90 research outputs found

    Study on interoperability problems among CAD/CAM systems in automotive industry

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    In automotive supply chain there are many different CAD/CAM systems that been used. Each system has its own proprietary data representation. As a result, product data are created and stored in multiple, frequently incompatible formats to other software's. Therefore, interoperability problems exist when files are being transferred between systems. Even with all the advances that have been made in the area of data transfer between CAD/CAM systems, this problem is still a major issue. This project studies the scenario on CAD/CAM data transfer problem particularly in automotive industry in Malaysia. Referring to others study at USA, Germany and Australia, a framework on how Malaysia's automotive industry can react proactively to the problems is proposed

    Experimental implementation controlled SPWM inverter based harmony search algorithm

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    An optimum PI controller using harmony search optimization algorithm (HS) is utilized in this research for the single-phase bipolar SPWM inverter. The aim of this algorithm is to avoid the conventional trial and error procedure which is usually applied in finding the PI coefficients in order to obtain the desired performance. Then, the control algorithm of the inverter prototype is experimentally implemented using the eZdsp F28355 board along with the bipolar sinusoidal pulse width modulation (SPWM) to control the output voltage drop under different load conditions. The proposed overall inverter design and the control algorithm are modelled using MATLAB environment (Simulink/m-file Code). The mean absolute error (MAE) formula is used as an objective function with the HS algorithm in finding the adaptive values of  and  parameters to minimize the error of the inverter output voltage. Based on the output results, the proposed voltage controller using HS algorithm based PI (HS-PI) showed that the inverter output performance is improved in terms of voltage amplitude, robustness, and convergence rate speed as compared to PSO algorithm based PI (PSO-PI). This is to say that the proposed controller provides a good dynamic responses in both cases; transient and steady-state. Finally, the experimental setup result of the inverter controller is verified to validate the simulation results

    Hybrid Fuzzy-PID Bidirectional Speed Controller for BLDC with Seamless Speed Reversal using Direct Commutation Switching Scheme

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    Brushless Direct Current (BLDC) motors have attracted a lot of attention due to their performance capabilities. The Proportional Integral (PID) controller remained popular due to its simplicity. However, PID’s performance deteriorates during nonlinear loads conditions. Controllers have been developed to overcome the limitations of the PID controllers but focused on forwarding motor only. Furthermore, lack of literature regarding the bidirectional speed control of BLDC motor has been reported. In this paper, a Hybrid Fuzzy-PID speed controller for BLDC with seamless speed reversal using direct commutation switching scheme was proposed. The controller uses Fuzzy rule base and the switching scheme for bidirectional operations. MATLAB/Simulink was used to develop and test the controller. The controller was tested for several test cases and compared to a ZN-Tuned PID controller. The controller performed efficiently for all the test cases and has better results compared to the PID controller under same test cases

    Modeling and Performance Analysis of Plug-In Split Hybrid Electric Vehicle

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    Regarding increasing of concern over the environment and ever stringent emissions regulations, the electric vehicle has been investigated as an alternative form of transportation. However, the electric vehicle suffers from relatively short range and long charging times and consequently has not become an acceptable solution to the automotive consumer. The addition of an internal combustion engine to extend the range of the electric vehicle is one method of exploiting the high efficiency and lack of emissions of the electric vehicle while retaining the range and convenient refuelling times of a conventional gasoline powered vehicle. The term that describes this type of vehicle is a hybrid electric vehicle. Many configurations of hybrid electric vehicles have been designed and implemented, namely the series, parallel and power-split configurations. This project discusses the modelling and simulation of split plug-in hybrid electric vehicles. Modelling methods such as physics-based Resistive Companion Form technique and Bond Graph method are presented with powertrain component and system modelling examples. The modelling and simulation capability of existing tools such as ADvanced VehIcle SimulatOR (ADVISOR) is demonstrated through application examples. Since power electronics is indispensable in hybrid vehicles, the issue of numerical oscillations in dynamic simulations involving power electronics is briefly addressed

    Simulation on modified hysteresis current control in half-bridge bidirectional DC-DC converter

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    This paper proposes a modified hysteresis current control method for half bridge bidirectional DC-DC converter (HBDC). Hysteresis current controller is modified by adding logic circuit at input signal S1 and S2 to change performance of inductor current, IL. According to current direction transition, IL stays at zero in a moment. It is happens when Irefp is crossing zero and continues bouncing when Irefm is crossing zero. This method is applied to reduce loss in HBDC performance, which as a result will achieve reduction in switching losses and conduction losses. The conduction losses and switching losses has been analyzed which conduction losses has slight changes in losses reduction and switching losses is reduce from 6.31 J to 4.53 J. The proposed hysteresis current controller was simulated using PSIM and the losses is verify on each switching changes. The result validated proposed hysteresis current control capability in losses reduction

