Now showing 1 - 10 of 10
  • Publication
    Integrated clustering development using embedded meta evolutionary-firefly algorithm technique for DG planning
    Recent trend changes have created opportunities to achieve numerous technological innovations including the use of distributed generation (DG) to achieve different advantages. A precise evaluation of energy losses is expanding rapidly when DG is connected to the electricity sector due to developments such as increased competition and real time pricing. Nevertheless, non-optimal DG installation either in the form of DG locations and sizing will lead to possible under-compensation or over-compensation phenomena. The integrated clustering resulted from the pre-developed Embedded Meta Evolutionary Programming-Firefly Algorithm (EMEFA) has been used to ensure the optimum allocation and placement of DG. The study also considers the different types of DG. The aim of the technique is to consider the computational time of the optimization process for DG planning in achieving the minimal total loss. Two test systems have been used as test specimens to achieve the efficacy of the proposed technique. In this study, the techniques proposed were used to establish the DG size and the appropriate place for DG planning. The results for total losses and minimum voltage for the system were recorded from the simulation. The result in this study will be compared with the ranking identification technique to ensure the capability of this technique. The power system planner can adopt the suitable sizes and locations from the obtained result for the planning of utility in term of economic and geographical consideration.
  • Publication
    Design of concentrated solar power water desalination system (CSPWDS)
    ( 2023-03-29)
    Mahmood A.N.
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    El-Khazali R.
    This work focuses on designing a concentrated solar power water desalination system (CSPWDS). A set of four Fresnel lenses (FRL) are used to concentrate the solar power at their corresponding focal points. The objective is to focus the irradiance power at a small area, where the temperature could reach over a 1000 Cat its focal point. This study investigates a design method of a CSPWDS that includes an investigation of the effectiveness of using FRLs for water desalination. The system automatically tracks the sun to improve its production rate. Four spiral copper pipes receivers are designed to convert the saline water into a steam that is directed upward to benefit from the gravitational force. The salt residue in the steam is then filtered out due to both using a special membrane and due to gravity force. A condensation process is then followed to condense the steam into water. The salinity of the condensed steam is tested to ensure a good quality of the desalinated water. The process is continuously monitored to improve the quality of the generated water. If the level of water salinity is still high, a feedback path is implemented to repeat the process until the quality of the desalination is met.
  • Publication
    Grid integration of multiple PV inverters with reduced number of interfacing transformers— A dedicated controller for elimination of DC current injection
    ( 2023-03-01) ;
    Adam G.P.
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    Williams B.W.
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    Rahim N.A.
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    The injection of dc current offset into ac networks may impacted the lifespan of the distribution system equipment including isolation transformers and measurement devices and in serious event may cause equipment's malfunction. This paper intents to eliminate dc current offsets in the output currents using a combinational of proportional-integral (PI) and proportional resonance (PR) controls embedded in one inverter unit. Resultant output currents of this method are sinusoidal and clean from dc offset before entering the point of common coupling. This method gives advantages for transformerless option for group of interfacing inverters in the medium-scale solar farm or in arrangement of inverters restricted in a small locale. Moreover, the use of expensive and high-accuracy measurement sensor nor complex transformer can be omitted, whilst indirectly give positive impact to the operational cost of the farm. The simulation verifications proved the usefulness of the proposed method by introducing varying unknown dc offset levels in the phase currents, and a dedicated dc offset suppressor inverter able to successfully eliminate the dc offset to zero. The validity of the proposed method is demonstrated in simulation using MATLAB/Simulink.
  • Publication
    Comparative Evaluation of Three-Phase Inverter Topologies Based on Voltage Boosting Features
    ( 2023-01-01)
    Yee C.S.
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    Hwai L.J.
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    Zahari M.Z.A.
