Now showing 1 - 3 of 3
  • Publication
    Modified PQ and hysteresis current control in grid-connected single-phase inverter for PV system
    (Springer, 2023) ;
    Dahaman Ishak
    ;
    Muhammad Ammirrul Atiqi Mohd Zainuri
    This paper proposes a modified PQ method integrated with hysteresis current control (HCC) used in a grid-connected single-phase inverter for photovoltaic (PV) renewable energy system. The main aim is to achieve a smooth control of unidirectional power flow from the solar PV to the inverter and then from the inverter to the load, and yet bidirectional power flows from/into the utility grid. The system configuration consists of PV array, H-bridge single-phase inverter, ac load and ac grid. Incremental Conductance (InCond) algorithm is used to track the maximum power point of active power (P mpp) available from PV array even under varying environmental and load conditions. The inverter switching modulations are achieved by pre-defined double-band HCC which is calculated to minimize total harmonic distortions (THDs) in the ac output waveforms. The modified PQ method ensures that full synchronization is achieved with the utility grid, unity power factor (PF) is always maintained and bidirectional power flow is properly regulated. The proposed controller of the grid-connected single-phase inverter is tested for various operating conditions under varying loads and solar irradiance levels. The results show that the proposed controller can effectively regulate the delivery of active power and reactive power from the inverter to the connected load. The results also prove that the proposed controller successfully allows bidirectional power flow at the grid side. Total harmonics distortions of the voltage and currents are shown to be less than 5% maximum limit, as recommended in IEEE 519 standard. Another merit of the proposed controller is that it guarantees a unity power factor by forcing the grid voltage and current to be in phase without the use of phase locked loop (PLL) technique. Stable DC-link voltage at the inverter side is achieved without the DC boost converter stage. The efficacy of the proposed controller used in the grid-connected single-phase inverter is proven using MATLAB/Simulink.
  • Publication
    Improving the performance of solar panels by the used of dual axis solar tracking system with mirror reflection
    This work proposes the dual axis solar tracker with mirror reflection for optimum output of solar panel by using arduino unoR3 as the control unit. The objectives of this work are to track and optimize the maximum output power of the solar panel by designing and developing a dual axis solar tracker with mirror reflection. The system includes a 10 watt solar panel, an arduino unoR3 and a customized mechanical body to carry the solar panel. This system will track and detect the angle of the sun to locate the surface of solar panel at the position and the angle where it can get maximum amount of energy. The sensors will detect the position of the sun and servo motors act as free moving neck to make it easier to move freely depending on the angle detected. The Light Depending Resistor (LDR) will be used in tracking system. These LDR will detect the existence of sunlight and therefore the mechanical hardware will move horizontal and vertical axis depending on the value of LDR detected to follow the angular degree of sun in order to get maximum and best result of absorbing energy. The final result obtained from dual axis solar tracker showed that the output power has been maximized compared to stationary panel. Based on the experimental result, it show that the designed system successful improve the performance of the solar panel.
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  • Publication
    Improved control in single phase inverter grid-tied PV system using modified PQ theory
    (Tech Science Press, 2023) ;
    Dahaman Ishak
    ;
    Muhammad Ammirrul Atiqi Mohd Zainuri
    ;
    Muhammad Najwan Hamidi
    ;
    Zuhair Muhammed Alaas
    ;
    Mohamed Mostafa Ramadan Ahmed
    Grid-connected reactive-load compensation and harmonic control are becoming a central topic as photovoltaic (PV) grid-connected systems diversified. This research aims to produce a high-performance inverter with a fast dynamic response for accurate reference tracking and a low total harmonic distortion (THD) even under nonlinear load applications by improving its control scheme. The proposed system is expected to operate in both stand-alone mode and grid-connected mode. In stand-alone mode, the proposed controller supplies power to critical loads, alternatively during grid-connected mode provide excess energy to the utility. A modified variable step incremental conductance (VS-InCond) algorithm is designed to extract maximum power from PV. Whereas the proposed inverter controller is achieved by using a modified PQ theory with double-band hysteresis current controller (PQ-DBHCC) to produce a reference current based on a decomposition of a single-phase load current. The nonlinear rectifier loads often create significant distortion in the output voltage of single-phase inverters, due to excessive current harmonics in the grid. Therefore, the proposed method generates a close-loop reference current for the switching scheme, hence, minimizing the inverter voltage distortion caused by the excessive grid current harmonics. The simulation findings suggest the proposed control technique can effectively yield more than 97% of power conversion efficiency while suppressing the grid current THD by less than 2% and maintaining the unity power factor at the grid side. The efficacy of the proposed controller is simulated using MATLAB/Simulink.