Non-ideal frequency response (FR) and voltage non-linearity of high-voltage (HV) instrument transformers directly impact the accuracy of HV measurements in the presence of harmonics. Characterization of voltage instrument transformer FR is generally performed at low voltage (LV) with sinusoidal test signals. Those results may not accurately represent the response of the instrument transformer when subjected to distorted waveforms in modern power systems. This article presents a calibration system for the evaluation of harmonic measurement accuracy of single-phase instrument transformers with rated voltages up to 132/\surd 3 kV using multitone test signals containing a HV fundamental component and superimposed harmonics up to 10 kHz. Such signals would represent the realistic operating conditions of HV instrument transformers. The performance of the developed system was analyzed by obtaining the voltage ratio and phase displacement of the reference capacitive voltage divider (CVD) from
Baylor University mathematicians Dorina Mitrea, Ph.D., and Marius Mitrea, Ph.D., along with Irina Mitrea, Ph.D., professor of mathematics at Temple University,
Baylor University mathematicians Dorina Mitrea, Ph.D., and Marius Mitrea, Ph.D., along with Irina Mitrea, Ph.D., professor of mathematics at Temple University,
The objective of this research is to propose an innovative method for improving the efficiency and productivity of fuzzy logic controllers (FLCs) under the influence of harmonics in non-linear loads, by using particle swarm optimization (PSO) for solid-state transfer switch (SSTS). A PSO-based FLC (PSOF) fitness function is introduced to optimize the load transfer performance by minimizing the mean squared error (MSE) in a short period of time. The traditional and time-consuming method of deriving membership functions (MFs) is avoided by utilizing adaptive MFs created from the fitness function evaluation results, which are incorporated into voltage error and rate of change of voltage error for input and output. A harmonic filter is employed to remove unwanted harmonic components generated by both linear and non-linear loads. The effectiveness of the proposed control system is evaluated with and without PSO, and the results demonstrate that optimization with PSO reduces transfer times b
SRINAGAR: Dr Azhar Yousuf, a young mathematician from Kashmir has been awarded a postdoctoral position by IIT Mumbai. Yousuf recently completed his PhD from the Department of Mathematics, South Campus, University of Kashmir, under the supervision of Dr Firdous A Shah.