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Complicated terrains, specific regions, and high wind turbulence intensity frequently trigger shutdown protection of wind turbines due to vibration beyond the designated limit, resulting in serious loss of power generation. This paper aims at reducing the frequency of shutdowns and improving operational stability of wind turbines. Operational characteristics of wind turbines under complicated conditions such as specific regions and strong turbulent wind were analyzed. A fuzzy control approach was proposed based on pertinent theory, to deal with complicated operating conditions at specific sites. This strategy incorporates a vibration recognition algorithm to classify vibration conditions and a fuzzy control algorithm for vibration suppression based on the categorized conditions. Compared with the conventional shutdown or sector-based control methods, the proposed fuzzy control strategy of vibration suppression eliminates the frequent starting and stopping of wind turbines, thus ensuring power generation and improving operational stability. Furthermore, a simulation analysis was performed using Bladed software, taking 3.x MW wind turbines as the research object. Subsequent experimental verification was carried out at a wind farm. In the experiment, the application of the fuzzy vibration suppression control method effectively led to the quick ride-through of the wind turbine amid the complicated operating conditions including the specific region and strong turbulent wind. A 23.87% reduction in the maximum RMS of the front and rear accelerations of the nacelle demonstrated a substantial enhancement in the wind turbine reliability.

With the sustained growth of renewable energy, the flexibility of the power system has emerged as a critical indicator, influenced by frequent peak regulation. However, a dilemma exists between maximizing flexibility and optimizing economy, and a multi-objective optimization can serve as means of coordinating conflicts. In this study, condensing cogeneration units equipped with a molten salt heat storage system is research object, an optimization model for day-ahead scheduling is established, with flexibility and economy as the primary optimization objectives. To account for various constraint condition such as unit ramp rate, unit output and thermoelectric coupling properties, an enhanced version of the non-dominated sorting genetic algorithm-Ⅱ (NSGA-Ⅱ) is proposed to efficiently solve the optimization problem of a molten salt heat storage system. Flexibility and economy are used to compare and analyze the non dominated solution set obtained from the Pareto front. At the same time, the heat storage and release characteristics of a molten salt heat storage system are analyzed. The findings reveal that a focus on flexibility necessitates great motten salt heat storage to manage insufficient heating during low-load operations. Conversely, an emphasis on economy leads to frequent adjustments in heat storage to maintain optimal unit performance.

With the substantial increase of the installed capacity of wind power, it has brought great challenges to grid stability and safety. In order to improve the grid stability and the anti-interference ability of grid frequency, wind farms urgently need to have frequency regulation function and increase frequency response speed. According to the latest technical requirements such as starting time and adjustment time of grid, this paper analyzes the current mainstream frequency regulation schemes in the market. A frequency regulation scheme combining energy management platform and frequency regulation equipment is proposed, so that the wind turbine receives instructions from the energy management platform and frequency regulation equipment at the same time, and adopts different control strategies for inertia response and primary frequency regulation to adjust the active power of the wind farm to ensure the response speed and stability during frequency regulation.The scheme has been tested for inertia response and primary frequency modulation in a wind farm in Yunnan province. In the test results, the response time of inertia response is less than 1 sec, the control deviation is within ±1% of rated capacity, the starting time of primary frequency modulation is less than 2 sec, the response time is less than 5 sec, the adjustment time is less than 8 sec, and the control deviation of primary frequency regulation is within ±1% of rated capacity. All the technical indexes meet the requirements of Yunnan Grid.

Background: Inflammatory bowel disease (IBD), characterized by chronic inflammation of the digestive tract, involves angiogenesis as a key pathogenic mechanism. Ginsenoside Rg3, derived from the traditional Chinese herb ginseng, is recognized for its anti-angiogenic properties but is limited by low oral bioavailability. This necessitates the development of an alternative delivery system to improve its therapeutic effectiveness. Methods: Pluronic F-127 (F127) and Pluronic F-68 (F68) were used to construct Rg3-loaded thermosensitive hydrogel Gel-Rg3. Meanwhile, a series of physicochemical properties were determined. Then the safety and pharmacological activity of Gel-Rg3 were evaluated in vitro and in vivo using human umbilical vein endothelial cells (HUVECs) and colitis mouse model, in order to initially validate the potential of Gel-Rg3 for the treatment of IBD. Results: We engineered a rectally administrable, thermosensitive Gel-Rg3 hydrogel using F127 and F68, which forms at body temperature, enhancing Rg3's intestinal retention and slowly releasing the drug. In vitro, Gel-Rg3 demonstrated superior anti-angiogenic activity by inhibiting HUVEC proliferation, migration, and tube formation. It also proved safer and better suited for IBD's delicate intestinal environment than unformulated Rg3. In vivo assessments confirmed increased intestinal adhesion and anti-angiogenic efficacy. Conclusions: The Gel-Rg3 hydrogel shows promise for IBD therapy by effectively inhibiting angiogenesis via rectal delivery, overcoming Rg3's bioavailability limitations with improved safety and efficacy. This study provides new inspiration and data support for the design of treatment strategies for IBD. [ABSTRACT FROM AUTHOR]

Aiming at the problem that the current arc suppression method of coil cannot achieve full compensation. First, the calculation model of the full compensation parameters of the controllable voltage source is established by analyzing the grounding fault arc suppression principle of the independent controllable voltage source and the parallel arc suppression coil. Second, by analyzing the arc suppression characteristics of controllable voltage source, a PI automatic regulation method based on phase deviation‐fault residual voltage control is proposed. The method uses fault residual voltage and the change of output voltage amplitude of controllable voltage source to control the adjustment direction and fault residual voltage to control the output voltage amplitude of controllable voltage source. The simulation results show that when the capacitive current of the distribution network is 24.47 A, the fault residual voltage is 2.5 V and the residual current is 446 mA after compensation by the independent controllable voltage source. When the capacitive current is 40.8 A and the deharmonic degree of arc suppression coil is −9%, the fault residual voltage and residual current are 2.2 V and 60 mA after compensated by the parallel arc suppression coil of the controlled voltage source. The proposed PI control method exhibits good stability, resulting in low fault residual voltage, and outperforms traditional control methods, enhancing the arc extinction effect of ground faults. [ABSTRACT FROM AUTHOR]