Availability comparison between distributed and concentrated UPS control systems

Modern power systems require high reliability and availability standards in order to meet customer final expectations and market needs. In this context it is quite obvious that modern uninterruptible power supply (UPS) have started developing improvement strategies to achieve higher availability figures over time. At the same time power, dimension and performance constraints continued to be pushed up placing tight barriers to developers. UPS developers started therefore to design distributed systems where different functions could be allocated to different control board sections enhancing in this way with a limited effort the system availability and improving the overall device modularity and expandability. In this paper the authors tried to compare single core with distributed core boards availability performance including the possibility to model the board failure rates taking into account also environmental variations.