http://10.9.150.37:8080/dspace//handle/atmiyauni/227 B.Tech, M.Tech, Ph.D. Engineering 2026-04-27T18:57:53Z http://10.9.150.37:8080/dspace//handle/atmiyauni/2296 Title: Virtual Inertia Issue and its Mitigation Technique in Integration of Renewable Energy with Grids Authors: Kathad, Shilpa Keshubhai; Pandya, Dharmesh J. Abstract: The penetration of Renewable Energy Sources (RESs) into microgrids is gaining huge significance in recent times. RESs are integrated with conventional grid systems to meet the growing energy demand and to enhance the power quality. The increasing penetration of RES into the grid system affects the stability of frequency in microgrids due to the stochastic nature of photovoltaic (PV) and wind energy generation. Unlike in traditional power generation systems, the lack of rotational inertia in microgrids is one of the critical concerns which affects the integration of RES with the grid system through power electronic converters. This introduces more uncertainties into the system and hence the operation and control of such a system becomes more complicated. In order to maintain the stability of microgrids and to effectively utilize RESs and distributed generation (DG) systems, it is essential to control virtual inertia. Proper inertia control improves the flexibility of microgrid operation and as a result various controlling strategies have been proposed in the past to control the virtual inertia. This work presents a new virtual inertia control (VIC) approach with a multi power level controller (MPLC) for RES integrated microgrids. Considering the high-level penetration of RES, the proposed approach is designed to enhance the system performance under sudden load variations and frequency variations. The efficiency of the proposed control approach is validated with and without MPLC. Results show that the controller achieves better frequency stability with MPLC. Advanced control algorithms can be used to create virtual inertia, which can mimic the stabilizing effect of traditional rotating mass in conventional power systems. An interconnected power framework's complete framework inertia might be impressively decreased because of a sharp ascent in utilization of renewable energy sources (RESs) based on force converter, making a framework more vulnerable to framework instability. This work recommends another use of virtual inertia control to further develop recurrence dependability of the connected power framework because of high entrance level of RESs. We present the subsidiary control approach, expected for more significant level virtual inertia imitating applications. The suggested virtual inertia control circle has a second-request hallmark that further enhances recurring dependability and strength. Δf values differ between 17.4215 and 20.3621 with significant frequency variations due to conventional control. Equally, virtual inertia control exhibits a high level of efficiency in reducing frequency deviations; The Δf values were consistently smaller between 0.0236 and 0.0369 than the conventional control. 2024-07-01T00:00:00Z http://10.9.150.37:8080/dspace//handle/atmiyauni/2293 Title: Image And Video Watermarking: Machine Learning And Frequency Domain Approach For Achieving Dual Security Of Important Information Authors: Pithiya, Kiran Ashok; Kothari, Ashish M. Abstract: Digital watermarking is a technique used to embed a hidden message, such as a company logo, creator’s name, or other identifying information, into a cover medium like images, audio, or video. Effective digital watermarking algorithms must satisfy three key requirements: robustness, perceptibility, and payload capacity. These algorithms are categorized into two primary domains: spatial and transform. In the spatial domain, watermarking modifies pixel values directly based on the watermark. In the transform domain, the frequency components of the cover medium are manipulated to embed the watermark. Lastly, a hybrid approach combines DCT, DWT, and SVD techniques to leverage the strengths of all three methods, achieving improved performance. To evaluate watermarking effectiveness, two metrics are calculated: (1) Perceptibility: This is assessed using Peak Signal-to-Noise Ratio (PSNR) and Mean Square Error (MSE) at the transmitter end. (2) The quality of the recovered watermark at the receiver side is determined by calculating the correlation between the recovered and original watermarks. For assessing robustness, which measures the quality of the watermark retrieved at the receiver side, the correlation between the recovered watermark and the original message is calculated. A higher correlation indicates stronger robustness, ensuring the watermark remains intact even under various attacks or distortions. This thesis introduces a novel method for embedding watermark messages into the crucial part of an image, specifically the region of interest (ROI). The focus is on identifying the human face within an image and embedding the watermark within this detected face. Once the watermark is embedded, the altered face image is reinserted back into the original image. To achieve this, the method employs a face identification algorithm alongside two frequency domain transforms viz. Discrete Cosine and Wavelet as well as the powerful linear algebra technique known as Singular Value Decomposition (SVD). Additionally, the thesis utilizes three widely recognized visual quality metrics to evaluate the method’s effectiveness. At the transmitter side, Peak Signal to Noise Ratio (PSNR) and Mean Square Error (MSE) are used to assess the perceptual quality of the image after watermark embedding. At the receiver side, Correlation is measured to test the robustness of the algorithm. Finally A hybrid algorithm is introduced, which integrates Discrete Cosine Transform (DCT), Discrete Wavelet Transform (DWT), and Singular Value Decomposition (SVD). This combination harnesses the advantages of all three methods, enhancing the overall performance of the watermarking process. Experimental results demonstrate that the hybrid algorithm outperforms individual methods (DCT, DWT, or SVD alone) in both perceptibility and robustness. This makes the proposed approach a superior choice for applications requiring reliable and imperceptible digital watermarking. 2024-12-01T00:00:00Z http://10.9.150.37:8080/dspace//handle/atmiyauni/2283 Title: A Survey on Latest Wireless Technologies Authors: Mewada, K.M. Abstract: Wireless communication is among technology’s biggest contributions to mankind. Wireless communication involves the transmission of information over a distance without the help of wires, cables, or any other forms of electrical conductors. The transmitted distance can be anywhere between a few meters (for example, a television’s remote control) and thousands of kilometers (for example, radio communication). It is used as an advantage for working professionals in remote areas to remain in touch with their main headquarters. Moreover, it is wireless so it can be easily accessible without cables and wires. It is cheaper to install and maintain. 2016-02-01T00:00:00Z http://10.9.150.37:8080/dspace//handle/atmiyauni/2271 Title: Influence of Process Parameter on Lack of Fusion in TIG Welding of SS 304: A Review Authors: Shah, Sagarkumar; Acharya, G.D. Abstract: TheTIG welding or gas tungsten arc welding (GTAW) process is widely used in many appliances because of its versatility in industry. For GTAW process, metals like carbon steel, stainless steel, aluminium, copper, low-alloy steel and non-metal also are widely used in all positions. Butt joint, lap joint, T-joint, edge joint and corner joint are the common types of joints used in welding. The incompletely fused spots like porosity,which occurs after welding is known as lack of fusion that leads to undesirable results; and to overcome this, it requires change in welding techniques and parameters within the limits. A large number of resources are used nowadays for reworking the welds. But it causes higher cost of production and delay for completing the work. Higher amount of rejection of product may generate if the lack of fusion is not to be controlled physically during welding. This work is aimed to predict and reduce lack of fusion with TIG welding process parameters. Using various design of experiment methods, straight and indirect effects of the process parameters can be determined and process parameters can be optimized. 2019-01-01T00:00:00Z