China's "Whole County PV" programme has been dramatically expanding the use of solar power in rural areas, by building on government, comnmercial, industrial and residential rooftops. However, a large number of dispersed residential PV will have an impact on the power system, and accurately predicting the shortterm power generation of residential PV is a prerequisite for addressing the impact. However, in addition to its original volatility, residential rooftop PV also has the characteristics of small capacity, decentralized and offline operation, together with the lack of accurate meteorological data, making PV power prediction exceptionally complex. Therefore, under the limited data, this paper longitudinally detects similar samples from the previous power data of the residential PV to be predicted,and horizontally collects similar samples from the power data of neighboring residential PV, ultimately jointly realizing two dimensional data expansion, which overcomes the dependence of PV power generation prediction on some key input features to a certain extent. And then a residential PV generation prediction method is proposed based on LSTNet neural network, which has the functions of shortterm local features capture, longterm time series information reinforcement, and cyclical linear component extraction.

The pitch Angle is generally set to a fixed value in the design of vertical axis wind airfoil, which leads to the problem that the aerodynamic performance of the airfoil can't be fully utilized. In this paper, a design method of vertical axis wind turbine considering variable pitch Angle is proposed and applied to airfoil optimization. Then, based on the braking cylinder theory, the power coefficient is iteratively calculated, and the maximum power coefficient is directly taken as the objective function, and the profile and pitch Angle distribution are optimized by using genetic algorithm coupled with RFOIL software. Finally, the new airfoil VAWT250 of vertical axis wind turbine is optimized. Compared with the reference airfoil AIR001, the optimization results show that the aerodynamic performance of the new airfoil is significantly improved under both smooth and rough conditions, especially under rough conditions, the maximum lift coefficient and liftdrag ratio are increased by 16.1% and 17.1% respectively. Under rough conditions, the maximum power coefficient of the wind turbine is increased by 6.81% considering the pitch Angle. The results have a certain guiding significance for the optimal design of vertical axis wind turbine airfoil.

It is of great significance to optimize the planning and layout of new energy power generation projects on the basis of fully comparing the competitiveness of various new energy power generation projects to promote the highquality development of the regional new energy industry. In order to scientifically measure the competitiveness of various new energy power generation projects in the region and analyze the competition pattern of regional new energy power generation projects, this paper constructs a model of niche width, intensity and overlap of regional new energy power generation projects based on the niche theory, and takes the western region of Inner Mongolia as an example, combined with the operation data of new energy power generation projects in 2022, to measure and analyze the ecological niche of wind power and solar power generation projects in each league city. The results show that there is a mismatch between the niche "structure" and the "scale" width of new energy power generation projects in the western region of Inner Mongolia, and it is necessary to continuously optimize the structure and scale of new energy installed capacity in Ulanqab and Bayannur City. The intensity of new energy niche in the "HohhotBaotouOrdosWuha" area is low, and the development of distributed new energy power generation projects should be considered in the future. The ecological niche overlap between Wuhai and other cities in the western region of Inner Mongolia is low, indicating that Wuhai area has strong potential for new energy development. The research results can provide theoretical support for regional new energy planning, and also provide a decisionmaking basis for the project development of energy investment enterprises.

The thermal efficiency of the traditional bottomheated solar still is low, and the interfacial evaporation technology can limit the heat to the evaporation interface, and then quickly generate water vapor to realize the efficient utilization of solar energy. In this paper, a composite interface evaporator with carbon nanopowder as photothermal conversion material and coated with polyvinyl alcohol hydrogel was prepared, and on this basis, a singleeffect solar still was designed. In this paper, firstly, the energy distribution in the process of water production in the still is analyzed by theoretical calculation, and it is found that the sunlight reflection on the condensation surface and the heat conduction on the evaporation interface are the two biggest factors leading to the energy loss of the still. Then, by adjusting the wettability of the condensation surface, the light transmittance is improved, and the sunlight reflection is reduced, so that the evaporation interface can receive more solar energy. It was found that the thermal efficiency of the still was increased from 36.1% to 55.4% by adjusting the wettability of the condensing surface; the heat conduction loss of evaporation interface is reduced by optimizing the water supply structure of evaporator. When the proportion of water supply area is 20%, its thermal efficiency is improved to 64.6%. Finally, the water production performance of the still under outdoor practical conditions was tested, and the system operated stably without salt crystallization. The evaporation interface temperature and water production rate change synchronously with the change of irradiation intensity, and the wholeday water production reaches 2.89 kg/m². This study can provide theoretical guidance for the design and performance improvement of solar still.

