Adaptive model predictive control (AMPC) as a load frequency controller (LFC) in a multi-area power system has been proposed in this paper. The main objective of this research is to overcome the ...problems of frequency deviation against system parameters variations and load distuirbance. The idea of using AMPC is to vary the plant model in the structure of MPC on line to overcome the uncertainty due to governor and turbine parameters variation. In addition, The MPC technique is designed such that the effect of the load disturbance is reduced. The full model parameters of the system have been estimated using online estimation model based on Recursive Polynomial Model Estimator (RPME). Moreover, the output of the RPME estimator is used to online updating of the internal model of the AMPC. The online estimation is to achieve accurate and precise control with nonlinear control systems. A digital simulation has been used to investigate the effecinecy of the proposed scheme. Simulation results prove that, the application of the suggested AMPC with the control system results a robust aginst parameters uncertainties and loads disturbances. A comparison between the proposed technique and other schemes is carried out, confirming the superiority of the proposed algorithm.
This paper presents design and performance of high power quality single-phase grid inverter that fed from photovoltaic (PV) system through maximum power tracker for residential application. The ...proposed designed inverter is based on sinusoidal pulse width modulation (SPWM) technique in combination with series-resonance and high-pass filters at low side of inverter. The filters and SPWM are designed to reduce the total harmonic distortion (THD) to limit values that coincide with IEEE and IEC standard recommendations without harmonic resonance. The proposed inverter is equipped with synchronizing system with the utility grid at 220V and 50Hz. The synchronizing system of embedded Matlab software is based on phase locked loop (PLL), adjustable phase shift leading angle of inverter, and root mean square (RMS) of grid and inverter voltages philosophies to satisfy synchronization requirements. The performance of the proposed inverter is investigated through Matlab/Simulink simulations. The simulation results using Matlab/Simulink show good quality performance for 80W PV solar module. The results are excellent and the proposed inverter PV system is suited for practical applications of Egyptian consumers with utility grid.
In this paper, a proposed sensorless vector controlled induction motor drive using a modified full order observer taking core losses in to account has been presented. The full order observer is ...designed to simultaneous estimation of stator and rotor resistance and rotor speed. Matlab /Simulink package has been used to simulate the suggested scheme. The simulation results prove the effectiveness of the proposed induction motor drive. Moreover, a comparison between the convential full order observer and the proposed one with core losses compensation has been carried out.
Power Quality Issue of Grid Connected DFIG Wind Farm System Shazly Abdo Mohamed Ahmed; Montaser Abd El-Sattar
International Journal of Electrical Engineering and Applied Sciences (Online),
10/2019, Letnik:
2, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Quality of power is known as any power problem manifested as a non-standard frequency, current and voltage which cause failure of end customer apparatus. The wind utilization, generation and its ...penetration in utility grid are increasing worldwide. One of the master issues in wind generation is the insertion to the network. When the wind energy is injected to the grid generally controls the voltage disturbances on the system power quality, variation of voltage is the almost prevalent kind of disturbance which affects stability and the quality of power for grid-inserted wind system. This study investigates the two widespread kinds of voltage variations such as voltage dip and swell, which can happen if large amount of wind system is connected to an electrical grid. This research also studies the response and performance under faults of a wind farm inserted to distribution systems. In this paper, a wind turbine with induction machine (DFIG) is simulated by using MATLAB/Simulink program. The simulated model is subjected to disturbances which known as; voltages (dip and rise). The results of simulation presents that, how both variations; voltage dip & voltage rise lead to mal-operation as well as shut-down of entire system, therefore deteriorating the improvement of power quality for the grid.
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