document: New approach to standing phase angle reduction for power system restoration During power system restoration , it is necessary to check the phase angle between two buses before closing circuit breakers to connect a line between them . These angles may occur across a tie line between two systems or between two connected subsystems within a system . In case of large standing phase angle -LRB- SPA -RRB- difference the synchro-check relay does not allow closing of the breaker for this line . Therefore , this excessive SPA has to be reduced before attempting to connect the line . In this paper , a new and fast method for reducing SPA is presented . For this purpose , the standing phase angle difference between two specific buses is represented in terms of sensitivity factors associated with the change in active power generations and consumption at the buses . Then , the proposed method reschedule generation of selected units or shed load of selected buses to reduce excessive SPA difference between two buses based on sensitivity factors
doc_bio_tags: O O O O O O O O B I I O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I
extractive_keyphrases: power system restoration synchrocheck relay sensitivity factors
abstractive_keyphrases: standing phase angle reduction approach circuit breaker closing power line connection