The uncertainty of the wind power generation and complex constraints of the hydropower pose challenges for the short-term scheduling of coordinated wind power, thermal power, and cascaded hydroelectric system (WTHS). In this paper, a robust security-constrained unit commitment model is established for a WTHS. The proposed model ensures the utilization of wind power and economic return from the scheduling. Conservative adjustable uncertainty sets are used to characterize the uncertainty of wind power over temporal and spatial dimensions. In this model, pumped hydro energy storage (PHES) is incorporated to cope with the wind power fluctuations. A simplified affine policy is developed for the decision making of the adjustable variables. Based on a series of linearization techniques, the proposed model is formulated as a single-level mixed-integer linear programming (MILP) problem, where the numerical tests performed on the modified IEEE 30-bus, IEEE 118-bus, and Polish 2736-bus systems verify the effectiveness of the model. The comparative analyses quantitatively evaluate the contributions of the PHES in terms of economic performance and wind power accommodation. The test results reveal that the robustness of scheduling plans is enhanced by the use of the PHES, and the proposed approach is applicable to the largescale power systems. INDEX TERMS Wind-thermal-hydro power system, pumped hydro energy storage, robust securityconstrained unit commitment, mixed integer linear programming.

To improve the output characteristics of offshore wind power and to enhance the wind power accommodation, this paper analyzes its output characteristics along the southern coast in China, and then proposes an optimal sizing method of seawater pumped storage plant (SPSP) with variable-speed units in a connected mode on an islanded microgrid. Based on the constraints of variable-speed unit characteristics and power smoothness at the point of common coupling (PCC), the maximum static revenue as the objective function for the optimal sizing of SPSP is established. Notably, under an appropriate smoothness rate at PCC, the constraints that are mentioned above can adequately reflect the advantages of variable-speed units: fast power response and wide operating range. Additionally, they contain more concise models and variables than previously, which are friendly for optimizing the calculations. The results demonstrate that the proposed method is feasible and practical, by simulating and comparing in different scenarios.

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With millions of years of evolution, owls have developed many excellent characteristics in terms of their flight. The speed of an owl in flight is similar to the relative speed of the blade of a small wind turbine with respect to air. Therefore, the owl wing airfoil is selected as the design airfoil of the wind turbine blade to reduce the flow separation under low Reynolds number. In this study, we analyze an owl wing‐section airfoil and the non‐smooth leading‐edge shape of an owl's wing, and implement an orthogonal optimum design to optimize the wavelength and amplitude of the non‐smooth leading edge. We extract the cross‐sectional features of the airfoil and the non‐smooth leading‐edge shape of the wing. Based on the orthogonal optimum design results, we determine the optimal combination of the wavelength, amplitude, and airfoil, and then design a horizontal‐axis wind turbine blade through bionic coupling. The flow field at different tip speed ratios (TSRs) is simulated using the turbulence model at the rated wind speed. The results show that the power coefficient () of the bionic wind turbine at a high tip speed ratio is 17.7% higher than that of the standard type. Furthermore, we analyze the operation of the turbine at TSRs of 2 and 5. At a high TSR, the leading edge bulge of the bionic wind turbine blade can change the flow direction distribution of the airflow on the blade surface, make the airflow to adhere to the suction surface, and then reduce the stall area on the suction surface of the blade. Thus, the wind turbine produces higher torque, thereby generating higher power.

The advantage of wind energy is significant to the improvement of energy structure. This paper is mainly to demonstrate a bionic design for wind turbine blades inspired by the airfoil of owl wing and the herringbone groove structure of owl feathers. The blade of A 200 W horizontal axis wind turbine is taken as prototype blade. The design of bionic airfoil blade is based on 50% and 70% cross section airfoils of owl wing, which is combined with the parameters of the prototype blade. The design of bionic coupling blade is based on bionic airfoil blade, which is coupled with the herringbone groove structure. Numerical simulation is utilized to study the aerodynamic performance of all blades. These simulations utilize an incompressible Reynolds-averaged Navier–Stokes solver and shear stress transport k–ω turbulent model at different tip speed ratios (TSRs). Results show that the power coefficient (Cp) of bionic airfoil blades is higher than that of prototype blade in the TSR of 6–9; the Cp of bionic coupling blades is higher than that of bionic airfoil blades in the TSR of 6–10. The larger curvature of leading edge of blades leads to larger flow velocity, which leads to the smaller pressure on the leeward surface. The herringbone groove structure enhances the flow attachment by generating vortices, which reduces the pressure on the leeward surface of bionic coupling blades. Compared with the prototype blade and bionic airfoil blade, the pressure difference between the windward surface and the leeward surface of the bionic coupling blade is larger.