Nowadays, the smart microgrid is a promising solution to overcome the issues of depleting fossil fuel, climate change, global warming and environmental pollution. A microgrid depends on the installation of renewable and distributed generation sources beside the local loads to minimize the cost of power transmission and high reliability against sudden faults. Among the various renewable energy micro-sources (REMSs) utilized in distributed generation (DG) systems, photovoltaic (PV) technology has gained significant traction due to its modularity, declining costs, and environmental benefits. This paper presents a modified architecture for an AC microgrid that includes six master units (MUs) powered by PV cells. Unlike conventional PI controllers, the proposed Fractional Order Proportional-Integral (FOPI) controllers feature an additional tunable parameter, which increases the complexity of the controller design. To address this, Star Fish optimization techniques are utilized and compared for selecting the optimal parameters of the FOPI controller. The optimization process focuses on enhancing power quality and improving both dynamic and steady-state performance by fine-tuning the HC controller parameters. Multiple objective error functions are used and evaluated to minimize the total harmonic distortion of the grid’s output current. The effectiveness of the proposed FOPI controller is verified in MATLAB/Simulink, considering permissible variations in inverter output active and reactive powers, as well as under conditions of grid voltage distortion.
Nuevo León is the second state in Mexico with the highest number of Distributed Generation (DG) projects, making it essential for companies implementing Photovoltaic (PV) Systems to understand the impact of proper orientation and tilt in their installations. This study was conducted using PVSyst V7.2.5, simulating conditions for Monterrey, Nuevo León, Mexico, with a reference project of 6.6 kWp and 6 kW AC at optimal azimuth and tilt angles, in order to benchmark energy losses. Additionally, a dataset was generated that includes energy loss values by azimuth orientation from -180° to 180°, combined with tilt angles corresponding to maximum and minimum solar altitude at 3° intervals for Monterrey. The results provide a reference framework and scientific contribution for the positioning of PV arrays by azimuth and tilt in DG projects in Monterrey, taking into account the associated energy losses for both engineering design and business planning in the companies involved.
To lessen the negative impact of symmetrical voltage sag on the performance of a grid-connected wind-driven double-fed induction generator (WD-DFIG), four methods are suggested in this study. Adding RL impedance to the stator winding, adding RL impedance to the rotor winding, adding RL impedances to the stator and rotor windings simultaneously, and adding a passive filter to the stator windings are the four methods. At two voltage sag values at sub-sync and super-sync speeds, the response of the stator current, rotor current, rotor voltage, dc link current, dc link voltage, and electromagnetic torque under each suggested technique is compared at sub-sync & super-sync speeds.
The operating temperature of photovoltaic (PV) modules has a direct effect on electrical performance and short-term efficiency under real outdoor conditions. During periods of strong solar irradiance, PV modules are exposed to considerable thermal stress, which increases operating temperature and can reduce power production. In this study, the thermal behavior of a photovoltaic system under high-temperature operating conditions was analyzed using a set of empirical and semi-empirical thermal models. The analysis included the classical Ross/NOCT model, a wind-corrected NOCT formulation, an irradiance-adjusted NOCT approach, and the Faiman thermal model. In addition, a semi-empirical Thermal Performance Deviation Model (TPDM) was developed to investigate the combined influence of irradiance and thermal excess on PV thermal-performance behavior. The results showed pronounced daily thermal cycling and significant temperature rise during peak irradiance periods, with modeled operating temperatures exceeding 60°C under the most thermally stressed conditions. The estimated short-term thermal efficiency loss reached 10.83%, while more than 1100 operating hours exhibited efficiency losses above 3% and 552 hours exceeded 5% thermal efficiency loss. The proposed TPDM formulation achieved the best overall statistical performance, with an R2 value of 0.857 and an RMSE of 0.724, indicating reasonable agreement under variable outdoor operating conditions. The analysis additionally demonstrated the important role of wind-driven convective cooling in reducing thermal stress during outdoor PV operation, highlighting the importance of thermal stress analysis under high-temperature conditions.
This article presents an integrated numerical framework for the analysis of electromechanical dynamics and steady‑state behavior in a 17‑bus subset of the Spanish peninsular transmission system. Motivated by the severe blackout that occurred in April 2025, which revealed the vulnerability of low‑inertia, renewable‑dominated grids, the study couples the fourth‑order Runge–Kutta method with the Newton–Raphson method, as a power‑flow algorithm, to provide a unified representation of transient frequency evolution and static system equilibrium. The selected network subset includes a Slack bus, several PV buses, and multiple PQ buses with significant load concentrations and strong reactive interactions. The Newton–Raphson procedure exposes high sensitivity in nodes with intense reactive demand. This is the case around branches featuring large susceptance values, and when we use branch parameters and shunt contributions. Iterative behavior shows notable mismatch magnitudes in the flat start, substantial angle corrections, and conditioning challenges associated with reactive stiffening. At the same time, the dynamic model captures the influence of inertia, damping, and primary control on frequency trajectories following large disturbances. The coupled approach ensures consistency between electrical power evaluations and dynamic states at each integration step, enabling detailed assessment of electromechanical responses under stressed operating conditions. Overall, the study demonstrates that combining high‑order time integration with robust nonlinear algebraic solvers provides a reliable tool for understanding system sensitivity, evaluating operational risks, and supporting the design of protection and control strategies in increasingly renewable electrical networks.
