The fault ride-through capability and fault current issues are the main challenges in doubly fed induction generator- based wind turbines. Application of the bridge-type fault current limiter was recognized as a promising solution to cope with these challenges. This paper proposes a nonlinear sliding mode controller for the BFCL to enhance the FRT performance of the DFIG-based WT. This controller has robust performance in unpredicted voltage sag level and nonlinear features. Theoretical discussions, power circuit, and nonlinear control consideration of the (...) SMC-based BFCL are conducted, and then, its performance is verified through time-domain simulations in the PSCAD/EMTDC environment. To reduce the chattering phenomenon and decrease the reaching time, it used the exponential reaching law for designed SMC. Also, the SMC-based BFCL performance is compared with the conventional and PI controller-based BFCL for both symmetrical and asymmetrical short-circuit faults. Simulation results reveal that the SMC-based BFCL provides better performance compared with the conventional and PI controller-based BFCL to enhance the FRT. (shrink)

It is well known that the historical texts composed under the Macedonian dynasty (Theophanes Continuatus, Genesios, but also Leo the Deacon, Manuel protospatharios, John Skylitzes or even Michael Psellos) display certain element, which can be seen as attempts to make a clean break with the past; the formalist style of unbroken historical narrative was largely rejected in favour of historical biography in which the influence of rhetorical methods is self-evident. It is not known which criteria tipped the balance in favour (...) of such a development, though we would do well to consider both the influence of Antiquity, and the close ties that bound biography to hagiography, which from the empire's very beginnings (Vita Constantini) also served as a uniquely Byzantine mode of promoting the image of the emperor. It may be legitimate to speak of a new type of historical writing which is specifically designed for the extremely beautified career of its subject and constitutes a contemporary movement which manifested itself in various cultural contexts. (shrink)