Aided Verification (C.A.V.) is used to guarantee sound operation and properties. It is shown that a clear meaning exists for the designed Petri Nets and for the C.A.V. results, simplifying the role of each function while guaranteeing the security of the coordinated system.