Ali H. Kasem Alaboudy

Performance improvement of a PV-powered induction-motor-driven water pumping system

This paper presents a modified control strategy to improve the performance of a 3-phase induction motor drive system fed by a standalone PV power source. The main functions of the proposed control strategy are: 1) ensuring successful motor starting, 2) matching the on-site induction-motor pumping load with the available PV power, and 3) forcing the PV system to operate at the maximum power point. The maximum power point tracking (MPPT) is based on perturb and observe (P&O) algorithm. The system consists of a DC/DC boost converter, DC link capacitor, 3-phase inverter, 3-phase induction motor and PV power panels. The PV panel structure is designed to maintain the system operating point at the PV maximum output power at variable solar irradiations. Simulation results demonstrate the operation of the unified system with and without controller under constant and variable solar irradiations. The main control objective is to run system as close as possible to the maximum power point operation under constant and variable solar irradiations. Simulation results using boost converter along with the P&O algorithm show an accurate MPPT at rapid-change of solar radiation and the ability of the system to approach for MPP.

Dynamic performance of microgrid after fault provoked-islanding considering Induction Motor loads

Microgrids (MGs) are one of the most feasible structures that accommodate the increased penetration of the intermittent renewable distributed energy sources. Enabling MGs with renewable energy sources is crucial to meet the environmental concerns, and get economic benefits and reliability requirements. This paper details the effect of control strategies of an inverter-based distributed generation (DG) on the dynamic performance of MG after fault-caused islanding conditions with the presence of Induction Motor (IM) loads. The dynamic performance of MG is analyzed with different IM load conditions. Further, the effect of DGs penetration levels on the performance of MG is investigated. Voltage and frequency deviations are taken as a key indicator for MG stability. A MG model along with the control strategies is simulated on Matlab/Simulink environment. The model includes a composite generation consists of inverter-based DG and synchronous generator coupled with a critical load which contains static RLC load and IM loads. The simulation results declared that the control techniques of the inverter-based DG are highly affecting the MG stability. Moreover, the MG may lose its stable operation owing to IM loads and DGs penetration levels.

Controller performance of variable speed wind driven doubly-fed induction generator

With the advancements in the variable speed system design and control of wind energy systems, the power capturing capability and controller complexity of these systems are increasing in parallel. Doubly fed induction generators (DFIGs) with a partial-scale size back-to-back converter set are among the promising technologies in wind power generation schemes. This paper discusses the controller performance versus scheme complexity for DFIG-based wind turbines. The paper focuses on a simple control scheme to track the optimal power from a variable speed wind energy conversion system. The scheme has been examined under different wind speed profiles. The wind speed, wind turbine, DFIG, and power electronic converters along with their control schemes are implemented in MATLAB/SIMULINK environment. Simulation results show the feasibility and robustness of the presented control scheme for DFIG based wind turbines. Further, the results show that the wind turbine can operate at its optimum energy for a wide range of wind speeds.