Publications 2021

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https://hdl.handle.net/20.500.14170/3707

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Browsing Publications 2021 by Author "Aazmi M.A."
  • Publication
    Design new voltage balancing control series connected for HV-IGBT's
    ( 2021-08-01)
    Fahmi M.I.
    ;
    Mukmin M.F.
    ;
    Liew Hui Fang
    ;
    Wai C.L.
    ;
    Aazmi M.A.
    ;
    Syahrun Nizam Md Arshad @ Hashim
    The insulated gate bipolar transistors (IGBTs) are widely used in various applications as they require low gate drive power and gate voltage. This paper proposes an active gain circuit to maintain voltage stability of series-connected IGBTs for high voltage applications. The novel gate driver circuit with closed-loops control amplifies the gate signal while restricting the IGBT emitter voltage below a predetermined level. With the proposed circuit, serial-connected IGBTs can replace high-voltage IGBTs (HV-IGBTs) for high-voltage applications through the active control of the gate signal time delay. Closed-loop controls function is to charged current to the gate to restrict the IGBT emitter voltage to a predetermined level. This paper also presents the experiment on the gate driver capability based on a series-connected IGBTs with three IGBTs and a snubber circuit. The experimental results show a voltage offset with active control with a wide variation in load and imbalance conditions. Lastly, the experimental results are validated with the simulation results, where the simulation results agree with the experimental results.
  • Publication
    Direct torque control of induction motor with different energy storage for electrical vehicle (EV) application
    ( 2021-12-01)
    Aazmi M.A.
    ;
    Muhammad Izuan Fahmi Romli
    ;
    Muhammad Zaid Aihsan
    ;
    Liew Hui Fang
    ;
    Mohd Saifizi Saidon
    Energy demand worldwide is rising at an unprecedented pace. This has already shown its impact on the depletion of energy sources and environmental issues (global warming and the weakening of the ozone layer). This growing pattern of energy insufficiency will, of course, intensify in the future. Referring to the literature, significant energy savings can be achieved by controlling the speed of the electric motor system using variable frequency drives (VFDs). Efficient control of induction motor drives provides an excellent opportunity for energy savings. As a result, research into the optimal operation of induction motor drives is escalating and mainly focuses on the Direct Torque Control (DTC) control technique on improving the dynamic operation of torque control. However, the study on the type of energies on improving the dynamic response is least reported. This paper will study the effect of different energy supplies on the dynamic response of torque performance. The standard DC battery and supercapacitor will be used to energize the induction motor through the three-phase inverter and controlled with the DTC control scheme. The results are validated through MATLAB Simulink and it shows the supercapacitor has the better dynamic response in torque response compared to the standard DC battery. The comparative results are presented in a proper mannered way.