A generic, microprocessor-based relay with data logging for power system protection

The engineering of a protective relaying system can be divided into two categories--component or relay design and its integration into a power system network. Both categories represent fertile fields for research.; To date, there exists a problem in that relay design and application engineering are frequently carried out separately, leading to sub-optimal overall solutions. But, with the advent of microprocessors and the possibility of their fitting various application criteria, optimal solutions are in sight as both relay design and its application can be brought into harmony for the main objective, i.e., system protection.; This dissertation presents procedures to optimize the design and the satisfaction of relay application criteria. The result will be a generic relay capable of handling any of the standard protective functions by a change in this relaying algorithm which resides in the microprocessor. Besides the possibility of accommodating all the features which are common and necessary to execute about 100 protective functions on a microprocessor board inside a generic relay box, such a relay will also provide the opportunity to serve hitherto unavailable functions.; The intricacies of relay hardware design and application software have been designed to indeed enhance a system and not to degrade it by encumbering it with unnecessarily complex procedures and circuitry. In this work, the generic relay will use fast, special purpose, but integratable algorithms for solving protection problems at the system level as well as protection of individual, critical components such as transformers.; A new multifunction relay for utility/cogenerator inter-ties, with physical realization by means of the generic relay, will be used as an example of the concepts developed in this dissertation. The purpose of this new relay will be to protect the utility network from the internal faults of cogenerating plants. Such a relay does not exist and has not been reported in the literature. But with the increasing number of small cogenerating plants, it is only a mater of time when such a relay will be required.; An additional feature of the generic relay is real-time status reporting and data logging for later examination and as a database for simulation of important system responses to variations in system configuration, fault and relay settings, etc.