Voltage Variation Analysis by Using Gabor Transform

Voltage variations which include voltage sag, swell and interruption are simulated and analyzed in this paper. Various types of parametric equation are generated with the help of MATLAB software. Simulated signals are studies by using time-frequency distribution (TFD) technique. The TFD method used in this paper is the Gabor transform which is less applied by the researchers. The signal parameters used in this paper are the RMS voltage and instantaneous power can be extracted from the TFR to study the distinctives of the voltage variations. The parameters extracted can detect the voltage variation signals successfully. The voltage variation signals are successfully detected by using the K-Nearest Neighbors (kNN) algorithm with the implementation of signal parameters extracted as the input on the classifier. The voltage variations waveforms as well as the signal parameters obtained are suitable to be further analyzed

A Utilisation of Improved Gabor Transform for Harmonic Signals Detection and Classification Analysis

This paper presents a utilization of improved Gabor transform for harmonic signals detection and classification analysis in power distribution system.  The Gabor transform is one of time frequency distribution technique with a capability of representing signals in jointly time-frequency domain and known as time frequency representation (TFR). The estimation of spectral information can be obtained from TFR in order to identify the characteristics of the signals. The detection and classification of harmonic signals for 100 unique signals with numerous characteristic of harmonics with support of rule-based classifier and threshold setting that been referred to IEEE standard 1159 2009. The accuracy of proposed method is determined by using MAPE and the outcome demonstrate that the method gives high accuracy of harmonic signals classification. Additionally, Gabor transform also gives 100 percent correct classification of harmonic signals. It is verified that the proposed method is accurate and cost efficient in detecting and classifying harmonic signals in distribution system

Intensity-modulated abrupt tapered Fiber Mach-Zehnder Interferometer for the simultaneous sensing of temperature and curvature

AbstractAn abrupt tapered fiber In-Line Mach-Zehnder Interferometer sensor for simultaneous measurement of temperature and curvature is proposed and experimentally demonstrated. The sensor head is fabricated by arcing Corning SMF-28 using a commercial arc fusion splicer. The individual parameters discrimination was achieved by manipulating the unequal sensitivities of optical power to temperature and curvature obtained at two wavelengths within the sensing spectrum. The curvature and temperature sensitivities at λ1 (1537nm) and λ2 (1568.7nm) were found to be 11.8264dBm/m−1, 12.4885dBm/m−1 and 0.0829dBm/°C, 0.0833dBm/°C, respectively. The experimental results show unperturbed readings with rms deviation of ±0.1801m−1 and ±0.0826°C, for curvature and temperature measurements, respectively, through measurement of optical power response of the sensor. With this simultaneous sensing technique, the proposed sensor can be deployed for many field applications such as nondestructive structural health monitoring of civil infrastructure

Spectrogram Based Window Selection for the Detection of Voltage Variation

This paper presents the application of spectrogram with K-nearest neighbors (KNN) and Support Vector Machine (SVM) for window selection and voltage variation classification. The voltage variation signals such as voltage sag, swell and interruption are simulated in Matlab and analyzed in spectrogram with different windows which are 256, 512 and 1024. The variations analyzed by spectrogram are displayed in time-frequency representation (TFR) and voltage per unit (PU) graphs. The parameters are calculated from the TFR obtained and be used as inputs for KNN and SVM classifiers. The signals obtained are then added with noise (0SNR and 20SNR) and used in classification. The tested data contain voltage variation signals obtained using the mathematical models simulated in Matlab and the signals added with noise. Classification accuracy of each window by each classifier is obtained and compared along with the TFR and voltage PU graphs to select the best window to be used to analyze the best window to be used to analyze the voltage variation signals in spectrogram. The results showed window 1024 is more suitable to be used

An Improved Detection and Classification Technique of Harmonic Signals in Power Distribution by Utilizing Spectrogram

This paper introduces an improved detection and classification technique of harmonic signals in power distribution using time-frequency distribution (TFD) analysis which is spectrogram.  The spectrogram is an appropriate approach to signify signals in jointly time-frequency domain and known as time frequency representation (TFR). The spectral information of signals can be observed and estimated plainly from TFR due to identify the characteristics of the signals. Based on rule-based classifier and the threshold settings that referred to IEEE Standard 1159 2009, the detection and classification of harmonic signals for 100 unique signals consist of various characteristic of harmonics are carried out successfully. The accuracy of proposed method is examined by using MAPE and the result show that the technique provides high accuracy. In addition, spectrogram also gives 100 percent correct classification of harmonic signals. It is proven that the proposed method is accurate, fast and cost efficient for detecting and classifying harmonic signals in distribution system

An Analysis of Harmonic and Interharmonic Contribution of Electric Arc Furnace by Using Periodogram

Fast and accurate detection of the harmonic and interharmonic contribution of electric arc furnace (EAF) is crucial in identifying and to mitigate the undesired effects to the system.  In this paper, periodogram, a fast and accurate technique is introduced for the analysis of the contribution. Based on a rule-based classifier and the threshold settings that referred to the IEEE Standard 1159 2009, the analysis of the harmonic and interharmonic contribution of EAF are carried out successfully. Moreover, the impact of contribution is measured using total harmonic distortion (THD) and total non-harmonic distortion (TnHD). In addition, periodogram also gives 100 percent correct detection and able to analyze the contribution impact. It is proven that the proposed method is accurate, fast and cost efficient for analyzing the impact of harmonic and interharmonic of EAF

Microwave filter research in Universiti Teknologi Malaysia

This paper describes four microwave filter configurations that have been recently developed over the past five years. These are a direct coupled cavity waveguide filter, an internally- coupled hairpin-line filter, a meander-gap hairpin line filter and a three-element parallel-coupled filter

Physical activity level among undergraduate students in Terengganu, Malaysia using pedometer

A cross-sectional study determine physical activity level among 95 undergraduate students at UniSZA using pedometer. Subjects consented and completed socio-demographic details, weight and height were measured. Each subject was supplied with a pedometer and wear it for a week and record steps per day from the pedometer each night before bed. Descriptive statistic and independent T-test coefficient analyze the data using IBM SPSS version 22.0. Results showed that 66.4% of the subjects were classified as sedentary according to pedometer determined physical activity. Males recorded significantly more steps than female per day. Subjects in the age group of 18-20 years old had the highest mean average steps count than the older age group of 21-24 years old and ≥ 25 years old per day. Only 5.2% were classified as active and highly active using pedometer determined physical activity level.Keywords: physical activity; pedometer; steps; body compositio

Localization of Multiple Harmonic Sources for Inverter Loads Utilizing Periodogram

This paper introduces a new technique to localize the multiple harmonic sources that caused by power inverter loads in power distribution system utilizing periodogram technique with single-point measurement approach at the point of common coupling (PCC). The periodogram technique is used to analyzed and distinguish multiple harmonic sources location in power system whether at downstream, upstream or both stream by their impedances characteristics. The proposed localization of multiple harmonic sources method is based on the correlational relationship between fundamental impedance (Z1) and harmonic impedance (Zh) in order to identify the suspected buses. The adequacy of the proposed methodology is tested and verified on distribution system for several different cases