· Current & Potential Transformers – Errors, Burden, and Selection Criteria· CT & PT Testing and Performance Analysis

This comprehensive document provides a complete and easy-to-understand explanation of Current Transformers (CT) and Potential Transformers (PT) – also known as Voltage Transformers (VT). It covers the working principle, construction, equivalent circuits, and phasor diagrams of both instrument transformers. Key concepts such as turns ratio, ratio error, phase angle error, burden, and accuracy classes (metering vs. protection) are explained in detail. The notes also include important practical aspects like knee point voltage, saturation effects, polarity testing, and selection criteria for different power system applications. Perfect for electrical engineering students looking to clear their concepts and score well in exams. Written in clear, structured points with diagrams for quick revision.