Sy-Ruen Huang

Distinguishing Internal Winding Faults From Inrush Currents in Power Transformers Using Jiles-Atherton Model Parameters Based on Correlation Coefficient

This study proposes a novel method using Jiles-Atherton model parameters to identify small fault current results from winding turn-to-turn short circuit in power transformer inrush current. The waveform symmetry and hysteresis curve shapes of inrush current with fault current are different from inrush current without fault current; that means the magnetic parameters of transformer cores and windings are influenced. Moreover, cycle leakage inductance and cycle winding resistance also can be used to distinguish inrush current and internal fault current due to changes of permeability and the winding current density caused by transformer core or winding state changes. Jiles-Atherton parameters per cycle, leakage inductance per cycle, and the winding resistance per cycle are estimated from the exciting inrush current per cycle under no-load conditions using the differential evolution algorithm. This study uses two types of parameters: the first is the correlation coefficient of Jiles-Atherton parameters of a transformer under no-load exciting condition. The second type is the variation trend of the cycle leakage inductance and the cycle winding resistance. The study uses cross validation of the two methods to distinguish whether inrush current contains small fault current. The experiment has verified the feasibility and accuracy of the proposed methods in this study.

The living banana plant as a long-lasting battery cell

ABSTRACT Among citrus fruits, lemon is widely used as a low-power electrical source. Although, it can generate a potential difference, this phenomenon is only sustainable for few days, and no other alternative organism has been reported to provide a similar potential with longer duration. This study reports the discovery of living banana plant as an inexpensive, reliable, stable, and long-lasting power. A Zn anode and Cu cathode are inserted into banana plant to extract electricity, and the organic compounds of plant act as electrolyte. This new discovery may introduce an era of providing renewable energy to who live in proximity to banana plantations.