With the development of wind turbine technology, wind power will become more controllable and grid-friendly. It is desirable to make wind farms operate as conventional power plants. Wind turbine generators (WTGs) were mainly used in rural and remote areas for wind power generation. WTG-based wind energy conversion systems (WECS) can be divided into the four main types (type 1-4). Due to the inherent variability and uncertainty of the wind, the integration of wind power into the grid has brought challenges in several different areas, including power quality, system reliability, stability, and planning. The impact of each is largely dependent on the level of wind power penetration in the grid. In many countries, relatively high levels of wind power penetration have been achieved. This chapter shows the estimated wind power penetration in leading wind markets.
Flexible pressure sensors offer more significant advantages than rigid sensors in various applications, including human-computer interaction, medical health, and robot touch. However, this also places more stringent demands on the materials used. For example, the materials must be thin and soft enough to fit onto the surface of the human skin or be implanted into the body while also exhibiting good biocompatibility and matching the mechanical properties of biological tissues. Regarding device performance, flexible pressure sensor design primarily focuses on enhancing sensitivity, response time, detection limit, and stability. Researchers have recently been expanding these sensors' pressure response range, pressure resolution, spatial resolution, and tensile performance, which will further broaden their potential applications. This review provides an overview of the recent classification of flexible pressure sensors, covering their sensing principle, sensing performance, and future application prospects.
Action plan generation is essentially a planning problem, but the planning algorithm is not systematic, and it is difficult to effectively solve the problem of maritime rescue action plan generation. In this paper, a nested method for generating maritime rescue action plan is proposed. The specific steps are as follows. Firstly, a hierarchical scheme generation strategy is proposed. The scheme generation is mainly divided into two parts: task decomposition and resource scheduling. Then a task decomposition method based on genetic algorithm is established by learning the expert scheme. Through the mathematical modeling of the problem in the part of resource scheduling, a resource scheduling algorithm is proposed. Finally, the effectiveness of the proposed method is verified by simulation.
With the increasing proportion of renewable energy generation in the power grid, the stability issues induced by its grid connection becomes more and more important. The impedance-based approach has become an important method to analyze such issues because of its unique advantages. This paper gives a comprehensive review on impedance modeling of the grid-connected renewable energy generation system. Several commonly used impedance modeling methods are studied, including the dq-frame linearization and the harmonic linearization methods and their development. Then, the impedance modeling of the photovoltaic power generation system, direct-drive wind turbine, and doubly-fed wind turbine is introduced.
This paper presents the design of an L 1 adaptive controller for maximum power point tracking (MPPT) of a small variable speed wind energy conversion system (WECS). The proposed controller generates the optimal torque command for the vector-controlled generator-side converter based on the wind speed estimation. The proposed MPPT control algorithm has a generic structure and can be used for different generator types. In order to verify the efficacy of the proposed L 1 adaptive controller for the MPPT of the WECS, a full converter wind turbine with a squirrel cage induction generator is used to carry out case studies using MATLAB/Simulink. The case study results show that the designed L 1 adaptive controller has good tracking performance even with unmodeled dynamics and in the presence of parameter uncertainties and unknown disturbances.
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