Bus Type - Known Parameter - Unknown Parameter Load Bus -P, Q - V, phase angle Generator Bus - P, V (magnitude) - Q, Voltage phase angle Slack Bus Voltage - magnitude and phase angle - P, Q
In bias differential protection for transformer, There are two basic settings required to setup the percentage biased differential protection. 1. Minimum pickup 2. The slope.
The minimum pick-up covers the transformer magnetizing current typically 1-4% of transformer rating. A pick up of 0.2 to 0.3 times the TAP is recommended for general cases.
The slope is defined by determining the potential sources of differential current.
Simple logic of reactance diagram is that simplified equivalent circuit of power system in which the various components of power system are represented by their reactance. The reactance diagram can be obtained from impedance diagram if all the resistive components are neglected. So, from figure each of the component is represented by its reactance.