Based on a large six cylinder intake port injection ignition M100 methanol engine, the effects of injection timing on engine performance at 1100 r/min and 100% load were studied using a combination of bench tests and CFD fluid simulation software CONVERGE. In this paper, five different injection timings (449, 439, 429, 419, 409°CA ATDC) are set for simulation calculations. A comprehensive comparison of the simulation results shows that in terms of combustion, the forward movement of the injection timing can effectively improve the combustion quality of the engine. As the injection timing advances, the peak combustion pressure, cumulative heat release, and peak temperature in the cylinder gradually increase, and the phases corresponding to CA10, CA50 and CA90 gradually move forward. The combustion duration gradually decreases, the quality of the incylinder mixture gradually increases, and the ignition speed gradually accelerates. In terms of emissions, the forward shift of fuel injection timing can effectively improve the engine's CO, HC and SOOT emissions, but the NOx emissions have increased.

In this paper, a swirl staged burner with pyrolysis volatiles as fuel was designed. The flow field of the burner combustion process was simulated by ANSYS software, and the flow and combustion characteristics of the burner were studied. The results show that the swirling air of the burner effectively breaks up the pyrolysis volatiles, and achieves the effect of sufficient mixing, stable and uniform flow field and temperature field. The edge flow field generated by swirling air reduces the temperature of the inner wall of the burner (up to 815.69 K), slows down the high temperature corrosion of the wall and reduces the formation of NO₂; the NO₄ concentration in the flue gas of the burner is 43.33 mg/m³, which is significantly lower than the standard limit. The content of pyrolysis volatiles at the outlet of the burner is less than 0.2%.

Aiming at the optimal economic operation of energy management strategy for multi port configuration of AC/DC flexible interconnection system, this article proposes an optimization method for multi port AC/DC flexible joint energy control system based on improved Pelican algorithm, which is based on photovoltaic power generation curve, high fit between peak and valley electricity price ranges, and energy storage control. Construct an optimization model for a multi terminal oral DC flexible joint energy control system, with constraints on DC bus voltage, power control unit capacity, and power balance, to comprehensively consider the minimum network loss, optimal economy, and optimal energy storage charging/discharging state. Based on the Pelican optimization algorithm, the model constructed is solved by introducing random mass disturbance behavior to improve the global search ability of the algorithm and prevent the model from getting stuck in local optima during solution. After simulation verification, the method proposed in the article can achieve optimal scheduling of multi terminal oral DC flexible joint energy control system.

To promote the realization of the "dual carbon" goal, the distributed new energy in different regions of the virtual power plant is coordinated and optimized through lowcarbon power generation. A multi region virtual power plant coordinated and optimized scheduling technology based on the Grey Wolf Optimization Algorithm is proposed. Firstly, construct an operational optimization model with the best economic benefits, connecting virtual power plants in different regions with distributed new energy, and jointly scheduling wind and solar power generation units and carbon capture units; Secondly, due to the difficulty in solving, strong nonlinearity, and high dimensionality of the constructed model, the advantages of the Grey Wolf Optimization Algorithm such as high search efficiency, fast convergence speed, and few optimization parameters are utilized to optimize the model. At the same time, an improved Grey Wolf Optimization Algorithm is proposed to improve the algorithm's global optimization ability and solve the problem of premature and local optima in the later stage of the algorithm; Finally, through simulation verification, the proposed method can achieve optimal scheduling of virtual power plants in different regions, reducing carbon emissions and net costs.

The fourwire voltage source inverters have become an advisable interfaced converter between the source and loads. However, the switching state of the Finite Control Set Model Predictive control does not change regularly in each cycle, which results in variable switching frequency of the inverter switch and large ripple of the output power. In addition, the direction and size of the inverter output voltage are fixed under the traditional FCSMPC control, which may not reach the boundary within the whole control track. Therefore, this paper proposes an online duty cycle modulation predictive control based on capacitor split four wire inverter. This strategy takes into account the advantages of fast dynamic response of FCSMPC and fixed switching frequency of modulation strategy, so the controller can achieve fixed switching frequency and zero error tracking at low sampling rates.

The article focuses on corn stover as the research subject and prepares black titanium dioxide (RTiO₂) photocatalyst using the sodium borohydride reduction method. Through comparisons of different pretreatment results, the alkali photocatalytic pretreatment technology was selected. With the yield of reducing sugar and the main components of corn stalks as evaluation indicators, the study explores the impact of various factors, including photocatalyst concentration, reaction time, H2O2 concentration, and NaOH concentration, on the pretreatment effectiveness. The FTIR, XRD, and SEM analyses show that, compared with other pretreatment methods, the physical properties and microstructure of corn stover undergo significant changes after alkaline photocatalytic pretreatment, the lignin removal rate is effectively improved is effectively improved, which favors the subsequent enzymatic hydrolysis of corn stover.