Mahmood Asghari - Electrical Engineering Dept., Faculty of Engineering Ferdowsi University ofMasshad, Mashhad, IRAN
Javad Sadeh

Load shedding is one of the most important tools to prevent voltage instability. Performing corrective actions on time in order to prevent short time voltage instability need to have protective plans in addition to original equipment protections that supervise whole power network in emergency conditions. These protective plans are called Special Protection System (SPS). In this paper, first of all, a suitable SPS is designed for power system. Next, a mechanism that considers two factors in load shedding, effective loads in voltage instability and low price loads, will be designed for SPS. This method can perform real time by system or manual by operators of power system.

special protection system (SPS), voltage instability, voltage instability indictor,optimum load shedding