Power Swing Phenomena and Comparative Study of Its Detection on Transmission Line

Power systems are subject to a wide range of small or large disturbances during operating conditions. Small changes in loading conditions occur continually. The power system must adjust to these changing conditions and continue to operate satisfactorily and within the desired limits of voltage and frequency. The power system should be designed to survive larger types of disturbances, such as faults, loss of a large generator, or line switching. Certain system disturbances may cause loss of synchronism between a generator and rest of the utility system, or between interconnected power systems of neighboring utilities. If such a loss of synchronism occurs, it is imperative that the generator or system areas operating asynchronously are separated immediately to avoid widespread outages and equipment damage. Here it is described to distinguish between power swing and real fault. It is also discussed recent enhancements in the design of out of step tripping and blocking protection functions that improve the security and reliability of the power system. In addition to that the behavior of distance relay element during power swing and during fault is simulated using MATLAB and SIMULINK simulations.