This paper describes the on-line Voltage Security Assessment methods implemented at the national control center of the Hellenic Interconnected System, within the framework of the OMASES project funded by the European Union. The heart of all computations is a fast time-domain method. Security is analysed with respect to power transfers in critical corridors or power consumption in load areas. Results take on the form of either pre-contingency secure operation limits, or post-contingency loadability limits, together with various diagnosis tips. Contingency filtering is performed to meet the real-time requirement. Typical results obtained during the test phase of the project are reported.
Abstract-This paper describes the on-line Voltage Security Assessment environment developed within the framework of the EU-sponsored OMASES project, as well as its application to the Greek Interconnected Power System. The heart of all computations is a fast time-domain method. Security is analyzed with respect to power transfers in critical corridors or power consumption in load areas. Results take on the form of either precontingency secure operation limits, or post-contingency loadability limits, together with various diagnosis tips. Typical results obtained during the test phase of the project are reported.
E l e c t r o n i c s w i t c h i n g i n A C / K c o n v e r t e r s r e s u l t s i n t h e g e n e r a t i o n of harmonics.The l e v e l of t h e s e harmonics depends on t h e i n t e r a c t i o n of t h e i n t e rconnected AC and DC systems.In a n a l y s i s methods f o r computing harmonic l e v e l s , t h e f o l l o w i n g i s s u e s have n o t been a d e q u a t e l y r e s e a r c h e d :( 1 ) modeling of t h e AC power system and i t s e f f e c t on t h e computed harmonic spectrum and ( 2 ) convergence of t h e s o l u t i o n method. This paper proposes a method which a d d r e s s e s t h e s e i s s u e s . The method i s used t o show t h a t t h e c h o i c e of t h e AC system model i s v e r y c r i t i c a l s i n c e t h e harmonic d i s t o r t i o n a t t h e i n t e r f a c e bus i s t h e r e s u l t of an i n t e r a c t i o n between t h e c o n v e r t e r and t h e AC system. The method c o n s i s t s of a comprehensive model of a c o n v e r t e r s u b s t a t i o n , t h e AC power system, and t h e DC system e q u i v a l e n t . A s o l u t i o n a l g o r i t h m based on t h e Newton's method i s proposed w i t h improved convergence c h a r a c t e r i s t i c s . A p a r a m e t r i c s t u d y i s p r e s e n t e d i n o r d e r t o i l l u s t r a t e t h e e f f e c t s of t h e AC power system model and t h e c o n v e r t e r c o n t r o l system on t h e harmonic g e n e r a t i o n . 1.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.