Showing 112 results for Ali
Ahmad Syukri Abd Rahman, Mohamad Nur Khairul Hafizi Rohani, Nur Dini Athirah Gazata, Afifah Shuhada Rosmi, Ayob Nazmi Nanyan, Aiman Ismail Mohamed Jamil, Mohd Helmy Halim Abdul Majid, Normiza Masturina Samsuddin,
Volume 21, Issue 2 (Special Issue on the 1st International Conference on ELECRiS 2024 Malaysia - June 2025)
Abstract
Partial discharge (PD) is a critical phenomenon in electrical systems, particularly in high-voltage (HV) equipment like transformers, cables, switchgear, and rotating machines. In rotating machines such as generators and motors, PD is a significant concern as it leads to insulation degradation, potentially resulting in catastrophic failure. Effective and reliable diagnostic techniques are essential for detecting and analyzing PD to ensure the operational safety and longevity of such equipment. Various PD detection methods have been developed, including coupling capacitor (CC), high-frequency current transformer (HFCT), and ultra-high frequency (UHF) techniques, each offering unique advantages in assessing the condition of HV electrical systems. Among these, coupling capacitors have gained significant attention due to their ability to improve the accuracy, sensitivity, and efficiency of PD detection in rotating machines. This study focuses on the advancements in coupling capacitor-based techniques and their critical role in enhancing PD diagnostics for monitoring and maintaining high-voltage rotating machinery.
Zahraa Talib,
Volume 21, Issue 3 (September 2025)
Abstract
Electronic systems reliant on solar sources need DC voltage over 50 volts; hence, the use of converters is essential to satisfy client requirements. Converters modify the output voltage based on the input voltage. Quadratic DC-DC step-up converters are often used to enhance voltage transfer gain and efficiency. This sort of converter circumvents the issues associated with regular cascaded converters. Alongside the primary aims of its use, the researcher must address the practical aspects of the suggested approach, including duty cycle operational range, output voltage fluctuations, reduction of component consumption, cost, and complexity. This article examines and compares quadratic step-up converter topologies from recent years, highlighting researchers' endeavours to attain high voltage transfer gain, regulated output, and efficiency. The comparison results of the high-gain converter are shown (Table 1) to assist in selecting an appropriate high-gain topology for a particular application. Cross-references should be used there.
Gholamreza Khademevatan, Ali Jalali,
Volume 21, Issue 3 (September 2025)
Abstract
A novel simplified EKV model base analog/RF CMOS design pre-SPICE tool is presented in this paper. Addition to facilitating the sizing process, this CAD tool can also optimize circuit characteristics. By having a web address, users can access it without installing any software. Using a graphical and a numerical view, the designer can select degrees of freedom and observe the MOS circuit performance. Through the use of charts versus IC, the graphical view can show tradeoffs in circuit performance in real-time. Charts can be displayed simultaneously in both linear and logarithmic scales. IC CRIT , is also available and can be displayed on the charts. This tool is not limited to one process and it is possible to select different processes. It is efficient for pre-SPICE designs, enhancing intuitive understanding and the designer's experience for future projects while eliminating the need for trial-and-error simulations. Furthermore, the predicted results align well with simulation outcomes, demonstrating the effectiveness of the design and optimization method presented. Two methodologies for selecting optimum ICs are presented by this tool. These are illustrated by the study of linearity indices, AIP3 and IIP3, in one-stage and two-stage differential amplifiers and the design of a single-ended OTA.
