In order to solve the problem of unified setting of yaw control parameters of wind turbines and the delay of yaw startup of wind operation, a yaw control parameter optimization method based on wind direction fluctuation characteristic evaluation and multiobjective particle swarm optimization algorithm was proposed. The yaw control parameters under different wind speed ranges were optimized by taking the power generation of the unit and the rotation Angle of the engine room under yaw control as optimization objectives. A yaw control strategy optimization method based on VMDEEMD –LSTM –LSSVM wind condition prediction model is proposed. Through predicting the average wind speed in a period of time, the optimized yaw control parameters are set in advance, and through predicting the wind direction, whether yaw starts in advance to the wind action is judged and controlled. The results of example analysis show that this strategy can effectively improve the power generation of wind turbines and reduce the cabin rotation Angle under yaw control, which is beneficial to the economic benefit of wind farms.

In order to further reduce the cost of wind power, employing 15 MW or even higher capacity wind turbine has been the major development trend in the future wind energy market. This paper has developed the soil structure interaction model of the IEA 15 MW monopile wind turbine using a set of linear springs by improving the capability of FAST due to the demand of investigating the SSI effect on the dynamic responses of nextgeneration large offshore wind turbines. The nacelle vibration and bending moment of the support structure under normal power production and extreme conditions are obtained. The results indicate that the ignorance of SSI effect significantly underestimates the towertop and mudline bending moments under power production load cases. The SSI effect has an insignificant influence on the dynamic responses of the wind turbine under the extreme conditions. Specifically, the fatigue damage of the support structure at the mudline is only predicted with an error lower than 3% under the 50year return period extreme condition. Nonetheless, the SSI effect has a dominant influence for the low wind speed conditions. The tower top and mudline bending moments are underestimated by 37.6% and 20.1%, respectively, if the SSI effect is ignored. The axial mode of the foundation is activated, resulting in an intense nacelle vibration and a huge increase to the fatigue damage of the support structure. The study has verified that the SSI effect is mandatorily considered in the design of large offshore wind turbine structures.

Under the context of "dual carbon," an optimization scheduling model considering carbon emission flow and staged carbon trading mechanism is proposed in this paper to promote the lowcarbon economic operation of distribution networks. Firstly, the participation of distribution networks in the carbon trading market is taken into account, and the theory of carbon emission flow is introduced to determine the carbon emission status of each node within the distribution network. Subsequently, the stochastic states of electric vehicles are determined using the Monte Carlo algorithm, and the carbon quota of power generation equipment is obtained based on the entropy weight method. Simultaneously, a carbon quota model for electric vehicles is constructed, and a staged carbon trading mechanism is applied to model electric vehicles, photovoltaic units, wind power generation, and thermal power units. Finally, the system is optimized using an improved particle swarm optimization algorithm, with the objectives of minimizing the system operating cost and maximizing the system carbon income. The proposed model is verified through case studies conducted on an improved IEEE33 node distribution network system, where four operating scenarios are set. The research results demonstrate that the proposed model reduces carbon emissions by 539.43 tons, and the amount of wind and light discarded is reduced by 555.27 kW·h, which also makes the system's carbon revenue increase by 79.627 9 yuan.

Wind turbine blades are subjected to various loads during operation, which can cause deformation, and yaw can make the force situation of the blades more complex. To investigate the dynamic flapping deformation of blades under yaw conditions, experimental research was conducted using digital image correlation (DIC) technology to explore the influence of changes in yaw angle, wind speed, and speed on the dynamic flapping deformation of blades. The results show that the dynamic flapping deformation of horizontal axis wind turbine blades varies in a sinusoidal pattern, and the higher the wind speed, the greater the dynamic flapping deformation. The higher the rotational speed, the greater the dynamic flapping deformation, and at the same time, the time it takes to reach the maximum value is also shorter, with more variation cycles experienced; The existence of yaw angle changes the force situation of the blade. The larger the yaw angle, the greater the trend of dynamic flapping deformation. The shorter the time it takes to reach the peak, the earlier the peak position is. At the same time, the proportion of positive dynamic flapping deformation decreases, and the proportion of negative dynamic flapping deformation increases. The most obvious trend is at a 30° yaw angle. The research results of this article can provide experimental data support for effective control of blade deformation and subsequent research on the impact of blade deformation on the aerodynamic characteristics of wind turbines.

In order to solve the problem of deterioration of heat transfer performance caused by cold air backflow and the excessive unevenness of the headon wind speed on the outdoor side heat exchanger during the heating operation of common air source heat pumps, a new integrated solar and air energy heat pump for public buildings is proposed by combining solar heat gain in the outdoor side heat exchanger. The mathematical model of the outdoor side heat exchanger was established to study the airflow distribution and heat transfer performance of the common air source heat pump, and the simulation results were verified by experiment to prove the accuracy of the mathematical model; two new outdoor side heat exchanger structures of singleinversion type and doubleinversion type are proposed, and their airflow distribution and heat transfer performance are studied. The results show that both singleinversion and doubleinversion structures can improve the unevenness of the headon wind speed of the heat exchanger, among which the doubleinversion structure has a more obvious improvement effect, with the unevenness of the headon wind speed of the outer and inner heat exchangers reduced by 46% and 83%, respectively, compared with that of the common air source heat pump outdoor side heat exchanger; In the case of the same heat exchanger area, fan type and number, the doubleinversion structure increase the heat exchanger by 5.4% compared with the singleinversion structure.

