International Journal of Engineering Research

Design and Implementation of an Innovative Balun Configuration for Planar Antenna Use

2024-03-28T08:11:55+00:00

The main parts of balanced circuits, including push-pull amplifiers, balanced mixers, frequency multipliers, and antennas, are baluns. Due to the increased integration of most of these applications, baluns must be inexpensive and of small size. This research paper presents a novel method for designing planar baluns. The approach begins by examining a symmetrical 4-port network features an open-circuit termination on one port, utilizing both even and odd mode stimulations. The suggested balun, supported by comprehensive design equations, showcases a completely balanced output and excellent input alignment, with measurement outcomes aligning closely with the simulated values.

A Comparative Study of Field Oriented and Backstepping Control Strategies for Wind turbine PM Synchronous Generator

2024-01-19T11:42:04+00:00

In this paper, a comparative study of Field Oriented Control and Backstepping Control methods has been conducted to control a Permanent Magnet Synchronous Generator for wind power application. These control strategies are described and designed, then implemented using the Matlab/Simulink environment. Finally, the two different strategies are compared in response to active power, current, voltage, electromagnetic torque, and rotor speed. FOC allows us to independently control the torque and the flux of our machine in the same way as a DC machine with separate excitation, where the inducing current controls the magnetic flux, and the induced current controls the electromagnetic torque. We transformed the stator instantaneous currents to two current components, one which controls the flux (along the d axis), and the other controls the torque (along the q axis). The adaptive Backstepping control relies on the nonlinear model of the controlled system. It harnesses the principles of the Lyapunov stability theory to regulate various parameters and uphold the overall system’s stability. The findings of this research showed that firstly, backstipping control method is faster, less ripple, and more stable than the FOC method. Secondly, the THD in FOC method is higher than in backstipping control method. Finally, both control techniques have sinusoidal current and voltage waveforms. So, they can satisfy the grid code.

Performance Analysis of Awbari Gas Turbine Power Plant with Crude Oil

2024-03-29T01:11:03+00:00

The performance of a gas turbine can be evaluated by its efficiency and net power output which both are affected by ambient conditions (atmosphere air temperature and humidity) and used fuel.In this work, the performance of the gas turbine (SGT5-2000E) has been modelled using HYSES ASPEN software and evaluated by assessing the efficiency, net power, specific fuel consumption (SFC), and fuel-air-ratio (FAR) in a hot weather region at sea level (the Sahara Desert in Libya ).

Evaluation of the performance of SGT5-2000E (Awbari gas turbine power plant, south of Libya) has been carried out by modelling the units of the power plant using HYSYS ASPEN and validated against the design data provided by the manufacturer. In addition, two performance scenarios (two different fuels) were drawn for the gas turbine power plant. The first is at a fixed Pressure Ratio (PR) of 12 with a variation of the compressor inlet temperature (CIT)between 0 ^oC and 50 ^oC, and the second is at a fixed CIT of 15 ^oC with a variation of PR ranging from 7 to14 bar.

Additionally, a performance analysis of the Awbari power plant is performed based on CIT and PR. The results show that the CIThas a linear effect on the turbine’s efficiency, while the PR has a non-linear effect on the turbine's efficiency. The effect of PR on the net power at fixed CIT has different behaviour depending on its CIT. For different CIT values, the net power reaches the peak at the PR values between 9 and 12. Moreover, using Natural gas as fuel for gas turbine units promotes proper turbine performance compared with crude oil as fuel.

The effect of austenitizing temperature on thenormalising processing behaviour of 34CrNiMo6 steel

2024-04-01T02:42:22+00:00

The aim of this study is to carry out research about the effect of austenitizing temperature of 34CrNiMo6 low alloy steel on the normalising heat treatment process. Moreover, a comparison of the austenite grain size that formed after the deformation at two austenitizing temperatures of 1100°C and 1200°C with that one resulted after the normalising process at temperature of 860°C. Moreover, to study the effects of increases of holding times of 6, 30 and 60 minutes at normalising process with both austenitizingon the grain size variation, and the consistency of microstructure, which in turn influences on the resulted mechanical properties. It was observed that deformation the specimens at austenitizing temperature of 1100 °C prior normalising process; gives a smaller grain sizes than those when using austenitizing temperature of 1200 °C. Furthermore, Increase in the normalising soaking times does have no influence the increasing of the grain size of austenite. However, it has an effect on The arrangement and shape of grains by making the grains equiaxed and creates a uniform structure. Furthermore, oxides scale thickness was observed at austenitizing temperature of 1200 °C, and particularly when soaking time at that temperature increased.

A Microcontroller-Based Face Recognition Attendance System

2024-03-29T17:06:14+00:00

Attendance management system is an indispensable system by which every organisation tracks employees or students attendance. The manual process of marking attendance by using a paper-based or file-based system is susceptible to loss, falsification or disaster. One of the most interesting and important ways used in the past two decades in attendance management systems is the face recognition systems.

This paper proposes a face recognition attendance system using ESP32-CAM development board, which is a low-cost microcontroller with built-in camera and Wi-Fi capability. The system captures and registers a facial image of a student, many student images are stored in the ESP32-Cam permanent internal storage. When attendance tracking is enabled, the face of a student in front of the camera will be detected and recognition process is performed where the tested image is compared with the stored images; once recognition is done, the recognized student data is sent wirelessly via http protocol to a MySQL database for further attendance report management.

Spiral Microstrip Bandpass Filters

2024-03-29T06:53:38+00:00

Microstrip bandpass filters based on spiral resonators are designed at 700MHz for 5G applications. In order to achieve size reduction, spiral resonators are used. The proposed filters are of third and fifth orders. The filters are printed on FR4 substrate with thickness of 1.6mm and dielectric constant of 4.5. The filters are simulated using CST electromagnetic simulator. The simulated results show that the presented filters exhibit good return losses, low insertion losses within the passband. Furthermore, a good selectivity is obtained. The simulated reflection coefficients are -15 dB and -12 dB for the 3^rd and 5^th order filters respectively. The fifth order bandpass filter provides higher selectivity but higher insertion loss as expected.

Bearing Misalignment and Eccentric Wear: A Study on Condition Monitoring

2024-03-28T19:58:49+00:00

This study investigates ball bearing failures and evaluates the performance of various methods for detecting such failures. Experimental tests were conducted on a motor-generator system supported by ball bearings, where several types of real-time faults were intentionally introduced. Vibration signals were collected to capture the early stages of bearing faults. The monitored vibrations successfully predicted impending failures in the outer race, inner race, and ball of the bearings. To assess the effectiveness of the prediction methods, different stages of fault development were considered. Additionally, the feasibility of implementing these techniques in real-world systems and real-time applications was examined. The vibration monitoring technique proved to be suitable for analysing various defects in bearings and providing early indications of malfunction. Vibration measurements were recorded at each housing of the rotor bearings. The results indicated that a deteriorating or faulty ball bearing had a significant impact on the vibration spectra. To identify different defects in ball bearings, time domain, frequency domain, and Fast Fourier Transform (FFT) analysis were employed. The findings demonstrated the usefulness of each of these techniques in detecting problems associated with ball bearings.