The Demand for Power is increasing day to day and the resources are decaying in the same proportion.The best solution to meet the power demand in future is to convert the existing Double Circuit Three Phase Transmission lines into a compact Six Phase Transmission Line. This conversion will increase the power transfer capability to 1.732 times with in same Right-Of-Way. The other benefits are better voltage regulation, less audio & radio noise levels, low clearances etc.This Book presents the various advantages of Six Phase Transmission, Negative sequence detection in Three Phase and Six Phase Transmission System. A complete Logic Based Protection scheme by using Negative sequence currents is discussed to protect Three phase and Six Phase system against all types of faults such as Shunt, series of both Symmetrical and Unsymmetrical by using MATLAB/SIMULINK. This book initiates the further research in the area of Six Phase transmission systems.