Open and Short Circuit Switches Fault Detection of Voltage Source Inverter Using Spectrogram

In the last years, fault problem in power electronics has been more and more investigated both from theoretical and practical point of view. The fault problem can cause equipment failure, data and economical losses. And the analyze system require to ensure fault problem and also rectify failures. The current errors on these faults are applied for identified type of faults. This paper presents technique to detection and identification faults in three-phase voltage source inverter (VSI) by using time-frequency distribution (TFD). TFD capable represent time frequency representation (TFR) in temporal and spectral information. Based on TFR, signal parameters are calculated such as instantaneous average current, instantaneous root mean square current, instantaneous fundamental root mean square current and, instantaneous total current waveform distortion. From on results, the detection of VSI faults could be determined based on characteristic of parameter estimation. And also concluded that the fault detection is capable of identifying the type of inverter fault and can reduce cost maintenance

Speed Control Analysis of Brushless DC Motor Based on Maximum Amplitude DC Current Feedback

This paper describes an approach to develop accurate and simple current controlled modulation technique for brushless DC (BLDC) motor drive. The approach is applied to control phase current based on generation of quasi-square wave current by using only one current controller for the three phases. Unlike the vector control method which is complicated to be implemented, this simple current modulation technique presents advantages such as phase currents are kept in balance and the current is controlled through only one dc signal which represent maximum amplitude value of trapezoidal current (Imax). This technique is performed with Proportional Integral (PI) control algorithm and triangular carrier comparison method to generate Pulse Width Modulation (PWM) signal. In addition, the PI speed controller is incorporated with the current controller to perform desirable speed operation of non-overshoot response. The performance and functionality of the BLDC motor driver are verified via simulation by using MATLAB/SIMULINK. The simulation results show the developed control system performs desirable speed operation of non-overshoot and good current waveforms

Comparison of Open and Short-Circuit Switches Faults Voltage Source Inverter (VSI) Analysis Using Time-Frequency Distributions

Power electronics are highly expanded area in industrial process which offers reliability, survivability and continuous operation. However, the emergence of switches fault has become a major concern in the development of advanced. Switches faults founded in VSI causing equipment failure and cost increased in manufacturing process. Therefore, the fault detection of voltage source inverter (VSI) is necessary to identify the VSI switches faults. This paper presents the analysis of VSI switches faults using TFDs which are short times fourier transform (STFT) and spectrogram. From time-frequency representation (TFR) obtained by using the TFDs, parameters of faults signal can be estimated such as instantaneous of average, RMS, Fundamental, Total Waveform Distortion (TWD), Total Harmonics Distortion (THD) and Total non-Harmonic Distortion (TnHD) of current signals. Based on the characteristics of the faults calculated from the signal parameters, VSI switches faults can be detected and identified. The performance of TFD for the faults analysis is also demonstrated to select the best TFD for switches faults detection and identification system

Development of an Artificial Nose Using 3D Printing Technology for Patients with Tumors

A prosthetic nose is an option where the patient can gain an artificial organ for aesthetics. Thus, this study includes the 3D scan and reconstruction of the 3D model of an artificial nose and analyzes different material properties, which are thermoplastic polyurethane (TPU), thermoplastic elastomer (TPE), and nylon 6 (PA). This research aims to fabricate an artificial nose model using 3D printing technology. A 3D scanner can scan the human head before reconstructing the nose. The analysis of different materials on the artificial nose model is to determine the appropriate material for the artificial nose to fit perfectly into the patient’s face. The artificial nose will use TPU material with a deformation value of 0.00413mm and a maximum stress value of 0.4930 MPa. This prosthesis nose enables people to interact in their social and family lives, making them happier and more comfortable

Sustainability of TVET TE programme: an exploratory sequential mixed method design

Like any other teacher education (or training) institutions, TVET Teacher-Education (TVET TE) institutions also aim to produce quality TVET educators. As a matter of fact, the development of the human resources in TVET system had been highlighted in national policies and strategic planning of every nation across the world. However, due to the development of technology and the rapid life changes , the suitability and relevancy of current TVET TE programme in producing a quality TVET educator has become questionable in the development of human resource. This problem has called for a review for the existing TVET TE programme in order to cater for the needs of the stakeholders. Therefore, this study aims to produce a framework for sustainable TVET TE programme that is capable of dealing with challenges in the 21st century. This study will take up an exploratory sequential mixed method which consists of Fuzzy Delphi Method (FDM) and Survey Method. FDM, which involves 12 experts in TVET TE, will be used to explore the domains and elements that are required in the framework for sustainability of TVET TE programme. The consensus of ideas among the participating experts will be analysed through the use of Triangular Fuzzy Number and Defuzzification. The drafted framework will then be validated by means of a survey method which will be involving TVET educators from several higher learning institutions in Malaysia. The data will be analysed using Confirmatory Factor Analysis. The analysis will be expected to produce a validated framework for sustainable TVET TE programme

