A Holistic Approach to and Automation of Wide Area Protection Coordination

Abstract

The electric power transmission network of today is undergoing significant changes in terms of the operational requirements, connected distributed energy resources technologies, and regulatory requirements. In conjunction with an aging infrastructure, these changes have presented new challenges to utilities in their fundamental mission of providing reliable electrical power to the customers. Thus, protection systems must overcome additional challenges towards safe and reliable operation of the power system. Increased investigation of protection system performance is therefore needed to ensure proper coordination of protective relays. However, the complex and integrated nature of the modern protection and control systems call for more sophisticated modeling and study tools for the simulation and analysis of both the dynamics of the interconnected transmission systems and interactions among numerous sets of intelligent electronic devices. Although the protection technology designed for transmission systems is mature, coordination of devices is still a major challenge. This thesis presents a holistic approach to conducting wide-area protection coordination studies through the use of a practical automation-assisted methodology. The wide area protection coordination solution covers process and data management considerations. It also provides a framework workflow for the execution and review of coordination studies, as well as processing and documentation of results to support reliability improvements. The fundamental concept behind the proposed approach is the utilization of software-based automation in a number of key tasks. Firstly, the execution of large-scale protection system coordination studies can be largely automated through utilization of specialized scripts running within short circuit simulation software packages. Secondly, the vast amounts of data inherent in the protection system coordination study results are processed in a manner that assists protection engineers in the identification and resolution of coordination issues. Finally, user friendly automated study summaries are generated that can be used as a record of protection setting recommendations. The effectiveness of the proposed solution is demonstrated through simulations conducted in the CAPE software environment for short circuit studies. Keywords: Protection and Control, Protection Coordination, Power System Reliability, Wide Area Protection Coordination, WAPC.