Nasibeh Heshmati Moulaei, Seyed Ali Seyedalian, Alireza Sinaee Oskouie, Eisa Zarepour,
Volume 21, Issue 3 (September 2025)
Abstract
As the demand for continuous online remote monitoring of patients grows, the energy consumption of wearable home-care monitoring systems (WHMSs) requires careful evaluation. Selecting the right communication protocol therefore is crucial to minimize energy usage and extend device lifecycles. Recent versions of Bluetooth Smart (IEEE 802.15.1 are promising for WHMSs, offering low energy consumption and extended coverage range. However, their energy consumption in WHMSs remains underexplored. This paper investigates the energy consumption and maximum coverage range of Bluetooth V4.2, V5/1MB and V5/2MB in various home-care environments. We propose a software and hardware-based energy monitoring framework to practically measure the energy consumption of the protocols, conducting extensive experiments in typical home scenarios with obstacles like kitchen cabinets, brick walls, and the human body. Our results show similar power consumption for BLE v4.2 and BLE v5 modules, but the BLE v5/2MB has lower energy usage than BLE v5/1MB due to faster transmission. Additionally, obstacles significantly impact energy consumption and range, with BLE v5/1MB achieving a maximum range of 108m in line-of-sight conditions, which drops to 45m and 29m with brick walls and human bodies, respectively. Finally, the BLE v5/2MB effective range in all experimental scenarios is about 80% of BLE v5/1MB.
Elahe Rezaee Ahvanooii, Sheis Abolmaali,
Volume 21, Issue 3 (September 2025)
Abstract
Touch, one of the fundamental human senses, is essential for understanding the environment by enabling object identification and stable movements. This ability has inspired significant advancements in artificial neural networks for object recognition, texture identification, and slip detection applications. However, despite their remarkable capacity to simulate tactile perception, artificial neural networks consume considerable energy, limiting their broader adoption. Recent developments in electronic skin technology have brought robots closer to achieving human-like tactile perception by enabling asynchronous responses to temperature and pressure changes, thereby enhancing robotic precision in tasks like object manipulation and grasping. This research presents a Spiking Graph Convolutional Network (SGCN) designed for processing tactile data in object recognition tasks. The model addresses the redundancy in spiking-format input data by employing two key techniques: (1) data compression to reduce the input size and (2) batch normalization to standardize the data. Experimental results demonstrated a 93.75% accuracy on the EvTouch-Objects dataset, reflecting a 4.31% improvement, and a 78.33% accuracy on the EvTouch-Containers dataset, representing an 18% improvement. These results underscore the SGCN's effectiveness in reducing data redundancy, decreasing required time steps, and optimizing tactile data processing to enhance robotic performance in object recognition.
Mohammad Ali Razavi, Farid Tootoonchian, Zahra Nasiri Gheidari,
Volume 22, Issue 1 (March 2026)
Abstract
Synchros are electromagnetic sensors utilized to determine the angular position of a rotating shaft. This paper examines the impact of leakage flux from the Rotary Transformer (RT) on the induced voltages and the position detection accuracy of the Wound-Rotor (WR) synchro. Various methods are proposed to mitigate the negative effects of leakage flux from the RT. The leakage flux paths, which couple with the signal winding, are identified. Based on this analysis, the optimal distance between the sensor and the RT is calculated to minimize the adverse effects of leakage flux on the synchro's accuracy. Additionally, the RT structure is modified to reduce the leakage flux. Another effective approach involves the use of Electromagnetic Interference (EMI) shielding. In this context, a shield frame is designed for the RT, and the impact of different shield materials on reducing leakage flux is investigated. The results show that a copper-based shield significantly reduces the adverse effects of leakage flux and improves the sensor’s accuracy. To evaluate the effectiveness of the proposed methods, they are assessed through 3-D Time-Stepping Finite Element Analysis (3-D TSFEA) and experimental measurements on a prototype sensor. The experimental results show close agreement with the 3-D TSFEA, confirming the accuracy of the findings.
Hamid Ebrahimi, Hossein Torkaman, Alireza Sohrabzadeh, Hamid Javadi,
Volume 22, Issue 1 (March 2026)
Abstract
Ali Esmaeilvandi, Mohammad Hamed Samimi, Amir Abbas Shayegani Akmal,
Volume 22, Issue 1 (March 2026)
Abstract
This paper introduces an improved multi-conductor transmission line (MTL) model for transformers' high-frequency transient and frequency response analysis, overcoming limitations in traditional models that fail to capture complex electromagnetic interactions during high-frequency events, such as lightning strikes and switching operations. The model accurately reflects real-world transformer behaviors under transient conditions by integrating particle swarm optimization (PSO) for efficient parameter estimation and incorporating frequency-dependent losses. The combined use of PSCAD and Python minimizes computational overhead, enabling high-fidelity simulations closely aligned with experimental transformer data. Validation against real transformer measurements demonstrates the model’s reliability in capturing high-frequency responses, essential for transformer diagnostics. This novel approach offers a practical tool for studying transformer frequency response analysis, which is an important tool in transformer diagnosis.
