Comprehensive monitoring for digital secondary systems

Solutions based on digital secondary systems (DSSs), specifically digital process bus, distribute protection and control functions across multiple devices that exchange protection data via communications networks. In such systems, effective monitoring plays a vital role, if properly designed it provides information with respect to the health of the system and complete visibility into the operational status. monitoring assists in trouble shooting of the system under fault conditions. . Presently DSS designs recurrently prioritize network redundancy to increase system reliability and availability and relegate monitoring capabilities to the background. However, if equally prioritized this would result in optimal performance of the DSS. This paper presents a comprehensive, standards-based monitoring solution for a DSS-based protection system that is operational in a 138 kV substation. It explores the concepts of redundancy and repair, highlighting the challenges created by misconceptions about them and the benefits when they are properly considered. Further, it details the data points necessary for implementing an effective solution and provides practical examples with monitoring screens of the relevant information, which ultimately contributes to increased reliability and availability of a DSS.