In order to investigate the economy of installing largediameter wedge shaped monopiles to support offshore wind turbines in shallow coastal waters. The Coupled EulerianLagrangian (CEL) approach is used to establish the finite element model of monopiles under highfrequency vibration load in ABAQUS, and the pile sinking characteristics of wedgeshaped monopile with the same amount of steel and monopile with the same section are compared and analyzed. By analyzing the four aspects of pile penetration speed, frictional resistance, soil displacement, and soil stress, this paper explores the influence of wedgeshaped structures on monopiles installation. The research results show that the total pile sinking time required for wedgeshaped monopiles in sandy soil is reduced by 38% compared to monopiles with equal crosssection, which has good economic benefits in construction; However, in the later stage of pile sinking, the peak displacement position of the shallow soil moves back, and the peak increment increases. The energy transmitted to the foundation is more intense, and the disturbance to the soil is more intense. The radial disturbance range of the surface increases by 0.01r. The research results not only provide a basis for the design of the cross section type of monopiles for offshore wind turbines in the future, but also provide an important reference for exploring the potential value of large diameter wedgeshaped monopile in offshore wind power projects.

With the leapfrog development of renewable energy in China, the problem of new energy electric power utilization has become increasingly prominent. This paper, constructs an electric and photovoltaic complementary electric heating system with phasechange thermal energy storage, and a mathematical model of the thermal performance of the system is constructed, which can reflect the dynamic thermal performance of the indoor thermal environment of the system, and the control strategy of the flexible thermoelectric load regulation of the system is designed. A case study was carried out on a lowcarbon building in Beijing, and the load transfer capacity and photovoltaic absorption capacity of the system were simulated and studied. The results show that the system with this rooftop photovoltaic was able to reduce the peak electricity consumption of the case building by 93.9% and the primary energy consumption by 23.9%, with the indoor temperature being maintained at 18 °C. In this study, the peak power consumption can be reduced by 75.1% to 97.4% compared to the system without PV using different PV installed capacity installation methods and areas, and the improvement of the storage capacity has a significant effect on the improvement of the system's flexible load transfer capability, and the improvement effect gradually decreases when the storage battery capacity is larger than 15 kW.h.

Enhancing the inertia of a direct current (DC) microgrid is a key issue to prevent the induction of DC voltage oscillations caused by the introduction of constant power DC loads. Considering the differences in the required supplementary power response rates under various voltage change rates, this paper first proposes a multimode virtual inertia control strategy for the energy storage battery terminals of the DC microgrid, using linear and exponential modes to provide inertia power at different rates, thereby reducing DC voltage fluctuations. Secondly, the equivalent virtual capacitance expressions for both modes are derived, establishing a dynamic relationship between the virtual capacitance and voltage adjustment. Finally, a simulation model of a DC microgrid system with energy storage is constructed to verify the effectiveness of the proposed control strategy in supporting DC voltage stability.

Taking the existing wind turbine pitch control system as the research object, the impeller aerodynamic test with variable incoming flow and angle of attack was carried out, and the fluidstructure coupling calculation was completed by selecting the Fluent module and Transient Structural module in the workbench 2021 platform. The results show that: the maximum error of the power and lift coefficient of the model and test within the test range is 3.7%, 5.8%, and the average error is 2.2%, 3.4%, and the maximum power of the impeller in the rated wind speed of 10 m/s is 2.5 kW, and the lift coefficient of the angle of attack of 14° is the maximum of 1.05. The incoming wind speed has a more obvious effect on the strength of the vortex in the wake area, and the higher the incoming wind speed, the higher the surface pressure on the blades at the same position coordinates. The higher the incoming wind speed, the higher the surface pressure of the blade in the same position coordinate, the smaller the velocity attenuation of the impeller tail, and the maximum stress and deformation suffered by the blade is proportional to the incoming wind speed; the lower the ambient temperature, the higher the surface pressure of the blade in the same position coordinate, and the maximum stress and deformation suffered by the blade is inversely proportional to the ambient temperature, and the ambient temperature is in the range of 20~20 °C, and the maximum stress and deformation caused by the temperature are 1.45% and 2.37%, the results of the study are of guiding significance for the operation of wind turbines in harsh environments.

New energy power stations, while balancing the promotion of consumption and active support of scenario demand configuration for energy storage, will face problems such as random and complex appearances in different scenarios, cross coupling in time series, long solving time of traditional multiobjective optimization algorithms, slow convergence speed, and susceptibility to getting stuck in local solutions. Based on this, this article proposes a new energy storage configuration method suitable for multiple scenarios in new energy power plants. Based on the output data of new energy power stations, daily power prediction data, grid frequency data, etc., typical operating condition curves of energy storage demand are extracted, and an energy storage optimization configuration model is constructed. An improved multiobjective particle swarm optimization algorithm is proposed to solve the optimal energy storage configuration of new energy power stations. Finally, simulation analysis was conducted on actual new energy power plants to verify the effectiveness and practicality of the method proposed in this paper.

