FUZZY LOGIC CONTROLLED STATCOM WITH A SERIES COMPENSATED TRANSMISSION LINE ANALYSIS

Series compensation of transmission line networks is increasingly being considered for bulk power transfers from large wind farms. Series-compensated long transmission lines with wind turbine generators experience sub-synchronous resonance (SSR). To prevent SSR, it is necessary to reduce its occurrence as much as possible. To solve this issue, this paper proposes an effective FACTS (flexible ac transmission system) based voltage control device, namely a static compensator (STATCOM) and static synchronous series compensator (SSSC) to moderate the SSR. In this work, the fuzzy logic control based on STATCOM and SSSC is developed to enhance the stability margin of a wind turbine. Detailed eigenvalue analysis was carried out to demonstrate the successful mitigation of SSR by two controllers in a series of compensated wind farms. To find the dominant control scheme, the eigenvalues of the proposed controllers are compared with PSCAD/EMTDC simulations. Finally, a comparison study is carried out between the two proposed SSR controllers. The results have been validated with the IEEE 1st SSR benchmark system. The results demonstrate that fuzzy logic controller (FLC) based SSSC performs better than STATCOM.