A novel fuzzy logic controller for UPFC

The main purpose of this paper is to propose a novel controller based on fuzzy logic able to enhance dynamic performance of unified power flow controller (UPFC) control modes: shunt compensation, series compensation and phase shifting. As is well known, the UPFC consists of two solid-state voltage source inverters (VSIs) connected by a common DC link that includes a storage capacitor. The first one is a static synchronous compensator (STATCOM) the second one is a static synchronous series compensator (SSSC). The proposed fuzzy logic controller is used to arrange the controls of the STATCOM and SSSC, in order to take into account, by approximated reasoning, the system nonlinearity and devices interaction. Some simulation cases are considered to compare the performance of the proposed controller with respect to that of other controller schemes. For this investigation ATP-EMTP (ATP-Electromagnetic Transients Program) is used as study tool