Short-Circuit Switches Fault Analysis of Voltage Source Inverter using Spectrogram

The identification of faults in voltage source inverter is highly required to ensure the reliability of the inverter. Early detection of the faults can greatly assist in maintenance of the system by avoiding possibly harmful damage borne out. This paper presents the analysis of short-circuit switches fault of voltage source inverter (VSI) using time frequency distribution (TFD). The TFD which is spectrogram represents current signal of the VSI in time-frequency representation (TFR) that provides temporal and spectral information of the signal. From the TFR, parameters of the signal are estimated such as average current, root mean square (RMS), total harmonic distortion (THD), total waveform distortion (TWD) and total non-harmonic distortion (TnHD). The results shows that the analysis using spectrogram gives information of the current signal of the VSI to identify shortcircuit switche

Voltage Source Inverter Fault Detection System using Time Frequency Distribution

Open-switch and short-switch in a three-phase voltage source inverter (VSI) have a possibility to fault due to problems of switching devices.Any failure of the system in these applications may incur a cost and risk human live. Therefore, knowledgeon the fault mode behaviour of an inverter is extremely important from the standpoint of system design improvement, protection and fault detection. This paper presents detailed simulation results on condition monitoring and fault behaviour of VSI. The results obtained from the developed monitoring system allows user to identify the fault current. The developed system showed the capability in detecting the performance of VSI as well as identifying the characteristics of type of faults. This system provides a precaution and early detection of fault, thus reduces high maintenance cost and prevent critical fault from happening

Efficiency comparison of trapezoidal and sinusoidal method for brushless DC motor drive

This paper compares overall efficiency of trapezoidal BLDC motor which is excited by trapezoidal drive and sinusoidal drive. The different characteristics and performance of trapezoidal brushless DC (BLDC) motor is formed by driving methods. Sinusoidal drive that excites trapezoidal BLDC motor generates greater maximum torque than trapezoidal drive. However, with regard to high frequency loss caused by a pulse width modulation (PWM) carrier and switching loss, the trapezoidal drive has potential to achieve higher efficiency than the sinusoidal drive. Thus, these two drive methods excite trapezoidal BLDC motor are compared to study the performance of efficiencies. The motors drives are simulated by using MATLAB and their efficiencies are measured. The results show that the trapezoidal BLDC motor with trapezoidal drive has higher efficiency compared to trapezoidal BLDC motor with sinusoidal drive

Lithium-ion Battery Parameter Analysis Using Spectrogram

Nowadays, energy storage improves the reliability and efficiency of electric utility system. The most common device used for storing electrical energy is battery. Obtaining an accurate data of battery parameter is important because it will be avoid unexpected system interruption and prevent permanent damage to the internal structure of the batteries. The objective of this study is to apply time-frequency distribution (TFD) which is spectrogram technique in analysis of voltage charging and discharging signal for lithium-ion battery. Spectrogram represents the battery signal in time frequency representation (TFR) which is appropriate to analyze the signal before displaying the instantaneous RMS voltage (Vrms), direct current voltage (VDC) and alternating current voltage (VAC) parameter value. This paper focuses on lithium-ion (Li-ion) battery with nominal voltage of 6 and 12V and various storage capacities from 5 to 50Ah. The battery model is implemented in MATLAB/SIMULINK. From the results, the Li-ion battery parameter could be identified using spectrogram

Novel Statistical Clustering Method for Accurate Characterization of Word Pronunciation

This paper discusses the development method to determine the accuracy of pronunciation of the word using global statistical signal analysis parameters. An engineering word that has been chosen is ‘leaching’. The pronunciation of the word ‘leaching’ in the French language has been recorded from 1 native speaker and 4 students. The recording processes use a microphone-laptop system configuration and the signal analyzing processes use MATLAB software. Time and frequency domain plots show a variety of waveforms according to the recorded pronunciation. For data processing, statistical signal analysis parameters involved to extract the signal’s features are kurtosis, root mean square and skewness. The mapping process has been performed to cluster each data. The position of the samples from the students is referred to the samples from the native speaker. The result of the accuracy of the pronunciation of words for each student can be evaluated through the comparison of the position of all the samples. In conclusion, the development of mapping and clustering methods are able to characterize the accuracy of the pronunciation of words