This study focuses on microgrid systems incorporating hybrid renewable energy sources (HRESs) with battery energy storage (BES), both essential for ensuring reliable and consistent operation in off-grid standalone systems. The proposed system includes solar energy, a wind energy source with a synchronous turbine, and BES. Hybrid particle swarm optimizer (PSO) and a genetic algorithm (GA) combined with active disturbance rejection control (ADRC) (PSO-GA-ADRC) are developed to regulate both the frequency and amplitude of the AC bus voltage via a load-side converter (LSC) under various operating conditions. This approach further enables efficient management of accessible generation and general consumption through a bidirectional battery-side converter (BSC). Additionally, the proposed method also enhances power quality across the AC link via mentoring the photovoltaic (PV) inverter to function as shunt active power filter (SAPF), providing the desired harmonic-current element to nonlinear local loads as well. Equipped with an extended state observer (ESO), the hybrid PSO-GA-ADRC provides efficient estimation of and compensation for disturbances such as modeling errors and parameter fluctuations, providing a stable control solution for interior voltage and current control loops. The positive results from hardware-in-the-loop (HIL) experimental results confirm the effectiveness and robustness of this control strategy in maintaining stable voltage and current in real-world scenarios.

This work presents linear and nonlinear control strategies applied to a grid‐connected multiple‐source renewable energy system (wind and photovoltaic), in order to extract the maximum power and to enhance the control of the active and reactive powers. A new robust control strategy known as the active disturbance rejection control (ADRC) is proposed and applied to the hybrid renewable energy system (HRES), and it is based on the extended state observer (ESO) which allows us to estimate the internal and external disturbances such as modeling errors and parameter variations. The studied system consists of two conversion chains which are linked via a common DC bus and interconnected to the grid through a voltage source inverter (VSI); the first chain consists of a PV system and a DC‐DC boost converter, and the second chain consists of a direct‐driven wind turbine, permanent magnetic synchronous generator (PMSG), and of a AC/DC rectifier converter. The extraction of maximum power from the PV system and the wind energy conversion system is ensured by using the voltage based perturb and observe (VPO) and the optimal torque control (OTC) MPPT techniques, respectively. The ADRC technique is utilized to control the active and reactive powers by acting on the grid currents. In order to verify and validate the effectiveness of the proposed control strategy, a detailed model of the studied system is designed and evaluated under the MATLAB/Simulink software. The simulation results prove the effectiveness of the MPPT techniques in terms of maximum power extraction during the variation in the environmental conditions. Additionally, the regulation of active and reactive powers is ensured by ADRC, and the system is operating at a unity power factor. Moreover, it is demonstrated that the suggested strategy is efficient in terms of fast tracking and robustness to internal and external disturbances compared to the classical PI controller.

Low voltage ride-through is considered as one of the key technologies for the operation of grid-connected photovoltaic power generation systems. At present, the most used control methods are based mainly on PI controllers, and their robustness results are still unsatisfactory. In contrast, this article introduces a new robust control strategy that uses the compensation effect of “total disturbance” before affecting the system; this control strategy is called Active Disturbance Rejection Control (ADRC) method. In addition, most of the controllers use the standard SRF PLL to achieve the phase lock and grid synchronization. However, when the grid voltage is distorted or other unbalanced, it is necessary to use the positive sequence voltage component of the fundamental wave as a reference, but the component of the negative sequence cannot be effectively filtered because of its narrow bandwidth, and then, accurate phase lock cannot be achieved, which may cause a failure. In this purpose, a Double Second Order Generalized Integrator based Frequency Locked Loop (DSOGI-FLL) is proposed and used to improve the system operating performance and non-off-line capability. In order to confirm the robustness of the proposed control strategies, a multiple simulations tests were done by utilizing the Matlab/Simulink software. The results have demonstrated the superiority of the proposed methods and their robustness to symmetrical and unsymmetrical faults.

Modeling and Robust Control of a Grid Connected Direct Driven PMSG Wind Turbine By ADRC