Magnetically Coupled Resonant Wireless Power Transfer (MCR-WPT) shows great potential, but the coordinated optimization of efficiency and output power remains a critical issue in practical applications. To improve the overall transmission performance of MCR-WPT systems, this paper proposes a parameter configuration method based on the Improved Multi-Objective Artificial Hummingbird Algorithm (IMOAHA). An LCC-S MCR-WPT model is established to study how key parameters affect transmission performance. Efficiency and output power are then selected as the optimization objectives, while operating frequency and transmitter-side compensation inductance are taken as optimization variables to build a constrained parameter optimization model. IMOAHA is used to obtain a Pareto optimal solution set under topology and device stress constraints, and a parameter scheme with better overall performance is selected. The optimized parameters are verified by MATLAB/Simulink simulation and experiments. Results show that the proposed method improves output power while maintaining similar efficiency, and it also keeps stable performance under misalignment, confirming its effectiveness and robustness.
The ground potential rise caused by lightning is an important technical index for lightning protection design of wind turbines. A realistic approach is presented in this paper to calculate the ground potential rise in wind turbine grounding systems under lightning stroke. The electrical parameters of the grounding conductors are given by resistance, conductance, capacitance and inductance. The soil ionization due to dissipating lightning current can be taken into account by the effective radius estimated by the critical electric field intensity of soil ionization. According to the electrical parameters, the grounding conductors are replaced by π‐type circuit units and the circuit model is built for transient analysis of the single wind turbine grounding system and interconnecting configurations of multiple wind turbine grounding systems. The calculated results from the circuit model are compared with the measured ones to perform the model verification. Then, the circuit model is implemented into calculation of lightning transient responses in wind turbine grounding systems with attention to the ground potential rise. © 2026 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.
A virtual synchronous generator (VSG) achieves grid synchronization through its power control loop. During grid faults, the stable equilibrium point (SEP) may vanish, leading to loss of synchronization (LOS). This issue is particularly pronounced in weak grids under remote short‐circuit faults. In these cases, the VSG's fast voltage support sustains a high terminal voltage that obscures the remote grid sag, thereby impairing power‐matching control. To address this issue, this paper analyzes the mechanism of the SEP loss in VSGs under weak grid conditions and reconstructs the reference power as a function of the terminal voltage. The proposed algorithm enables an adaptive adjustment of the reference power curve according to the depth of the grid voltage sag. By analyzing the constructed function characteristics, it is shown that, under different grid strengths, the proposed power reference function and the active‐power feedback can always yield an SEP. Finally, simulations and experiments validate that the proposed strategy can automatically regulate the operating point to a steady‐state equilibrium corresponding to the sag depth. © 2026 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.
Wireless Sensor Networks (WSNs) commonly form part of smart monitoring and data collection systems, in which energy‐efficient communication is still a challenging issue caused by the insufficient battery capacity of sensor nodes. A hybrid fuzzy logic‐based clustering and Gray Wolf Optimization (GWO) based routing, ECFGWO, called ECFGGO, is proposed in this paper for sustainable and adaptive data transmission in WSNs. The suggested fuzzy‐based inference mechanism for cluster head selection takes two variables, namely distance from the base station and remaining energy, into account, resulting in optimized energy usage and better network stability. To further enhance routing efficiency, the GGO algorithm exploits the V‐formation flight behavior of greylag geese to construct energy‐aware and balanced communication paths between cluster heads and the sink node. In addition, the adaptive optimization strategy enhances the convergence behavior of the routing process and mitigates premature stagnation commonly encountered in metaheuristic optimization. MATLAB‐based simulations demonstrate that the proposed ECFGGO framework outperforms the compared routing protocols regarding network lifespan, energy efficiency, packet delivery ratio, and throughput. The results support the potential of the proposed intelligent optimization framework for sustainable and reliable communication in WSN environments. © 2026 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.
With the growing penetration of renewable energy in dual‐high power systems, the interaction between direct‐drive permanent magnet synchronous generator (PMSG) wind turbines and weak AC grids causes critical stability problems, especially wide‐frequency oscillation caused by converter control coupling and time‐varying grid impedance. Conventional linear active damping with fixed parameters cannot handle large parameter perturbations and digital control delays. This paper presents a novel active defense control scheme based on nonsingular fast terminal sliding mode control (NFTSMC) for PMSG wind farms. A detailed impedance model considering digital delay is built to reveal the high‐frequency instability mechanism under low short‐circuit ratio. Grid impedance variations and delays are treated as lumped bounded disturbances, and a robust NFTSMC law is designed with Lyapunov proof to achieve finite‐time convergence and reshape converter impedance, avoiding singularity. Hardware‐in‐the‐loop results validate that the proposed method suppresses resonance, limits current distortion to meet grid codes, and improves system robustness under extremely weak grid conditions. © 2026 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.