    Miniature tool for characterization of supercapacitive charge storage

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    A new protocol to characterize supercapacitive charge storage parameters from discharge voltage measurement and using an electrical model is presented. A distribution of capacitances and resistances in three charge storing time domains (fast, medium, and slow) are derived through this protocol. The method relieson recording the self-discharge data (open circuit discharge) and using it along with the charge redistribution within the supercapacitor to obtain the parameters for the equivalent circuit model. The results are validated using the galvanostatic charge discharge cycling. The method proposed here uses comparatively lesser number of variables, thereby making it easier to compute and the validation shows a good match between the experimental and the simulated results

    Potential Data Collections Methods for System Dynamics Modelling: A Brief Overview

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    System Dynamics (SD) modelling is a highly complex process. Although the SD methodology has been discussed extensively in most breakthroughs and present literature, discussions on data collection methods for SD modelling are not explained in details in most studies. To date, comprehensive descriptions of knowledge extraction for SD modelling is still scarce in the literature either. In an attempt to fill in the gap, three primary groups of data sources proposed by Forrester: (1) mental database, (2) written database and (3) numerical database, were reviewed, including the potential data collections methods for each database by taking into account the advancement of current computer and information technology. The contributions of this paper come in three folds. First, this paper highlights the potential data sources that deserved to be acknowledged and reflected in the SD domain. Second, this paper provides insights into the appropriate mix and match of data collection methods for SD development. Third, this paper provides a practical synthesis of potential data sources and their suitability according to the SD modelling stage, which can serve as modelling practice guidelines

    Overviews of Uncertainty: Concepts, Categories and Coping Strategies in Decision Making

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    Uncertainty is not a new issue in decision making. A wrong decision made of a lack of certainty is every decision maker’s nightmare. Although uncertainty is broadly discussed in academic literature, uncertainty has been defined in many definitions, terms and conceptions. Some of the terms often overlap with similar terms from different perspectives. In the light of this, this paper takes the opportunity to explain uncertainty under 3 C’s perspectives; the Concept, the Categories and the Coping Strategies. An overview of uncertainty concepts pro- vides the basis for understanding how it is defined from a particular perspective related to decision support for decision making. The categories of uncertainty are explained based on their characterisation to provide a better understanding. Since there is no fixed way to treat uncertainty, this study takes the opportunity to compile the possible coping strategies in handling uncertainty. As an outcome, the contributions of this study come in two ways. First, this paper provides insights on uncertainty concepts and uncertainty categories that are worthy of being reflected in decision support for decision-making research domains. Second, this paper provides solutions and ideas for potential mix-and-match coping strategies that might be helpful in dealing with uncertainty in decision-making

    Numerical Investigation on Serpentine Flow Field and Rhombus Electrolyte Compartment of Vanadium Redox Flow Battery (V-RFB)

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    Selection of suitable material, fitting for prototype design and pumping rates are three affecting element for cost effectiveness and improve performance of vanadium cell prototype investigation. Therefore, three-dimensional numerical model isothermal computational fluid dynamics (CFD) model of vanadium redox flow battery (V-RFB) is studied. In this work, V-RFB with different electrolyte compartments is proposed and the effect of serpentine flow field is investigated. The performance of two V-RFBs with diamond and square electrolyte compartment is numerically tested. This work has been performed to optimize flow rate, electrolyte compartment design, avoid stagnant fluid and flow field application in VRFB. For the simulation, the flow was assumed to be incompressible, isothermal, steady state flow, laminar and Newtonian flow. Results show that the application of flow field and Rhombus type electrolyte compartment can facilitate the distribution of electrolyte in the unit cell uniformity and avoid stagnant in the tank. Simulation results indicate the diamond shape and serpentine flow field at optimal flow rate show the most suitable for V-RFBs than square shape

    Selective harmonic elimination using MFO for a reduced switch multi-level inverter topology

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    This research article proposed a new modified single-phase multi-level inverter topology with an optimal switching control strategy to reduce the inverter output harmonic distortion. The topology is configured to operate in asymmetric mode to generate eleven levels of output voltage steps. Additionally, a selective harmonic elimination technique has been deployed to minimize the switching loss and EMI. The Moth Flame Optimization (MFO) algorithm is deployed to compute the optimal switching angles. The proposed MLI topology is simulated in PSIM software using the optimized switching angles. The inverter performance parameters such as the total harmonic distortion (THD), harmonic amplitudes, switching, and conduction losses, were also analyzed and reported. The topology total harmonic distortion is 2.4%, hence satisfying the IEEE 519 standard
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