A New Wide-Area Protection Scheme for Single- and Double-Circuit Lines Using 3-D-Phase Surface

The modern power system and complex interconnected smart grid have many parallel transmission lines to increase reliability and security. The current complexity of the large-scale power system configuration has led to cause difficult situations for the relay engineers for system coordination and operating time of the distance relays. A new centralized wide-area monitoring system is used for parallel and single lines protection. A new wide-area main protection system based on phasor measurement units “PMUs” is deployed on a real interconnected large-scale power grid. The main concept of the idea is based on describing by differential equations the dynamic operation of the transmission lines during the fault. The differential equations can be solved through paths movement in a phase diagram. The time is added as a third axis to the phase diagram to enhance the performance in three-dimensional (3D)-Phase Surface. The solution curves corresponding to paths are represented graphically in 3D - Phase Surface. The solution curves can move closely or widely separate from the equilibrium point indicating the case of the transmission lines as being faulted or not. The fault on the lines can be precisely recognized using this concept. The simulation of the interconnected system network using MATLAB/SIMULINK is used. The relay showed for the first time a solution for the parallel transmission-lines problems in a wide area.