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    Voltage source inverter (VSI) is commonly used in industrial due to its stable operation and low cost. However, VSI needs to operate with an extra converter stage which is a DC-DC converter for voltage boosting purposes. In contrast, current source inverter (CSI) inherits voltage boosting features may become an alternative option to VSI. Yet, there were minimal research on CSI that dedicates to the voltage boosting features. This research focuses on comparing the voltage boosting features of CSI and VSI in both open-loop and closed-loop conditions. The performance of VSI and CSI are simulated using MATLAB/Simulink. Under open-loop operation, CSI produces a voltage boosting capability at approximately 55% higher than VSI. Yet, CSI suffers high THD percentage as compared to VSI for the same switching frequency. This high THD shortcoming can be easily resolved by using a simple CL filter. For closed-loop operation, VSI and CSI with voltage-controlled synchronous frame PI control systems are proven to have good reference tracking and harmonic rejection and are suitable to be implemented for household applications or for a standalone system. Interestingly, CSI closed-loop system can achieve a wider range of output due to the voltage boosting capability and provide a better quality of output waveform as compared to VSI.
  • Publication
    A hybrid multi-objective Evolutionary Programming-Firefly Algorithm for different type of Distributed Generation in distribution system
    ( 2022-12-01)
    Noor Najwa Husnaini Mohammad Husni
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    ; ;
    Hussain M.H.
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    Musirin I.
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    With the rise in electricity demand, various additional sources of generation, known as Distributed Generation (DG), have been introduced to boost the performance of power systems. A hybrid multi-objective Evolutionary Programming-Firefly Algorithm (MOEPFA) technique is presented in this study for solving multi-objective power system problems which are minimizing total active and reactive power losses and improving voltage profile while considering the cost of energy losses. This MOEPFA is developed by embedding Firefly Algorithm (FA) features into the conventional EP method. The analysis in this study considered DG with 4 different scenarios. Scenario 1 is the base case or without DG, scenario 2 is for DG with injected active power, scenario 3 is for DG injected with reactive power only and scenario 4 is for DG injected with both active and reactive power. The IEEE 69-bus test system is applied to validate the suggested technique.
  • Publication
    Current control of grid connected three phase current source inverter based on medium power renewable energy system
    ( 2021-01-01) ;
    Adam G.P.
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    Rahim S.R.A.R.
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    Williams B.W.
    Current source inverter (CSI) features simple converter structure and inherent voltage boost capability. In addition, it provides low instantaneous rate of voltage change with respect to time in comparison to voltage source inverter (VSI) and multilevel inverter (MLI). Nonetheless, CSI does not outshine as grid interfacing unit in photovoltaic (PV) generation system. This is because of requirement of large sizing of dc-link inductor and sluggish performance during light load condition. Contemplating both advantages and disadvantages of CSI, this work is aimed to investigate and analyze the superiority of CSI in PV system. The proposed system employs direct regular-sampled pulse width modulation (DRSPWM) as modulator and multi-loop proportional-integral (PI) in synchronous frame as the controller. The grid-connected CSI system is further evaluated along with photovoltaic maximum power point tracking (PV-MPPT) control. Simulation verification highlighted that the option of using CSI as medium power PV grid integration unit in exchanging active-reactive power with grid network is very satisfactory. In addition, balanced sinusoidal output currents with acceptable harmonic limit are successfully achieved; like other topologies in PV grid integration. The proposed CSI system is proved to be able to track the references in event of varying input condition from PV array. The theoretical equations and modeling are described, and the simulation are conducted in MATLAB / Simulink platform.
  • Publication
    An Effective Salp Swarm Based MPPT for Photovoltaic Systems under Dynamic and Partial Shading Conditions
    ( 2021-01-01)
    Jamaludin M.N.I.
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    Ahmed J.
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    Babu T.S.
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    Alhelou H.H.
    This study proposes a duty cycle-based direct search method that capitalizes on a bioinspired optimization algorithm known as the salp swarm algorithm (SSA). The goal is to improve the tracking capability of the maximum power point (MPP) controller for optimum power extraction from a photovoltaic system under dynamic environmental conditions. The performance of the proposed SSA is tested under a transition between uniform irradiances and a transition between partial shading (PS) conditions with a focus on convergence speed, fast and accurate tracking, reduce high initial exploration oscillation, and low steady-state oscillation at MPP. Simulation results demonstrate the superiority of the proposed SSA algorithm in terms of tracking performance. The performance of the SSA method is better than the conventional (hill-climbing) and among other popular metaheuristic methods. Further validation of the SSA performance is conducted via experimental studies involving a DC-DC buck-boost converter driven by TMS320F28335 DSP on the Texas Instruments Experimenter Kit platform. Hardware results show that the proposed SSA method aligns with the simulation in terms of fast-tracking, convergence speed, and satisfactory accuracy under PS and dynamic conditions. The proposed SSA method tracks maximum power with high efficiency through its superficial structures and concepts, as well as its easy implementation. Moreover, the SSA maintains a steady-state oscillation at a minimum level to improve the overall energy yield. It thus compensates for the shortcomings of other existing methods.
