Improving Transient Stability Assessment by Installing Super Capacitor Energy Storage using Critical Trajectory Method based on Modified Losing Synchronism

Transient Stability Assessment (TSA) in electrical power system is one of the main aspects to achieve continuity and reliability of the system due to the changing of the load and the interconnection of the system become more complex. Meanwhile, the protection system has to be accurate in isolating the disturbance. Critical Clearing Time (CCT) became the main issues to determine the stability of the system after a disturbance happened. Critical Trajectory is a method to obtain CCT which is accurate and has faster calculation than other methods. In addition, Super Capacitor Energy Storage (SCES) is one of the reliable energy storages to store and supply massive electric power simultaneously. It is suitable with the nonlinearity pattern of transient stability. In order to improve the value of CCT, SCES is installed in the system. This proposed method is tested using IEEE 3-machine 9-bus system. The simulation result shows that the proposed method gives higher value of CCT in average range 0.0143s. It means the operation time of protection system is longer and it also has a longer time when a failure in protection system occur. As a result, the system will remain stable after a disturbance happen and it can improve transient stability of the system.