In today’s modern power devices and rapid growth power demands, the need for precise and accurate protection relays is a must for the power distribution system. That is, to segregate faulty sectors within fewer cycles, power relays should perform at the highest level of accuracy to detect abnormal conditions in power distribution. Therefore, this work will investigate the enhancement of the numerical relay testing in terms of harmonic distortions effect on the digitized output waveform as direct causes of relay failures. However, as it is an expensive process of testing the digitizing element of the numerical relay, this paper proposes a new algorithm of Wavelet transforms in power quality signal processing testing using MATLAB simulation. As this newly proposed method of advanced waveform analysis algorithm will enhance the testing process of digitizing elements, and reduce data compiling complexity, a comparison between conventional Fourier Transforms testing and Wavelet algorithm under abnormal conditions will be simulated based on inserting multi harmonics effect. As a result, based on the Wavelet bank of filters, de-noising, and decomposition structure filters, Wavelet has provided promising results in defining the effect of waveform distortion tripping time, fault location, total harmonic distortion, signal-to-noise ratio, and spurious-free dynamic range.
Temperature transducers are commonly used to monitor process parameters that are controlled by various types of industrial controllers. The purpose of this study is to design and model a simple microcontroller-based acoustic temperature transducer based on the variations of resonance conditions in a cylindrical resonance tube. The transducer’s operation is based on the generation of an acoustic standing wave in the free resonance mode of generation within a cylindrical resonance tube which is converted into a train of pulses using Schmitt trigger circuit. The frequency of the generated standing wave (i.e., the train of pulses) is measured by the Arduino Uno microcontroller, where a digital pin is used to acquire pulses that are counted using a build-in software function in an Arduino IDE environment. Experimental results are performed for three sizes of diameters to investigate the effect of the diameter of resonance tube on the obtained results. The maximum nonlinearity error according to Full-Scale Deflection (FSD) is about 2.3 percent, and the relative error of the transducer is evaluated using experimental findings and the regression model. The circuit simplicity and design of the suggested transducer, as well as the linearity of its measurements, are notable.
1 August 2022 in International Journal of Electrical and Computer Engineering (IJECE)
The present study is mainly concerned with solving the problems associated with energy losses resulting from starting transient conditions. In the present study, the possibilities of decreasing starting transient condition energy losses are investigated. Additionally, a comparison of the energy losses using different starting methods is also conducted. In this work, a complete description for deriving the equations used to calculate energy losses, mathematical analysis of the energy losses, the models of the different methods in this work were simulated using MATLAB/Simulink; and the results of energy losses and the dynamic characteristics are provided. Simulation results showed that the minimum starting energy losses were accomplished by soft starting method, in which the starting current could be reduced to the minimum value.
1 September 2018 in Bulletin of Electrical Engineering and Informatics
Digital color images are now one of the most popular data types used in the digital processing environment. Color image recognition plays an important role in many vital applications, which makes the enhancement of image recognition or retrieval system an important issue. Using color image pixels to recognize or retrieve the image, but the issue of the huge color image size that requires accordingly more time and memory space to perform color image recognition and/or retrieval. In the current study, image local contrast was used to create local contrast victor, which was then used as a key to recognize or retrieve the image. The proposed local contrast method was properly implemented and tested. The obtained results proved its efficiency as compared with other methods.
1 May 2023 in Indonesian Journal of Electrical Engineering and Computer Science
Phase shift transformers (PST) are a special type of transformers used to regulate active and reactive power on 3-phase transmission networks by adjusting the difference of voltage phase angle between system nodes. Problems related to power flow and stability, particularly voltage stability issues, are important at the extra high voltage (EHV) and ultra high voltage (UHV) levels due to their extreme sensitivity to active and reactive power changes. Several studies investigated these problems using three-phase systems. Accordingly, this research aims to demonstrate the impact of using PST with single and double transmission lines and to compare its performance under various operational modes.
1 March 2024 in International Journal of Power Electronics and Drive Systems (IJPEDS)
The current work was designed to study the operating modes of electromagnetic impact mechanism (electromagnetic hammer) comprising idle and working stroke windings that are enclosed in magnetic conductor, and reciprocating ferromagnetic striker. Investigation was conducted by modelling in MATLAB environment and performing verification tests with different hammers. Simulation model of the hammer was derived using experimentally obtained static characteristic curves of flux linkage and thrust force for each of the windings. Results revealed that at maximum working stroke winding voltage-varying idle stroke winding voltage, the impact energy did not change, but the impact frequency varied between 0-187 bpm. At maximum idle stroke winding voltage and working stroke winding voltage ranging between 0 to maximum value, the impact energy varied between 84-360 J, the impact frequency varied between 96-187 bpm. Maximum losses over the working cycle were associated with electric losses in the hammer windings and can be reduced by reducing winding currents through increasing the striker speed. The mathematical model of the current study allowed quantifying energy parameters of the electromagnetic hammer. The impact machine cycle includes three operating modes, each determines the main energy parameters: efficiency, impact energy, and cycle time.