This paper presents an optimization methodology for the design of square and rectangular substation grounding grids with equal conductor spacing, ensuring compliance with IEEE Std. 80-2013 safety criteria while minimizing construction costs to minimum possible limits. The proposed algorithm systematically performed parameters sweeps on all the design variables as stipulated in the standard, including grid burial depth, surface layer thickness, conductor material, conductor size, conductor spacing, and the number and length of ground rods. For optimization, two different cost functions were used: one based solely on the material costs of conductors, rods, while the other incorporated additional factors such as installation, and excavation costs. The algorithm’s performance is evaluated using eight different test grid systems published in the literature, and results were validated with the optimization results obtained from ETAP software. The results demonstrate significant cost reductions while maintaining safe step and touch potentials, offering a practical tool for designing safe, reliable, and cost-effective grounding grids for electrical substations.

For efficient operation of nanoscale optoelectronic components, realization of nanophotonic waveguides confining high mode powers is imperative. In most cases, this requirement is further compounded by the requirement of fabricating nanostructures supporting the fundamental mode only. We carried out an extensive numerical analysis based on rigorous full-vectorial finite difference method with perfectly matched layer boundaries to identify the single mode operation region of sub-micrometer silicon-on-insulator rib waveguides in terms of the waveguide geometric parameters. We particularly emphasized on achieving high mode confinements while designing a single mode waveguide and provided a way to engineer the confinement factor. Contrary to what has been established in the case of large cross-section rib waveguides, we demonstrated that determination of theoretical single mode conditions is possible for sub-micrometer waveguides with accuracy approaching 100%. To the best of our knowledge, this is the first such analysis which covers both, the deeply and the shallowly etched rib waveguides (0.1≤(slab height/rib height)≤0.8) and reports the single mode condition for entire sub-micrometer range (0.2µm≤rib height, rib width≤1.0µm) while adhering to design specific mode confinement requirements.

Silicon photonics is the most viable and cost-effective platform for next generation optical interconnects. One of the key optical devices in these interconnects is an optical modulator which, along with photodetectors, effectively defines performance of the whole optical link. However, due to its centrosymmetric structure, silicon does not offer linear electro-optic effects, leaving plasma dispersion effect as the only feasible modulation mechanism for high speed applications. The performance of plasma dispersion-based modulators is affected by several design variables, affecting various modulator figures of merit (FOMs) where performance trade-off exists. This necessitates design optimization, requiring reasonably accurate mathematical predictive models for all the FOMs. This paper presents a rigorous full 3D model for the junction capacitance of silicon-on-insulator interleaved junction optical phase modulators with submicron dimensions. Junction capacitance is instrumental in calculating power consumption per bit, modulation speed and efficiency of optical modulators. Solution of Drift-Diffusion and Poisson's equations were carried out on 3D finite-element-mesh and Maxwell's equations were solved using Finite-Difference-Frequency-Domain (FDFD) method on non-uniform rectangular grid to calculate confinement factor. Whole of the modeling process has been detailed and all the coefficients required in the model are presented. Model validation suggests < 10 % RMS error.

The increasing integration of renewable energy in smart-grids, usage of modern power-electronic devices having nonlinear behavior and environmental factors have raised power quality disturbance (PQDs) issues. PQDs result in malfunctioning, damaging or shutdown of sensitive equipment and disturb the smart grid networks' safe and economical operations. Different approaches have been used to detect and classify the PQDs along with Convolutional Neural Networks (CNNs). Recently a machine learning model, Vision Transformer (ViT) has gained much recognition for outshining the CNNs if trained on a sufficient amount of data. This work proposes a method of two-step, combining Smoothed-Pseudo Wigner-Ville Distribution with Vision Transformer (ViT-SPWVD). This is the firstever application of ViT-SPWVD for PQDs classification. Firstly, a set of synthetic PQDs have been generated through MATLAB model. Secondly, SPWVD technique is developed to convert 1-D signals into a 2-D images, then ViT model is developed for image classification. The features from image are automatically extracted with the help of self-attention mechanism. The proposed technique has proved its capability as additional valuable tool in the field of PQDs detection and classification. At culmination, the paper presents a comparison of ViT and CNN based approaches to PQD classification.