Design a marine ammonia fuel SOFCGT hybrid power system based on the power requirements of ships, and establish a detailed model of the hybrid power system. Analyze the influence characteristics of ammonia decomposition conversion rate of ammonia decomposer under changes in ammonia flow rate and inlet temperature. Under the limiting conditions of fuel cell temperature gradient, compressor surge safety zone, and turbine inlet temperature, the operational performance of the hybrid power system was analyzed. The effects of ammonia flow rate and ammonia decomposer inlet temperature on the performance of the hybrid power system were studied. The main conclusions are as follows: the output power of the hybrid power system reaches 350.5 kW, and the power generation efficiency reaches 62.40%. When the inlet temperature is above 1 050 K, the conversion rate of ammonia decomposition is close to 100%. The ammonia decomposition conversion rate shows a decreasing trend with the increase of flow rate. When the inlet temperature is high, the influence of flow rate on the decrease of ammonia decomposition conversion rate gradually decreases. When the ammonia flow rate gradually approaches 1.80 mol/s, the performance of fuel cells, gas turbines, and systems gradually increases with the increase of ammonia flow rate. However, the ammonia flow rate in the system should not be too high. When the ammonia flow rate reaches 1.80 mol/s, the turbine inlet temperature has exceeded the safe operating range. When other operating conditions are design conditions, the overall performance of the system improves as the inlet temperature of the ammonia decomposition reactor gradually increases to 1 129 K.

China's shallowsea development potential is 1 730 GW, and deepsea development potential is 1 830 GW, making China the country with the largest offshore wind power development potential in Asia. In recent years, with the continuous breakthroughs in floating wind turbines and concerning technologies, offshore wind power is gradually moving towards the deep sea. The development and delivery costs will drop rapidly. According to calculations, by 2030, the LCOE of floating wind power will drop to 0.28 ¥/(kW·h), and by 2050 it will drop to 0.14 ¥/(kW·h). The use of VSCHVDC for deepsea floating wind power, by 2050, the transmission costs of offshore 100 km, 150 km, and 200 km are estimated to be 0.050, 0.059 ¥/(kW·h)and 0.068 ¥/(kW·h) respectively in the basic scenario. Under the scenario of rapid technological progress, the estimated results are 0.033,0.040 ¥/(kW·h) and 0.046 ¥/(kW·h) respectively.

Lowcarbon development of the power industry is an important measure for the dualcarbon goal. In order to promote carbon emission reduction and improve the economy, reliability and environmental protection of the multienergy system, an optimization model for the carbon emission reduction of the multienergy system considering the coordination of economy and reliability is proposed in this paper. Firstly, the coordination model of LowCarbon MultiEnergy System (LCMES) is established by analyzing the topology of the LCMES including electricity, gas and heat; Secondly, based on the fault characteristics of the energy conversion and storage equipment in the LCMES, the multistate reliability model of the LCMES is established; Then, under the conditions of operation constraints and reliability constraints, an optimization model of carbon emission reduction of the LCMES considering the coordination of economy and reliability is proposed with the objective of minimizing the operation cost and carbon emissions of multienergy system; Finally, it is verified by simulation numerical example that the multienergy system optimization model proposed in this paper can ensure the improvement of the operation reliability and economy of the multienergy system while achieving the carbon emission reduction.

As a clean and lowcarbon energy system, the integration of wind, solar, and hydrogen microgrids plays an essential role in facilitating the transformation of energy structures and enhancing energy utilization efficiency. This paper investigates the capacity configuration issues of wind, photovoltaic, and hydrogen storage microgrid systems. A model of the windsolarhydrogen microgrid system has been developed, taking into account the uncertainties in wind and solar outputs. Based on historical data, typical daily scenarios are selected using an improved Kmeans clustering algorithm, and the uncertainty probability distributions are jointly constrained by both the 1norm and infinity norm within a confidence set. This study proposes a twostage distributionally robust model for the capacity configuration of windsolarhydrogen microgrids. The first stage determines the capacity of each component with the goal of minimizing investment costs, while the second stage aims to minimize operational costs. The solution to the model is derived through the application of the ColumnandConstraint Generation (C&CG) algorithm. The results indicate that the model can achieve a rational configuration of capacity, and it enhances the energy utilization efficiency and economic performance of the windsolarhydrogen microgrid.

With the development of photovoltaic(PV) industry, high capacity ratios have gradually become popular in the PV power station. To find the optimal charging/discharge strategy of energy storage (ES) in PV subarray with a high capacity ratio, one operation strategy based on working mode recognition was proposed to coordinate two competitive objectives—load shifting and smoothing. Furthermore, a capacity configuration model with the objectives of life cycle net present value maximization and output fluctuation minimization was constructed considering the generation income, ES cost, fluctuation characteristics, and typical day type. Moreover, taking a 1 MW subarray with 1.8 capacity ratio in a northeast utilityscale PV power station as a case, the optimal capacity of 700 kW·h was obtained. The simulation results under different typical days verified the feasibility and the effectiveness of the proposed ES operation strategy as well as the configuration model.