Voltage Stability Enhancement of Wind Generator System Using Superconducting Fault Current Limiter

Wind generator systems have stability problems during network faults. The superconducting fault current limiter (SFCL) has the ability to prevent the magnitude of short-circuit current from increasing. This work proposes the SFCL device to enhance the voltage stability of a fixed-speed wind generator system.In this work the performance of SFCL is compared to that of the thyristor switched capacitor (TSC) method and the pitch control method. The comparison is done in terms of voltage stability enhancement, controller complexity and cost. The effectiveness of the proposed methodology is tested considering permanent and temporary, balanced and unbalanced faults in the power system model consisting of a wind generator and a synchronous generator.From the simulation results it is evident that performance of SFCL is better. On comparison it can be concluded that SFCL performs better when compared to TSC or pitch control method. Simulations are performed through Matlab/Simulink software

Comparison between SFCL and TSC for voltage stability enhancement of wind generator system

This work proposes superconducting fault current limiter (SFCL) device to enhance voltage stability of the fixed-speed wind generator system. In order to evaluate the effectiveness of the proposed SFCL methodology in detail, its performance is compared to that of the thyristor switched capacitor (TSC). The comparison is done in terms of voltage stability enhancement, controller complexity and cost. The effectiveness of the proposed methodology is tested considering both permanent and temporary faults in the power system model consisting of a wind generator and a synchronous generator. In order to evaluate the system performance, we have used indices in terms of terminal voltage deviation and real power deviation of the wind generator. Simulations are performed through Matlab/Simulink software. Simulation results show that both the SFCL and TSC are effective in limiting the fault current as well as minimization of the voltage sag of the wind generator system. However, the performance of the SFCL is somewhat better than that of the TSC. Therefore, the proposed SFCL can be considered as an effective means of the voltage stability enhancement of wind generator system. © 2013 IEEE

Antipyrine Based Arsenate Selective Fluorescent Probe for Living Cell Imaging

Condensation of salicylaldehyde and 4-aminoantipyrine has yielded a new fluorescent probe (<b>APSAL</b>) capable of detecting intracellular arsenate at the micromolar level for the first time. The structure of the probe has been established by different spectroscopic techniques and confirmed from X-ray crystallography. Common anions, viz., F^–, Cl^–, Br^–, I^–, N₃^–, NCO^–, NO₂^–, NO₃^–, SCN^–, CN^–, CH₃COO^–, SO₄^2‑, ClO₄^–, and HPO₄^2‑ do not interfere. The binding constant of <b>APSAL</b> for H₂AsO₄^– has been determined using the Benesi–Hildebrand equation as 8.9 × 10³ M^–1. Fluorescence quantum yield of <b>APSAL</b> (0.016) increases more than 12 times upon binding arsenate ion