Optimized relay testing systems

With the appearance on the market of electronic test equipment that is controlled by software from personal computers, automation of classical test methods has been achieved and new methods have been developed. For engineers and technicians in charge of performing integrity and application tests, steady-state and dynamic tests can provide helpful information used in design, commissioning and preventive and corrective maintenance. These test methods result in savings of time and the cost involved in these tasks. Since 1990, the Spanish electric utility, Iberdrola, and the Electrical Department of the University of the Basque Country have been developing tools to: automate protective relay testing; analyze the location and characteristics of faults in the power network on the basis of oscillographic records; and simulate real or hypothetical fault conditions on a protective relay in order to monitor its behavior. Two automatic relay testing systems and experience of their use are introduced in this article. Particular testing protocols of different relays are incorporated and all useful features available to increase the automation grade are considered. Both systems minimize power system protection relay maintenance times and costs and improve the quality and reliability of relay management