Ali Amini, Farshid Mahmouditabar, Nick Baker, Abolfazl Vahedi,
Volume 22, Issue 1 (March 2026)
Abstract
In recent years, due to the increase in electricity generation, the need for optimized Wound Rotor Synchronous Generators (WRSGs) has been felt more than ever. One of the important characteristics of a generator in a power system is its voltage harmonics. In addition to this, the amount of generated power and efficiency are also important. The goal of this research is multi-objective design using dampers, with improved number and shape. WRSGs have been selected as a case study. With the help of surrogate modeling and the PSO algorithm, which are more efficient and accurate than classical methods, the final design has been presented. In the end, the comparison of the initial and final designs shows the realization of all goals. Also, economic issues in terms of the selection of damper material have been investigated.
Mahsa Taghilou, Mojtaba Mirsalim,
Volume 22, Issue 2 (June 2026)
Abstract
In contemporary power systems, it is crucial to ensure stable voltage levels to mitigate the fluctuations resulting from diverse load conditions. On-load tap changers (OLTCs) play a pivotal role in addressing these fluctuations by dynamically adjusting the number of turns in the transformer winding. This study investigates the integration of OLTCs within transformer designs, focusing on various methodologies related to tap winding order and configurations, which are vital for both electrical and magnetic performance. A comprehensive review of the operational principles governing different types of OLTCs is provided, highlighting their significance in voltage regulation. Furthermore, this paper analyzes the impact of linear OLTC winding order on the short-circuit impedance of a 30 MVA transformer. The findings underscore the importance of OLTC selection and design in optimizing transformer performance.
Duaa A. Kareem, Zaineb M. Alhakeem, Nawar Hayder Tawfeeq, Batool Dahham Al-Ali, Heba Hakim,
Volume 22, Issue 2 (June 2026)
Abstract
Signal forecasting in the medical field has many applications, such as signal correction and anomaly detection. According to this application, robust forecasting is required to obtain a signal identical to the original signal. This study proposes a forecasting technique that obtains a robust signal that can be used in different applications. A long short-term memory neural network (LSTM-NN) was used to predict future samples from present and past samples. An Electroencephalography (EEG) dataset was used to test this technique. Four channels were used as input examples, one of which was the predicted output. All four channel samples were fed into the four networks to predict the future samples. To decrease complexity, only one hidden layer is used for this purpose. The statistical results are promising for applications that require an almost perfectly predicted signal. The number of hidden cells is first very low (five cells only), which gives a Root Mean Square Error of less than 20, whereas when the number of hidden cells is increased to 100, the Root Mean Square Error (RMSE) is approximately 7.5 for all four channels.
Paramjeet ., Saptarshi Gupta, Rupali Singh,
Volume 22, Issue 2 (June 2026)
Abstract
CMOS technology, after contributing a lot to electronics world, is now facing difficulties in designing of more efficient circuits in terms of compactness, power efficiency and speed. It is happening due to various side effects being generated on account of further down scaling of feature size. The Quantum Dot Cellular Automata (QCA) technology seems to be alternate and promising technology for designing of more efficient circuits. The cryptographic encoder and decoder are the key component for secure and safe communication. This paper presents an efficient design of 1:2 demultiplexer, 1:4 demultiplexer and 4:1 multiplexer which are further used to design a cryptographic nano communication circuit. The proposed circuits are efficient in terms of energy, area and speed. The architectures are designed through multilayer approach in QCA technology that makes it compact. The efficiency of the proposed circuits has been verified through the tool QCA Designer 2.0.3.
