The article provides an overview of protective relaying principles and their applications for high-voltage power system components. It covers the protection methods for generators, transformers, buses, and transmission lines using various relay types to detect and isolate. IEEE/IAS/I&CPSD Protection & Coordination WG Chair Jacobs Canada, Calgary, AB rasheek. Ideal for Electrical, EEE, ECE, and Mechatronics final year students with expert guidance from Aislyn Technologies, Bangalore. In HV (High Voltage) and MV (Medium Voltage) substations, relay protection safeguards critical assets such as transformers, circuit breakers, and lines. We hope you will find it useful in your work.