Protection and Metering SLD, Principles of Grading

This course provides a practical understanding of protection and metering single-line diagrams (SLDs) used in electrical power systems. It explains the purpose and arrangement of protection devices, CTs, PTs/VTs, relays, meters, and associated equipment. Participants learn how to read and interpret protection and metering SLDs for substations and electrical distribution systems. The course covers the basic principles of protection coordination and grading between different protection devices. It explains how fault current levels and equipment characteristics influence protection settings. Participants understand primary and backup protection concepts and the importance of selectivity. The course also introduces CT selection, metering arrangements, relay connections, and measurement requirements. Practical examples help participants understand how protection zones and grading sequences are represented in SLDs. Emphasis is placed on developing accurate and coordinated protection schemes for reliable system operation. By the end of the course, participants can confidently interpret protection and metering SLDs and understand the fundamentals of protection grading.