In order to improve the fuel economy of fuel cell hybrid electric vehicles during short range driving, a vehicle speed prediction model structure VBSnet based on hybrid deep neural network was constructed. This structure not only further improves the convolutional network based on the VGGNet structure, but also introduces a bidirectional long shortterm memory neural network to effectively learn the spatiotemporal dependencies of the entire vehicle speed prediction sequence. Simultaneously considering the influence of prediction time domain and input sequence length on the prediction accuracy of shortrange vehicle speed problems, Bayesian optimization hyperparameters are used to further improve the prediction accuracy of VBSNet. To address the online optimization and computational efficiency issues of energy management strategies, a multiobjective optimization based on model predictive control (MPC) energy management strategy was designed. This strategy can achieve a balance and optimization of hydrogen consumption, lithium battery state of charge (SOC) maintenance, and fuel cell utilization efficiency. Finally, under actual vehicle conditions, the proposed strategy was compared with rulebased strategies, resulting in fuel economy improvements of 7.25%, 9.94% and 19.23%, and better SOC maintenance characteristics.

In the current design process of offshore wind turbine monopile foundations, the shape of the local scour pit is usually ignored and directly simplified to the global scour, which leads to a conservative design of monopile foundations. A hyperbolic py curve for largediameter monopiles was adopted to construct the pilesoil interaction model. The concept of equivalent depth was introduced and modified to establish a simplified onedimensional monopile analysis model considering the shape of scour pit based on available centrifuge test data currently. The rationality of the proposed model is verified by comparison with the test results. Furthermore, several modified models were compared and analyzed, and the prediction effects of each model on the lateral response of monopile foundations subjected to local scour were discussed. The results of the study show that the local scour mainly leads to the reduction of the soil resistance along pile in the shallow range of seabed, so a reasonable correction of the py curve of shallow soil is the key to the analysis of lateral response for monopile subjected to scour. Because the existing models underestimate the effective vertical geostress of shallow soil after local scour, whose prediction results of lateral responses of monopile are closer to those of the global scour model.

The largescale gridforming wind turbine generators (WTGs) will change the frequency response characteristics of the power system, while the traditional lowfrequency load shedding strategy has not taken into account the impact of gridforming wind power, which may lead to unreasonable system load shedding after high power shortage. This paper proposes a lowfrequency load shedding strategy for power systems that considers the frequency response of gridforming wind power. Firstly, based on the virtual inertia of gridforming wind power and the primary frequency control model, a simplified system frequency response model is established that takes into account the frequency response of gridforming wind power. Secondly, the impact of the active power response characteristics of gridforming wind power on the unbalanced power amount of the system is analyzed, and then the unbalanced power amount used to guide multiple rounds of load shedding in the power grid is finely estimated, thus proposing an adaptive lowfrequency load shedding implementation strategy. Finally, the feasibility and effectiveness of the lowfrequency load shedding strategy proposed in this paper were verified through numerical analysis.

In order to achieve the target of "dual carbon", it is important to develop renewable energy resources. There are many factors that affect the development of renewable energy. The extent to which the view of residents influences this needs further research. Therefore, this study focuses on the cognition, attitude, behaviour, and policy opinions of residents in Liaoning Province on renewable energy resources. According to the population, available arable land area, and calculations of available roof area, questionnaire numbers for each city are designed by Neiman Distribution. The survey is conducted both online and offline. Among the 1 332 questionnaires, more than 20.00% of residents have misconceptions about renewable energy. The proportion of residents willing to promote the development of renewable energy is 63.62%. Residents prefer enterprises to play a greater role, accounting for 65.57%. By conducting principal component analysis and regression analysis, it is found that occupation type significantly impacts residents' renewable energy cognition and behaviour. The knowledge levels concerning China's energy resources and household energy storage systems are observed to be 9.66% and 18.20% higher among corporate residents than noncorporate residents. Enterprise residents display a 10.37% increase in their willingness to actively select green energysaving appliances with slightly higher prices when compared to nonenterprise residents. Additionally, nonstudents exhibit a 10.93% higher inclination than students to pay premium electricity tariffs for renewable energy generation. Residents who support the development of renewable energy resources industries in Liaoning are more likely to accept highpriced green energysaving appliances and support their lowcarbon behaviour with green credits or carbon credits. Based on the above research results, it is proposed that: ① Government departments carry out social activities to enhance residents' awareness of renewable energy in Liaoning Province; ② Financial institutions are encouraged to increase research investment in renewable energy technologies, thereby reducing product prices and increasing residents' participation enthusiasm; ③ The authors design an overall operational framework for renewable energy to promote green point trading and create a batch of demonstration zones with net zero carbon emissions in Liaoning Province.

To further understand the interaction in copyrolysis of biomass and waste plastics, the pyrolysis characteristics of poplar wood(PW) and the effect of polypropylene (PP) addition on the product distribution and composition of PW and PP co pyrolysis were studied by thermogravimetric analysis and fixed bed reactor. The results showed that 500 °C is the optimal temperature for PW pyrolysis to obtain tar product, and the maximum tar yield is 31.2%. The experimental value of the maximum weight loss rate of copyrolysis is slightly greater than the theoretical value in the low temperature range, and the peak temperature of the DTG curve in the high temperature range shifts to higher temperature zone. Copyrolysis of PW and PP has a positive synergistic effect on the generation of gas products, increasing the low heating value of gas products. Copyrolysis has a negative synergistic effect on the generation of tar. However, the oxygencontaining compounds (phenols, acids, ketones and furans) in tar decrease, and olefin compounds increase significantly. In addition, the degree of graphitization of copyrolytic char becomes higher.