  • Publication
    Design and Development of Cascaded Current Control in DC Motor Variable Speed Drive using dSPACE
    Even today, DC motors are still used in variety of applications, including home appliances, transportation, as well as industrial crane and rolling machine. However, achieving precise speed and torque control in DC drives at industry level could be challenging, as instability and reduced efficiency remains at large. This project focuses on developing a cascaded control system for a Separately Excited Brushed DC motor using dSPACE platform. The cascaded control system, designed using MATLAB Simulink, incorporates a proportional-integral (PI) controller at the speed loop and a Hysteresis controller at the current loop to improve robustness and dynamic performance. The experimental setup utilizes the dSPACE 1104 platform, an asymmetric bridge converter board, gate driver, and electrical load. Speed measurement is done using an incremental encoder, while current is measured using the ACS712 current sensor. The drive system was tested in alternate low and high speed cycle on various load level to test for stability, robustness and dynamic performance. The proposed control system was compared with PI-closed-loop control and open-loop control determine the best drive performance. Experimental results showed significant improvement in term of transient response and ripple reduction of speed and current for proposed cascaded current control over the closed-loop design.
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  • Publication
    Assessment of Control Drive Technologies for Induction Motor: Industrial Application to Electric Vehicle
    Nowadays electric vehicle has increasingly gained much popularity indicated by growing global share market targeted at 30% by 2030 after recording 7.2million global stock in 2019. Compared to Internal Combustion Engine (ICE) counterpart, Battery Electric Vehicles (BEV) produce zero tailpipe emission which greatly reducing carbon footprints. Induction motor has been widely used and its control technology has evolved from scalar type volt/hertz to recent predictive control technology. This allows induction motor's application to expand from being the workhorse of industry to become prime mover in electric vehicle, where high performance is expected. Among vector control scheme, Direct Torque Control (DTC) has gained interest over Field Oriented Control (FOC) with simpler structure, better robustness and dynamics performance yet suffer from high torque and flux ripple. In electric vehicle applications, high ripple at low speed is highly undesirable, potentially causing torsional vibration. High performance control requires speed sensor integration, which often increase complexity in the design. The work aims to review the best control technology for induction motor in electric vehicle application through performance parameter evaluation such as improvement on dynamic response, torque and flux ripple reduction, and component optimization. Several arise issues in motor control and possible methods to circumvent are highlighted in this work. In conclusion, model predictive torque control (MPTC) is the most promising scheme for electric vehicle with excellent dynamic response, good low speed performance, and 50% torque ripple reduction compared to conventional DTC and potential integration with sliding mode observer for sensorless solution.
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  • Publication
    Fuzzy Logic Cascaded Current Control of DC Motor Variable Speed Drive using dSPACE
    Two-wheel e-scooter falls under low power segment for Battery Electric Vehicle (BEV) and has gain more popularity in urban commuting. Most entry level e-scooter is still powered by DC motor due to low cost and ease of control. However basic open-loop DC Motor control employed through throttling is plugged with limited efficiency, precision, and range of speed control. Closed-loop control enables real time adjustment according to preset speed which becomes handy during auto cruising. To ensure good dynamic response, improved robustness and stable wide speed control range, a good control scheme for the motor is essential. In this project, a variable speed control scheme, namely fuzzy logic cascaded current control system was designed using MATLAB Simulink, comprising speed control loop and a current control loop 185 W Separately Excited Brushed DC Motor. The proposed control system was tested on hardware using dSPACE DS1104 platform. The system's output speed is obtained using an incremental encoder, while the output current is measured with a current sensor. Subsequently, the control system's stability, robustness, and dynamic performance were evaluated by driving the system on 120 W electrical load at varying speed. The system performance has proved superior to closed-loop by 70% on low speed ripple reduction and is on par with PI cascaded current control scheme.
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